texts: Converting multiple btc private keys in standard text format to WIP

texts:
Ok, going crazy! I have a file that lists my old private keys (2011) (not original wallet.dat, just keys txt file).  I need to convert each of these keys (not one at a time) into either a WIP key (base58) format or inserted into a new-wallet.  The only solutions I have seen are to convert one at a time.  I need a script to convert the raw private keys in the file with an output of the WIP keys, allowing me to import all at one time into a wallet ...

any suggestions ?  much thanks!  sky


texts: New to BitCoin - Purchased Coins but they haven't shown up in my wallet yet - Wallet still syncing

texts:
I purchased some BitCoins last night.  I downloaded the BitCoin client around a year ago but and only had it open once or twice for just a short time.

Because of that, my wallet is still synchronizing and looks like it will continue doing so for quite some time.  lol

Needless to say, my wallet is still at zero...  Did I screw myself over by transferring coins before my wallet ever initially synced?

It was a small, small amount thankfully, just to try it out (as I said, I'm a newbie).  :)

Any help is appreciated it.

Thanks!


texts: What is the algorithm used to sign data within Nxt?

texts:
I understand that Nxt uses Curve25519 to generate pubkeys for user accounts, however, I can't find a reference that states what which signing algorithm/process is used for transactions and blocks. (Sorry, I also don't have access to the source at the moment.)

How does Nxt sign and validate transactions and blocks?  Note, I'm not interested in discussing POS.  I'm strictly interested in how Nxt signs and verifies its data.


texts: Do bitcoin exchanges own the bitcoins they trade with?

texts: If I have a balance in USD with any exchange, and I placed an order to buy bitcoins, how does it work for the exchange? do they need to hold enough bitcoins to cover all the "buy" transactions and sell those bitcoins to me from their wallet? or, they will find someone on their platform who wants to sell that amount at that price and withdraw his bitcoins to my bitcoins?


texts: How does a Merkle proof differ from the Merkle tree?

texts: I'm not sure how Merkle tree and Merkle proof are different. I thought Merkle proof is the same as the Merkle root in each block. However, it seems like Merkle proof contains all Merkle roots of all blocks. Could anyone explain about Merkle proof visually?


texts: bitcoind starting and then quickly shutting down automatically

texts:
Lenovo E460, 8GB RAM,
Fedora 26,
bitcoin core command line version 0.16.0,
All blocks completely downloaded on a flash drive with 256GB capacity.

I rebooted my machine today without stopping the bitcoind before and since then the following happens:
1) starting "bitcoind -daemon -datadir=/path/to/flash/drive"
2) I see with "top" the process 'bitcoind'  running  for about 30-45 seconds
3) Suddenly under same process id the process names changes to "bitcoin-shutdown" and disappears a second after.
4) Stop or new start of bitcoind is not possible, message is "Error: Cannot obtain a lock on data directory /path/to/flash/drive. Bitcoin Core is probably already running."
5) Only way to start bitcoind again is to reboot the linux. Then loop 1)-5) starts again.

Any help appreciated!
Thanks!


texts: Are bitcoin wallets money service businesses (MSB)?

texts: Do hosted wallet services located in the USA need to register with the fenCEN as a MSB?


texts: cgminer settings "--load-balance" vs "--balance"?

texts:
http://www.amilitalia.it/github.com/ckolivas/cgminer.html

I'm looking for the best balance:

--load-balance Change multipool strategy from failover to quota based balance

and

--balance Change multipool strategy from failover to even share balance

How exactly it works?

E.g. there are 2 pool for different alt-coins with scrypt algo.

1st pool: difficulty 1.1234
2nd pool: difficulty 10.123

Is --balance set my cgminer to 90% for the second pool? Say, it will waiting for balance of ACCEPTED shares.

And --load-balance set power of cgminer to 50%/50%?

I'm afraid that one pool might go slow, will not give jobs. Will cgminer wait for this pool with --balance to keep balance of shares?

Peoples, I know that this is very old, overgrown with moss topic. Could somebody provide me with true link to the answer?


texts: I am a Bangladeshi. I know little about bitcoin and I have no credit card. Is it essential having bank account to earn bitcoin? How will bitcoin help me? How and where can I start earning bitcoin?


texts:
Who is responsible for ensuring that the bitcoin protocol is not violated in the network?

The market forces behind the supply and demand of bitcoin
Miners
Consensus of the miners
Developers of the bitcoin protocol


texts:
If you know someones BTC address, can you also find out what their balance is?

Does it also apply for the transaction history for that address?

I'm mainly asking because I want to know if it's possible for me write a script that can do this.


texts:
What's the most efficient way to detect a fork in the blockchain?

My app polls for changes to user deposit addresses on each new block.

Deposits are credited to user accounts with a record in a database then the funds are transfered to cold storage.

When users get refunds those refunds come from the cold storage and a record is added to the database.

My concern is the following happening:

User deposits Btc and the database record is created.
Chain is forked from 51% attack or software incompatability.
User gets refund from cold storage but I no longer have access to the funds they sent so its out of my pocket.

It seems that everything but rechecking every deposit is marginally risky.

If I rely on height plus hash that can be manufactured by the attacker so the new chain looks like the old chain.


texts: Does bitcoind store timestamp at which private key was imported?

texts:
If we import a private key using bitcoin-cli importprivkey <key>, is there anyway to find out when the import was done?

I am hoping a timestamp is included.


texts: Is there a roadmap to lift the current limit of 220M transactions per year?

texts:
I've seen that Bitcoin just supports ~3 TPS. This is 220 millions transactions per year. If every US citizen wanted to perform a single transaction on a year, they simply couldn't.
I've also read a lot of "Bitcoin's vision" that is completely incompatible with that fact.
Is there a plan or roadmap? What do you think will happen?


texts: How do I know how much each address own in a wallet?

texts:
My wallet has 3 address. One main address is shared with my other computer. The other addresses are not.

Does money belong to a specific address or to a whole wallet? What happen if I send money to one of my own addresses?

What happen if I delete some of the addresses?


texts: How Can i Extract a Z value of a specific Bitcoin Transaction that Belongs to a merkel tree/root transaction?

texts: am trying to find a z value of a transaction that is signed in a merkle tree/root block , i coudn't find a raw tx id in hex  of that specific transaction that signed with  specific address while a raw tx id hex is the hashing of all other addresses in the block , so i couldn't extract Z value from it .. !!!


texts:
Is it necessary to run a "full node" including port forwarding in order to solo mine Bitcoin without any involvement of a pool?
I see that pools are offering solo mining as an option, but why would I trust them to not take my 25 BTC?
I am willing to free up 30GB for the blockchain data on my hard drive.


texts: I have a physical Bitcoin, how can I exchange it for dollars

texts: I aquired a Bitcoin back in 2013,can I exchange it for dollars at a bank.


texts:
I've got a HW.1 a while back at a conference without any additional information. I had played around with it a little bit then, but didn't intend to use it as a wallet immediately.

Now, I've been trying to set it up as a wallet. When I start the Ledger Wallet Chrome Plugin, it tells me that I should do a Chip-Firmware-Update.

Unfortunately, it will not let me progress with the Update unless I put in the "Security Card QR-Code". I don't have it, as I just got the plain card, and didn't make note of anything when I was playing around with the HW.1 at first.

So, the Chrome plugin won't let me do anything except go to "update", but won't let me do the update without the Security Code.

How can I reset or reinitialize the HW.1?

Update:
I've found the page on Ledger's site to generate a new Security Card. By entering the code, I got to a new page requsting that I check a sample from the Security Card. Unfortunately, clicking "Continue" on that page doesn't seem to have any effect. So, I'm still stuck.

I've already written the usb-rules to my system.


texts:
I’m seeking help from the Bitcoin community to recover lost funds from a wallet.dat file. Someone I know asked me to help recover their lost funds - but I’m stumped and now seeking help from the experts.
Facts

A wallet.dat file was created in approximately July 2017

Ubuntu Linux (v17.10?)
Bitcoin Core QT (v0.16.2?)
The original wallet.dat file was backed up and remains accessible

Bitcoin was purchased on Coinbase and sent offsite to an initial receiving address within this wallet
A few months pass…
Additional bitcoin is purchased on Coinbase and sent offsite to NEWLY GENERATED receiving addresses (99% sure the same wallet)
A few years pass…
The person now wants to send their funds back to Coinbase for sale
They have the original wallet.dat file, but Bitcoin Core software only displays one receiving address (the initial one)

Problems

The wallet.dat file was backed up ONLY ONCE, and PRIOR to the generation of those additional receiving addresses
The device used to create the new receiving addresses cannot be found!
Loading the wallet.dat file into current Bitcoin Core software does not display the subsequent transactions or receiving addresses! Only the initial receiving address!

Questions

Can the funds for all transactions be recovered?
What about the funds which were sent to the new receiving addresses, which were created POST BACKUP of the wallet.dat file?
BONUS: If they can be recovered, what’s the best software to accomplish this, and can it also be done for the Bitcoin Cash which presumably remain associated to this wallet.dat file? Ideally without re-syncing the whole blockchain.

I was under the impression that the wallet.dat file contained a private key which corresponds to any / all newly created receiving addresses, but I must be mistaken.
Any advice would be greatly appreciated. The person is at a dead end and I'm fresh out of ideas.
Thank you


texts: How much escrow/ Multi-signature transactions are done?

texts: I have read here about the possibility of Multi-signature transactions. Is there a statistic available how much of these are done?


texts:
Running out of hard drive space, I bought a 256 GB SD card formatted with the FAT filesystem and moved my Bitcoin directory to it. After getting error messages I decided to delete it and redownload (don't worry wallet/keys are backed up). Now it has downloaded about 11 GB and crashes with an error message. I can initiate reindexing and it will proceed, until at some point it crashes again.

After the failed reindexing when I relaunch Bitcoin Core I get this message:

MinGW Runtime Assertion

Assertion failed!

Program: C:\Program Files\Bitcoin\bitcoin-qt.exe
File: validation.cpp, Line 2322

Expression: !setBlockIndexCandidates.empty()

Abort   Retry   Ignore

I have excluded the Bitcoin directory from on-access antivirus scanning, thinking maybe that was interfering but I am still getting this problem.

Any suggestions on how to resolve this issue and get Core fully online again? Could the use of flash media for storage of the database be contributing to the problem?


texts: What are some of the pitfalls of a 100% proof of stake currency (pos) like NXT?

texts: Bitcoin has the vulnerability of a 51% attack for a proof of work currency, but what pitfalls does a 100% proof of stake (pos) currency have like NXTcoin?


texts: How difficult is it to confirm a Bitcoin Block?

texts:
If I have done the math right to come up with this hash, to confirm a true block and this is a confirmed hash. You can look it up here Bitcoin Block #570240

00000000000000000027b68db9d26885fec8dd3e785013f2355271b3ed991829

That should be 64 digits. If I try it on my phone calculator, is it y to the x power the right button to push? That gives a result of 26 lowercase letters + numbers 10 to equal 36. Would I push in 36 y to the 64 power? That gives a result of 4.01199191 to 99 digits long almost 100.

