texts: After sending some bitcoins, why do I have zero available to spend when I clearly didn't send my entire balance?

texts:
With some of the clients I use regularly (Multibit, Bitcoin for Android), I've noticed that, after I send bitcoins to an address, I have 0 BTC available to spend despite having perhaps a several bitcoin balance.

Looking more closely at the transaction details on Blockchain.info or Blockexplorer.com, I observe that the client sent my entire balance back to myself in the same transaction.

For example, my balance in my wallet before the transaction is 1 BTC. I send 0.5 BTC to address C from my wallet, plus 0.0005 BTC for transaction fees. I should have 0.4995 available immediately to spend on another transaction. However, the clients show 0 BTC available, but a balance of 0.4995 BTC.

When I look at the transaction, I see two input addresses, addresses A and B. The outputs are 0.5 BTC to address C, the destination of my payment, and 0.4995 to address B.

Why then do I have 0 BTC available when I clearly should have 0.4995 BTC available?


texts:
I am using the 0.4.0 release. Is it possible to send bitcoins without paying a fee?
Who gets the fee ? Is it only miners discovering new blocks?


texts: Should I keep my bitcoin-qt wallet running all the time?

texts:
It can take a day or more to get in synch, so it's somewhat problematic to only start it when I want to transact.  But are there any security issues in keeping it running constantly?

What's the general practice for those using local wallets?


texts:
I often read that checkpoints protect the network from a 51% attack because an attacker cannot reverse transactions made before the last checkpoint.

How exactly does this checkpoint mechanism work? And who creates the checkpoints?


texts: Why isn't there a fast blockchain update inside a LAN behind a router between two Bitcoin clients?

texts:
This is the scenario:

2 computers on a LAN with private IPs (192.168.X.X)
router forwards port 8333 only to one of them (the 2nd one).
one computer has the full blockchain updated in its Bitcoin client,
the 2nd computer has only half the size of the block chain (Bitcoin client has not been run for a long time).

Why doesn't the Bitcoin client from the second computer detect the first computer and receive the remaining missing blocks at high LAN speed?

What i see is a very slow update of the chain on the 2nd computer.


texts: Where does one obtain the most widely accepted Bitcoin/Euro exchange rate?

texts: I want use Bitcoin to make a purchase from a private seller in another country. The good which I want to purchase is priced in Euros, so I need a Bitcoin/Euro conversion rate which both of us must accept for the moment when the Bitcoin is transferred.


texts:
I use bittrex api and python for trading.

I am interesting about lowest Ask and highest Bid prices on the pair.

In this example:

I want to sell XRP on 0.00008215 price and on 0.00008245

What RATE I would pass? 1.0, or 1.1 or different? And what for lower prices?

What is this number exactly mean?


texts: How to check if an output has been spent?

texts:
Using an rpc client (e.g. bitcoin-cli), for a given transaction and index of an output of it, how can I tell if the output is currently an utxo, or if it has already been spent?

In the latter case, I'd also want to know the transaction which spent it.

I looked at the gettxout command, but it isn't clear to me how to extract the answer from the data it returns.

I'm running a full node with txindex=1.


texts: Choosing Rights Host For Dependency Make

texts: I am working on on creating builds for windows, mac, and Unix. I am working on Ubuntu 18.04 but on a windows OS. I figured  out host-platform-triplets for windows and mac and generated prefixes for them but not sure how to determine the best Unix prefix. I was hoping to run this in a unix container out in gcp as a test harness. Any recommendations or guidance?


texts: Can Ethereum support compressed secp256k1 public keys to compute Keccak addresses?

texts: Starting from a private key, a working functional example provides details for how an Ethereum address can be calculated from an uncompressed secp256k1 elliptic curve public key. This functional example made it clear the computation of an Ethereum address had to use the proper Keccak hashing function, quite different from the NIST SHA3 implementation. Was wondering if Ethereum supports compressed secp256k1 public keys, if so are there any test vectors for testing implementations?


texts: I don't know if this is the correct forum for asking this kind question please let me know. Anyway, I have a small rig with two GPUs (SAPPHIRE Pulse Radeon RX 580 8G GDDR5 Dual HDMI/DVI-D/Dual DP Graphics Card), the GPU temperature is running at 74℃, the inboard fans are running in AUTO at 20%, I have two external fans that I would like to use to cool it. My question is where should I position the fans? in front, back, below or uppers side  of the GPU? The back side where the name of the GPU is, is the hottest part of the device, I am afraid to set the external fans in an incorrect position and make the inboard fans workload. Any help is more than welcome.


texts: When is the version 0.7 of the standard client scheduled to be released?

texts: The 0.7 version of the standard client is slowly looming, but has not yet been released. Some websites, such as the Testnet Faucet appear to be using that version already. However, not wanting to use a beta release, I'm wondering when the full 0.7 version of the standard client is scheduled to be released?


texts: Did Satoshi ever acknowledge that his name was a pseudonym?

texts:
I am curious if Satoshi publicly acknowledged that he was concealing his real name, or if he actually claimed that was his real name.

Like the title says, did Satoshi ever publicly acknowledge that his name was a pseudonym?


texts: How can I view in my shell, live, ALL activity my bitcoind is generating?

texts:
Having examined the output of

bitcoind -h

and searched through all the bitcoin-cli rpc items listed here

https://bitcoincore.org/en/doc/0.19.0/rpc/

I did not find anything which produces a live stream to stdout of all the tasks my full node is running/performing.  What is required to make all that visible?

One is led to understand that the main benefit of running one's own full node is to be able to independently confirm transactions and that is all fine, but another important effect is supposedly the continual assistance the node provides to the network, serving historical blocks and so forth.  That traffic is what I would like to see.


texts:
connected to stratum.bitcoin.cz diff 1 with stratum as user xxxxxxxworker1
block f9aa8c61...Diff 4.25 started [20:26:18] Best share 0
Stratum from pool 0 detected new block

I just started doing this and it looks like I'm doing it wrong. Am I?


texts: Will there be a testnet4? Or do we not need a testnet reset once we have Signet?

texts: The last testnet reset was for the current testnet3 back in 2012 (not including segnet which was a testnet for SegWit before SegWit was activated on mainnet). Are we due another testnet reset? Or is there no need for testnet anymore with the introduction of Signet?


texts: Pros/Cons/Limitations of Mnemonic Phrases - BIP39

texts:
BIP39 mnemonic phrases replace considerations about how to store one private key, with considerations about how to store the seed to a series of private keys.

The idea is that the private keys are hard to remember, worse to write down, and prone to discovery when stored digitally, so the solution is that you can have a phrase of words that act as a seed to a hierarchical deterministic series of addresses.

It seems like this idea has been lost in translation as the phrase length of mnemonic phrases has increased from 12 words, to 24 words, with the "more secure than thou" using even longer words and phrases, and security minded companies alike promote writing down the mnemonic phrase, in multiple places.

or splitting the phrase, or putting an additional passphrase on top of the HD sequence, or using Shamir's secret key.....

all of which simply create more points of failure.

Ultimately: instead of one paper wallet compromising one private key, your paper phrase will compromise ALL of your private keys. OOPS. or you forget the secret key, or you lose a piece of the phrase, or you misspell it

At least we can be confident that the words themselves contain enough entropy to prevent guessing, RIGHT GUYS? RIGHT?

What are the pros, cons, limitations of BIP39, or at least my concerns. I have read the wiki and the github markdown on BIP39, and these do nothing to alleviate these concerns because these BIPs are a centralized process


texts: Lessons from the Mt. Gox Hack - 850,000 Bitcoins Stolen

texts:
Mt. Gox was a bitcoin exchange based in Shibuya, Tokyo, Japan.
Launched in July 2010, by 2013 and into 2014 it was handling over 70%
of all bitcoin (BTC) transactions worldwide, as the largest bitcoin
intermediary and the world's leading bitcoin exchange.

Mt. Gox announced that approximately 850,000 bitcoins belonging to
customers and the company were missing and likely stolen, an amount
valued at more than $450 million at the time

Today that amount of Bitcoin would be worth nearly $40 billion dollars (depending on the day of the week).
Reading the above makes me concerned. If the world's (once) largest exchange was unable to prevent a hack of this magnitude, how can any exchange (without a multi million dollar security budget) be reasonably certain that hack like this won't effect them?
Is there a consensus (or at least a plausible theory) as to what went wrong on the technical side that allowed such a large exchange to be hacked? What practical lessons can one learn from this story in terms of securing their users funds?


texts: I have Bitcoins in a local wallet, how do I get my Bitcoin Cash without using an exchange?

texts:
I have a few Bitcoins in a local wallet and I own my private key.

I know that on 1st August 2017, Bitcoin is splitting into BTC and BCC.

How do I get Bitcoin Cash without transferring my Bitcoins to a 3rd party exchange?


texts: RTX 2070 and GTX 1660 super in same rig with 1000W Corsair power supply - rig shuts down

texts:
I just got my computer back from the shop. I have an MSI RTX 2070 and a GTX 1660 Super in my machine. I swapped out the power supply for a 1000W PSU. Whenever I run ethminer for more than 10 minutes my machine shuts down. I had a technician install the parts because my physical handicap makes me susceptible to damaging the hardware.

I set both of the cards fans to 100% in Afterburner, as well as giving both cards maximum power (electricity is free for me so I don't care how much power I use). Still, regardless of my afterburner settings, my machine shuts down.

I'm pretty sure I have the correct drivers. I didn't give the shop my Windows 10 password so I had to download nVidia's drivers myself. What I don't get is I am maxing out the fan and power settings, so I honestly have no idea why my machine shuts down.

When I just browse the web and do basic computer stuff, everything's fine. However, whenever I run ethminer that's where my problem arises. I'm not a gamer, but I have a few installed whenever I do feel like playing computer games, However, I'm too scared to run ethminer or games because I don't want to damage my computer.

I'm still fairly new to crypto mining so forgive me if this sounds stupid. Thanks a bunch!


texts: If I bought bitcoin in the early days in some exchange for $10, would it have been lost if I kept it in the exchange?

texts:
I just want to get some history perspective of Bitcoin.  Say in the early days when Bitcoin was $1 or $10, if I decided, "ok, I may invest in US$3000 at the software startup I work for, but that US$3000 is likely to go to $0, so I will just invest $1000 in Bitcoin anyway, assuming it could be lost but not a big deal".
So what places was available for me to buy Bitcoin at that time?  If I bought it from BitInstant, Mtgox (I am not familiar and will need somebody who knows the history to answer this), then would that mean that $1000 could become $3 million, except it was all lost or stolen along the way during the BitInstant and Mtgox time?
But if I bought it and immediately transfer to my own wallet, and didn't forget the password, then it would have been ok?


texts: How long does it take for an unconfirmed transaction to reverse?

texts: I have had an unconfirmed transaction for 1 week. Will this transaction automatically reverse or do I need to do something?


texts: Unconfirmed Transaction disappeared when I pressed "repair wallet"

texts:
I bought some bitcoins and send them to an a receiving address on Multibit HD, It has been maybe 3 or 4 hours without any confirmations, so I decided to press "repair wallet", which said it would resynchronize etc.

