texts: Bitcoin.conf setting for CPFP - how can I enable longer 'chains' of unconfirmed transactions?

texts:
I often receive an -32700 'Insufficient Funds' error when attempting to create 'child pays for parent' (CPFP) transactions using unconfirmed change output. This can be problematic since it can prevent me from sending further transactions until the parent transaction is confirmed.
My question:
Is there a bitcoin.conf setting (or other workaround/solution) that would allow for the acceptable length of chains of CPFP transactions/unconfirmed change outputs to be increased, and thereby avoid being stuck, unable to broadcast further bitcoin transactions until parent txs are confirmed?
A related side question - I have not yet discovered the logic behind how bitcoin core decides to allow an additional CPFP transaction to be chained, and when it gives an 'Insufficient Funds' error. It seems to be anywhere between a chain of 1 to ~5 (i.e. sometimes I get 'Insufficient Funds' error when there is only a 'chain' of one tx, other times, up to around 5) and it is not clear to me how this is determined. What is the logic here?


texts: Does the block reward comes from a bitcoin treasury? If yes, then how is it issued?

texts:
The miner adds the relevant block reward to himself (i.e. 12.5 bitcoin as of now) in something called the coinbase transaction.

Where do these 12.5 bitcoins come from? Does it comes from bitcoin treasury? If yes, then how is it issued?

Could I get a less-technical and self explanatory answer please?

Note that my question is not sufficiently answered on Where does the money I get from mining bitcoin come from? which was suggested as a potential duplicate.


texts: Bcoin wallet always has unconfirmed balance

texts:
I have locally running bcoin node in testnet and acquired test bitcoins through faucet. Now, when calling balance check via bcoin cli wallet balance (when synchronization completed) I always receiving following result:

{
  "wid": 1,
  "id": "primary",
  "account": -1,
  "unconfirmed": 550722654,
  "confirmed": 550722654
}

I see that wallet contains amount but a bit confused that unconfirmed field contains the same value as confirmed one. Is it correct?


texts: Mathematical areas of research within the Bitcoin field?

texts:
I'm doing my IB math SL internal assessment on bitcoins. We have to incorporate a lot of math into a 6-12 page essay on our topic. What parts of Bitcoin involve or can be modeled by mathematics, such as calculus/probability/statistics?

I'm hoping to find at least a few equations I can discuss in my writings. I'm fairly good with math, but I'm not a complete expert, so if you would take that in to consideration with your answers that would be great! :) Thanks!


texts: scriptsig-not-pushonly (code 64) during send transaction in regtest

texts:
I create a transaction in regtest without send it, I have transaction data signed.
I modified a little bit the scriptSig in order to replicate transaction malleability, I add two operations (2 OP_DROP) and increase the scriptSig length from 6A to 6C.

this is my final result.

0200000001b6a6018077d7e817c13074f4127a641a3225b44e56318ef61d2b746b0271e308000000006c527547304402205fa24c98406b9f18732a586a2d5a5cf8ed5e033afca89dda772963f87bff457d022020c796be2fd4c6c47733214293263e244828211a51f044872090e610d5e1e8820121024f29076388ac6ed18b281a149e88043be7e78f72e138f3498853d8918f7f5448ffffffff01606b042a010000001976a914f1edb261a91e7cb03737708d718b2c47b7aa5c8e88ac00000000

When I try to send rawtransaction I receive this message:

error code: -26
error message:
scriptsig-not-pushonly (code 64).

I'm using bitcoin-core 0.19.0.1


texts: blockchain.com saying I do have enough funds

texts:
I have had 0.3097 of a BTC in a wallet for a couple of years. Needing to pay for something, I went into blockchain.com and entered the login link and password and the system showed me the balance which was correct. So far so good.

I then called up SEND and entered the balance (I want to send all the money in the wallet to a certain address). No matter what I enter in the amount box, red letters come up saying "insufficient funds".

What do I do ?


texts: How to connect bitcore library to my local bitcoin core

texts: I am running a full node bitcoin core on my server and just recently came to realisation that I need to work with some APIs and libraries to be able to build my application interacting with the bitcoin network. I found bitcore as a pretty smooth and functional set of libraries and APIs to be used. However, I wanna use my current local node and I don't want to connect to the nodes hosted by bitpay. So, how can I use my local node in correlation with bitcore libraries installed on my server?


texts: Why can't I create a fork of BTC that has no difficulty changes so I can premine the rest of the coins?

texts: I don't want to necessarily do this, but what prevents this scenario from being possible? [just timestamps and a difficulty modifier alone? - if that's the case then why can't I modify the client to be set at a much higher difficulty to mine stuff in anticipation of a harder target as opposed to simply using network difficulty?]:  How come I cannot make a modified version of Bitcoin QT and all historical transactional data re-utilized to mine all past stale blocks and simply premine all remaining bitcoin without difficulty?


texts: I would like to start accepting bitcoin donations on behalf of a set of charities that don't accept it.  I'm thinking this may be a stepping stone to get them to accept bitcoin directly because they will see money coming in.  I don't want to take any fee or commission... just convert into fiat and pass 100% to the charities.  Does anyone have experience doing this?  Do I need permission from the charities?


texts: Difference between crypto coin vs crypto block?

texts:
I have several doubts about cryptocurrency when I started(bitcoin) reading about it. I google it around and it only added to more confusion.