Is that math right for how many combinations there are?


texts: How to view Bitcoin Cash (BCC) on Trezor Wallet

texts: I'm on beta-wallet.trezor.io and I've updated the Firmware to 1.5.1 and still can't see any Bitcoin Cash listed (BTC).  Perhaps I'm being impatient?


texts: Is there a way to maintain a continually updated copy of blockchain without running a wallet?

texts:
This question is in response to being stupid, as I just tried to spend from my B-Qt wallet before it was finished syncing (power outage fun yesterday). Was scary when it froze after hitting send, had to force quit the app and relaunch. Hopefully nothing was actually sent and I can redo the transaction. The bitpay invoice did expire, so I'm hoping for the best.

But it got me to thinking if there was a way to keep an updated copy of the blockchain without actually having to keep my Bitcoin-Qt wallet running. Because security? Presumably I'd be able to point the Qt client at this updated blockchain in the event it hasn't been synced for any amount of time, and it would negate the need to get caught up.

Is anything like this possible or already in existence?

I know I could use a sync-free online wallet but I do not want to store coins anywhere but locally. The point being to have a non-wallet blockchain sync but only activate the wallet part when I want to spend.


texts:
I've read a great deal about the impact of quantum computing on cryptocurrencies in:

https://github.com/theQRL/QRL/blob/master/QRL_whitepaper.pdf
What effects would a scalable Quantum Computer have on Bitcoin?
https://bitcoinmagazine.com/articles/bitcoin-is-not-quantum-safe-and-how-we-can-fix-1375242150/

IOTA also claims to be quantum resistant, unfortunately in their whitepaper that is just briefly mentioned in the last paragraph.

I believe they are talking about the impact from Grover's algorithm where doubling the bit-size help. I can't find any information on how they deal with signatures (which would be broken due to Shor's algorithm) however.

Their wallet code mentions:

  You can use an address for receiving as long as you have not used it for any outgoing transaction. What this means is that once you have sent a transaction with a specific address as input, you should never use it again. This is because IOTA uses Winternitz one-time signatures which degrade security exponentially after each reuse.

So I suppose they are using a Winternitz variant of Lamport's OTS scheme. But how exactly?

I also found an interesting pull request

  In order to prevent the reUse of adresses a message could be display to say that if you re-use the same adresses for transaction the security of your wallet will decrease quadratically .

What does it mean that the "security of your wallet decreases quadratically"? Do they have some Merkele tree with keys to be used? Or how is the relation between address and public/private key in IOTA? If there can only be one transaction with a given input that somehow implies that you always have to transfer all funds?


texts: How do I fund BTC-e and transfer money there instantly from other exchanges?

texts:
A few services claim they support sending money to BTC-e, but I haven't actually found the option to do it.

Does anyone know of an instant way to send money to BTC-e or transfer money to BTC-e from another exchange like Mt. Gox?


texts: Unable to replicate block header validation errors: time-too-old and time-too-new

texts:
we are playing with the regtest and we don't able to replicate the two blocks validation error managed here
https://github.com/bitcoin/bitcoin/blob/5b24f6084ede92d0f493ff416b4726245140b2c1/src/validation.cpp#L3493-L3499

We understand that GetBlockTime and nAdjustedTime have values near os now() time so move manually the os clock can trigger the validation errors.

But we were unable to :(

Step to reproduce "time-too-old"

start bitcoin regtest daemon
mine 101 block
change the os clock 1h behind
mine a new block

we expect to get "time-too-old" validation error but we got no error

Step to reproduce "time-too-new"

start bitcoin regtest daemon
mine 101 blocks
change the os clock 3h forward
mine a new block

we expect to get "time-too-new" validation error but we got no error


texts:
Can I do mining with a normal PC in my house?

I will setup Linux (Ubuntu) for mining. It will be open 24/7. I don't have too many expectations. Maybe 0.1 in one week?


texts: Will the upcoming block size increase be more profitable for miners, or less so?

texts: According to the article US vs. China: The 20 MB Miner War That Could Destroy Bitcoin (Op-Ed) critical decisions are about to be made regarding the size of Bitcoin blocks. Will this cause mining to be more profitable or less?


texts: Can I modify the source code of Bitcoin to generate addresses people have already used?

texts:
Each time you start bitcoin-qt.exe program will generate new random address

But what happen if I modify source code and compile new version:

instead of new random address I can hard code in source code address which already exist on the network with BTC on it ( for example http://blockchain.info/address/1933phfhK3ZgFQNLGSDXvqCn32k2buXY8a )

After I sync "new" wallet with the chain I can retrieve all BTC on it

to do the same I can also modify RANDOM generator source code to generate any address which already exist on the network with BTC on it as above

So the question is:

It's possible to modify source code, compile to EXE and generate THAT way existing BTC address with private keys inside wallet.dat (I believe that private keys are created FROM BTC address by bitcoin-qt.exe) to steal the money


texts: Once a wallet file is initially created, does the reference client generate additional private keys?

texts:
I'm just assuming that the wallet.dat file created by the reference client contains just one private key. (Correct me if I'm wrong here)

I want to know if the client generates additional private keys and if so, under what circumstances? Does a keypoolrefill affect the quantity of private keys? Does generating a given number of addresses cause an additional private key to be generated? etc...


texts: There is at least one totally "offline" backup of blockchain?

texts:
I know that it can be a little paranoid yet, but anyone ever did an offline backup of blockchain in case of a kind of geomagnetic storm? Imagine if all clients of the world lost the data. I know the entire world will be a mess, but the Bitcoin could keep safe.

Maybe it isn't necessary (or even possible) to keep an offline copy of blockchain, but it could be in a hard disk isolated in a special hardware.

Is it possible? Am I thinking something wrong? Thanks.


texts:
Ignore any of the concerns about doing this. If I've got an old laptop laying around, how do I go about mining Bitcoin using Bitcoin Core?
I've just downloaded Bitcoin Core and there doesn't appear to be any way of doing this and I've found no reliable guide online about how to do this. Just lots of nonsense about buying gear or all the hype around it all.
I'm just wanting to do a basic proof of concept so I can understand how it all works for contributing to the network.
It's my understanding (correct me if I'm wrong!) that it's highly unlikely that you will earn any Bitcoins/Satoshis from doing this as you have to hit on that highly unlikely point in time when you actually win the race to compute the calculation etc. I don't really understand how all that works to be fair. I guess what I'm saying is that it's not like you can leave a laptop lying around for 1 hr and see 1 Satoshi deposit into your wallet, and 2 within 2 hrs etc. as a contribution of effort.


texts: At most two outputs according to Bitcoin whitepaper. Multiple outputs in real transactions. How come?

texts:
The original Bitcoin whitepaper mentions that there can be at most two outputs:

  Normally there will be either a single input from a larger previous
  transaction or multiple inputs combining smaller amounts, and at most
  two outputs: one for the payment, and one returning the change, if
  any, back to the sender.

However, I see transactions like this:

https://blockchain.info/tx/c18ff55d09c596ffbad30321719171c0d5b4d677d3554fc6ab3d12167ea8b9d6

that has many outputs.

Is this contradicting the Bitcoin paper or is there something I'm not getting?


texts: OP_RETURN marks transaction or output as invalid

texts:
I am currently looking into the Bitcoin script. I want to create a transaction with one output with OP_RETURN and some data, and one output which pays coins to some address. I am confused, does OP_RETURN mark the whole transaction as invalid or just the output.

I am especially confused because the wiki is not clear on this issue:
https://en.bitcoin.it/wiki/Script#Flow_control
(says the whole transaction is marked as invalid)
https://en.bitcoin.it/wiki/OP_RETURN
(says just the output is marked as invalid)


texts: Height mismatch between bitcoin-qt and bitcoin explorers

texts: I am running bitcoin-qt on the testnet. The count of the last block is 787794 which is way ahead of what I see on blockchain explorers such as https://test.webbtc.com/, which shows the last block as 787747. Why is there this difference ?


texts: Is there a way to publicly raise Bitcoin funds?

texts:
What services are available to publicly raise Bitcoin funds?

I'm considering setting up a Bitcoin fund that would accept BTC donations. If the fund doesn't reach a certain value after a time, I'd like it to refund the BTC. Also, I'd like to give donors the option of withdrawing their donations once a week. It needs to be safe from hackers (eg. the BTC are stored on MtGox with Yubikey protection), and transparent.

Obviously I don't want to use a regular bitcoin wallet address as the public wouldn't trust it.

Does anything like this exist?


texts:
My seed from Electrum has 12 + 2 extension words. Iconomi ask for 12, 18 or so. How can i do to claim my BTG?
Any way to convert 12+2 seed to bip39?


texts:
by doing a mistake i have send BCH to my BTC address into my own Wallet,the wallet is Bitgo i know they have a tool to recover the BCH when they are send to a non segwit address i have already tried the tool e the tool give error, so i think that my address was a segwit, Bitgo say that when the Address is a segwit address -> Unfortunately, when you sent your transaction, you sent it to a Bitcoin address that was using the new Segregated Witness format. As this format is not supported on Bitcoin Cash, we cannot recover these funds.

It's possible to have another solution

Best regards


texts: What are the benefits of using btcd instead of bitcoind?

texts: btcd 1.0 was released October 3, 2013. Why use it instead of bitcoind?


texts: What happened to the nonce distribution between blocks 24480-69120?

texts:
See: http://pastebin.com/raw.php?i=Sk6vyBRu (each row represents 1440 blocks, each column represents a range of 100M values, covering blocks 0-216000)

I've been doing some simple nonce analysis, as you can see, and it appears that something happened to nonce distribution between roughly blocks 24480-69120. As you can see nonce distribution between the range 0-2^32 is usually very evenly dispersed, so it appears something happened here and was corrected.

Can anybody point me at anything related to this or inform me of what happened?

For ease, this correlates to the start of October 2009 through till mid July 2010.


texts: Mining Difference with Multiple Rigs between Bitcoin and Zcash

texts:
I try to understand how the mining hardware environment is different between Bitcoin when centralized mining ecosystem is more encouraged compare to Zcash or Ethereum where pooling is more encouraged.