Now the "+Unconfirmed transaction" bit isn't even showing anymore and it isn't in the payments section. Here is the bitcoin transaction:

https://btc.blockr.io/tx/info/111df2572b8550724c78f30bf70f4cafee61417924058fdd624adb172968637a


texts: What is the structure of blk001.dat and blkindex.dat?

texts:
Can anyone tell me where I can read about the structure of the files

 blk0001.dat
 blk0002.dat
 blkindex.dat

I know that in these files bitcoin is saving all the information about transactions.
I would like to parse the files and save the information from these files in my local database.

[Note-these files are no longer used for Bitcoin-Qt/bitcoind version 0.8 and above.]


texts:
I am trying to sign a raw transaction that spends output #2 (txindex 1) from this transaction: 267c6d75851efa18afb7edeb2da00c09afc575231db84b3277fc7ea3e174ecbd

The output is a 1-of-4 multisig P2SH and I think I may have a mistake in the transaction structure used to generate the signature. The signature I calculate is different (as in cryptographically different) to the one that bitcoin core gives me using signrawtransaction.

As I see it this is the transaction structure which must be signed:

Version:   01000000
TxIn:      01 bdec74e1a37efc77324bb81d2375c5af090ca02debedb7af18fa1e85756d7c26 01000000
subScript: 17 a9 14 37fe3f20433380be4c742c978d3a9712c509656e 87
Sequence:  ffffffff
TxOut:     OUTPUTDATA
Locktime:  00000000
Hashtype:  01000000

The double-sha256 value used to calculate the signature is 9d384de385512525b4faf08c97651e410e77f2906aa8baeefdee151cc0994655

But the Bitcoin network rejects my transaction calculated from this transaction structure.

I will happily provide more information such as redeemScript and pubKeys/privateKeys if the mistake should not be in the transaction structure.

Any help is appreciated! Thanks!


texts: Why can non-standard transactions be mined but not relayed?

texts:
As far as I understand, a non-standard transaction can be mined in to a block (and this block will be accepted by all nodes), but nodes will not relay a non-standard transaction to other nodes.

Why is it that miners have the freedom to construct non-standard transactions, but everyone else is limited to standard transactions?

I've heard that limiting the types of transactions that get relayed is some form of protection (against unusual script types that could cause problems). However, if this is the reason, doesn't this just leave miners with the ability to perform an attack whilst leaving everyone else restricted?

I'm not against standard transactions. I'm just not sure how this situation came to be.


texts: BTC wallet recovery: I have a 17 word backup, what do I do?

texts: I have a 17 word seed phrase from a 10 year old Bitcoin-qt/core? acct, but don't know what tool to use to turn it into a wallet. I also wrote down the 17 letter associated private-key itself. It starts with "q" and has two commas and a space in it?? Is that valid? Obviously I am terrified to put the seed phrase into any ONLINE tool. I want to practice offline somehow to see if I even wrote it down properly. I tried looking thru the sourcecode: https://github.com/bitcoin/bitcoin to see there is a word-list.. No joy. One guy said Electrum, but it didn't help decipher the individual words, just kind of a 'put them all in', sink or swim endeavor.... Thanks!


texts: What happens when I buy BTC with XRP from the Ripple client?

texts: I don't see anywhere in the ripple client that shows my bitcoin address, and I can't recall if I entered it. When I make an offer to buy X BTC for Y XRP, where does the BTC go when accepted?


texts:
I am small tech store owner and I was recently thinking about selling bitcoins for cash into my store. A lot of clients asked me if I could install a BTC ATM in my store.

But investing in an ATM machine isn't possible for me at the moment. So I wondered if I could possibly sell them for cash directly. The question is: is there any service out there that provides an API to buy bitcoins with my credit card and send them to the client's wallet directly ?

I could possibly create that API myself and send the Bitcoins from my wallet but that would mean that I'll have to invest in Bitcoin and could possibly be losing if the BTC price falls down.

Do the ATM companies actually own Bitcoins ? Or are they purchasing them when someone uses the device ?


texts: Standard multi-signature transaction BitcoinCore

texts:
I created a transaction with a script for a Multi-Signature in the form of

M <A pubkey> [B pubkey] [C pubkey...] N OP_CHECKMULTISIG

It is documented (https://bitcoin.org/en/developer-guide#multisig) that this type of script would belong to the standard transaction types.

When i put that transaction into Bitcoin-CLI via decoderawtransaction, it says:

"vout": [
    {
      "value": 0.00250000,
      "n": 0,
      "scriptPubKey": {
        "asm": "2 <PublicAdress 1> <PublicAdress 2> <PublicAdress 3> 3 OP_CHECKMULTISIG",
        "hex": "XXX",
        "type": "nonstandard"
      }
    },

I then sent the transaction via sendrawtransaction and it is sent, accepted and mined successfully to the Blockchain but it seems to be invisible for my wallet.

Also when i send such a transaction to my BitcoinCore wallet, Bitcoin Core doesn´t notify me about it.

Is there simply no support in Bitcoin Core for that type of MultiSig transactions or am i doing anything wrong?


texts:
How does Litecoin compare to Bitcoin and what are the differences?

I heard Litecoin is more advanced technology. Is that true?


texts: How long does it take to validate a full block?

texts:
I'm interested to know how long does it take to validate a Bitcoin block on average home pc.
I'm less interested in a precise number. I'm fully aware that it can be different between different machines.
I'm more interested in an estimation.
Previous answers didn't provide a number or even rough calculation.


texts: How to use BitCoin private keys (a primer)

texts:
I am learning about BitCoin private keys and trying to figure out what the best way to use them are. I get their purpose and that they need a strong password, etc. But what I don't understand in particular is how they relate to transactions and wallets.

I just ran bitcoin-cli importprivkey <key> (which has been running for like 5 minutes, who knows how long this will take, and I am brand new). I am actually not sure what the point is for adding the key to the wallet. Does it somehow relate to transactions? Why do I need to add a private key to my wallet? Can/should I add more than one to a wallet? Or, oh! I think I remember, the wallet key is just for storing your private keys. But why don't I just store it myself in a different way? What advantage does having it stored in a wallet offer?

Then the second part of the question is, what key I should be signing my transactions with, and how. Can I say "wallet, give me a key by name" or something?

Final part of the question is, how many keys I should have. Should I just have 1 key for everything? 2 just to switch it up every now and then? 10 or 100 or 1000? A new key for every transaction? I don't know, what is the ideal here? Is it best to use some keys for one thing, and others for another?


texts:
I'm developing a parser bitcoin core and I have a problem whit the type CVarInt, I using the decodifier mode of the CCompact size but at the block 976 I Have a problem whit the type, because the value id is unusually, so I have a question why the bitcoin core decided the change implementation to
CCompact size into CVarInt?

What was introduced in the bitcoin core versions to require a change of implementation?

Sorry for my terrible English but I'm learning.


texts: Google Authenticator not verifying for MtGox bankruptcy site

texts: I am trying to file a claim on the mtgox.com site for rehabilitation and part of that requires setting up two-factor authentication via Google Authenticator, but when I enter the 6-digit code it says "code does not match" and refuses to allow me to proceed. I tried calling the service number, but it just hangs up on me. What should I do?


texts: Is it possible generate three public key( address ) by only one private key?

texts:
I hear that each address has one private key.
Is it possible generate three public key address by only one private key?


texts: I was wondering how bitcoin public and private keys are generated. E.g., a certain number of characters etc.  And how one could tell a litecoin address from a bitcoin address for instance.


texts: Add a transaction generated offline to the official client

texts:
I have a transaction that I generated/signed using a custom tool.  I'd like to make sure it was generated correctly by submitting it to the official client and watching the logs to see if it is accepted.

What is the best way to manually submit a transaction to the official client (either json or binary)?  Thanks!


texts:
let said ALice own 10 BTC at address "ABC", at block height 3,456,700, it was hard-forked to Bitcoin "Zaza".
At block height 3,500,000. The stable version of Bitcoin"Zaza" wallet is available.
Thus, at block 3,456,710, Alice uses her old bitcoin wallet software and transfer out all her coins into another address "XYZ".
Then, at block height 3,500,000, she uses Bitcoin "Zaza" wallet to claim her Bitcoin Zaza.
Is this method safe?


texts:
Here is a testnet address I've been experimenting with,

Here is some test BTC leaving the address,

I didn't initiate the transfer though, is this a feature of the testnet to keep the faucets stocked perhaps?

My wallet is provided by TP's bitcoin faucet from here.

Thanks in advance :)


texts: Why is your Bitcoin balance displayed on paper wallets?

texts: Sites like bitaddress.org and Blockchain.info where you can print out a paper wallet also show your current Bitcoin balance on your paper wallet. But your balance is something that is constantly changing, so why would it be printed on a paper wallet?


texts: Is there a way to create decentralised rating system akin to #bitcoin-otc?

texts: I'm wondering if there is a way to create a ranking system similar to #bitcoin-otc, but making it decentralised?


texts:
hi can someone help I forgot to send fee one time is there anyway to speed up

https://blockchain.info/tx/fb4840af0ad51804eb8975d7e0afacd2e2c176748e98de502a9ffd19ed46d53b

thankyou


texts: Private key to WIF compressed: which one is correct?

texts:
This is how we can find the WIF from a private key:

private_key = '000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f'
decoded_private_key = bitcoin.decode_privkey(private_key, 'hex')
wif = bitcoin.encode_privkey(decoded_private_key, 'wif')
# 5HpHgWkLaovGWySEFpng1XQ6pdG1TzNWR7SrETvfTRVdKHNXZh8

But how to get the WIF compressed?

Should I do:

private_key = '000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f'
compressed_private_key = private_key + '01'
wifcomp1 = bitcoin.encode_privkey(bitcoin.decode_privkey(private_key, 'hex'), \
             'wif_compressed')
# KwDidQJHSE67VJ6MWRvbBKAxhD3F48DvqRT6JRqrjd7MHLBjGF7V

or

wifcomp2 = bitcoin.encode_privkey(bitcoin.decode_privkey(compressed_private_key, 'hex'), \
            'wif_compressed')
# KwFfpDsaF7yxCELuyrH9gP5XL7TAt5b9HPWC1xCQbmrxfFzfMakg

It seems that #1 is correct and not #2.

Also it seems that:

the non-compressed WIF, imported in Electrum, produces finally a non-compressed Base58 address,
the compressed WIF, imported in Electrum, produces finally a compressed Base58 address

which seems obvious. But I'd like to be sure that compression of WIF and compression of addresses at the end is really linked.