I am not able to understand the difference between a bitcoin transaction block and a bitcoin as a coin. Aren't bitcoin currency also a bitcoin transaction block in case of a newly minted bitcoin?

Bitcoins are mined after solving cryptographic puzzles, but in the initial days did the author(s) had to create lot of unnecessary transaction to solve the puzzles to create new coins until the general public picked it up? (Or how did they create currencies without any transactions in initial days)

I hope the questions are clear. Do let me know if it needs more editing/clarifications.


texts:
I am a PHP developer and want to learn about bitcoin development.

I've searched on Google many times, however I can't get any perfect links that explain what is the requirement to become a bitcoin developer.

I don't currently understand bitcoin terminology, so all the articles are above my comprehension level.

So my questions are:

To become a bitcoin developer, how much knowledge do I need to have and from where I can get?
I'm a PHP and JavaScript developer; what type of development on that I can try?
Where can I get knowledge about bitcoin, wallet and BlockChain terminology?
I've also checked bitcore, bitcoin, and bitcoincore websites, however there are no beginner type tutorials.

In short I'm a blank slate with regards to BitCoin and BlockChain technologies.  Can you provide any guidance to start in this new field?


texts: How and where to pay in bitcoins into online wallet if I have address and ID

texts:
I just found my "old" wallet.dat.
Is it possible to "send" it to an online-wallet in order to avoid downloading the whole blockchain again?
Or can I do it directly because I have the Address and ID of the coins?


texts: Are there time-series of Bitcoins in circulation?

texts:
For a study on Bitcoin, I would like to find (or construct) a timeseries of the total value of all Bitcoins in circulation (market capitalization). At least for the last two or so years. This could be quoted in e.g. US Dollar.

Is there such a time series? If not, is there a timeseries with the total amount of unlocked bitcoins, which could then be multiplied with an exchange rate?


texts: How to run a bitcoind on a hosting securely?

texts:
I'm developing a web site which should receive bitcoins and display the amount of received coins. As this is my first bitcoin experience I would like to know if the following scheme is secure enough:

I'm planning to run a web server and bitcoind with the encrypted wallet on a hosted server in a datacenter. No payments will be made through this bitcoind so the wallet will be locked all time and just will be used to monitor the transactions. The front end will communicate to bitcoind by JSON-RPC. There will be regular backups of the encrypted wallet file.

The payments will only be done from another machine which has a copy of the wallet and is secure (both physically and from IT side).

Will this work?


texts: is there any viable rust implementation of Bitcoin

texts:
Request :
I am wondering if any developer has already developed a Rust implementation of the Bitcoin protocol.

if there is any repos, post or any relevant document please share it with me.


texts: Have there been any examples of people manipulating transactions in a way that waiting for more than 1 confirmation would avoid?

texts:
A lot of bitcoin exchanges require some minimum amount of confirmations before they consider money deposited.

Is there any evidence that this actually does anything? Has someone ever before manipulated a transaction on the bitcoin ledger because the recipient didn't wait for 10+ confirmations before accepting that the bitcoin has been exchanged successfully.

Or is this just to stop a theoretical attack from happening?


texts: `walletcreatefundedpsbt` with unconfirmed inputs

texts:
I would like to create a psbt using walletcreatefundedpsbt spending unconfirmed ouptputs. Is this possible?

When I call that RPC command with 0 confirmed balance but with sufficient unconfirmed outputs, I get an Insufficient funds error.

Thanks in advance!


texts: Has PoS really been proven secure under comparable assumptions as Bitcoin?

texts:
I am just reading this paper which claims to be a formal proof that Cardano's latest Ouroboros PoS protocol ("Genesis") gives similar security guarantees than Bitcoin's PoW protocol. Unfortunately, it is 64 pages long and presupposes a lot of earlier work that I need to get comfortable with, as well, so even though I am relatively confident in my understanding of these things, a thorough evaluation will take me quite some time.

So I was wondering if anybody (say Andrew Poelstra, Pieter Wuille?) had already checked this out and could give their opinion. Because on one hand this is a very bold claim that would invalidate the folklore view on this topic (PoS has fundamental security issues that can't be overcome), and on the other hand the authors seem quite legit and serious in their approach.

I do realize that even if it were true, this doesn't mean that PoS is useful for bootstrapping a system like Cardano. But couldn't it be an alternative for Bitcoin, say, after another one or two halvings?


texts:
I'm doing some testing and often find myself needing to generate 6 blocks quickly to confirm some tx.  Each block takes a few minutes to generate on my macbook so this slows things down considerably.

Is there a way to adjust difficulty?  Note that this is not for testnet in general but for the private testnet in a box with just 2 nodes on my development machine.  Thanks!


texts: Proof of Elapsed Time Susceptible to Random number generator attack?

texts:
Since Proof of Elapsed Time (POET) uses a Random Wait time to elect a leader, would it be susceptible to Random number generator attack?