So is it true that when you have 2 separate rigs mining bitcoins, each individually not joining a pool, they could compete with each other, as oppose to mining Zcash or Ethereum, the 2 rigs join forces to mine together
in the same pool?
regards


texts:
I know that i can use getheader 'hash' from bitcoin core, but i can't use it for all blocks, it's time consuming.
Is there a site where i can find all bitcoin blockheader? Like a blockchain site but shows the blockheader?
Help is appreciated, thank you


texts: does Bitcoin Core automatically use reindex when you specify txindex=1 with existing sync'd chain?

texts:
I sync'd a bitcoin node with Bitcoin Core Qt GUI. Hundreds of GB, naturally.
I realized I needed txindex on for Lightning node stuff, so I changed the conf file via the GUI to include txindex=1. I launched it on my Mac and then slapped myself in the face - how would I tell it to reindex instead of throwing away my database?? Didn't wanna download all those GB again.
But then I noticed debug.log started saying this:
2020-11-30T06:07:43Z Syncing txindex with block chain from height 498564
2020-11-30T06:08:28Z Syncing txindex with block chain from height 500148

which, if I remember right means it's doing a reindex, not a full-blown restart of a sync. Checked on disk, and indeed, files still there.
I'm grateful, but also mystified. Questions:

does Bitcoin Core see when you're about to throw away a full sync with txindex=1 and then inject a -reindex into the start command?
how can I see the startup command that bitcoin-qt uses when I start with with the Mac OSX launcher?


texts: I read that wallet/account is not the same as bitcoin address. The address can be used only for single transaction. How do you receive donations on your address? Are wallet addresses unique for the network so that I can generate my wallet in one service, eg. blockchain.info, and used it in different service? How do you call the address of the wallet if not address?


texts: Using seed to send bitcoin from a wallet's specific private key

texts:
I'm new to bitcoin and I've recently been reading on the concept of wallet. If I understand correctly, a wallet is a collection of one or more pairs address + private key (an address is where BTC can be sent to, and a private key is used to spend BTC from its associated address). I'm not sure if there is something between the private key and the address known as public key.

If I understand correctly, the difference between nondeterministic wallets and deterministic wallets is that with non-HD wallets each pair "address + private key" is generated separately, whereas with HD wallets all pairs "address + private key" are generated with a single list of words known as seed.

I'm interested in HD wallets but I know almost nothing about them and all the terminology I've found on the internet is very confusing to me. I've found terms like BIP39 Mnemonic, BIP39 Passphrase, BIP39 Seed, BIP32 Root Key, Master Private Key, Derivation Path, BIP44, m/44'/0'/0'/0/0, and so on (see iancoleman.io/bip39, for example). I'd like to be able to organize this into something that makes sense and I can understand.

Once I've created an HD wallet and I have a list of pairs "address + private key", how can I access it and spend funds from a specific private key from the list? Which software shoud I use and what is the easiest way to do it without compromising security?


texts: My mining pool has merged with Namecoin, and I need a Namecoin address. How do I create one ? Do I need to install another client ?


texts: Say the first n blocks on the block chain were mined by the creator of the currency. What's to stop everyone unanimously deciding to ignore those first n blocks at a later date and therefore "bankrupting" the creator. Obviously agreement between a large number of parties to do this is unlikely in practice, but is there anything theoretical that prevents this?


texts: Import two wallet.dat into Bitcoin-Qt client

texts:
This is very closely related to Import wallet.dat into a new Bitcoin-Qt client, but I feel this is not a duplicate because the (great) answer to that Q is for only restoring one wallet.

I used Bitcoin-QT about a year back and had two separate wallets within it.  I have these backed up as two separate wallet.dat files.  After some computer wipe, I now need to restore the two wallets into the one Bitcoin-QT client.

Using the prior Q, I have been able to import one of the wallets back into the Bitcoin-Qt client.  I now need to bring the other one in.

How can I import a second backup into my existing account, without the need of sending my first wallets amount to a separate external wallet?


texts: How to get uncompressed BTC address and private key from bit module for Python?

texts:
I am new in programming and BTC. I want to make some BTC address with private keys. Till now I learn that we have compressed and uncompressed private keys. But I get only compressed private keys and address. How I can get uncompressed private key and adress with bit module? This number is just for example. I don't use them for my address. Please do the same. It's not safe to use it for your address. I made this code till now

from bit import Key
dec=115792089237316195423570985008687907852837564279074904382605163141518156494336
key = Key.from_int(dec)
print(key.address)
print(key.to_wif())

I get this results 1A7o1vWzF4fx1yqmA1NzFbhnP97P9uYQ2Q L5oLkpV3aqBjhki6LmvChTCV6odsp4SXM6FfU2GppfKbjNXRE2Ge

I use this module https://pypi.org/project/bit/

If you know someone who can help please share with me. You can see code here https://pastebin.com/6gk1Ua2b


texts: Trouble with mtgox's withdraw bitcoins api call

texts:
I have been trying to transfer bitcoins via mtgox's withdraw bitcoin api call with this http address

https://data.mtgox.com/api/1/generic/bitcoin/send_simple

and when I log the response to console I get

{ result: 'success',
  return: { trx: 'a748ee68583a1cedbdde694a5716909cad8feea1545e946145f48f95ced15037' } }

yet the number of bitcoins in my account remains unchanged.

What could possibly be causing this?

and I'm positive my api key has the correct permissions (unless it's merchant)


texts: I’m using Copay as my Bitcoin wallet. I see it is opensource with the code available in github. What guarantees that they uploaded binary based on that source code? Does it go through Apple approval? Storing more money in bitcoin, I want to be sure my password / credentials are safe and that the developers are not sending out in a hidden way, via backdoor.


texts: What exactly is the benefit of buying a hardware wallet for Bitcoin?

texts:
Let's say I invest in a physical Bitcoin wallet. They aren't exactly free, so it's going to cost me money, effort, time and energy (to set it up and put coins on it).
Then what?
It's not like I can actually use it in physical stores. And if I'm supposed to use it as a secure storage device for all my coins, doesn't it just scream "STEAL/SEIZE ME!" to burglars and the cops? And if I keep it hidden in my fireproof safe, why buy such a hardware wallet instead of just an encrypted USB stick with a wallet.dat on it? Much cheaper and the convenience of a hardware wallet is gone if it's physically tucked away in my safe anyway.
Basically every way I look at it, it seems like a bad idea.
The only situation I can think of where it would be good is if I were to meet up with a person physically to buy something from them with Bitcoin. I wouldn't want to take a computer with me, even a laptop, so then that hardware wallet would come in handy, if I "load it up" from my Bitcoin Core before leaving my home.
But that's a pretty specific and rare (to me) scenario. It's never happened, in fact.
As nice as it first sounds to have a dedicated hardware device which in theory allows me to easily pay people Bitcoin "on the go", I don't see the actual use of this in this world as it is now. Is this only useful in some theoretical future when Bitcoin has taken over? If so, is it really a good idea to buy a hardware wallet today and risk it becoming obsolete by the time Bitcoin ever takes off?
Is there something I'm missing?


texts: Old blockchain info wallet password lost

texts:
I have a very very long time not used my blockchain info account (it is from before blockchain info has new version)
and I forgot my password + my second password, but I find this saved data from my wallet on my stick.

The data looks like:

{
    "guid": "8d07f7c2-b947-4b3d-80a7-3138dcf3fa80",
    "sharedKey": "eb8bab6b-f00a-4861-83b3-24d7b2938a74",
    "double_encryption": true,
    "dpasswordhash": "76296efc1718b4b57a4ebe0287a35ad4565bf84d4e4437963bd2d06a5b981b1f",
    "options": {
        "pbkdf2_iterations": 10,
        "fee_policy": 0,
        "html5_notifications": false,
        "logout_time": 600000,
        "tx_display": 0,
        "always_keep_local_backup": false,
        "transactions_per_page": 30,
        "additional_seeds": []
    },
    "keys": [
        {
            "created_device_name": "javascript_web",
            "addr": "132uY8ULMT6efFdqWjQ74BfaMt46MgpW2F",
            "priv": "mFmbijM0I7Vn7lOv3XcaayhjxXu0qkhd3gNapgknJdudpQn8H9zZw/uOZ/zZ2HDFDkgQV4n1ZX8VjX12qCymDw==",
            "created_device_version": "1.0",
            "created_time": 0
        },
        {
            "created_device_name": "merchant_api",
            "addr": "1AdbcgN8jFYqErMLiUfhFwSJ2jAa3qYCpv",
            "priv": "PG8w31iFpUiWdTjybhy3fK8Lb/VGqVChZxD0S7U4PgGsyLJbUKFNkipC8PMeD7oUt4HYHqmPzvWspHMyO/jSHQ==",
            "created_device_version": "1.0"
        }
    ]
};

Its someone used blockchain info in last year was a export option for key - and that I will recompensate all professional help and working idea how to import this data in any type of new wallet to I can have access the coins.


texts: what is the difference between OP_CHECKMULTISIG and OP_CHECKMULTISIGVERIFY

texts:
I would like to learn the difference, explained as simple as possible, between OP_CHECKMULTISIG / OP_CHECKMULTISIGVERIFY and OP_CHECKSIG / OP_CHECKSIGVERIFY. The only explanation I found is: Same as OP_CHECKMULTISIG (or same as OP_CHECKSIG) except OP_VERIFY is executed afterward.

For OP_VERIFY: Mark a transaction as invalid if top stack value is not true.

Can this be better explained? How does OP_CHECKMULTISIGVERIFY and OP_CHECKMULTISIG differ in practice and in logic of creating scripts? What are the effects (pros and cons) of OP_VERIFY being executed afterward or before? Examples would be highly appreciated.


texts: Watching and spending from a huge number of offline private keys

texts:
We plan to accept bitcoins on our eshop website. What we want plan on doing is:

1) Keep all private keys always offline (cold storage).

2) Generate at least 100,000 keypairs of which only one will be stored on our web server.

3) Frequently change our Bitcoin addresses on our webserver to prevent third parties from knowing how many Bitcoins we have received in total. The web server will only contain our public key (Bitcoin addreses), not any of the private keys.

Now my questions are:

I) Is there a way to monitor the SUM of all bitcoins sent to ALL of our addresses?

Something like a wallet that supports import of a huge number of "watch-only" addresses without requiring the import of the private keys? If the wallet is an application, it must support SOCKS proxy connections. (Armory allows watch-only keys, but I don't know if it supports mass bulk import and SOCKS proxies? Also, it seems to be suffering severe RAM overuse bugs as of now, according to its developer...).

II) Is there a way to sell the SUM of all bitcoins ever sent to ALL of our addresses AT ONCE?

III) Will an attacker be able to find out how many bitcoins we have earned in total?

Thanks!


texts: How does the network handle changing IPs?

texts:
From what I understand, when a node first comes online, it requests a list of known IPs from all of it's peers. I'm assuming that by doing that, it shares its own ip to all of the peers, which in turn save it into their list. At this point, the network is in sync.

My question is, what happens when the node in question changes IPs?


texts: Can you include a signature in a bitcoin payment?

texts: I know you can use the bitcoin client to sign messages (for which you own the private key) and verify messages from other public addresses. But can you actually embed a signed message into a transaction so its on the blockchain for anyone to verify? When I say "signed message" i'm referring to an arbitrary message like in the attached example.


texts: Can't understand specific problem of Bitcoin anonymity

texts:
There is an problem shown in bitcoinwiki:

  Someone runs both a money
  exchanger and a site meant to trap people. When Mr. Doe buys from the
  exchanger and uses those same coins to buy something from the trap
  site, the attacker can prove that these two transactions were made by
  the same person. The block chain would show:

  Import coins from address A. Send 100 to B. Authorized by (signature).

  Import coins from address B. Send 100 to C. Authorized by (signature).