Can we conclude that the use of a compressed or non-compressed WIF (both encoding the same private key) will determine, when importing them in Electrum, if the public-key (and thus the address eventually) will finally be compressed or non-compressed?


texts: Unconfirmed bitcoin transaction for more than 3 days

texts: i sent bitcoins on 14.3.2016. the amount has been debited from my wallet but remains unconfirmed. i am waiting for the transaction to go through but maybe because i checked try and sent with 0 transaction fees the transaction is not being confirmed. i want to know how to get the bitcoins back and whether there is some way that a beginner like me can stop the unconfirmed transaction so that the coins are returned to my wallet.


texts: How important is Graphics Ram for hashing

texts:
Some altcoins are designed to be "memory intensive" to avoid use of ASICs to mine them.

Does the RAM refered to here, mean the RAM of the computer or the RAM on the GFX card itself.

When looking at passmark these two GFX cards get almost the same score 8687 vs 8773:
GTX 1060 (3GB) vs GTX 1060 (6GB) comparison on passmark

For gaming the ram can be important for having high-resolution textures in ram. But how much does it matter for hashing memory intensive hashes?


texts: What if two people want to spend same input at the same time

texts:
Lets say me and my friend both have access to same private key which can sign some new transaction. What would happen if me and my friend broadcast transaction with same input at the same time to a different nodes ?

Also what would happend if i broadcast it 1 minute after him and pay much larger fee and his transaction is still unconfirmed? Would miner take my transaction than because it includes higher fee or would the stick with his transction because he broadcasted it first.

Thanks


texts: My system is syncing headers, what does that mean?

texts: My system got shut down while I was syncronising. Please help me, it's showing "Unknown. Syncing Headers" and estimated time is unknown.  What is happening here?


texts: Has Bitcoin Cores encryption wallet security ever been bypassable?

texts: Every few years there seems to be an exploit found in Trezor that allows people to bypass the security. I was wondering has there every been the same case for Bitcoin Core wallet encryption?


texts: how to split transactions based on send and receive Json rpc bitcoin

texts:
I am creating new wallet for bitcoin and want to know how we can get the separate list of send and receive transactions using JSON rpc.

I cant see any method for json rpc that give list of send and receive category


texts: How to get the number of the confirmed transactions from Bitcoin QT Rpc

texts: We are building a generic wrapper around Bitcoin-Qt. I wonder if there is way to get the information about the confirmation count of a transaction from a Bitcoin-QT having an empty wallet using the RPC command.


texts: What's a good resource to learn how [technically] bitcoin works?

texts:
What are some good resource(s) for learning how bitcoin works?

I can't seem to find any resources that are any more detailed than the basics - how you have wallets, the blockchain, confirmations, mining, etc. The source code for bitcoin is also a little beyond me.

What are some good resources that explain the maths behind bitcoin? i.e. things like:

How to mine bitcoin, step-by-step ('manually' - not how to setup cgminer or GUIMiner)
How to generate a new bitcoin wallet address
How to update the blockchain
etc


texts: In which cases do transactions have multiple "from-account" but a single "to-account"?

texts:
Taking a sample block on blockexplorer, I see that the generation reward is split between lots of recipients, I figure this is the pool that solved.

But looking at other transactions, there a few with over 100 'From' addresses, and a single 'To' address. The only reason I could think of, is merging many wallets into one. Since I see this in every block I am looking at, I wonder if there's another use-case.

Thanks!


texts:
i went to configmyrig.com and selected the options to hit something close to 5mh.
here is a screenshot:

http://s28.postimg.org/uayj19exp/Screen_Shot_2014_01_09_at_11_21_58_PM.png

i'll be scrypt mining at a multipool and the total that came up for the complete setup is about $5,000 seems like alot but let me know if you have any suggestions. What i'm wondering is how many PSU's would I will need and what kind is recommended? I'm thinking it would be a gold or platinum for the PSUs but i'm not sure how many and what kind would suit 6 Radeon R9 290x's. Also is the motherboard & cpu selected good enough? I'll be using a milk carton for the rig instead of a case so i'll need to get a hold of a good one.


texts: What is the maximum size of a transaction?

texts:
I see from the source code (script.cpp) that there is an upper limit in the script size. It there any other limit to avoid a single transaction preventing other transactions of smaller sizes to get into a block?

How is this kind of attack prevented?

I've read in CTransaction::AcceptToMemoryPool the line:

if .... ::GetSerializeSize(*this, SER_NETWORK) < 100)
    return error("...");

Does this line means that the maximum transaction size is 100 bytes?


texts: What does "Safe mode: Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues." mean?

texts:
My bitcoind client that runs on testnet has started returning a lot of errors today. It has been doing so for a few of hours (as of 2014-08-29 9:50 UTC).

When I call it via RPC, I get the following response on ALL requests

{
  "result":null,
  "error": {
    "code":-2,
    "message":"Safe mode: Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues."},
    "id":"1"
  }
}

It doesn't seem to be downloading any new blocks. It seems that I'm not the only one who's affected. As of now, http://tbtc.blockr.io/ is also stuck on blocks that are almost 5 hours old.

The version of bitcoind I use is 0.9.2.1, and the debug log says:

2014-08-29 05:11:59 ProcessBlock: ORPHAN BLOCK 0, prev=0000000000000e819b253066739275290fb4274b580bf62fbd279c518e6e2ebd
2014-08-29 05:11:59 ProcessBlock: ORPHAN BLOCK 1, prev=0000000000000e70d898fa12f328b9ee2d97912e9a495fc80eaeeb781096cadf
2014-08-29 05:11:59 ProcessBlock: ORPHAN BLOCK 2, prev=000000000000256194246bdabb62d3b50e2c309217258b17c543d13ec839367c
2014-08-29 05:12:00 CheckForkWarningConditions: Warning: Large valid fork found
  forking the chain at height 277766 (000000009cf297bc2a9610af823b49fc1d98e001239e99204c3c410e1ad3fe54)
  lasting to height 277767 (0000000000000e819b253066739275290fb4274b580bf62fbd279c518e6e2ebd).
Chain state database corruption likely.
2014-08-29 05:12:00 UpdateTip: new best=00000000735de11454d7de10a71a14e9695135f59b70a4eb906b1107df842270  height=277770  log2_work=61.959615  tx=2398741  date=2014-08-29 05:20:26 progress=1.000001
2014-08-29 05:12:00 UpdateTip: new best=00000000e9cc8d1bea3894d11cd4bacf4099dac3b644cb4f39b4ba3ad89ed2f8  height=277769  log2_work=61.959615  tx=2398732  date=2014-08-29 05:00:09 progress=0.999999
2014-08-29 05:12:00 UpdateTip: new best=00000000d553cd36cc43b3d1255ec395c05e1d4ad730178cd987e960931399ae  height=277768  log2_work=61.959615  tx=2398721  date=2014-08-29 04:39:40 progress=0.999997
2014-08-29 05:12:00 UpdateTip: new best=0000000000000f46520ca51be43443905945d2db5b513f35c2283c2d95a41077  height=277767  log2_work=61.959615  tx=2398683  date=2014-08-29 04:19:31 progress=0.999995
2014-08-29 05:12:00 UpdateTip: new best=000000009cf297bc2a9610af823b49fc1d98e001239e99204c3c410e1ad3fe54  height=277766  log2_work=61.959004  tx=2398667  date=2014-08-29 04:16:35 progress=0.999995
2014-08-29 05:12:00 UpdateTip: new best=0000000000000e819b253066739275290fb4274b580bf62fbd279c518e6e2ebd  height=277767  log2_work=61.959615  tx=2398670  date=2014-08-29 04:15:08 progress=0.999995
2014-08-29 05:12:00 UpdateTip: new best=0000000000000e70d898fa12f328b9ee2d97912e9a495fc80eaeeb781096cadf  height=277768  log2_work=61.960226  tx=2398674  date=2014-08-29 04:24:20 progress=0.999996
2014-08-29 05:12:00 CheckForkWarningConditions: Warning: Large valid fork found
  forking the chain at height 277766 (000000009cf297bc2a9610af823b49fc1d98e001239e99204c3c410e1ad3fe54)
  lasting to height 277767 (0000000000000e819b253066739275290fb4274b580bf62fbd279c518e6e2ebd).
Chain state database corruption likely.

What does this message mean? How is a fork of a single block a "large valid fork"? Why is this that this seems to completely freeze bitcoind? How can I fix it?


texts:
For non-native speakers talking about Bulletproofs with correct grammar is tricky.
I tried to use the white paper as a reference, but it is not consistent. Even in the abstract it mixes plural and singular.

  Bulletproofs are especially [...] Moreover, Bulletproofs supports...

Should I use plural of singular after Bulletpoofs?
Bulletproofs are often abbreviated as BP. Is this a good abbreviation or BPs or something else would be better?
If BP is the correct way to abbreviate, then how should it be used? "BP is" or "BP are"?


texts: Is there a way to only sync up to a certain block?

texts: I am planning on doing some transaction analysis on the blockchain, however, I only want to do it on a small part of the blockchain first and then run it on the full blockchain later on. I have downloaded the bitcoind client, is there any way to only sync up to a certain block?


texts: Bitcoin and Bitcoin Cash blockchain split

texts:
What is the safest way to make sure on August 1st that I get the amount of BTC I own in BCC?

For example Coinbase is going to keep all the BCC. So if you have BTC in Coinbase you won't get the equal amount of BCC.

I want to make sure I get the equal amount of Bitcoin Cash as I have of Bitcoin once the blockchain splits.


texts: HD Wallets, XPUB and child private key leaks

texts:
So some generalisations on xpubs and current wallet providers.

Ledger and Trezor wallets can create xpubs which can show all transactions of a wallet
When a passphrase is added, this counts as a new set of private keys along with a new xpub
The children public addresses created from sending/receiving bitcoin are bound only to the xpub from the mnemonic phrase + passphrase i.e. if you create a new passphrased wallet it will have a new xpub
Children created by these wallets are not hardened
If an xpub is leaked for a mnemonic phrase + passphrase, if you have any of the children's private keys, you can compromise the entire wallet linked to the xpub and all other children, hardened or non-hardened BUT the attacker will not be able to compromise any other meomonic phrase + paassphrase you have as it has a different xpub, and ultimately different children

My question, assuming the above is correct, it's becoming more commonplace for 3rd parties (i.e. tax tools) to make use of xpubs - I want to know how it's even possible to leak a childs private key on a trezor or a ledger as none of the outputs are able to leak these, unless I'm wrong.
Just want to make sure I'm not leaving myself too open.


texts: Ardor Transaction was generated on a fork error

texts:
I tried to sign a transaction and then broadcast it, but I get the following error:

Error! Failed to broadcast transaction: ecBlockHeight 221000 does not match ecBlockId 932...., transaction was generated on a fork.

What could be the cause of this?