Nathan Aw


texts: unable to read macaroon path (check the network setting!): admin.macaroon: no such file or directory on lncli getinfo

texts:
Just started lnd for the first time connected to a bitcoind node. Do lncli getinfo and this is the error message. How can I get past this?

EDIT: Would like to add that I'm using lnd on testnet, however lncli is looking in the mainnet folder


texts: Is there any limitation on the monetary size of transactions to be paid through BitCoins? I conduct a consultancy business where payments from clients can vary between about $5 for White papers to $15,000 for a major consultancy assignment fee. I have not been able to find out this information from the website.


texts: How many shops accepted BTC? Is it somewhere roughly statistics data?

texts: I am writing bachelor thesis. I need to include a graph on "how many shops or companies accepted BTC". Do you know where I can find historic data or a graph for this?


texts: Is there a calculation for exchange rate stability?

texts:
Exchange rate stability can be used as an indicator to determine how consistently you will earn the same profit over a period of time when mining a cryptocurrency. My current thinking is that a chart of the daily average exchange rate values from the last 14 days can indicate the exchange rate stability of a coin based on exchange rate fluctuations in the last 14 days.

But I have no idea how to actually go about calculating a metric like this or what the units would be.


texts: What information will someone need to give me money?

texts:
I want to use BitCoin to earn money from someone else for working for them.
I want to give them as little information about me as possible

What will I HAVE to give them so I can accept money, what personal info will have to be given?


texts: How to create a Safe and secure Bitcoin Paper Wallet?

texts: I am looking to dump my bitcoins in safe place. So can anyone suggest me or tell me the method for creating a secure bitcoin paper wallet.


texts: How is someone not able to steal my bitcoin with Dumpprivkey command?

texts: In an online course the instructor told us that anyone can find the private key of a wallet by using dumpprivkey(address), address being the address that is created from the key (which is public in a transaction on the bitcoin chain).He said that this command returns a WIF object. I assume that is not true because then anyone would steal anyone's bitcoin by looking up the addresses in tx's on the cahin and running the command. Can someone enlighten me about this dumpprivkey command please ?


texts:
basically a newbie and received mining transactions from a pool in 2013/14. cannot remember which pool. recently pulled out wallet.dat and now have TXs which are not in the mempool with 0 confirmations.  when rebroadcasting says missing parents or missing inputs.  how can i find the parents or inputs.  help will receive btc as reward.

can anyone help please!


texts:
Is the number of independently owned and operated full Bitcoin nodes more important than the total number of full Bitcoin nodes with regards to Decentralization?

Assuming the answer to the above question is yes:

How can the number of independently owned and operated nodes be counted and verified?
Is there an answer to question 1 above that would not violate the privacy of the nodes owner/operator?


texts: Where is the spec of HashCash so that I can implement it in Java from scratch?

texts: I would like to implement HashCash in an efficient/fast/garbage-free way. Is there a spec to do so? How can someone go by implementing HashCash from scratch?


texts: Is there a way to run bitcoind without being a full node?

texts: I want to be able to run bitcoind on a VPS I rented, but I neither have good bandwidth nor RAM so I do not want to be a full node.  How would I go about configuring things so that I can run bitcoind without acting as a full node or relaying transactions?


texts: How Can I create a wallet on Electrum from address or QR code?

texts:
Suppose I signed up in a website which creates me a bitcoin wallet address for my account and provides me with this address (someting like 2RfG1Ph5KlojhnFi8Dg36lfeshnfDiL3Ji) and the QR code.

How can I create a wallet on Electrum from this info?
If so, will the balance be spendable?


texts: Is there any way to revoke or update private key?

texts:
Suppose my private key corresponding to an address is stolen.
Is there any way to revoke private key or update the private key?


texts: Bitcoin-qt, OS X Mountain Lion, blockchains, and bootstrap.dat

texts:
Edit:  Rewording this question to be more clear and concise.

Background Info:

Was running bitcoin-qt .0.8.1 on osx mountain lion.
experienced a kernel panic, likely from some conflict between mac ports and homebrew. Hardware was tested and does not seem to be the culprit.
upon next restart of bitcoin client I have a corrupted database and eventually the entire blockchain needs reloading.
only had a small amount of coins in wallet but was hoping to use them sooner than an entire blockchain download would take using the client (x days where x >= 2).

Things I tried

Restoring the relevant files in the data directory from the last
backup before the crash. Actually had one from that morning.  Did not
really work -- client would trying to verify the db and eventually
would crash.
Got the latest bootstrap.dat from torrent, and tried placing  in data
directory. This eventually sort-of worked after next two steps.
Eventually imported wallet.dat at blockchain.info as a stop-gap, but it turned up a few bitcents short. I think because I had sent something to a wallet address before this happened and it hadn't synced yet.  I'll figure that one out once I'm fully synced, and if I ended up losing $5-10 worth of btc into the ether somewhere, I'll get over it.
Fixed the probable cause of kernel panic and reinstalled/upgraded to
latest 0.8.3 client and retried the above steps.
Also had to pretty much nuke the data directory in order to get bootstrap working.  (renamed/moved actually just in case) Saved wallet.dat (encrypted) elsewhere.