  Bitcoin transactions do not have a "from" address, but if the attacker
  believes that address B is controlled by Mr. Doe because the attacker
  received $5 from Mr. Doe's PayPal account and then sent 100 BTC to
  that address then they can infer the identity of the party sending to
  C. This assumption is not always correct because address B may have
  been an address held on behalf of Mr. Doe by a third party and the
  transaction to C may have been unrelated.

I can't understand several issues. Is "someone who runs both a money exchanger and a site meant to trap people" attacker? If so, than I (as attacker) already know the owner of address B, don't I? why I need trap site?


texts: Can you create empty Bitcoin transactions?

texts: Is it possible to create Bitcoin transactions of zero value, or in other words sending 0 bitcoin to an address?


texts:
I've got a bitcoin address A with its relative encrypted key K stored in a persistence storage.
I am launching bitcoinj through the WalletAppKit class and calling awaitRunning to wait for the blockchain header being downloaded.
I am adding the key pair (A,K) to the wallet after decrypting the key.
I am using the hex of an unspent transaction from the address A and using it as an input for a new transaction with an address B as output.
I am trying to propagate the newly created transaction to the network but i get "Unknown confidence level" message also if the input transaction has many confirmations.

I think the spv blockchain has to be synced after adding address A but i don't understand how to do it.


texts: how to track sendtoaddress / sendmany in case of network failure

texts:
Suppose you call sendmany or sendtoaddress on bitcoind RPC.

Suppose the transaction is created and send to the network, but RPC time out and sender process unable to read the txid.

Suppose there are several send to same address with same btc amount.

How this can be tracked programically?

I know you can pass comment to each send but I am unsure how I can collect it programically.


texts: Where is the string that generates the hash with 18-20 zeroes?

texts: When bitcoin miners mine, they have to solve a difficult and extremely repetitive math problem using the SHA256 algorithm. The miners are trying (basically playing lottery and almost always working in large groups) to get a hash with (currently) at least ~18.81 zeroes. (I put a decimal/float number because the value is inconsistent.) But, I want to put the hash into a hash function and get that super hard-to-compute number for a story I have where a superhero calculates this number. How do I get this string (nonce) that calculates to this zeroed hash and where do I find this on a block explorer, such as blockchain.com, or on bitcoin-cli?


texts: A question about full nodes, lightweight nodes and merkle trees

texts: What is the purpose of full nodes storing merkle roots? Why don't they save the transactions only? The hashes could be calculated only when a lightnode asks for them and the merkle roots could be saved only be the lightnodes. Am I missing something here?


texts: Manually extracting ledger nano s wallet public / private keys using "Mnemonic Code Converter" from ledger

texts:
I have the following example seed:

  morning twist board pelican denial retire middle inherit evil
  ritual omit fade general toddler grace evoke recipe
  sad minor destroy public dawn scissors cube

I'm trying to generate the same addresses on the ledger site which is showing up on my device: https://www.ledgerwallet.com/support/bip39-standalone.html

My intial pin was 5555 and my first bitcoin address is: 12mCn27...

I also set a "passphrase" of just the letter "a" which generates btc address: 1NSXBid...

I then did an attach to pin with the pin: 4555 which generates btc: 17Dn62...

I then added a passphrase to the 4555 pin with just the letter "b" and I get the following btc address: 1HBPpj...

When setting up ledger nano s initially is the address randomized? And what deviration path does it start from?
I tried pasting the example seed into https://www.ledgerwallet.com/support/bip39-standalone.html and I can't find the initial pin 5555 setup of address: 12mCn27
If I'm able to set different pins, where do I type this pin on the Mnemonic Code Converter page? It's not the passphrase field thats for sure.
If I wanted to recover all those private keys with the above scenarios with different pins  and passphrases. How can I?


texts: How can i sync only the last month of the blockchain with bitcoin core?

texts:
Anyone have any idea how can i do with bitcoin core.

Thanks in advance.


texts: Why tx informations of a specific transfer in BITCOIN protocol will send to many IP addresses?

texts:
Recently I send a specific value from a wallet to another wallet and Simultaneously I caputred the related traffics in source and destination.

after that, I found that value and it's related address in different packets which their difference was just in source and destination IP addresses.

Why these information(transferred value and it's output address) where distribute to different addresses and which address is main?


texts: Check how much money there is in my Bitcoin address/wallet

texts: Is there a website or service that can quickly lookup how much bitcoins are there in a given wallet/address, so I can look up my own wallet from a friend's computer which doesn't have the Bitcoin client installed?


texts: How do I get my Bitcoin private keys from app.thorswap.finance which is a native BTC cross chain swapping system?

texts: I'm testing out app.thorswap.finance for native bitcoin. Supposedly Thorchain is a cross chain swapping service with no centralized parties. Going to the app, I generated a keystore file and it comes with a Bitcoin address. I'm assuming when I send my BTC to this address, it resides under my control until I want to swap it to another coin. How do I access my Bitcoin private keys on app.thorswap.finance generated from my keystore?


texts: What made the old versions of the bitcoin wallet insecure?

texts:
According to the downloads for the Bitcoin client, versions older than ~0.3.0 were "insecure".  Since they are not available for download (and the lack of security is the given reason) no one can learn from them or verify the reason.

The question I have is, 1, does anyone have a copy of the original wallets and or their source code for download and, 2, does anyone know what made them insecure?


texts:
I want to exchange BTC with other payment methods on my website.

person A will fill the form with email, name or other required fields and then fill amount of BTC he want to exchange. that form will take him to payment form (like Paypal checkout form) after that, I will "manually" transfer him dollars to his bank account/paypal or any other payment service.

I've seen Paypal integration, and I've tested it with my sandbox account. but I don't find any tutorial for bitcoin.

I tried to use blockchain but for API they require website URL and currently I am developing on localhost.


texts: The difference between mempool "bytes" and "usage"

texts:
getmempoolinfo returns bytes and usage. Currently, the value I have for bytes is 1316363 and the value I have for usage is 4826112.

I'm assuming that bytes is how much space these transactions would require if they were to be included in a block while usage is the size they are currently taking on my computer. That would imply that the transactions get compressed somehow (or some nonessential info gets stripped away) before they're included in a block. Is that correct or am I way off?


texts: QBitNinjaClient.GetBalance() how to find Sender's Address?

texts:
var address = new BitcoinPubKeyAddress("My Pub Key", Network.TestNet);
var client = new QBitNinjaClient("http://tapi.qbit.ninja/", address.Network);
var balance = await client.GetBalance(address);

I can find all the received coins in balance.Operations.ReceivedCoins.
But how can I tell who is the sender?


texts: Is it possible to get ticker of bitcoin.de using an api?

texts: I did not found anything in the site. They have an api? It is for my Android App Bitcoin Paranoid.


texts: Is it possible to transfer blockchain data from one machine to another?

texts: I want to run a bitcoin full node at home but the initial sync-up is taking days because of my slow internet connection. Can I download the blockchain data from a machine with faster connection and transfer over to my home machine? Is this possible and if yes, how?


texts: Bitcoin Transactions Detailed distinction between TxHeader TxInput TxOuput

texts:
Related to post Murch Explanation of Segwit Tx Fee Rate he breaks a TX down into:

TxHeader
TxInput
TxOutput

To calculate the weight and the final virtual size of a transaction (P2PKH,P2WPKH,P2SH-P2WPKH)
My question relates to what is the TxHeader in detail. I haven't heard about this classification in any articles.


texts: Private Key leakage due to reusing same address, how to prevent?

texts:
1 What precisely is the meaning of "reusing"? Is it receiving multiple times coins to the same btc address? Or is it also about sending coins?
2 How can people avoid this leaking of information when using a wallet, best practices?
3 How many times of reusing could be enough to seriously allow leakage/reingeneering of the key? Just one time is enough ? Possible to make any estimations?
4 Is this reusing problem only inherent to bitcoin? Or which other blockchains would you know of with same issues?


texts: how to calculate transaction bytes of a x BTC? x=0.2

texts:
i have read : How to calculate transaction size before sending

but i will not understand what are in and out.
as describe in this link in=40 and out=16

what does it mean???

i will send only one address to 0.20BTC of 1BTC account.
please describe this transaction size.


texts: Why can't an intermediary Lightning node take (nearly) all fees?

texts:
Consider a Lightning payment: Alice wants to pay 100 sat to Dave via two intermediary hops: Alice - Bob - Charlie - Dave. Both Bob and Charlie advertise a fee of 2 sat. Alice sends 104 sat to Bob, expecting him to forward 102 sat to Charlie. But Bob only forwards 101 sat. Then Charlie has a choice: either to fail the payment and get nothing, or forward it for just 1 sat. It seems that the economically rational choice is to forward anyway. If this is true, why first hops not always take nearly all fees for themselves?

Of course, due to onion routing, Bob doesn't know whether Charlie is the last hop. If Charlie is the ultimate recipient and he won't get the sum he expected, he won't reveal the preimage, and Bob will get nothing. But can such strategies be profitable on average, over many attempts?


texts: I'm digging for Dogecoins at Hashfaster (Wow! To the moon!), and I'm trying to understand the statistics page. What is the difference between a block (my cpu miner software detects new blocks all the time) and "rounds" (which seems to be some metric on the Hashfaster dashboard)?


texts: Why does Bitcoin no longer have checkpoints?

texts:
I've read that checkpoints in Bitcoin were removed because they were not preventing any meaningful attack.

Why should a regular checkpoint not prevent majority attacks? For instance, if a checkpoint is made every N blocks and (for example) 3/4 of the hash power agrees, would this not be possible to be used as a mechanism to create a permanent confirmation of the transactions before the checkpoint? Assuming, of course, that clients would check for those checkpoints and enforce them to be included in the valid chain.


texts:
Is it normal for ABE to get "out of sync" whilst re-creating it's blockchain?

I am concerned that the number on the left does not match the number on the right. I have no idea what those two numbers are, I just know that the examples show them both being the same thing, and that they did indeed start out being the same:

 block_tx 1 1
 block_tx 2 2
 block_tx 3 3

Here's what it looks like now:

This process has been running for a number of hours now, and is only getting further and further "out of sync" with the original number as it does so.

Just curious if I should stop it now and start over?


texts: Using funds that have not been completely transferred yet for a new transaction

texts:
What happens if I start a new transaction with funds from a transaction which isn't 100% complete?

Let's say, the incoming transaction shows 2/3 of the green dot, but the sum is counted as full by my Bitcoin Wallet for Android.


texts:
I have recently migrated machine. I used the Apple Migration Wizard and when it was finished my new machine's copy of Multibit appears to have my BTC within it.

My next task is to wipe the old machine, so I want to be sure that everything is in order before I do that. I just opening Multibit enough to ensure this? Are there anymore checks I can do?


texts:
I have an bank account that allows me to exchange between currencies at no extra premium other than the exchange rate.

I am noticing large spreads between some of the BTC prices in various currencies.