If i sign the transaction and broadcast it manually via the ardor desktop gui wallet via "broadcast", it works. I'm just not sure how this error is occurring or what does it mean?


texts: How much of BIP 62 ("Dealing with malleability") has been implemented?

texts:
BIP 62 lists nine source of malleability:

Non-DER encoded ECDSA signatures
Non-push operations in scriptSig
Push operations in scriptSig of non-standard size type
Zero-padded number pushes
Inherent ECDSA signature malleability
Superfluous scriptSig operations
Inputs ignored by scripts
Sighash flags based masking
New signatures by the sender

...and proposes new rules that would fix the first seven. How many of these fixes have been implemented in Bitcoin Core?


texts: How to create a signed transaction offline using electrum?

texts:
I remember that on Electrum, it used to have a Preview button inside the Send tab. By clicking the Preview button I could export the unsigned transaction, and then sign it.
I cannot find this button anymore, I can only see Pay button, and when I clicked it I got a "Not Enough Funds" error. This is because I am doing this in my offline desktop computer (offline wallet).
Is it still possible to create a signed transaction offline using electrum?


texts: How can a person reasonably prove they're running a full node?

texts:
I mean running themselves in a computer they control and not just fetching blockchain data from a public blockchain API or something like that.

I imagine that may be impossible, but there could at least be some operation that is trivial/fast to do with a local full node that's difficult/slow to do with a blockchain API.


texts: Is there a way to import bitcoin wallet into BitcoinJ?

texts:
I tried to create bitcoin wallet that could be available as from BitcoinJ as from standart desktop wallet client (Bitcoin.com client e.g.) but it seems that I don't get something important.
I exported the wallet from desktop client which looks like
this.
After decrypting it with https://bitwiseshiftleft.github.io/sjcl/demo/, I got this.
The problem is the Wallet.class methods to import wallets are all eventually have seed creation time as a parameter, which is not stated in exported version of the wallet (setting it randomly doesn't help).
So basically I need any options to transform this exported data into working BitcoinJ wallet.
Any help or advices would be gratelly appreciated!


texts: I am trying to withdraw Ethers from Cryptsy to geth account. Cryptsy says address, where I enter my account id, is invalid. Do I need to create a separate addresses besides running geth account new to create a new account?


texts: Is proof-of-stake a viable alternative / augmentation to proof-of-work?

texts:
Meni mentioned Proof of Stake as a possible way to augment Proof of Work as the underlying mechanism powering Bitcoin confirmations.

Is it viable? What are its downsides? Who has analyzed it? (I don't see a lot of people on this thread)


texts: I know what it means. But I can't understand why Bitcoin decided to make such a model, where you have no balance, only unspent transaction outputs. And isn't the same thing as having the balance? I assume if you didn't spend coins, you have them in balance. What advantage does it have over a usual (non-UTXO) model? With comparison with other cryptocurrencies which has no UTXO, if possible, please.


texts: where to get specifications about how to make a block in bitcoin mining

texts:
I read that i have to hash 3 things(previous block's header, nonce, current block contents) using the sha 256 algorithm to get a hash that has required number of zeros at the start, in order to add my block to the blockchain.

where are the specifications for combining to form a block?

I have a sha 256 program that can perform a hash. I need to know
1. where to get the latest block?
2. what parts of the latest block to use?
3. where to get the latest transactions?
4. what parts of the latest transactions are to be put in a block?
etc

there must be specifications for these. can anyone please tell me where to find it?

Thanks much,
ms


texts: How does Ethereum domain registration works?

texts:
I am wondering how does the Ethereum domain registration works? From what I can see in the whitepaper, I know there is account-specific data storage, but I don't know if that would be the ideal way to register domains. Generally, one would need some shared data storage between all accounts to have globally unique domains.

How does data registration in Ethereum work?


texts: I don't understand the "51% attack" problem. Why does a mining pool have power with a 51% share?

texts: What gives a mining pool power to maliciously dominate the system if they're mining over the majority of the coins? Profits are disseminated to miners individually. I really don't understand how this enables a bunch of individuals to conspire to warp the market. I think I'm fundamentally misunderstanding the problem. Can someone explain how having a 51% share enables a pool to prevent, reverse, or double spend transactions?


texts: how to free up disk space after running bitcoind for the first time?

texts:
I am following Antonopoulos' Mastering Bitcoin.  I have installed Bitcoin core and ran bitcoind for the first time. Although the book said it will remind me to create a configuration file, it did not.  It rapidly used up the disk space (I am running it on VM Ubuntu) and I had to interrupt it.

I want to free up the used space and try again with configuration file, but I do not know what to do.


texts: I'm using Ledger wallet, and it recently prompted me to migrate to new Segwit address type. If I want to use Segwit transactions from Armory, do I have to do something similar (I have installed bitcoin 0.15)?


texts: How to prove to my landlord that bitcoin came from my wallet?

texts:
Let's say I'm paying my monthly rent using bitcoin. I'm going to set up a script to send 5 bitcoin from my wallet to my landlord's address every month. I will not be able to tell beforehand which addresses the bitcoins will come from, nor does my landlord want to verify signatures on many addresses.

How can I prove that 5 bitcoin is leaving my wallet every month and going into my landlord's account?


texts: How can I print these information using this library?

texts: I want to know how through using this library I can print information about the current block that the world mine right now and I mean by that: Version, Previous Block, Merkle Root, Time, Bits, and how many zeros we are looking for for the output of the hash.


texts:
I currently have BTC 0.38 in a wallet on a computer and I want to transfer all those Bitcoins on another machine.

As I have the Bitcoins on a relatively new address (it has received 1 payment and also some Bitcoins through the move API call), it wouldn't let me transfer the Bitcoins without paying a fee.

I don't want to pay this fee, as it is pretty high for what I'm trying to transfer.

Do I just have to wait some time before spending them again to be able to do so without this fee? Or should I do something else?


texts: Sudden Drop in Hash Rate GeForce 650 GPU Card

texts:
I'm running on a 15" Retina MBP and have just been playing around with mining on it a little bit.  I realize GPU mining is almost dead at the moment, but bear with me.

Overnight last night I was running the BitMinter Java client and getting around ~20Mh/s.  I fired it up again this evening, and for some reason, am now only getting around 5Mh/s.  I'm seeing the same rate on both the BitMinter java client as well as with cgminer.  Nothing has changed on my system over the last day other than having to reboot it a few times for other reasons.  Does anyone have any idea why my Mh/s output rate has fallen so much?


texts: Does the synced blockchain always grow in size?

texts:
Every time the Bitcoin-Qt is launched, the blockchain syncs to update to its latest state. Does this mean the data stored locally will always grow continously, eating up all available space eventually? Or is there a size-limit so that only the latest info is kept? How does it work?

At the time of writing, my folder is 5.82GB; let's see if this changes..


texts:
I recently created a bunch of bitcoin addresses (public starting with 1, PK starting with 5) from a paper wallet, that I downloaded from their github (https://github.com/walletgeneratornet/WalletGenerator.net) and ran offline.

I imported the first PK in my full node, it translated to the pub address I expected and I control this address.

I don't feel comfortable sending coins to addresses I don't know for sure I control. How can I check securely and "easily" that I control them ? Adding all of those PK in Bitcoin core is long and decreases security.


texts: How to import an extended public key into bitcoin core 0.16

texts:
I exported an xpub key from a HW wallet and want to import it into my own node to keep track of changes to the balance. My node is running satoshi 0.16.1

Can someone help me find the right syntax for bitcoin-cli, or make a statement about whether it is possible at all to import extended public keys?

Edit: @aantonop seems to state in this video (https://youtu.be/8mpDcBfNA7g) @ 16:55 that this is possible in bitcoin core though I may be getting it wrong and also he isn't omniscient.


texts: Can I use my "chainstate" folder for anything?

texts:
I've recently found an old folder called "chainstate" in my PC.
Can't remember why I saved it but inside it there's the following files:
"000003.log"
"CURRENT"
"LOCK"
"MANIFEST-000002"
Are these of any use at all? Could I access an old wallet using these? What does it mean?


texts: How are transaction fees claimed from a technical point of view?

texts:
A typical transaction has one or more inputs and one or more outputs. Since there is no amount specified for inputs, the rule is that ALL of the inputs is always transferred. Any discrepancy between the value contained in the inputs and the total value of the outputs is lost forever.

When a transaction is first submitted there may be a discrepancy between the values of the inputs and outputs. The miner assembling the block may redirect that unaccounted for difference to themselves or any address they wish, called a "transaction fee", however my question is how do they do this?

It would seem the only way to do this would be to add new output to the transaction and new script to send the value to the output. So in other words the miner would change the transaction from the form submitted by the original poster, to a new form including the fee transmittal.

However, isn't the transaction hashed to prevent someone from altering it? If a miner can alter it, why not alter it to just direct all the input to themselves?


texts: Transaction verification process in full nodes

texts:
I'm having some trouble understanding the process of transaction verification on full nodes. I understand how a transaction is verified via public cryptography (hashes, signature, etc, as it's explained in the original Satoshi paper), but i can't find how this process is done on the real software, involving the UTXO database and any other optimizations that may be done in the actual full node clients.

I've started to dig on the reference implementation code, as a I'm a programmer and i hope to understand the process a little more by looking at the sources but, until then and maybe as a guide, could some expose how that process is done with a little example, even in broad terms it could be helpful, or point toward some technical resource where I could find that description ?


texts: How will Bitcoin and the Blockchain scale in the future?

texts:
I wonder how the whole Bitcoin blockchain system will scale in the future. Given the fact that the size of the blockchain will grow exponentially (roughly a tenfold every ~3 years, looking at the recent years) but HDDs only tenfold every ~5 years, this will become a problem.

The conclusion here would then be that individual users could not save the whole Blockchain on their PCs anymore. This, again, would mean that people would need to prune their Blockchains, but by doing so, old Blocks would be deleted and they could not create new transactions anymore (is this correct?).

And by looking at the largest miners, the 51% problem is already a major thing which only would get worse if small players could not participate anymore.

This would then lead to an Oligopoly of Bitcoin masters that could easily control the truth, not so far away from todays centralized banking system.