At this point the bootstrap method seems to be working.  The client reports importing block from disk.  However, it soon becomes apparent that this method does not really make things any faster.  It seems to load the blockchain from my HDD at about the same rate it downloads from the network.  Also, latest update was apparently 13 weeks old, and those last 13 weeks make-up most of the payload...

So for now I've got my old wallet imported onto electrum, and bitcoin-qt is back home chugging away finishing the download so hopefully I can find that change when it's done and be done with it.

OK, so what are my question(s)?

Wy does it seem to take just as long for the client to import from the local HDD as it does from the p2p network?  If I were smart I would have put the bootstrap file on my SDD, but it appears that's not the case. But still, I'd assume it would be faster than from the cloud.  Any ideas? I don't remember if I have the 5200 or 7200RPM hdd; I probably just got a 52 since I was buying an SDD along with it.
Any blockchain-scalability plans in order for future releases of bitcoin-qt?  Evidently this is growing faster than they expected.
Anybody have a full working procedure for restoring data directory files when you have backups available?  Found a few ideas elsewhere on the net but nothing that worked.  My backup software keeps old versions of files so it's not too difficult to assemble a snapshot with the /chainstate and /block directory contents from some specific date.  But the client was barfing on this method.

Thanks, hope that is somewhat improved.


texts: How can Forks and Orphan Blocks be used to attack a Blockchain?

texts:
So I'm trying to learn about the security aspects of Blockchains and one of the papers I'm reading (https://arxiv.org/pdf/1904.03487.pdf) states that Forks and Orphaned Blocks can be used to attack a Blockchain. Now, I've read up on what Forks and Orphaned Blocks are, but I'm still not certain about how they can be used in order to attack a Blockchain. Can anyone help clear this up for me?
Thanks.


texts: May it be a risk to use the origin as the change address?

texts:
Follow scenario: The balance of my origin address is 1 BTC. I'm transfering 0.1 BTC to a shop where I'm buying some goods, my wallet returns the change to my origin address. Now my origin address has a balance of 0.9 BTC. I buy another 0.1 BTC on an exchange and transfer it to my origin address, which now has again a balance of 1 BTC (as much as it had at the beginning).

As far as I understood a transaction is a block of data containing the transaction's details and a signature generated with my private key. If I redo the first transaction to the shop the data block created will look binary identical (same amount, same origin, same receivers), and also the balance of the origin is high enough.

What hinders someone else to resend my transaction in the blockchain network, or a miner to duplicate my transaction, as soon as the balance has refreshed to a value high enough to fulfill the transaction. I'm still missing a hint what invalidates a transaction after it was confirmed.

If I never use a bitcoin address twice, I would be safe.

I am very grateful for any tip what I might have overlooked!


texts: I can't find my bitcoin address and my bitcoin core is out of sync by 3 years

texts:
Hey guys I am a newbie at Bitcoin just recently found out about it.

I downloaded Bitcoin core; I encrypted the wallet; I created a backup folder, but it is out of sync by 3 years 4 weeks and i can't seem to find my Bitcoin address due to it. How do I find my Bitcoin address if it is out sync?


texts: Is it possible to combine two separate transactions into one transaction by only using their signatures?

texts:
I have two valid txs and two valid signatures for those txs.

Right now they look like:

1) A -> B
2) C -> D

A and C are inputs & B and D are outputs.

I want to be able to combine them into:

1) A, C -> B, D

Is there a way that I can combine these two tx's and their corresponding signatures into one valid tx without having access to the keys?


texts:
A Belgian website says the price of electricity in Belgium is between 0.22 and 0.44 Euros/kWh.

For electricity [...]

low consumption (orange curve: Da - 600 kWh single consumption on an annual basis, 1 person),
average consumption (blue curve: Dc - 1,600 kWh daily consumption and 1,900 kWh night consumption on an annual basis, 3 people),
high consumption (green curve: De - 3,600 kWh daily consumption, 3,900 kWh night consumption and 12,500 kWh annual nightly consumption only, 4 people).

I have an Antminer S9 which uses 1600W.
I have a CPU/11 GPU rig which uses 1200W.
Is it uneconomic to do mining in Belgium? (As in that there won't be any profit because all mining gains will be taken away by electricity costs?)
How to fix it, so that I have at least some profit?


texts: Can the Bitcoin protocol be configured to *never* rollback after a certain block?

texts:
Is it possible to hard code a block and its block hash into the client so that the block chain will never diverge from the main chain past that block?