For example

1 BTC USD is 9283
1 BTC GBP is 5382 (7338 USD)

I am seeing this correctly, does it make sense .....is this an arbitrage opportunity?


texts: What is the difference between Ripple and Stellar?

texts:
I went through the site but I don't see how Stellar differs from Ripple. I see that there are differences in distribution, everything is made open source from day one and the company is non profit instead of for profit as in Ripple.

Both were co-founded by the same person and the technology seems to be the same.

What am I missing?


texts: How can I get stealthVersion from bitcoin's source code?

texts:
I found that a library called Bitcoinkit use stealthVersion.
Network.swift

public class Mainnet: Network {
...
    override var stealthVersion: UInt8 {
        return 0x2A
    }
...

I tried to search 0x2A,0x2a and 42(decimal from 0x2a) but find nothing in source code.

Is this calculated in bitcoin source code?

PS:
I found some Altcoin have a stealth.cpp which defined stealthversion:
(Verge)

const uint8_t stealth_version_byte = 0x28;


texts: Who do i see the commissions taken by miners?

texts:
I'm a bit confused by the commissions. My understanding is there should be none in Bitcoin.

But a friend of mine told me miners get a cut. What does this mean? I want to learn how much commission I pay to the miners. Could you please tell it in detail and tell me where I can see it?


texts: I understand the motivation for SIGHASH_NOINPUT - it would help with offchain payment channels. It was proposed already in the Lightning paper but Eltoo will effectively work just with something like that. But what exactly is the ANYPREVOUT BIP about? It seems like some extension to be used with taproot scripts. But I don't seem to get why you need a special public key type and chaperone signatures. Can anyone explain this part in plain english please?


texts: Broadcasting a transaction as a 3rd party

texts: In a scenario I have a signed transaction from A to B and ready to broadcast. As C, I want to broadcast it but the part I am having hard time to understand is as the transaction is already signed and everything is settled how can I change the transaction fee I would like to pay? Can I pay extra from my wallet for example? Thanks.


texts: When I enter the deposit address of where I sent my bitcoin, the Blockchain says that the transaction is "Spent" What does this mean? It's been like this for 3-days now. Please help!


texts:
I've built a mining rig running Ubuntu 11.10 with 3 Radeon 6850 GPUs.

When I run ./poclbm.py without any arguments, it returns the list of available devices as...

[0] Barts
[1] Barts
[2] Barts
[3] AMD Sempron(tm) 145 Processor

giving me the (possibly erroneous) idea that I seem to have the drivers setup correctly.

When I start up one miner and pass the argument to use device 0, the hash rate is reported at slightly over 200 Mhash/sec. However, when I start up another pointed at device 1 in a separate term window, the hash rate for both is reported at around 100 Mhash/sec. And when I fire up the third miner and point it at device 2, then all three miners report their rate at around 60-70 Mhash/sec.

This suggests to me that the miners are not honoring the device argument that I'm passing and all dogpiling on one of the devices (probably the freckle faced red-headed one).

This happens with both m0mchil's poclbm and with PhoenixMiner.  Below are the arugments I'm passing to each...

./poclbm.py http://username.worker:pw@host.com:port -d 1 -v

./phoenix.py -u http://username.worker:pw@host.com:port -k phatk2 DEVICE=2 VECTORS BFI_INT

Any ideas what I might be doing, or have done, wrong?


texts: Monitor paper wallet balance without importing private key?

texts:
I generated a paper wallet offline and running from fresh OS, and I'm not going to ever type that private key into a computer until it's time to spend the coins.

But I will send coins to this address as a 'piggy bank'

My question: can the Qt client be configured to track an address and update the available balance for an address, without the private key ever being entered?


texts:
Is there anyway to create my own Bitcoin Network?

I'd love to put my first block into self-own Bitcoin Network and make it grow : )

Any ideas?


texts: Why does bitcoin create several "empty" wallet addresses?

texts:
I'm currently running bitcoind -testnet. I ran bitcoin-cli dumpwallet ~/wallet-output just to explore the output and it looks like it created 102 private/public key pairs that I assume are just sort of pre-generated just for the convenience of having them on hand.

However, I'm surprised they all seem to be somehow "recognized" as part of the testnet blockchain already, even though they've never been used. For example, when I search for one of these addresses in Block Explorer I see an address with zero transactions and a 0 BTC balance: https://testnet.blockexplorer.com/address/mxwDTWg556BDzZhEWvJ1EeYwSYxG42wKZC. This is different from addresses I've created "outside" of the bitcoin tools (e.g., https://www.bitaddress.org). For example, Block Explorer "can't find" this address: 1XitCFAkFhNR6PoJsPcxjsFzkMegx4Ky5. I would expect that to happen to all of the addresses pre-generated in my wallet until I actually use them.

Why did bitcoind "register" these addresses on the testnet blockchain? And how exactly did it do that? Is that a special transaction type?


texts: Can you transfer Bitcoins from one address to another address directly without going through the web?

texts:
If you and a recipient both have a wallet on a flash drive, is it then possible to transfer bitcoins from one wallet to the other using a computer without going through the web?

Example in life: "Here you go nephew, I'll give you 5 bitcoins for your birthday." Then we go to the computer with our wallets and transfer the funds, without waiting for people to decrypt bits and pieces of it across the web, just relying on the local computer.


texts: How do I test that blockchain p2p replication is properly, securely exposed to the internet?

texts:
I have bandwidth and CPU to spare and I'd like to participate in the P2P nature of sharing the blockchain to other peers.  How can I properly, and securely participate?

Also, how can I test or verify my client that its working correctly?

Can I participate in the same (port 8333) blockchain replication if I run in server mode?


texts: does bcoin support simplified payment verification (SPV)?

texts: Does bcoin support simplified payment verification (SPV)? I can't seem to find anything about it online


texts:
Suppose you have multiple computers on the same network. Also, you use a block-level (note that 'block' is different in this context than what it usually means in Bitcoin) deduplication filesystem  like SDFS to deduplicate blocks between these computers.

How much disk space would this save when running Bitcoin Core? Assume that all of the computers are running the same version of bitcoind.


texts: Why does the chart on a coin vary between exchanges?

texts:
Look at the BCH chart for instance, the 8 november there is a wild selloff following the cancelation of the new scaling protocol for bitcoin. This has nothign to do with BCH but causes a selloff nevertheless, on big volume with  a long deep red candle. This is on Bitfinex. Then look atr the same
chart at Kraken. No long deep red candle, no selloff.

So I guess either the chart was edited (manipulated) afterwards, or no Kraken customers sold any BCH outside that range on the chart?


texts: How bitcoin transaction fromat design can be explained?

texts:
Can someone clarify?

Why is there bitcoin address in the transaction, when the bitcoin script already contains the pubkey hash?
Why isn't the amount a part of the script?
Why does bitcoin script allow to sign only parts of the transaction?


texts: How do block explorers determine propagation through nodes/P2P protocol?

texts:
On several Bitcoin blockchain explorers, I have seen unconfirmed transactions given a dedicated "propagation" value that tells a user how much of the Bitcoin network has become aware of this transaction.

For example, BlockCypher provides a "confidence" value for unconfirmed transactions:

This has always lead me to wonder how exactly they can calculate this? Do they personally have a large distributed network of nodes that are constantly kept track of? Surely this would be cost ineffective and less decentralized.

Their documentation states:

  By monitoring transaction propagation, the number of nodes that have received it, and how quickly they received it, we can calculate its probability to be the “winning” transaction at any given point in time, if a double-spend was attempted.

I have had quite a difficult time finding documentation on what exactly nodes can request from each-other directly. Can a node simply ask its peers if the transaction exists in their mempool with a getData request?


texts: If well-built wallet software can avoid transaction malleability, why does the lightning network need an additional malleability fix?

texts: My understanding is that wallets can avoid creating malleable transactions. If so, why does a lightning network need SegWit or some other tx malleability fix?


texts:
Im using bitcoin core debian linux to process payments on my shop using RPC API calls.
Now im switching wallet server, do I need to download whole block chain in order to process transactions on my shop? like create addresses for customers, see balance for customers,,,etc


texts: Can any one help me with required information how a newly created coin value is assigned ? and how does the rate fluctuations occur


texts: I would like to know what "upgrading" fees are? The guy who's mining my account says I need to pay him $1005.50 more in Bitcoin before they can go on. I only invested $300.00. Does it sound correct?


texts:
I have ordered Antminer S9. After doing some research I discovered that APW3+-12-1600 PSU 1600W is a recommended power supply however it requires 200+ voltage which is not available to me.

I live in the US and the standard wall socket output voltage is 110V.

Could you recommend a power supply that  would work well with S9 in the US without impeding its designed performance?

A recommendation or a reference to a working guide would be highly appreciated.


texts: Problem with importing key to blockchain.info

texts:
Problem

downloaded my wallet into a drive which does not have enough disk space left.
has not currently synced yet
transferred bitcoins by mistake whilst it was syncing
I have backed up my wallet but have not encrypted it yet.
I'm trying to gain access to my coins via importing of keys to .blockchain website.
I followed this guide:

  To export a private key from your Satoshi bitcoin-qt client:

launch your bitcoin client as usual and wait for it to load the blockchain and start up
click on 'help' in the menu bar (top right)
click on 'debug window'
select the 'console' tab
type: walletpassphrase "your walletpassphrase here" 600
type: dumpprivkey [your public key here]
this will return the private key, you can copy it now; ensure you clear your clipboard/history afterwards
type: walletlock    }

All it says in the console..

safemode,warning what is not displayed may be incorrect
might need to download upgrade, and nodes   code-2

I want to access my coins via blockchain website. My operating system is Windows; the client is bitcoin-qt version 0.8.1.

How do I export these keys?


texts: Bitcoin Wallet Empty after importing using key phrase

texts:
I've recently tried to recover my Bitcoin wallet after changing phones however after importing the wallet using the 12 word keyphrase my wallet is empty (there was Bitcoin in the before). I've scanned the wallet for transactions but none are found.
Any idea what has happened and if/how I can recover my Bitcoin?
Thanks


texts:
It seems I have a stuck "send" transaction.  I transferred the entirety of my BitCoin Core wallet to Newton.  (purely so I could offload the blockchain off my PC)
I am sure the fee was too low after the reading I've done. I have the transaction details, yet can't seem to even look it up.  I've waited a few days now, before panicking, but I'm starting to approach that stage.
I also can't offer a higher fee as it was the total amount left in that wallet.  Does anyone have any ideas how I can force terminate or cancel this transaction?  Or is my only solution to wait it out and hope?
I appreciate any suggestions or tips.
Thank you everyone.


texts: Difference between Bitcoin and omni layer

texts:
I am really confused on bitcoin core and omni core. I have several doubts, regards this,

it is possible to use bitcoin node for omnicore.
can we use the bitcoin address for usdt.
if we can, how to get the blockchain raw transaction using json rpc.


texts: Should signature verification by key recovery ignore compression status?

texts:
The bitcoinj library's API offers a signMessage method of the ECKey class which returns a signature (r,s) as 65 bytes encoded as a Base64 string. The crunch of the encoding lies in the additional leading byte which allows key recovery (the 64 bytes of (r,s) alone are not enough for that purpose). In particular, the leading byte of the encoding includes information regarding the compression status of the signing key.