I hope all my assumptions are correct and somebody can follow up and answer this, thanks.


texts:
I'm not using omnicore by RPC calls, I dont want to put a server up and make those RPC calls, I want to make a simple transaction on the TetherUS(USDT) network, this is my code:

const getUnsignedTransaction = async (data) => {
  let { pubKey, fromAddr, toAddr, amount, fee, testnet } = data;
  let params = new URLSearchParams;
  params.append('transaction_version',1);
  params.append('currency_identifier',31);
  params.append('fee',fee);
  params.append('testnet',testnet);
  params.append('pubkey',pubKey);
  params.append('amount_to_transfer',amount);
  params.append('transaction_from',fromAddr);
  params.append('transaction_to',toAddr);
  return await Axios.post('/v1/transaction/getunsigned/0', params);
}

When I call this function above

  let a = await getUnsignedTransaction({
    amount:    '0.00001',
    fee:       '0.00005',
    testnet:   false,
    toAddr:    '1KH34S5mAmgAzu3mJAqrS3wjP15qYKZQXx',
    fromAddr:  '17UrxYAAF5WkjtFKeuZ2S7ojDWoJY2LunF',
 pubKey:'03f26647f3bbf4566318d00e2438036be0f1a68ee5deea604be6fa6cad68349888',
  }).then(e => e.data);
  console.log(a);

I got this response:

{ sourceScript:
   'OP_DUP OP_HASH160 4715b028de4327f5f87915d89d1d074db3f03992 OP_EQUALVERIFY OP_CHECKSIG',
  status: 200,
  unsignedhex:
   '0100000001131184d4a10bbf1acef3cb137d37ecc8f36cb3da208c9ebe86fb988821d532b40100000000ffffffff034d160000000000001976a9144715b028de4327f5f87915d89d1d074db3f0399288ac22020000000000001976a914c87aa36f1402052ef87ea433c2fa252ae9a9794988ac0000000000000000166a146f6d6e69000000000000001f00000000000003e800000000' }

Now here is the question: How can I make this unsigned raw transaction an valid transaction to the Tether network and so, broadcast this signed raw transaction

This is the blockexplorer I'm using: https://api.omniexplorer.info/#request-v1-transaction-pushtx

Code solution

As the @Raghav_Sood chosen answer, I had to use bitconjs-lib to wrap this transaction and to sign it.

For those who wanna see in the future how I made the transaction, was kinda this:

let tx  = bitcoinjs.Transaction.fromHex(raw);
let txb = bitcoinjs.TransactionBuilder.fromTransaction(tx);
txb.sign(0, keyPair)
let raw = txb.build().toHex();

let d = await pushtx(raw).then(e => e.data);

function pushtx

async function pushtx(raw) {
  let params = new URLSearchParams;
  params.append('signedTransaction',raw);
  return await Axios.post('/v1/transaction/pushtx/',params);
}


texts: What is the best way to buy bitcoin for long term investment to sell for cash later?

texts:
I apologize if this is a duplicate of this question, but it might be because of my ignorance about this topic that I think I am asking for different information.

I would like to buy some bitcoin. About $100 USD worth. From today's rate that is a little more than 0.1 bitcoin. I am fine with hanging on to it for a few years. Maybe five or longer. My concern is that there doesn't seem to be an easy way to sell bitcoin, like through mt.gox. Maybe I'm mistaken about that. I just want to make the purchase and have it to easily sell later, like I do with stock on Scottrade.

Also, if it is on topic, suggestions for litecoin and peercoin would be very much appreciated. It seems like it is on-topic according to some meta posts.


texts: What are Channel Factories and how do they work?

texts:
One of the open research questions for Lightning Network is that it will take a massive amount of on-chain transactions to create enough payment channels for all the Lightning Network users. Lately, I've seen the term "Channel Factories"¹ pop-up in this context.
What are Channel Factories? How do they work? How does that help scale the Lightning Network?

¹ Apparently, the term was introduced by the paper Scalable Funding of Bitcoin Micropayment Channel Networks by C. Burchert, C. Decker and R. Wattenhofer


texts: What is "Verifying last 288 blocks at level 3"?

texts:
Upon every start of bitcoind, I see the following in de debug log:

Verifying last 288 blocks at level 3

come up. At this point, no new blocks have been downloaded and the block chain was 100% up to date when I last closed bitcoin. Bitcoind does not do anything before it has 'verified' these 288 blocks (the server does not answer until this phase has passed).

Why do the last blocks need to be verified if nothing new has been added since shutdown?
Does this verification make any changes to any files? Does it save anything to the blocks / chainstate / database directories?


texts: Where could I sell micro BTC and is it possible?

texts: I would like to know if is it ok to sell micro BTC? Like a few decimal places like 0.01 BTC? And where would I sell it to exchange for other currencies? And how do I get the exchange safely?


texts: How to use Bitcoinj to authenticate signed messages?

texts:
I'd like to authenticate from java code on a website that makes use of javascript/ajax authentication like below:

var key = new Bitcoin.ECKey(Crypto.util.hexToBytes(SHA256(password)));
var signed_challenge = Crypto.util.bytesToHex(key.sign(Crypto.util.hexToBytes(SHA256(challenge_key))));

I found that the library bitcoinj offers classes like ECKey, but I don't know what I might use as replacement for CryptoJS here?

Maybe you could help me translating the JS to Java?


texts: Is possible to send transactions with blockstream satellite?

texts: Noob question here. Is it possible to send bitcoin transactions using Blockstream Satellite node or is it used only for receiving blocks?


texts: Can I mine bitcoin with a gaming computer?

texts:
Awhile ago i built a rather nice gaming computer it has
CPU: intel i5 6600k
GPU: Nvidia GTX 1080
Ram: 16 GB ddr4
PSU: corsair Ax1200W
Water cooled system

Would this be a decent mining machine. If so what would you predict its stats to be. What should I upgrade.


texts: Does anyone have a network trace of a successful 'Block found'

texts:
I'm working on porting some front-end pool software to Postgres. I've got at test net set up and can mine directly to litecoind from cgminer. But I'm getting false positives reported to cgminer and other weirdness when I attempt to mine through pushpool. cgminer will go through three or four 'accepted' lines, then "block found", the shares get recorded in the database, but there's no 'upstream_result'. I've been running network traces, and cannot find anything that differentiates an accepted share to a 'found block'.

From the network traces, all the litecoind does is send new work to pushpool. I see no work from pushpool being submitted to litecoind.

Is there something I'm missing?

EDIT: One thing I missed in my test configuration was that I didn't have a "blocknotify" process in place. I've corrected that, but I'm still looking for a trace of 'block found' through pushpool.(06/06)


texts: Is two-phase encryption planned for the standard client?

texts:
Currently, the standard client supports encryption, but only for actions that change its state (send money, generate address).

I would like the client to require two passwords - one to view any information, and another for mutating it (send money, generate address).

Is this feature planned?


texts: How can address' hash160 be used to determine information for malicious purposes? (Ie reusing of the same address)

texts:
I've been playing around with Richard Kiss's Pycoin app which is clarifying how P2PK works. I see that the hash160 of the value: (0x04) (x-coordinate) (y-coordinate) (for an uncompressed Testnet private key in this instance) gives a hash160 value used to prove ownership of the private key.

How is this detrimental for reuse of private keys if there is no issue with PRNGs providing low entropy? I understand how the Android bug was exploited (to a degree, it reused "random values"), but I fail to understand why only sharing the hash160 in a single transaction can be maliciously exploited. To clarify, I'm not talking about privacy concerns of tracking addresses through the Blockchain.

EDIT: The vulnerabilities in question (as specified in the answer are related to quantum computing and/or EDCSA weaknesses, neither of which exist)


texts:
I've seen posts on how to do it and I've read the wiki on what it is, however these explanations are too complex. Can someone explain what it is and why it's called Base58Check encoding? Are addresses generated without going over those steps still valid in Bitcoin?

This is the explanation provided by the original bitcoind client in base58.h

// Why base-58 instead of standard base-64 encoding?
// - Don't want 0OIl characters that look the same in some fonts and
//      could be used to create visually identical looking account numbers.
// - A string with non-alphanumeric characters is not as easily accepted as an account number.
// - E-mail usually won't line-break if there's no punctuation to break at.
// - Doubleclicking selects the whole number as one word if it's all alphanumeric.

To further this question, what do npm packages like bs58check do exactly? The description is as so

  A straight forward implementation of base58check extending upon bs58.


texts: Synchronising official bitcoin wallet for the first time; at 95% started going backwards

texts:
I.E. 9900 blocks remaining, 9904 blocks remaining and the total percent synced is decreasing. Is this normal behaviour? I'm on a mobile broadband connection but http connections are working just fine. It also says I have 8 active connections which I understand to be the maximum?

Thanks.


texts:
About 4 years ago i gave my son some BTC for his Birthday....
Trying to teach him a bit of financial responsibility.....
he created a wallet, on an exchange i believe, i wasnt part of that, as i insisted he take charge and responsibilty for his own, and, keep passwords, seed etc safe.
Fast forward till now..... He can not remember which exchange he created the wallet on, i do have the original wallet numbers however...... dont have seed.
it there anyway to tell which exchange it went to , he " thought he saved all the info on his computer..... kids huh.


texts: Legal issues / banking issues selling Bitcoins to people OTC?

texts:
I'm wondering what the practical / legal limits are on selling Bitcoin as an individual using Craigslist and LocalBitcoins. Will I run into legal issues / frozen bank accounts as I scale this? Right now I'm doing about $1K of selling per month, but I could see that expanding to $1K - $3K per week.

I take all the payments in cash, so this will be 1-3K per week in cash going into my credit union ATM.


texts: Authoritative list of Bitcoin resources?

texts:
Has any website compiled a reasonably authoritative and trustworthy list of Bitcoin resources? I'm building an appendix for my course and I'd like to see if I missed anything.

https://www.udemy.com/bitcoin-or-how-i-learned-to-stop-worrying-and-love-crypto/

Edit:

To address Nick's concerns, let me clarify the purpose of this question. I am not asking for your favorite Bitcoin links. I am asking for authoritative and trustworthy lists of Bitcoin resources. For example: https://www.spendbitcoins.com/places/ is a reasonably trustworthy list of bitcoin commerce sites.


texts: What is the command for primecoind and bitcoind to see my address?

texts: i just installed primecoind and bitcoind and datacoind and i want to know how i can get my address. what is the command options for it? I dont see it in the help list.


texts: Is there a limit on the number of orphan transactions a node can cache?

texts:
I´m asking this because a possible attack would be to send an flooding number of orphan transactions, which will never be redeemed. Then clients would have to cache them, increasing storage requirements and reducing lookup time. This can lead to a resource-exhaustion attack.

If there is a limit on the size of the cache, then a DoS can be mounted to exhaust the limit.
In both cases, a DoS attack can be mounted.

If there is no protection, adding a proof-of-work to each transaction would help to prevent such attack.


texts: Unseen BTC transaction in a blockchain Wallet

texts:
if a BTC transaction is made in to a blockchain wallet address and it is not seen in it activities but appears in the blockchain explorer that the transaction has been made  What will I do
266fddc5f0ca7a8afb89931ea71ee0cb21b6b6f84f3061e2428f656fcf25b9f9


texts: Are there any Bitcoin wallets with native I2P integration?

texts:
Tor usage seems to be fairly common with Bitcoin, but I have heard less about efforts of integrating with the I2P efforts.