My thought is that this will improve confidence for long term investors that their transactions are "safe" and can't be rolled back without consensus of the network (a.k.a 51% of the clients have that block as hard coded and can't be rolled back)

Is this a reasonable idea?
Has it been discussed before?
Is it already implemented in some form?


texts: Why some transactions disappear from the mempool?

texts:
Just before block 537562, I had the following transactions in my mempool:

 'a4ca904361952c8a27bcf1fd36e5bc8ccdc5d42ceb72cfba60c017fb9cbbb0e5'
 '69718e60b6e7d20d5e56e097b2de9789007fb230d0205a90a1411ef8086672a0'
 '346b93674d91bfc5b5568f7e77dc969b5c87351135a1c75d551c1418533164f2'
 'e8fddfc634f2e3d535ad81d7dce314e543047bc0281854d9eded4d107fa4f525'
 'da2fd9ed1a8ba7612b885377dc7018d8d0c35ad4cdd03a24829b9a0b8edbf123'
 '3318d59ac00f5dbdd223fcf9ab953e0eee2765b4d1d72285c33c75121e888eee'
 'fc4aea4f7f3ae94bf65c6cc23b73e594f7c849ab5f1362ac78d157cf4af8bc8a'
 '1e7b6ebefd9cd4983f598831ed8082bcdab6b7857f2d302e7d4952e4f145f8e7'
 'f0f20dcf5142895d19140b60830bd9f15b664294d8535c3dcc09ebe3398a2fa3'

These transactions simply disappeared from the mempool later without ever being mined. Why did this happen? At a time when fees are so low, I doubt they were the target of a replace-by-fee. What are the possible reasons for a mempool transaction to disappear? and is there a way to investigate what happened to these specific ones?

EDIT: these transactions had a feerate above the default minrelayfee of 1 satoshi/Byte

EDIT2: I admit that I was not aware of question How do transactions leave the memory pool? , but my question is still different. I am interested in finding out why a specific transaction has disappeared from the mempool without ever being mined. Now it's a bit late to see if the transactions that I gathered were replaceable or not (nLocktime equal to 4294967294 - 0xffffff-1 - if I am not mistaken), but I will repeat my analysis taking this into account in the future.


texts:
Theoretically speaking:
I take a random hash as a previous hash and compute whole block of hashes.
I'll wait for work on some mining pool until by some miracle this hash will be generated.
Would I get whole bounty if I upload this block straightaway?


texts:
Long story short. Can't see transactions from blockchain.info as blockchain.com is now the website.
Long story:
Created a miner in 2013. Mined it from BTC Gui... and had it sent to BLO.....IN.INFO was able to check my account via bloc...in.info .
One day, it went to zero.
I didn't know what to do. So I just assumed I lost it all.
Well. I logged on to the now BLO...IN.COM..... and it shows a zero balance. BUT WITH NO TRANSACTIONS.
I put in the mnemonic that I wrote down in 2013 to recover the wallet.... all it gives me is the PASSWORD... not the wallet ID. This is obviously a legacy wallet.
How do I recover this old account to see transactions from 2013?
Note:
I do not have wallet addresses from the miner to blo...ain.info
I do not have access to the miner
I want to see the transactions from 2013 and I want to try to see where this coin went just for peace of mind that I know it didn't just go to zero.
Thanks for any help.


texts:
I have an Electrum bitcoin wallet on my PC. If my house burns and my PC is destroyed and the seed (written on paper) is destroyed, my bitcoins are lost. I want to prevent this situation.
What is the best I can do?

Storing the wallet file on another server (not possible with Electrum)
Export the private keys - address combinations and storing them AES256-encrypted on another server.
Storing the seed AES256-encrypted on another server.
something else?


texts: what is the primary factor responsible for the increase of block size?

texts:
Blocks are made up mostly of transactions.

I understand that the larger the transaction output is in coins, the greater the transaction size must be because it must list all previous transaction inputs that lead up to this transaction and add up to the net output of this specific transaction.

Is there any other factor I might not have accounted for that increases transaction size or block size?


texts: With the current hashrate, how does it still take 10min to solve a bitcoin block?

texts:
No matter how high the difficuly is (or how low the target is), I don't understand how the Bitcoin network takes an average of 10 minutes to solve each block.

For any given block header, there are only 2^32 possible values for the nonce. Even if we take into account that the timestamp can be changed by up to 1 hour (for example), that's 3600 x 2^32 possible combinations, which is approximately 1.5e13

On blockchain.info it says the current hash rate of the network is 7,991,378,504 GH/s, which means that, every second, there are multiple orders of magnitude more hashes being calculated than the number of possible hashes that can result from the current block header.

So howcome blocks aren't solved in only a few seconds, and take about 10 minutes instead?

I understand that miners want to include as many transactions as they can in a block to collect the fees, so one could argue it's best to wait until there are many transaction in a block before solving it. But even that doesn't make sense, because there's absolutely nothing to lose in solving each block as fast as possible anyway.


texts: How to update my RaspNode? no GUI only CLI

texts:
I would like to know the best way to update my RaspNode (rPi 2 B+) to the 0.12.1 bitcoind version.

I did

  sudo apt-get install bitcoind

I also did this:

Erased /bin/bitcoin folder

then into /bin/

git clone https://github.com/bitcoin/bitcoin.git
./autogen.sh
./configure --enable-upnp-default --disable-wallet
make -j2

but it's still the same version 0.11.2


texts: Is it sometime advantageous to split a transaction into multiple smaller ones?

texts:
When I updated Bitcoin Wallet on my Android device, it automatically created a new address and transfered all my funds from my old address to it due to the recently found security issue in Android's random number generator.