Now I assume this specific signature encoding was implemented for a very good reason, which I suspect is the fact that it is a standard encoding, present in many other bitcoin libraries and in core.

Now when verifying a signature through key recovery, the verifyMessage method ignores the compression status of the recovered key and simply ensures that the corresponding elliptic curve points match. Sure, this is a pretty good check, but why do we bother encoding the compression status of a signing key, if we are going to ignore it later? Is this the semantics other known libraries have adopted, or indeed core? I attach a small snippet for illustration:

import org.bitcoinj.core.ECKey;
import java.security.SignatureException;

public class Test
{
  public static void main(String[] args)
  {
    String message = "some arbitrary message";

    ECKey k1 = new ECKey();      // random , compressed
    ECKey k2 = k1.decompress();

    // Signature (r,s) encoded as 65 bytes, with leading byte
    // allowing key recovery (including compression status)
    String sig1 = k1.signMessage(message);
    String sig2 = k2.signMessage(message);

    // compression status is encoded in signature => differing leading byte
    System.out.println(sig1);   // INgDhkt98Mme9m9AQ+nqtjyvjj ...
    System.out.println(sig2);   // HNgDhkt98Mme9m9AQ+nqtjyvjj ...

    // signatures are verified succesfully
    try
    {
      k1.verifyMessage(message, sig1);  // compressed case
    }
    catch(SignatureException e)
    {
      System.out.println("it should not happen");
    }

    try
    {
      k2.verifyMessage(message, sig2);  // uncompressed case
    }
    catch(SignatureException e)
    {
      System.out.println("it should not happen");
    }

    // in fact, compression status is ignored ...
    try
    {
      k1.verifyMessage(message, sig2);  // should it throw ?
    }
    catch(SignatureException e)
    {
      System.out.println("it does not happen");
    }

  }
}


texts: How does my wallet allow me to double spend? As soon as I make a payment, shouldn't my wallet delete those bitcoins or does it leave them until the transaction is added into the blockchain?


texts:
Can I store my wallet on one machine while running the client on another?
I'd like to help the p2p aspect of the network by leaving a dedicated machine connected...


texts:
I have old items that I want to sell for bitcoins. This includes digital content and physical objects.

What websites can I use to sell them?


texts: How to sign a transaction and also get the signature part from it using electrum console?

texts:
How do I sign a transaction with following things:

Unsigned Tx: 0100000001e939fb23e9991ebbc75fd08c736da32ca12d98a4ff1b8e970e97f5661927ee410000000000ffffffff01db400f00000000001600147f6757aebaf775d9ce50b2005d551e2501b1e80d00000000
Private key associated with one of the public keys used for creating 2-of-3 multisig:
p2wpkh:cQ8KpCuZ11wm8ARD3pPeaqyuUBPusrH9pnVRwDu47kLpxwCZ4ap6

Once the tx is signed, how do I get the 'signature' part from it?

Public key: 0318370919cfceb3d260081eeca3cae19f941eec321f597c48a64839178ea1e3e0
I tried signing the transaction with unsigned tx and private key however it returns something that doesn't make sense. Whats wrong here and how do I resolve this?
signtransaction(tx, opt_privkey)
>> signtransaction('0100000001e939fb23e9991ebbc75fd08c736da32ca12d98a4ff1b8e970e97f5661927ee410000000000ffffffff01db400f00000000001600147f6757aebaf775d9ce50b2005d551e2501b1e80d00000000','cQ8KpCuZ11wm8ARD3pPeaqyuUBPusrH9pnVRwDu47kLpxwCZ4ap6')
"02000000000000000000"


texts: Cryptocurrency Exchange Technical architecture? How to build it? (Developer Point of View)

texts:
I'm a softawre developer & newly involved in Blockchain Technology.

  I need information about How Cryptocurrency Exchange Technically work?
  i.e Buy ETH using BTC or exchanging any coin with another coin etc.

I know all the other terms/things needed for exchange like, Legal, security, KYC, peer to peer etc.

I search many articles but didn't found any technical architecture. found following

  There are readymade API's like block.io, chain.com, blockcypher.com etc who provide such thing.
  but want to develope it from core ie bitcoind Github.

I have good conceptual knowledge of Blockchain, Solidity etc.
Working with Bitcoin Core for creating new address, sending BTC to another address vai CMD prompt.
Able to implement Block Explorer etc.
Able to create new Coin/Currency in Solidity using ETH Compiler.

What I really need is Direction & path to follow.
As the technology is new, resources are very few. Any technical help I really appreciate.

Thank you, Have a great day.


texts: Online BTC wallet implemention with bitcoin-core

texts: I have written a php code to register users and create wallet for them on bitcoin-core full node.My question is how can i manage users wallets.if i use loadwallet to load USER A wallet and get address and other managements what happen if USER B call it on same time?. how can i seperates users!


texts: Should I verify the Bitcoin Core release signing keys?

texts:
I have been running Bitcoin Core on an old Macbook for about a year, and I updated to v0.18.0 a couple of months ago which I downloaded from bitcoin.org.

I have recently been delving deeper and I realized that I never checked the keys.

Is it recommendable/indispensable?

Can I still check the keys once it is up and running?

Will I have to reinstall and download the entire blockchain again?


texts: Created an HTML5 Game, best way to integrate Bitcoin?

texts:
Okay so I just finished up a ping pong HTML5 game I've been working on as practice, and I was thinking of integrating Bitcoin into the game so when a user wins vs. the CPU, they get a small amount of bitcoin sent to their account, or to an account created for them.

Can anyone point me to a resource to get this done?

I think I can do this with BitcoinJS but it is not available for Windows.

Not sure what I'm doing, so any help would be great!


texts: Importing private key for watched address in bitcoind, rescan necessary?

texts:
If I have a watch only address in my wallet and then I import the private key corresponding to it, will I need to do a rescan or will it automatically update my available balance with any UTXOs for that address (at least those created since I began watching it)? It seems to me like it shouldn't require a rescan but I'm wondering if anyone has actually done this successfully.

If I don't get an answer here after a while I can test it out myself and report back.


texts: How can I define the change address of a transaction using createrawtransaction?

texts:
This question is almost the opposite of How to find the change / sender address given a txid?

If I am making a transaction using createrawtransaction how can I define the change (sender) address?


texts: Is there still a shortage of available inbound connection slots?

texts:
David Schwartz's answer to this question states the following:

"For some reason that isn't well-understood, the Bitcoin peer-to-peer network is consistently short of available inbound connection slots. This makes it more difficult for newly-started clients to establish a resilient connection to the Bitcoin network."

Is that still a problem? If so, could it be because of some sort of attack (or selfish behaviour) on the Bitcoin network?


texts: I had a few bitcoins in a Multibit wallet version 0.5.14 on my old computer.  I decided to start up the old computer again and transfer the bitcoins to a hard wallet.  I opened it up and there's nothing in it.  The wallet appears to have synchronized.  I can remember before I used to input a password to see what was in my wallet but that option doesn't come up anymore.  Does anybody have any advice?  Please don't be too technical in your replies.  Thanks.


texts: Different languages are used in coding the blockchain these days. Which was used in coding BTC and how is it superior to others?


texts: Determine address balance using bitcoin core

texts:
I'm having a hard time figuring out how to compute the balance of a given bitcoin address using only the standard RPC API. I would like to extend this logic to bitcoin clones as well so the solution should use standard API calls only (e.g. only calls listed here https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list )

Can you think of a way of doing this?


texts: Does my wallet need to be unlocked to mine?

texts:
Currently I am mining at around 775Mh/s and have been for only 12 hours.  I want to make sure everything is setup properly.

I have encrypted my wallet and Bitcoin is reporting that the wallet is encrypted and locked.  Does the wallet need to be unlocked in order for the mining process to yield its results?

This question was helpful.


texts:
So is there anyway to generate address and then check the address to see if enough fund is sent and enough confirmation without using any 3rd party API?

Works on software written in C# or/and Web PHP.


texts:
actually this is not Bitcoin but Litecoin 0.13.2 on Linux Mint,

litecoind stopped with "bus error" just on start verifying blocks:

tail ~/.litecoin/debug.log
...
2017-05-06 21:15:26 Verifying last 24 blocks at level 3
2017-05-06 21:15:26 [0%]...2017-05-06 21:17:25

but just after this on the second try it started normally and I ran "litecoin-cli verifychain 3 0" and it passed successfully,

and now I'm not sure should I also run "litecoind -reindex"? or verifychain is enough to be shure that everything is ok?

what exactly verifychain does?


texts: Export a list of addresses associated to blockchain.info account

texts:
Is there any straightforward way to export just a list of my addresses I have in Receive money tab?
I would like to easily extract them to keep on the side to occasionally run curl on those addresses to get all unspent outputs for each without going to blockchain.info website and logging in.
I can do a copy-paste and grep whole content for addresses but maybe there is some more reliable way?


texts:
I can use getblock json rpc method to get parsed block, but I need raw data.
Is there any way to get raw block data using bitcoin core?


texts: Getting current Bitcoin Fees from Command LIne?

texts:
I have a shell script, that fetches current bitcoin fees from https://bitcoinfees.21.co/ with this command:

curl -sS -L --insecure https://bitcoinfees.21.co/api/v1/fees/recommended

When I run this command from (Central-) Europe, I never encountered an issue. Now I am in Africa, and obviously there is JavaScript injected by Cloudflare, asking for a Captcha. This prevents to get the values with a  shell script (command line). Is there a way around it, or are there other services for an overview of fees for BTC?


texts: What would a country adopting Bitcoins as official currency have to reinvent?

texts:
Let's say that a country decided to ditch their currency and go for Bitcoins. What would this country have to reinvent. The reason why I ask, is because I believe that if a tiny country was to adopt Bitcoins as their official currency, then this would remove all legal issues related to this currency, and hence would enable it to get adopted more widely.

Some of the issues that could require reinventing something could be in relation to:

Transparency requirements for the government to efficiently tackle

Black economy
VAT and general taxation fraud
Financing of terrorism

Ability to peg the currency to other currencies if this is judged as a good idea
Have an efficient banking system
Ability to fight deflation

Any other issues, which I have not thought about. Please note that you do not have to answer all these issues in any one answer, just one of them.


texts: Is there a protocol limitation (I suspect there is) that does not enable transactions across different platforms to access a 3rd party remote server (Chaumian server?) through API and create a coinjoin every let's say 2 minutes or 100 users from all platforms/wallets? If someone implemented such a server, this would highly increase coinjoin liquidity and privacy.


texts: When does client decide to stop/cancel proof of work algorithm?

texts:
I have been reading about bitcoin and blockchain in the last few days, but I have something I don't clearly understand.

The "proof of work" may take a long time for a simple node to guess, but if we combine all nodes, they guess it in 10 minutes.
Now lets say another node guessed it faster than me, how do I know when I should stop my proof of work algorithm?
Is there any point on keep trying to guess it?
When do you start trying to guess the next proof of work?