Tor and I2P both have their pros and cons, but I am curious to here about what I2P efforts have been made to this point and why more attention has so far focused on tor.


texts: Are there any super nodes in the network?

texts: Similar to BitTorrent trackers. Or are all peers equal in ability and importance?


texts: How can I seamlessly extend disk for bitcoin-core full node?

texts:
I'm running a bitcoin-core full node and serve customers wallet service (e.g. creating a wallet, sending tx). I set the chain data disk size to 400GB when first setting the node up and the disk is almost full now.

I'd like to increase the disk size without halting or stopping wallet service. Can I get advice or tips for doing it?

I'm using a cloud service for running the node and it's highly likely to stop bitcoind process if I increase disk size on the cloud console. (I don't think bitcoind can write to disk while the cloud service working on the disk)

Any help would be appreciated. Thanks!


texts:
I am creating an online exchange website. I need to have a reliable bitcoin wallet on my website.

Do I need to have a full node to create an online bitcoin wallet?


texts: Bumping unconfirmed transaction with sendrawtransaction

texts:
I have a transaction which doesn't confirms for last 3 days and is not most likely going to confirm at all in near future due to a recent situation in mempool.

Will it be working if I'll do the following? Are there any risks to loose my bitcoins forever, or even to get banned by system for double-spend?

Dump that transaction with 'getrawtransaction'
Decrease one of it's outputs by X in my hex editor, so that X will be added up to transaction fee
Sign that transaction with 'signrawtransaction' and send it


texts: Rationale behind accepting btc as a mode of payment?

texts:
Tesla has said they "expect to begin accepting Bitcoin as a form of payment for our products in the near future."
But Bitcoin doesn't scale. It achieves about roughly 6 transactions per second, paling in comparison to the likes of Visa, which facilitates around 1,700 transactions per second.
What's the rationale behind their decision?


texts:
I just completed parsing the Testnet3 Bitcoin blockchain stored in the blk.dat files into a database. Since I was using multi-processing to parse several files at the same time, I didn't add the height to the blockchain while parsing it. Instead, I did this after the whole blockchain was parsed.
Everything was going smoothly while adding the height to the blocks for the most part. However, approaching the end of the blockchain (the last 7%), my code started to crash because it started to find 2 different blocks that had the same previous block (basically, a fork), and I had already constrained my database to avoid having 2 blocks with the same height. All these tiny forks I have been finding are just one block long, and it looks like the closer I get to the end, the most common it is to find these tiny forks.
I have had to look both block-ids up in a block explorer to find out which one is the official block and which one is the fork ("fake" block). One of them is always non-existent for which I know it is not an ID misplacing. I have been manually deleting the link of the "fake" block so my code can keep adding the height, but as I said before, it becomes more and more common to find these tiny forks the more I approach the end of the blockchain.
I was just wondering if this is normal, or if there is something really wrong with my blk.dat files.


texts: Is my idea of getwork protocol for bitminer right?

texts:
I am trying to understand the idea behind getwork protocol, by sniffing my communication with a bitminter miner pool.

Previously I have read the discussion here, but looking at my packets, I think that there are some things which are implemented differently. I can understand that my question can be too vague, because mostly I am expressing my ideas how the protocol works, which can be totally wrong. But please do not be too harsh.

I want to go through the protocol and explain my thoughts, if I am wrong at any point of time, please explain me were I am wrong:

1) my client is authorizing on the server by sending post request

POST/HTTP/1.1
Content-Type:application/json
Accept:application/json
X-Mining-Extensions:longpollbcidmidstaterollntime
X-BCID:somenumber
X-Mining-Hashrate:my
Authorization:mySignature
Content-Length:39
Host:mint.bitminter.com:8332
Connection:Keep-Alive
User-Agent:BitMinter/1.3.0[BitMinter]

As far, as I understood the client is just telling what extensions it can support, his hashrate (based on this a server will give him a work to do), his authorization credentials.

A few things I can not understand here. What is X-BCID and what prevent client for submitting wrong hashrate? As far as I understood the server can not verify the work of all clients, so he will not be able to spot the wrong hashrate. I understand that most probably I am wrong here, but I just can not understand how is it done

2) after accepting approval for clients credentials it is asking to get work. Sometimes it has a huge string inside the params field. I can not understand what that string represents and why is it appears.

{
  "method":"getwork",
  "params":[],
  "id":1
}

3) the server is replying with the information that he supports, time after which the replies to the server would be outdated. Here also appears this X-BCID which I can not understand.

HTTP/1.1 200 OK
X-Stratum:stratum+tcp://eu1.bitminter.com:3333
X-Long-Polling:/lp
X-BCID:someNumber
X-Roll-NTime:expire=7Date:Mon,07Jan201319:52:20GMT
Server:Outpost/1.1.0 beta1
Content-Length:374
Content-Type:application/json;charset=UTF-8
Connection:Keep-Alive
Keep-Alive:timeout=895,max=5

4) together with the work that client has to do:

{
  "result":{
     "data":"huge string",
     "target":"smaller string"
  },
  "error":null,
  "id":1
}

from the above mentioned source, I understood that huge sting contains the information about the work for client (from which string to which string it has to iterate and calculate hashes) and to compare it to smaller string. So, if during the calculations I will encounter value, hashes of which will give me a smaller string, I will finish a block.
I did not understand why do I have an error field here. What is it testing?

So, my questions are:

what is X-BCID field in request 1 and 3
how the server validates the hashrate, which is submitted by the client in request 1
what is the params field in request 2, why sometimes it is empty
is my understanding about the request 4 correct, and why do we need 'error' : null, response. Is this just because of the standard of JSON-RPC and it is always null, or there can be reasons when it will be null.


texts: How do bitcoin nodes agree who first mined ablock?

texts:
Once transactions are broadcast and a node starts working on a proof of work, and finds it, it broadcasts it to all other nodes for that block to be verified and added onto their blockchain. All nodes agree to add another transaction that mints a certain amount of bitcoins to the miner.

However, I am confused about what protections there are against a bitcoin node receiving a proof of work for a new block that it did not find itself, and then sending the that block around as though it mined it!

How do bitcoin nodes who originally mined a block and how does the bitcoin system prevent tampering with this?


texts: How can i verify my txs with my own full node?

texts:
Hey i run a full bitcoin+lightning node on a rpi. Can anyone eli5 me how can i verify my own tx if send some coins from an exchange to a public address i control?

Lets say i plug in my hw, send some coins, then i wanna actually verify if i got those coins or at least they are (verify able) on the  mempool waiting to be mined.

I have always struggled with the how do i really “verify, don’t trust” quote.

Thanks in advance.


texts: Would a normalized, hashed, protected chainstate reduce miner storage costs?

texts:
Spending freshly generated coins is prohibited by the protocol until there are at least 100 blocks on top of the block from which they came.  This is because the chances of a 100-block reorg is virtually zero.

The chances of a reorg of 1,000 or 10,000 blocks is even lower.  If the chainstate data is normalized, then its hash can be included in each block so that messing with it is as impossible as messing with the blockchain itself.  Would we then be able to prune off all but the last 10,000 blocks?

I know the transaction history is valuable, but under the assumption that we will never see a reorg larger than a particular number of blocks, I suspect it isn't necessary for mining once the chainstate is protected as well as the entire blockchain has been.

It seems to me that normalizing the chainstate so that it can be hashed and protected (like block headers are) would allow validation and mining without having to save the entire blockchain.  That way, only those who really want the history would need to save it.

Am I missing something?


texts: Where in the source code of the Core Client is the GetBlockValue() function?

texts: I was reading Antonopoulos' book and there is a piece of code in chapter 8 in the part about Coinbase Reward and Fees and the code is a GetBlockValue() function. I was looking for it on github but didn't find it. I found something about a function called GetBlockSubsidy() that works in a similar way and is apparently a newer version but I can't find this one either. Also all the links I found linking to main.cpp in the repository don't work. Where is this part of the code now or what am I missing?


texts: Do they just sit there unconfirmed (e.g. when you be evil and don't pay a tx fee) forever? Or do they get deleted after a few days?


texts: What is the difference between accounts and adresses? As discussed in this question accounts are a component of bitcoin wallets, different from addresses. What are they? How do they work?


texts: How scalable is the current routing implementation for lightning?

texts:
What are the weaknesses we face with lightning routing currently?

How many nodes do we expect it can handle now?

What is being done to make it scale in the future?


texts: What Bitcoin wallet will allow me to participate in an ICO?

texts:
I have bitcoins stored in an online Coinbase wallet. I've read this wallet should not be used for investing in an ICO as this will be Coinbase's wallet (not mine) and I won't have access to the private keys.

Is this true?

I looked into creating a multi-sig Coinbase vault as this seems like a good and safe middle ground. However, I noticed the vault has a 48 hour waiting period which is not desirable for buying into an ICO.

I'm running Mac OS X. Is Electrum wallet this best way to go about this?

What do people recommend?


texts:
How to get both confirmed and unconfirmed transaction details of foreign(non-wallet) addresses from bitcoin-node server?
Actually i have generated the addresses using third party library and sent some btc on it. Now i want to know confirmed and unconfirmed transaction details using my own local bitcoin-core node server. Can Somebody help me? Thanks in advance.


texts: How does the electrum wallet 'payto' command work

texts:
Hello fellow bitcoin users,

I'm currently working on developing an application that takes advantage of the Electrum wallet in order to receive and payout to users of my service.

My application uses the built in json-rpc server from Electrum to communicate. I am able to accept and monitor incoming payments just fine with the request mechanism but I'm facing some difficulties in terms of paying out.

By running the 'electrum -h' from command line I see that I should be using the 'payto' command to make payments. I need to specify an address and an amount at minimum and then also a password if required.

In order to see what sort of response I'm expected I first tried this directly from the command line using 'electrum payto [BTC_ADDRESS] [AMOUNT]' and then I'm prompted for my password.

Also when entering an incorrect password I get denied (so this isn't the reason).

I enter it and receieve the following response:

{
"complete": true,
"final": true,
"hex": "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"
}

I was expecting perhaps a transaction ID but as the documentation for the API is lacking (or I can't find it more likely) I'm not sure what to expect. The payment is not executed by this command so perhaps I'm missing something.

TL;DR: How do I send bitcoin using Electrum from the command line?

Thanks


texts: Why does Bitcoin need transaction fees prior to hitting its maximum coin limit?

texts: I have a question regarding the theory of Bitcoin . Why does Bitcoin build in transaction fees before it hits the maximum allowed amount of coins?  That is, shouldn't the reward of coins for mining a block be enough to keep the system going?  In addition to the trouble we're seeing now (a high value of Bitcoin makes doing simple transactions uneconomical), it seems like building in a transaction fee taht the user can select would rig the system such taht higher fee transactions would get prioritized over lower-fee ones, which would restrict some people from using Bitcoin.  I guess all cryptocurrencies do this so there is no way of avoiding it.


texts: Keeping consistent market depth using Mt.Gox API

texts:
I'm trying to write a program using the Mt.Gox API to keep an up-to-date consistent view of their market depth. My current approach is as follows:

Connect WebSocket and subscribe to depth updates
Wait for 1 minute, collecting updates
Request full market depth data via http://data.mtgox.com/api/1/BTCUSD/depth/full
Merge the collected updates into the market data by time-stamp (more recent wins)
Continue merging all future updates into data

After playing around with this for a while, I noticed that the full depth data download doesn't always match the data generated from updates. That's why I added the 1min delay, thinking that maybe the Mt.Gox server only updates the full depth data periodically, but doesn't generate it on the fly.