However, it didn't do it with a single transaction. Instead it did two transactions, so I had to pay the transaction fee (0.0001) two times.

Did it perhaps split it into two smaller transactions to keep the size down (only a guess) for the sake of the network? Or is a smaller transaction processed faster? Or was this necessary for completely emptying the old address? Or was my old address fragmented after multiple transactions to and from it in its history (if that is even a thing/possible)?

My questions above are only speculation. And my real question is: is it sometime advantageous to do two (or more transactions) to the same destination instead of a single, big one?


texts: Ripple's validation of transactions / Ripple white paper?

texts:
Is there a ripple white paper or some safe source to understand how the transactions are validated and made in the ripple network?
VS Bitcoin, XRP is not mined, so how is the agreement reached? (I understand that there is some kind of prioritisation of transactions and the first one agreed gets validated to avoid double-spending, but how does that work if it is not via mining?)
Is there some complete explanation to how Ripple works? Not the oversimplified stuff, but something that actually explains the whole process?

Thank you!


texts: Why do some pools require a worker name with an underscore and others require a period?

texts:
The majority of pools I see that they use a period such that:

username.workername

others use:

username_workename

I see that it definitely is not interchangeable.  How come some pools use underscore (such as bitminter and btcguild)  and others use a period (like gigahash.io)?


texts: Explorer showing different balance then my Blockchain wallet

texts:
My Blockchain wallet address on the explorer, shows a low balance (under .001) but when I log into the wallet I can see what should be there about .25 BTC. My Electrum wallet is also doing the same. When I look at the explorer I see "unspent" transactions together with actual transactions.

It seems there are what seems like sub-addresses or something that are holding the rest of the coins. At first I thought coins were missing but I did a transfer to another account and it went through fine even though it was for more btc than what the exporer showed I had.... Confused to say the least,.. Thanks in advance for any insight.


texts: How chaining the blocks protect against altering data?

texts:
I am confused with the block chaining, as i know a block header contains a reference to the previous block header hash with the merkle root and other fields. This header hash is related (computed) to the header and not including the block of transactions, so if the header is tampered the chain will fail. I understood that, but if the transactions in the block are edited, it will not change the header hash only if the merkle root is re-calculated.

My question is when a node receive a block, how it verifies it (just rehashing the header, or recalculating merkle root first then rehashing the header)?


texts: Bitcoinjs-lib how to add multiple utxos in addInput

texts:
Hi i want to make transactions of bitcoin bech32 addresses using bitcoinjs-lib , here is my code below, it works fine when my address has only one utxos but when it increases to two or more as its array which doesn't pass into addInput method, so it fails. Please help me out to loop through it or what is the solution to handle multiple utxo as input.
Thanks

    // THIS THING I WANT BUT CANT DO IT BECAUSE LITECORE-LIB DOESNOT SUPPORT BECH32.
//---------------------------------------------------------------------------------------
const litecore = require('litecore-lib');

let utxo = [{
        txId: 'a3f2565ab944629bc0ca46990593c8ec49c50b5eaee0789d58b1b4bc97a76eb9',
        outputIndex: 1,
        address: 'ltc1q9umns6nuxv3xrhzdwlmhkzujewu6hulyuwgx30',
        script: '00142f37386a7c332261dc4d77f77b0b92cbb9abf3e4',
        satoshis: 3000000
    },
    {
        txId: '9d1517a2499ce5496ba3c826785b25982c63dc5b59b0c256303bf19128e44747',
        outputIndex: 0,
        address: 'ltc1q9umns6nuxv3xrhzdwlmhkzujewu6hulyuwgx30',
        script: '00142f37386a7c332261dc4d77f77b0b92cbb9abf3e4',
        satoshis: 2000000
    }
]

let to = 'ltc1q9umns6nuxv3xrhzdwlmhkzujewu6hulyuwgx30'
let from = 'ltc1q9umns6nuxv3xrhzdwlmhkzujewu6hulyuwgx30'
let privateKey = ''
let value = 1000

// // 4. Create transaction
var transaction = new litecore.Transaction()
    .from(utxo)
    .to(to, value)
    .fee(1000)
    .change(from)
    .sign(privateKey);

console.log(transaction)

//----------------------------------------------------------------------------------------

// NOW I WANT TO USE THIS LIBRARY AS ABOVE.
const bitcoin = require("bitcoinjs-lib");

let utxo = [{
        txId: 'a3f2565ab944629bc0ca46990593c8ec49c50b5eaee0789d58b1b4bc97a76eb9',
        outputIndex: 1,
        address: 'ltc1q9umns6nuxv3xrhzdwlmhkzujewu6hulyuwgx30',
        script: '00142f37386a7c332261dc4d77f77b0b92cbb9abf3e4',
        satoshis: 20000
    },
    {
        txId: '9d1517a2499ce5496ba3c826785b25982c63dc5b59b0c256303bf19128e44747',
        outputIndex: 0,
        address: 'ltc1q9umns6nuxv3xrhzdwlmhkzujewu6hulyuwgx30',
        script: '00142f37386a7c332261dc4d77f77b0b92cbb9abf3e4',
        satoshis: 30000
    }
]

let NETWORK = bitcoin.networks.litecoin;
let txb = new bitcoin.TransactionBuilder(NETWORK);