Hope the question is clear.


texts: In the Script, when one is checking whether a value is true of false, should the length of the expression be checked? For example, 0x01 is evaluated as true, but can the same be said  about 0x0001, 0x000001, etc?


texts:
I have download bitcoin source and change genesis in regtest. and i try to generate 1 block by command ./bitcoin-cli -generate 1 it does not show any mining block. i try over 10 times but it is still the same result why?
here the result:
{
  "address": "tc1qltnl9t23yshlexxxxxxxxxxxx",
  "blocks": [
  ]
}

please kindly advise what happen what bitcoin source code ?


texts: What is the earliest block in the blockchain that has a spent coinbase? I have manually looked at the first dozen or so but they are all unspent.


texts: Does a bitcoin pool appear as one node or multiple nodes to the rest of the network?

texts: I'm guessing that it appears as a single node?  For example on http://getaddr.bitnodes.io/?


texts:
Let's say have 3 inputs (alice, bob, satoshi): 0.3, 1.3, 1.6.
We can mix these inputs for example like this: 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.1, 0.1.
Or like this: 1.3, 1.3, 0.3, 0.3.
Traditionally it is mixed like this (CoinShuffle/ZeroLink/BlindCoin): 0.3, 0.3, 0.3, 1, 1.3.

There are many combinations, but there are better and worse mixes. I intuitively figured I want to anonymize the most bitcoins in the cheapest way.
First take the sum of the anonymity sets weighted by the amount of bitcoins. With the second mix example (1.3, 1.3, 0.3, 0.3) it would be:

alice: 0.3btc - 2/1=2 anonset -> 2*0.3=0.6
bob: 1.3btc - 2/1=2 anonset -> 2*1.3=2.6
satoshi: 1.3btc - 2/1=2 anonset -> 2*1.3=2.6 AND 0.3btc - 2/1=2 anonset -> 2*0.3=0.6

And the sum is: 0.6+2.6+2.6+0.6=6.4

Next we want the cheapest possible mix, for this we need to minimize the number of outputs, in the second example it's 4. Finally divide the number of outputs by the weighted anonset sum: 6.4/4=whatever (1.6).
We want this whatever number to be as high as possible. This is how we can anonymize the most bitcoins the cheapest way.
With the traditional mix, whatever would be 5 weighted anonset sum / 5 output number=1.

So the my ad-hoc 2nd algorithm exactly 60% more efficient.
I also wrote a little software that compared 3 different algos with 100 random inputs (results below).
The first goes like this: take always the smallest input and pair it up with the rest. This generated many outputs (as you can see it created so many outputs, that it overflow by 173% of the standard maximum Bitcoin transaction size.)
The second algo always took the second greatest input and paired it up with the greatest.
During the third algo I used middle out, so I took the middle input and paired it up with as many inputs as possible. This provided by far the best whatever value: 149.

Test code: https://github.com/nopara73/ConsoleApp14/blob/master/ConsoleApp14/Program.cs

What algorithm can lead to the most optimal mix?


texts: What is the relationship between hash rate and accepted shares?

texts:
Specifically this question is about Litecoin, but I suspect the answer would apply to both.

Say you have a rig mining at 700Kh/s (LTC). It seems that you get, more or less, a one or a few accepted shares per second.

My understanding is that when mining, you're iterating through 0 to ~ 4 billion for your nonce. One of those nonce's is the number you're looking for and will result in an accepted share.

On average, you'd expect to solve for the correct nonce in about 2 billion tries. But, if you're only mining at 700Kh/s, the math doesn't add up. If you're only trying 700,000 nonces per second, it will take about 45 minutes to find the right nonce.

What am I missing here?


texts:
I run a Bitcoin node for about 1.5 months and I notice that there is no feeler connection is made in 25 days, hence the IPs in the tried table does not grow.

I also notice in the debug.log during the same period of time, many potential stale tips are detected:

  2019-02-20T13:26:59Z Potential stale tip detected, will try using extra outbound peer (last tip update: 2737 seconds ago)

Does extra outbound connection when tip is stale disable feeler connection?
If yes, is it normal to have stale tip for 20+ days?


texts: I need good mining SW for Linux where I can inject a hashing accelerator library. Recommendations?

texts:
I have access to a powerful accelerator for a number of hashing algorithms.
I'd like to get hold of mining SW for Linux that has the following features:

CPU mining
Offline benchmarking

My plan is to intercept calls to SW implementations of SHA-256 & resolve them in the accelerator.
I would then like to obtain a hashrate for the accelerated version.
Do you have any recommendations for good, reliable projects that can be useful for this purpose?


texts: How to determine the geographic distribution of the hashrate?

texts:
I would like to map the hashrate distribution geographically, which would require knowing the IP address of the winning miner for each block.

According to the paper by Miller et al
several aggregator websites, including blockchain.info, maintain low-latency connections to thousands of nodes and record the IP address of the first connected node to relay each block. Is this information provided somewhere? While blockchain.info provides a hashrate distribution, it is aggregated at the pool level while I would like to know more about how the hashrate is distributed among the pools' servers.


texts: Will Bitcoin scaling affect the amount of hashing power required to keep the network secure?

texts:
In Mastering Bitcoin Andreas Antonopulous asserts that

  "Bitcoin can scale up, achieve broader adoption, and remain secure without any increase in hashing power from today’s level."

Is this really the case?


texts:
I'm looking for an API which lets me query for UTXOs on the base of specific meta data, e.g:

When was the transaction containing the UTXO issued?
From which address?
etc.

I have found this question: What is the best way to download a "recent" UTXO set snapshot?

But it just contains the information that it's unsafe. I'm only interested in the meta data and don't want to run a wallet on it. Therefore I'm not interested in security aspects.

Is there a war to query on the UTXO globally, without a given address? Or a way to download the whole UTXO?


texts: Problems loading blockchain from existing folder

texts:
I once saved the "blocks" folder + the "index" folder of the Bitcoin wallet.

Now on another PC I thought I could load the chain that way by copy pasting these folders in Appdata. Wasn't very smart not to copy directly the whole file folder.

So in my situation what else do I need exactly to properly launch the wallet with a full blockchain ? Please help I don't want to download the chain again...

I get this error:

2017-02-01 02:56:15 ERROR: ReadBlockFromDisk(CBlock&, CBlockIndex*): GetHash() doesn't match index for CBlockIndex(pprev=0xd4ba3c0, nHeight=299478, merkle=4f27a1a8c5f19894e7012ce4ea4f83eba0ea846af888749980d855e5d7179e46, hashBlock=00000000000000001e66b8d27a6bcff234f06d502a01aa23fd4be311d8b2dbf2) at CBlockDiskPos(nFile=138, nPos=8)


texts: How Bitcoin wallets and it's transfer process work?

texts:
I am very new on cryptocurrencies, and like to understand it's transfer process. I think if I want to buy Bitcoin, I must download a Bitcoin wallet, then find a person who has Bitcoin. Then he/she must transfer that bitcoin from his/her wallet to my wallet. Then I will pay the price either in cash or with credit card to him/her bank account.

After that I can see this Bitcoin in my wallet. OK? But I have some questions:

How many wallets a person can download and use?
If I used a wallet in the above example, then I wanted to change my wallet, should I download a new one and do a transfer from my previous wallet to new one? I mean there is no unique ID for people that they can use it in different wallets to reach one unique account?(Like our stack account that we can reach to it by Chrome, Firefox, Edge, etc, considering the browsers are wallets)
How crypto exchange websites work? If I want to buy or sell 1 Bitcoin, should I pay the money/coin to their bank_account/Bitcoin wallet, and the other person should do that too, then the website will pay it to us? I mean is it a 2-step process or buyer/seller do a direct transfer?


texts: How can one estimate the amount of Watts that is consumed by the mining network as a whole?

texts:
I'm trying to estimate the Wattage used in mining operations over time and compare that YoY cost with mining physical materials (gold, silver, etc).  I hope that the electrical impact is less than that of mining for precious metals, but I'd like to quantify that to be sure.

What are some approaches I can use to measure and extrapolate the electrical and hardware cost of mining over the years?

Some data points that would assist in gathering this information would be

When was CPU mining invented/popularized?  To what extent?
When was GPU  mining invented/popularized?  To what extent?
When was FPGA  mining invented/popularized?  To what extent?
When was ASIC  mining invented/popularized?  To what extent?
What is the average cost of the above components?

For example, do we know how many FPGAs were in the wild on a per-vendor basis?  How much of the hashrate did that consume and what is left over?


texts: can attacker and honest node in double spend ever tie?

texts:
in bitcoin white paper there are only attacker and honest nodes.
you have p, and q for probabilities.

in double spend attack, in bitcoin whitepaper, can we talk about possible tie of attacker and honest nodes ? is a tie possible and what does it mean if it is possible ? in terms of block chain and blocks ?


texts: litecoin transaction time without transaction fee

texts: I've sent 927 ltc from my wallet to btc-e but didn't left enough in my wallet to cover the 0.01 transaction fee. My litecoin wallet is showing 'this payment has not been transmitted yet' and it's been a couple of days now. How long is it going to take? Is there a way to cancel the transaction?


texts: How to make the commission for withdrawal of Bitcoin on the exchange consistent with the miner’s fee viewed on the blockchain browser

texts: I transferred Bitcoin on the exchange and found that the fee charged for filling in is inconsistent with the miner’s fee viewed in the blockchain browser. How do I ensure consistency? Thank you!


texts: Why can't smart contract code just be stored on an immutable blockchain an just have another system execute this code?

texts: I understand that a smart contract is just a fancy term for code that just does something with accounts in an immutable blockchain. A good example is, if you wanted to send your friend 1 coin a week for 100 weeks. Why can't this code just be stored on a blockchain and have a 3rd party service or another blockchain system read this code to execute it? I understand that this code will have to contain the private key of the sender's account, but I'm assuming this is solved with existing smart contract systems? But either way, why can't the storage of smart contract code be put somewhere else and have another blockchain execute it?


texts: How does the computational cost of verifying transactions scale with the number of total transactions?

texts:
As more transactions are added to the block chain, does each individual transaction (ie. I send a bitcoin to a friend) get more expensive (in terms of FLOPS) to verify and commit to the chain? If each new transaction cost does change the difficulty of verifying subsequent transactions, how does this scale?

I'd appreciate any answers, links or even location in the code where this happens. Thanks.

Reference: bitcoin wiki on confirmations


texts:
Is it possible to start Bitcoin mining using an iPhone with 4G internet connection?
Storage is not an issue,or is it?
(Mine is 256GB).


texts:
points on curve secp256k1 form a group E(Fp) over field Fp.

p = 2^256 - 2^32 - 2^9 - 2^8 - 2^7 - 2^6 - 2^4 - 1  is prime.

n is the order of group E,
n=115792089237316195423570985008687907852837564279074904382605163141518161494337

Is n prime too?

Is E(Fp) a cyclic group?