But even with this protocol, if I run the program twice in parallel, I end up seeing different data in both instances.

Any idea what I might be doing wrong?


texts:
What hierarchical deterministic derivation path is used for FIDO authentication on a Ledger Nano S? Does it ask for a different key each time or is it always the same key?
If I connect to Google for 2FA can it ask for proof of whatever key path they desire or does it have to be a particular key?
I'm wondering how much privacy I lose if I use a Ledger Nano S that is not exclusively for a particular accounts 2FA. E.g. What happens if I use it for multiple Google accounts, other companies, or have crypto currency. Could Google discover a Bitcoin balance if the same Ledger is used for 2FA?


texts: Same identical R value of all transaction not provide corresponding privatekey

texts:
ECDSA Signature and the “z” value

from above link learn calculation of z value and to get private key

https://blockchain.info/tx/9ec4bc49e828d924af1d1029cacf709431abbde46d59554b62bc270e3b29c4b1

transaction you get

R = d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1

S1 = 44e1ff2dfd8102cf7a47c21d5c9fd5701610d04953c6836596b4fe9dd2f53e3e

S2 = 9a5f1c75e461d7ceb1cf3cab9013eb2dc85b6d0da8c3c6e27e3a5a5b3faa5bab

Z1 = c0e2d0a89a348de88fda08211c70d1d7e52ccef2eb9459911bf977d587784c6e

Z2 = 17b0f41c8c337ac1e18c98759e83a8cccbc368dd9d89e5f03cb633c265fd0ddc

z = 7a1a7e52797fc8caaa435d2a4dace39158504bf204fbe19f14dbb427faee50ae

private key = c477f9f65c22cce20657faa5b2d1d8122336f851a508a1ed04e479c34985bf96

but the other transaction not providing corresponding private key

with same identical
R value = d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1

https://blockchain.info/tx/47106ff70bf779efc32230f5ca956d0fc563f35a3c4395d1977fc38995327fe1

https://blockchain.info/tx/00b4dea9266283d93f35240f34b871b55e59c3d4a7705aa08d5745af398d9046

https://blockchain.info/tx/d6f071e082ebb8c7c7721a9019d7478489e3fd423cae6acabdbd2ffd28f5c300

https://blockchain.info/tx/83415dded4757181c6e1c55104e2742a6f8cff05a9a46fbf029ae47b0054d511

https://blockchain.info/tx/2bd15366f5bcc2046c480db4d6ad82450893f2a3370935ddee753325f1a7c6cc

https://blockchain.info/tx/e96feca9744b95533a5a3f657c346d7772a5004a76f4bc8de810b7ad015f6440

https://blockchain.info/tx/5a994f485039ebd83a0ed22cae943f0c792d85d218884f4cd80bd7cccdd75aae


texts:
I want to use bitcoin in Debian. I want to be able to receive BTC and make payments in BTC.

I want to keep my wallet locally, on my computer. I want a light client, I don't want to download the entire blockchain. I simply want to be able to pay and receive BTC.

What should I use?

When I search for this, I'm surprised to not find any binary packages for Debian. Last time I used BTC was many years ago, and it seems there still isn't any binary packages, for something as commonplace as Debian? Do I really need to download and compile the code myself?

Frustrated, I tried to compile bitcoin-qt, installed a ton of dependencies, but I encounter the following:

configure: error: libdb_cxx headers missing, Bitcoin Core requires this library for wallet functionality (--disable-wallet to disable wallet functionality)

Tried searching for this, hoping it was just another dependency, but I can't find a simple fix.

I also look at this question: https://superuser.com/questions/699315/how-to-install-bitcoin-qt-wallet-on-debian-7

But it seems to be too old, the instructions (downloading the key) no longer works.


texts:
I am programming a specialty wallet software. I am able to generate a EC_key and valid bitcoin addresses. I am not sure what to save to a wallet file in order to recover the EC_key in the future. Must I save both the private and the public key? Can I just save the private key?

What is the preferred format to save these keys and what openssl function should I use to restore the keys?


texts: What is "canonical transaction ordering" that Bitcoin ABC is considering implementing?

texts:
What exactly is "canonical transaction ordering", that Bitcoin ABC is considering implementing?

How does it help exactly, and why is it so controversial?

Could it be adopted in Bitcoin Core? Why yes/why not? Is that a protocol change, requiring a hard fork, or an implementation change?


texts: Which API provides the website URL for a cryptocurrency?

texts: I've been searching for an API that returns the website/URL for a cryptocurrency. Is there any public API which provides the website for a specific cryptocurrency?


texts: How do I recover bitcoin sent to a wrong wallet address

texts: I mistakenly sent bitcoin to the wrong wallet address... How can I recover the money back or get the information of the person I sent the money to?


texts: I am a programmer and I am working on a website. I want to find out how to integrate a blockchain into my website. (Please note that the wallet address changes as soon as it receives a payment). I'm particular about how to resolve this issue.


texts: How does solving math problems create bitcoins?

texts: If I understand correctly, Bitcoin mining software "creates" bitcoins by solving complex mathematical equations. Is there a need for these problems to be solved, is there a value to solving these equations? If not, where does the solving of the math problems fit into the whole Bitcoin scenario?


texts: What happens when there are no Bitcoins miners anymore

texts:
So if I'm not wrong, the proof of work is the way to validate all the transactions in a Block. The miner gets (at the moment) 12,5 Bitcoins as a reward for each validated block.
So my question is:

what happens when almost all the bitcoins have been mined and there are no miners in the system? who's gonna be there to validate the transaction blocks? (21Milloin bitcoins is the limit, so there will be someday such a big proof of work to mine that it won't be worth it, I think everyone's gonna stop mining). will the system still be working as it is right now?


texts:
Ok, so I have this bitcoin wallet backup.

I have the 12 word seed
I have a password
I have a number in this format ****/** that I wrote down.

I made this backup on an android tablet. Not sure which app. I think "Bitcoin Wallet", which is android only, apparently.

I obviously would like to restore it, but I don't own anything android anymore. Any way I can do this on any Mac/iOS app?

I tried putting my backup in Electrum's wallet folder, with no success.
I tried decrypting it as described here. Not sure what I'm supposed to do with the "decrypted" file that is as unreadable as the original.

help.

Update : I tried restoring with Multibit, which I read was compatible with Android Bitcoin Wallet because bitcoinj. Multibit accepted my seed and the ****/** number as a timestamp, did not recognize the backup file (which according to MB docs is not a big deal) and went on an all-night journey to 'sync' with the network.

In the morning I had a new wallet with 0 bitcoins in it.

Does this mean my wallet was empty all along? That I'm using the wrong seed? That I just need to find an old Android phone to try again?


texts: How to make a new blockchain from scratch

texts:
In the same vein as setting up a private DNS root server and using whatever domain names you want, how do you generate your own blockchain and mine your own coins?

P.S. I don't want any answers like "why would you want to?"  I want to do it because it can be done


texts: Is it possible to "send" Bitcoin to yourself (new wallet) without announcing it to the network and without paying any fee?

texts:
I want to make clear that I've already performed said transactions, so I'm not asking this because I want to do it right now. I'm just curious.
Basically, I've spent a number of very sweaty and nervous days "rearranging" most of my coins so that they will finally end up in an encrypted cold storage wallet.dat, after having spent years fully unencrypted and regularly coming into contact with my main PC. Yes, I know it's insane, but I was not just lazy, but also seriously worried that I'd end up losing access to my coins by forgetting the passphrase. That's why I never did it.
Anyway, I've been forced to pay two Bitcoin transaction fees when sending the coins to myself twice. Although I probably would not have ended doing it if it's complicated/scary, is there some way that I could have just "transferred" the coins by, I don't know, typing some kind of private key dump command in the console of Bitcoin Core and then imported them into the new wallet or something?
Or is the only technical way to move funds between wallets to use the Bitcoin network and thus announce to the world that "somebody sent X BTC"?


texts: Can Ripple facilitate business-to-business barter transactions?

texts:
Beverly Hills Hotel participates in the Ripple network and issues its USD-denominated IOUs which are redeemable for hotel stays.
Beverly Hills Performance Car Rentals participates in Ripple network and issues its USD-denominated IOUs redeemable for car rentals.
Both the hotel and the car rental shop have unrented inventory.
Daily room rental rate in USD is roughly the same as the daily rate to rent a Ferrari.

Question:

Can the hotel owner and the owner of the car rental business exchange their respective IOUs through either a mutually trusted gateway/nexus or directly (assuming they trust each other) or through a web of trust to allow a room to be rented out for a day of stay and a Ferrari rented out for a day of driving ?

Bonus question:

Is this the real purpose of the "issuer" field in the current Ripple user interface, i.e. to allow any participant to issue IOUs denominated in any currency of their choice ?


texts: ScriptSig does not validate with seemingly valid signature

texts:
I am trying to build raw transactions from scratch to improve my understanding. For comparison I am using the hexoutput from https://coinb.in/ as I can choose Testnet on there.

I am trying to construct a P2PKH transaction without Segwit (for now) which should use this tx 577735da1fccf6df79eac9ff42049a7729703ec5506efeb1602bca99df3bafd2 (index 0) and send 6889990 satoshi to mv4rnyY3Su5gjcDNzbMLKBQkBicCtHUtFB, the raw public key of the input address is 034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073d

So for the unsigned transaction my library produces 0100000001d2af3bdf99ca2b60b1fe6e50c53e7029779a0442ffc9ea79dff6cc1fda357757000000002221034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073dffffffff0106226900000000001976a9149f9a7abd600c0caa03983a77c8c3df8e062cb2fa88ac00000000 which matches what is produced by coinb.