//get unspent output details
let txid = "9d1517a2499ce5496ba3c826785b25982c63dc5b59b0c256303bf19128e44747"; //transaction id of the output you want to spend
let outn = 0; // n out

//need scriptPubKey for adding input
let WIF = ""; //private key of bech32 output
let keypair = bitcoin.ECPair.fromWIF(WIF, NETWORK);
let scriptPubkey = bitcoin.script.witnessPubKeyHash.output.encode(
    bitcoin.crypto.hash160(
        keypair.getPublicKeyBuffer()
    )
);

//add input
utxo.map(item => {
    txb.addInput(item.txId, item.outputIndex, null, scriptPubkey);
})

//add output - Total UTXO SATOSHIS are: 20000 + 30000 = 50000/ So sending 10000 rest should be in the same address
txb.addOutput("ltc1q9umns6nuxv3xrhzdwlmhkzujewu6hulyuwgx30", 10000);

//signing
utxo.map(item => {
    txb.sign(item.outputIndex, keypair, null, null, item.satoshis);
})
let tx = txb.build();
let txhex = tx.toHex();

console.log(txhex);


texts: Is it really safe to use vanitygen to generate your unique bitcoin address?

texts: I've been wondering if using vanitygen to create your own bitcoin address with a unique prefix, is safe from being compromise by others? I'm currently using a shared wallet address from a trusted website and I'm targeting now to create my own bitcoin address using vanitygen. Can someone enlighten me? Thank you!


texts: Difficulty adjusts by very granular percentages to target for 10 minutes blocks. But adding another zero at the end of the chain of zeroes from the header hash requirement for a valid block would increase the difficulty exponential. So how does the Alogrithm target so precisely the right difficuly only through the use of "zeroes"?


texts: What function does Mt. Gox's "Open Transaction" withdrawal option perform?

texts:
When withdrawing bitcoins from Mt. Gox, there is an option with a checkbox next to it titled "Open Transaction (6 confirmations)".

What does this do to my withdrawal?

I'm thinking this is probably a mislabeling for an option that ensures that even if the receiving address is for another customer account at Mt. Gox that the transaction will be sent through the blockchain.  Otherwise, if those transactions are handled internally without appearing on the blockchain then it is difficult to prove that a bitcoin payment was sent.


texts: Why did Bitfinex choose to have access to all of its customers' private keys?

texts:
These wallets were “multi-signature,” which meant they came with more than one private key to access them. Bitfinex held two keys, while the multi-sig security provider, a company called BitGo, held a third. It was more secure, in theory, because both parties had to approve a transaction before it could go through. However, I would assume it is poor practice for an exchanger to have a customer's private key. Please correct me if I am wrong.

I think that Bitfinex may have used its own customers' funds to give bitcoins to other customers. Perhaps this is why?


texts: Given that the Bitcoin node software not centrally controlled (auto updated) and many different versions and implementations exist around the world, how would a core change be possible if it is not forced to all nodes? Example one would want to make the block size larger or change the hashing algorithm to be resistant to newer technologies like quantum computing attacks, not everything can be made backward compatible. How can one ensure that the newer improved core makes it to the many nodes that exist.


texts: Transaction fees with Dogecoin or Ripple for small amounts

texts:
We are a company which sells low priced items online ($0.05 - $0.50). Due to the crypto currency hype, we also would like to accept payments through at least one crypto currency.

I have analyzed a couple of crypto currencies by their average transaction fees, market cap, avg. transaction confirmation, etc.

I found out that Dogecoin and Ripple have currently cheap fees, less than $0.01 cents average.

Question: Can we hire the company that integrates this in our E-Commerce backend or is there anything else important to know beside the exchange fees? Are our transactions too small?

So far I have taken following into account

Transaction fees are not fixed, but as of writing this question the fees are acceptable for my case
Exchange fees (mostly a bit higher since traded through BTC from USD/EUR)
Average fees are less than $0.01, but theoretically they can be higher (if not average)

For most transactions I would assume the fees are <= $0.02. This would be okay for us, but which crypto currency should we choose?


texts: Non-profit balking at linking bank account to BitPay

texts:
I volunteer as the webmaster for a non-profit and convinced them to allow bitcoin donations.  I integrated their website with BitPay and everything is working fine.  We got one large donation and a few small ones so far, despite very little publicity.

Recently I asked the treasurer for the banking info so I could link the bank account to BitPay and he balked!  We have gone back and forth on emails and the only explanation I can get is "I'm not comfortable with that".  I should mention that we have had PayPal integration for years and regularly send PayPal funds to the bank account.

So now we are accepting bitcoin with no way of getting it to the non-profit.  I don't think the organization has any expenses that can be bought with bitcoin. I would have thought if there were any objections it would have been to accepting bitcoin altogether, not at the point of linking the bank account!

I pasted the Wikipedia article on BitPay in an email to stress that it's an established company, but it had no effect.