Theorem.
Working over a finite field, the group of points E(Fp) is always either a cyclic group or the product of two cyclic groups.


texts: Generate QR code for multiple cryptocurrency addresses

texts:
I want to generate my own QR code with my main cryptocurrency addresses without using an online solution, is there maybe a command prompt way or particular piece of software I cam download for this, many thanks.

Also please move to correct section if this is in the wrong place


texts: How is the PRIVATE KEY actually created in the first place?

texts:
How is the "Private Key" created in the first place?

I understand that once you have your wallet, you will also gain access to your public key and private key...

But in order to have a wallet address, one first must have a public key and in order to have a public key, one must have a private key.

So back in the days when crypto wallets did NOT exist, how did it happen?

I am trying to understand what actually happens first. After all, a wallet simply provides a simple view into what is happening on the blockchain (allowing to send and receive), but there is actually no crypto in a wallet, since everything is attached onto the blockchain.

Actually, what is the data attached too? Is there some sort of account created on the blockchain, that then has private keys, public keys and wallet addresses associated with it?


texts: got a new hardware wallet and thinking of using my own set of bip39 words instead of wallet generated one, combined with a passphrase.


texts: Why does Blockstream.info say "SegWit fee savings: This transaction saved XX% on fees by upgrading to native SegWit-Bech32"?

texts:
Why does Blockstream.info have a section, when viewing a transaction such as this one, that says:

SegWit fee savings: This transaction saved 22% on fees by upgrading to native SegWit-Bech32

?


texts:
Back in 2013 I bought some bitcoin for a relatively low price, and stored them in an Electrum wallet on my PC. However, I changed PCs a year or two later, and forgot to copy the bitcoin wallet over.

Given the current soaring price, I now have a renewed interest in trying to recover these seemingly lost bitcoins.

I took a screenshot of the blockchain.info page that was displayed shortly after the transaction was completed. I believe this shows the transaction ID, plus the wallet Id it was transferred to.

Here's an edited version of the page I screenshotted, obviously with the IDs hidden so no-one else steals them :)

I've tried revisiting this website, based on the previous URL, which I believe was the transaction Id. I receive an error: Invalid Transaction Hash

Now, obviously bitcoin has split in two, and this was pre-split.

So, what are the various values that are shown on the screenshot (top left appears to be transaction id, bottom right is my wallet id?)

And can any of this be used to rescue the bitcoins?


texts:
What is the motivation for the faucet owner?

Just to get a browser visit/IP address/plant some cookies?


texts: Is there a real case where a very long blockchain got overtaken?

texts:
The longer the longest blockchain is, the harder it is to get overtaken by new blockchain with different sequence of transactions.
But is there a case where it happened? What happened afterwards if there's so many transactions which got deleted or override by new blockchain?


texts: What contributions have Chaincode developers made to Bitcoin?

texts:
Related question: What contributions have Blockstream developers made to the Bitcoin project?
Blockstream's contributions and involvement in Bitcoin is discussed a lot. I want to know Chaincode Labs's involvement, contributions and influence in Bitcoin.


texts: Reference an UTXO of a transaction that has not been yet mined

texts:
How to reference an UTXO that has not been yet mined? I want to prepare a transaction and, before spreading it, use its UTXO as input for another relative timelocked transaction. Then, spread the first prepared transaction.
How to do it?


texts:
Here is my run command:

cgminer -o stratum+tcp://coinotron.com:3334 -u user -p pass --scrypt

the only output in my terminal I get is (and only this):

[2013-11-30 11:34:02] Started cgminer 3.7.2

if Ctrl+C it I finally get this output:

[2013-11-30 11:34:43] Summary of runtime statistics:
[2013-11-30 11:34:43] Started at [2013-11-30 11:34:03]
[2013-11-30 11:34:43] Pool: stratum+tcp://coinotron.com:3334
[2013-11-30 11:34:43] Runtime: 0 hrs : 0 mins : 40 secs
[2013-11-30 11:34:43] Average hashrate: 0.0 Kilohash/s
[2013-11-30 11:34:43] Solved blocks: 0
[2013-11-30 11:34:43] Best share difficulty: 0
[2013-11-30 11:34:43] Share submissions: 0
[2013-11-30 11:34:43] Accepted shares: 0
[2013-11-30 11:34:43] Rejected shares: 0
[2013-11-30 11:34:43] Accepted difficulty shares: 0
[2013-11-30 11:34:43] Rejected difficulty shares: 0
[2013-11-30 11:34:43] Hardware errors: 0
[2013-11-30 11:34:43] Utility (accepted shares / min): 0.00/min
[2013-11-30 11:34:43] Work Utility (diff1 shares solved / min): 0.00/min
[2013-11-30 11:34:43] Stale submissions discarded due to new blocks: 0
[2013-11-30 11:34:43] Unable to get work from server occasions: 0
[2013-11-30 11:34:43] Work items generated locally: 1
[2013-11-30 11:34:43] Submitting work remotely delay occasions: 0
[2013-11-30 11:34:43] New blocks detected on network: 1
[2013-11-30 11:34:43] Summary of per device statistics:
[2013-11-30 11:34:43] GPU0     | (5s):0.000 (avg):0.000h/s | A:0 R:0 HW:0 WU:0.0/m

my GPU is properly detected:

11:34:56 me@ArchPC::~/Desktop cgminer -n
 [2013-11-30 11:36:35] CL Platform 0 vendor: NVIDIA Corporation
 [2013-11-30 11:36:35] CL Platform 0 name: NVIDIA CUDA
 [2013-11-30 11:36:35] CL Platform 0 version: OpenCL 1.1 CUDA 6.0.1
 [2013-11-30 11:36:35] Platform 0 devices: 1
 [2013-11-30 11:36:35]  0   GeForce 9600 GT
 [2013-11-30 11:36:35] 1 GPU devices max detected
 [2013-11-30 11:36:35] USB all: found 6 devices - listing known devices
 [2013-11-30 11:36:35] No known USB devices

What could the problem be?

EDIT: Just tried it without --scrypt... it works then, but I need scrypt for LTC. How do I fix this?


texts:
I did a small transaction as a test.  I wanted to convert BTS (BitShares) to LTC (LiteCoin).  Couldn't find any direct exchange, so traded a token amount to BTC on Crypto-Bridge, then tried a withdrawal to Coinbase.

This is the transaction:
https://cryptofresh.com/u/neal-walters-bridge

This is the screenshot of what i entered:

Even though I entered my CoinBase receive address, the above shows I sent to CryptoBridge.  Is just a matter of waiting for it to convert and send, or did I do something wrong.  Obviously I want to verify before doing a larger amount.


texts: No new UpdateTip. Just "Pre-allocating up to position ..."

texts:
I'm IBD'ing a new testnet node 0.21.0
Why are there long periods of no UpdateTip messages?  I have 10 connected peers.
Excerpt starting at 00:13:
2021-04-05T00:13:17Z UpdateTip: new best=000000000000005b0a40663b50cf4588f8dfd9c18bbbe8696fe2b549c893fbe4 height=1382700 ...
Then there are lots of pre-alloc messages and no UpdateTip messages:
2021-04-05T00:36:32Z ping timeout: 1200.048936s
2021-04-05T00:36:55Z New outbound peer connected: version: 70015, blocks=1969990, peer=737 (full-relay)
2021-04-05T00:39:17Z Pre-allocating up to position 0x7000000 in blk00112.dat
2021-04-05T00:43:15Z Pre-allocating up to position 0x8000000 in blk00112.dat
2021-04-05T00:44:59Z Socks5() connect to 165.231.163.24:18333 failed: general failure
2021-04-05T00:46:22Z Leaving block file 112: CBlockFileInfo(blocks=167, size=133222507, heights=1382791...1383090, time=2018-08-10...2018-08-11)
2021-04-05T00:46:22Z Pre-allocating up to position 0x1000000 in blk00113.dat
2021-04-05T00:47:43Z New outbound peer connected: version: 70016, blocks=1969991, peer=738 (full-relay)
2021-04-05T00:47:46Z Synchronizing blockheaders, height: 1969991 (~100.00%)
2021-04-05T00:49:10Z Pre-allocating up to position 0x2000000 in blk00113.dat
2021-04-05T00:50:18Z Socks5() connect to 2001:19f0:6001:3bf2:5400:2ff:febc:2f63:18333 failed: general failure
2021-04-05T00:51:03Z Pre-allocating up to position 0x3000000 in blk00113.dat
2021-04-05T00:51:43Z ping timeout: 1200.026721s
2021-04-05T00:51:44Z ping timeout: 1200.029607s
2021-04-05T00:51:57Z New outbound peer connected: version: 70015, blocks=1969991, peer=740 (block-relay)
2021-04-05T00:52:50Z Pre-allocating up to position 0x100000 in rev00113.dat

After about 40 minutes (why?), there is a new UpdateTip finally:
 2021-04-05T00:52:50Z UpdateTip: new best=00000000000000c771e3ffe2108fe02768164469d366e2f48c9e8b4ef7eeae54 height=1382701 version=0x20000000 log2_work=71.161934 tx=28150831 date='2018-08-10T05:40:01Z' progress=0.470404 cache=2824.5MiB(20668057txo)
2021-04-05T00:52:50Z UpdateTip: new best=00000000000000ad0e7806e25ae3628c709cbfd1eb100e8b4aeebf326fc603d9 height=1382702 version=0x20000000 log2_work=71.161974 tx=28152664 date='2018-08-10T05:44:22Z' progress=0.470435 cache=2824.6MiB(20668080txo)
I inspected machine health: Very little io-wait, and cpu is quite idle:
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 2  0 1523548 477268 133600 5865132    0    0    18    29    4    3  6  0 93  1  0
 4  0 1523548 477836 133600 5866108    0    0     0   580 3894 7616  2  1 91  6  0
 1  2 1523548 477648 133600 5866140    0    0    32   400 3650 6994  2  1 88  9  0
 0  1 1523548 477420 133600 5866140    0    0     0   452 4403 8249  1  2 91  6  0
 1  2 1523548 477696 133600 5866140    0    0     0   700 4414 8394  1  1 92  6  0
 0  1 1523548 477004 133616 5866140    0    0     0  1512 3007 4780  1  1 80 19  0
 2  1 1523548 476420 133616 5866144    0    0     0   460 4536 8690  2  2 92  5  0
 0  1 1523548 475532 133616 5866220    0    0     0   480 4616 9066  1  2 93  4  0
 2  1 1523548 475428 133616 5866220    0    0     0   480 4568 8689  1  2 92  5  0

Quad-core, Intel i7-3740QM CPU @ 2.70GHz. I am using conventional hard disk (platters).
I'm curious what might cause the delay. Reviewed the log and IBD seemed to progress steadily until this time.
I searched here and google but could not find an answer.
Update: I thought the multiple pre-alloc messages was a symptom of an issue. But now I'm thinking that's a red herring, and the real issue might have been instability (or other network issue) in the Testnet network at that time.  A few hours later, I was seeing a steady pace of UpdateTip messages again.