So to generate the signature for the sigscript I use the following code:

def sign_transaction(self, secrets):
    """
    Sign all inputs of the transaction with
    a secret key.
    :param ECPrivKey[] secrets: a list of private keys corresponding to the inputs
    :return: Transaction Signed version of the transaction ready to be published
    """
    unsigned = bytes.fromhex(self.serialize_to_hex())
    message = sha256(sha256(unsigned))
    copy = deepcopy(self)
    inputs = self.__inputs
    for i in range(0, len(secrets)):
        sk = secrets[i]
        inp = inputs[i]
        sig = SignatureFactory.gen_ecdsa_signature_bytes(message, sk)
        copy.set_signature(sig)
        sigscript = sig.get_asn1_encoded() + OP_SIGHASH_ALL
        l = len(bytes.fromhex(sigscript))
        script = compact_size_int(l) + sigscript + inp.get_sig_script()
        copy.__inputs[i].set_sig_script(script)
    return copy

Informally I use the hexoutput from the unsigned transaction, convert it to bytes, run two sha256 hash functions on it and append the SIGHASH ('01') byte

I validated the produced signature and it is valid so I feel like there is something wrong with the serialization. Here is my transaction after signing it:

0100000001d2af3bdf99ca2b60b1fe6e50c53e7029779a0442ffc9ea79dff6cc1fda357757000000006a47304402207da5c1e2d7db828e415db1ae060d65e4a44de2b13b71c50be61d6c52da82425b022010da9abb70c7b6047b559c5c572f68e078d6ae78ba03dfd6aa1890e512e376760121034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073dffffffff0106226900000000001976a9149f9a7abd600c0caa03983a77c8c3df8e062cb2fa88ac00000000

{"version": "01000000", "flag": "", "inputLen": "01", "inputs": [{"prevOutHash": "d2af3bdf99ca2b60b1fe6e50c53e7029779a0442ffc9ea79dff6cc1fda357757", "prevOutIx": "00000000", "sigScriptLen": "6a", "sigScript": "47304402207da5c1e2d7db828e415db1ae060d65e4a44de2b13b71c50be61d6c52da82425b022010da9abb70c7b6047b559c5c572f68e078d6ae78ba03dfd6aa1890e512e376760121034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073d", "sequence": "ffffffff"}], "outputLen": "01", "outputs": [{"value": "0622690000000000", "pubKeyScriptLength": "19", "pubKeyScript": "76a9149f9a7abd600c0caa03983a77c8c3df8e062cb2fa88ac"}], "locktime": "00000000"}

In more detail the value of sigscript:

47 Script length
30 DER signature marker
44 Signature length
02 r value marker
20 r value length
7da5c1e2d7db828e415db1ae060d65e4a44de2b13b71c50be61d6c52da82425b r value
02 s value marker
2010da9abb70c7b6047b559c5c572f68e078d6ae78ba03dfd6aa1890e512e37676 s value
01 Opcode SIGHASH
21 pubkey length
034323ee9ac23504779b40c1b02578d27f70c12c22b7fc4f452dbbde681e45073d pubkey value

If I try to broadcast the transaction on https://live.blockcypher.com/btc-testnet/pushtx/ I get Error validating transaction: Error running script for input 0 referencing 577735da1fccf6df79eac9ff42049a7729703ec5506efeb1602bca99df3bafd2 at 0: Script was NOT verified successfully..

Does anybody have an idea what could be wrong? Also the r and s value of the signature I did not encode in little endian and I am not sure if maybe this could be the problem?


texts: how to stop bitcoin transfers from unknown parties?

texts: How can you prevent bitcoins from unknown parties being transferred to any of your bitcoin addresses? if so, how? If not, why not?


texts: What is the schema of the data stores used by the reference client?

texts:
I'm interested in seeing the schema (layout and indexes) that is used in the reference client.  Namely wallet.dat, the bk** files and also the in-memory uncommitted tx.

Does this exist anywhere for the 7.x client or the newer BerkleyDB format?

I'd like to see what, if any changes are being made to accommodate BIP 0034.


texts: Generating Public & Private key pairs for cracking Bitcoin

texts: Would one of the better methods to crack Bitcoin be to start creating a massive database of key pairs? It would then be possible to reference the Private key required off the public key from the DB.


texts: How do i setup 2x TTbiT Usb Miners on CGminer?

texts: I'm having trouble connecting 2x TTbiT Usb Miners(sha256) through CGminer. Does anyone know how to set them up to mine BCH on Multipool?


texts: Bitcoin address types and specific prefix

texts:
I know that there are 3 major types of address types:

Legacy (P2PKH) start with: 1
Compatible (P2SH) start with 3
Native Segwit (Bech32) start with bc1

more inforamtion here:
Pros and Cons of each address types
However, recently I found that there are another stange prefixes like:

m-1ffe66d27929a1a197e1a4919b002230
d-fdf6c0e1f6e259ce32704f7091ca6dd3

Source: https://gz.blockchair.com/bitcoin/addresses/
A new type of address prefixes released?


texts:
Does it work differently in relation to a regular forex because of its underlying technology?

How can the market calculate its value?


texts: One seed phrase created two wallets with two script types

texts:
I have a wallet on blockchain.com and it is saved with the backup phrase. Due to issues I was not able to buy anything there, so I created an account at coinbase. This lead to the usage of coinbase wallet. I imported the wallet with the phrase. Everything went well unti I added coins from coinbase. This new amount appeared only in the coinbase wallet.
So now I figured out using Electrum that I have created two wallets. One with with script type p2pkh and one with p2wpkh. Both summed togehter cointains my whole number of coins.
How can I proceed to put all in one wallet together?
Since support on blockchain.com is not able to help I want to have all at one place again.


texts: Do we Need Pay Tax for Mining for US Govt

texts:
Do you need to pay Taxes for US Govt for doing Bitcion  Mining.??

I am in Singapore and mining through one of my friend in US.
Will the US Governement will issue TAX on My Name..?? Is it Legit ..?

If so, How much Taxation..?
Does Univted States TAx Revenue Board send the TAX Invioce on my Name

Thanks a lot


texts: Do blockchain.info wallets correspond to a single wallet on the blockchain?

texts:
To learn about bitcoin in a hands-on way, I decided to buy some. I created a wallet with blockchain.info, and then used Bitonic (A Dutch bitcoin seller, not an exchange) to buy a small amount of bitcoin. Later, I added some more.

So far, so good, the money arrived in my wallet, and I've been enjoying the recent surge.

However, I decided to use the blockchain explorer to have a look at what was actually happening during these transactions, and when I look at my wallet's address (the one I give to Bitonic), it's empty and there are are no transactions to it. Looking at the actual transactions that blockchain.info points to, there are outputs with the right amount, but they have different addresses.

I was expecting to find my wallet on the blockchain, with the current amount of BTC I own and two transactions going in.

What's happening here? Is Bitonic actually sending blockchain.info the coins off-chain? Bitonic only gets the wallet address, so they shouldn't be able to tell who manages the keypair for me. On the other hand, if bitonic sends it to the address I gave them, why does a different address show up on the transaction output? Is there some mapping between addresses going on inside the blockchain that I'm not aware of?


texts: Bitcoin Proof of work puzzle inconsistency

texts:
At this time, I am really confused about the Proof of work puzzle because as I have seen in some documents, there are 2 different ways to talk about them.

The first one I have seen is from some videos, and also the original of Bitcoin by Nakamoto: the answers to the puzzle will make the result of hashing the block header contains some number of zeros from the start consecutively.

Meanwhile, there are also some documents saying that the result of hashing the block header has to be below a difficulty.

So I wonder which one I can trust now. Could anybody tell me? Thanks in advance :-)


texts: How do I move my bitcoin from mycelium to another wallet?

texts:
I'd like to do this in a fee-less way.  This is the first step in claiming my BCH.  I've tried using this link

https://steemit.com/btc/@libert/step-by-step-guide-on-claiming-bitcoincash-from-mycellium-wallet-201783t112141477z

My bitcoins just never show up in the coinomi wallet.

I tried using this tutorial

How to sweep private extended key from mycellium into coinomi for bitcoin cash coins?

But the derived keys that are generated, and I've gone through at least 1000, are not for the "other addresses" that appear on my wallet.  The first in the list is my HD wallet but that has zero funds.  I have two "other addresses" with the BTC.  These don't appear. I only scanned the first 20 QR codes but searched 1000 for the prvt keys of the two addresses according to my backup.

Anyway I'll edit this if necessary I'm just trying to take this step by step.  Any help is greatly appreciated.


texts: How would tax and government revenue be enforced in a bitcoin run society?

texts: If we say, hypothetically, the future has a society that runs solely on Bitcoin as its currency. Because of its anonymity how would tax and government revenue be enforced in this society? At this point, naturally, Bitcoin will no longer be considered a commodity but rather a currency. I know that this may be speculative but it must be on a lot of minds with regard to the future of Bitcoin.


texts:
I recently made a post on stack, Calculate hash rate in IOS, in hopes of deciphering how the hash rate is calculated when benchmarking performance. The reason I wanted to do this is to compare against the results that are presented in Is it Possible to Mine Cryptocurrencies with an iPhone? After days of hunting around on the internet, I've come to a conclusion that calculating the hash rate is not as straight forward as it seems.
My Thoughts
I was under the impression, especially after reading How can I calculate how many hashes I generate per second?, Explaining Hash Rate Or Hash Power In Cryptocurrencies and How is hash rate of mining hardware calculated, that calculating the hash rate is done as follows:
Have collection of x number of messages (M) 80 bytes in size
Loop through records, and calculate the sha256(sha256(M))
Divide the number of computed hashes against elapsed time
    # the result is hash rate ( in seconds, given your elapsed time is in s )

After doing so, I see results up to 24000 hashes per second, or 24KH/s. Obviously, this is alarming, as the reference article I am attempting to compare to, has these results:

The iPhone 6 has 25/30 Hash Rate (H/s)
The iPhone 8 55 H/s
The iPhone X (iPhone 10) 65 hashes per second

I later continued my hunt, and stumbled upon this Stack post how to calculate hash rate of your rig?, and the accepted answer mentions that the hash rate is something that is defined empirically. While I do not doubt the author, I now find it difficult to determine what hash rate really is. ( Does the "nonce" have any impact on calculating the hash rate? i.e Is the standard hash rate determined by calculating the number of times my machine can ensure that the hashed result begins with 3 ( or 5, or 7 ) leading zeros in 1 second? )
TL;DR
I want to compute a hash rate for my IOS device. What algorithm and algebraic expression should I use to calculate the hash rate, to be able to compare my results against other devices, like laptops and graphics cards?


texts: What % of bitcoin transactions involve addresses of known charitable organizations

texts:
Blockchain analysis can come a lot way. Are we at the point where we can identify what percentage of transactions related to certain industries?

What percentage of transactions involve a receiving address than can be tied to a charitable organization with blockchain analysis?

If that question can be answered please also list any bitcoin transaction size data that is available.


texts: Can I recover funds where the wrong destination tag was used while transferring ripple to bittrex?

texts: Is a refund possible if i entered the wrong Destination tag and the right address while transferring XRP to my bittrex wallet.


texts: Multibit 0.5.1 wallet unconfirmed amounts no seed words

texts: please help. I am not technical and I gave bitcoin as a gift in 2017 in a Multibit wallet which is now defunct. I have opened the wallet but it says the amounts are unconfirmed. I have repaired the wallet twice. I don't have the seed words and don't know how to get them.