Any advice on how to proceed?


texts: How can I tell if my Bitcoin-Qt wallet is protected with encryption?

texts:
I am a new adopter of Bitcoins, forgive the ignorance. (note these are test transactions)

I am using the Bitcoin qt client and I am very confused and think I have done something wrong.

I have two computers A and B both with Bitcoin qt client on. I have made wallets on both computers.
After launching Bitcoin qt client for the first time on computer A I created two addresses using the 'new address' button. I then clicked 'Encrypt Wallet' and entered a passcode. Note I only did this process once, even though I created two addresses.
I then transfered two test transactions to the wallet on computer A from Bitstamp. These came through as:

http://i.stack.imgur.com/2ziI6.jpg

(don't know if anything looks wrong in that picture?)

I then tried my first ever test transaction and sent it to the address I created on computer B (I have never encrypted this wallet).
To my surprise this sent, even though I didn't have to enter any kind of passcode on computer A? Plus my address on computer B isn't even encrypted?
Does that mean anyone can use the funds I have in my wallet on computer A, without my passcode?
The status of the transaction on computer B is also,  8 confirmations? Is this a sign of a mistake. Also the 'from' is marked as unknown - is this important?
There is also no lock icon on my QT client, which I have been told there should be if the wallet has been encrypted?

I'm confused, please advise. Sorry for my ignorance, I am not a technically minded person but trying to adopt bit coins.


texts:
what do these values in chainparams.cpp do?

consensus.nMajorityEnforceBlockUpgrade = 2;
consensus.nMajorityRejectBlockOutdated = 3;
consensus.nMajorityWindow = 3;

and how do I find them in the existing blockchain when upgrading end for new?

first time I think it's when start diff grow up, but now think it's wrong.


texts: How does one work out hashrate based on number of submitted shares

texts: We are running a pool and are trying to get a total hashrate estimate.  How can we figure out how many hashes are being submitted to the pool based on the shares submitted?


texts: Is it possible for a country to control Bitcoin usage?

texts:
Imagine that I run a country named "MyAwesomeCountry". I accept Bitcoin as a currency that can be legally used to buy things and also pay taxes.

Then I say that there are some bad guys (let's name them "errorists") and say that if that known that some address is used by an errorist is will be blacklisted, so will be any future recipient from that address.

Then I build an information system to track and blacklist any addresses that received bitcoins from already blacklisted addresses. All that information is open and anyone can check any address to make sure if it's not blacklisted.

If someone is caught buying something using bitcoins from a blacklisted address s(he) will be put in jail.

So, none of the money that I don't accept can be used in MyAwesomeCountry. Then I can extend prohibitions not only to errorists but on other people (e.g. prohibit bitcoins of some organizations that I don't like). Then after some time, I can prohibit any bitcoin addresses that are not registered in my governmental databases.

So from now, I control bitcoins in my country like any other money.

Is it possible for a country to enforce blacklists/whitelists as described?
Can that be a problem for the citizens of MyAwesomeCountry?
If yes, what can people do to prevent such things from happening?


texts:
I am trying to call JSON RPS API Using C#. I have added my own IP address with its credentials.

Before writing API in C#, I have installed Bitcoin on my server. Now, using the server details, i would like to test the API whether it is working or not.

Here is the program.cs file.

public static void Main(string[] args)
    {
        var data = RequestServer("getaccount", new List<string>() { "value"});
        Console.WriteLine(data);
        Console.ReadKey();
    }

    public static async Task<string> RequestServer(string methodName, List<string> parameters)
    {

        string ServerIp = "http://***.***.**.***:8333";
        string UserName = "root";
        string Password = "********";
        HttpWebRequest webRequest = HttpWebRequest.CreateHttp(ServerIp);
        webRequest.Credentials = new NetworkCredential(UserName, Password);

        webRequest.ContentType = "application/json-rpc";
        webRequest.Method = "POST";

        HttpClient cli = new HttpClient();
        cli.DefaultRequestHeaders.ExpectContinue = false;

        string respVal = string.Empty;

        JObject joe = new JObject();
        joe.Add(new JProperty("jsonrpc", "1.0"));
        joe.Add(new JProperty("id", "1"));
        joe.Add(new JProperty("method", methodName));

        JArray props = new JArray();
        foreach (var parameter in parameters)
        {
            props.Add(parameter);
        }

        joe.Add(new JProperty("params", props));

        // serialize json for the request
        string s = JsonConvert.SerializeObject(joe);
        byte[] byteArray = Encoding.UTF8.GetBytes(s);
        Stream dataStream =await webRequest.GetRequestStreamAsync();
        dataStream.Write(byteArray, 0, byteArray.Length);
        dataStream.Dispose();

        StreamReader streamReader = null;
        try
        {
            HttpWebResponse webResponse = await webRequest.GetResponseAsync() as HttpWebResponse;

            streamReader = new StreamReader(webResponse.GetResponseStream(), true);

            respVal = streamReader.ReadToEnd();
            var data = JsonConvert.DeserializeObject(respVal).ToString();
            return data;
        }
        catch (Exception exp)
        {
            Console.WriteLine(exp.InnerException.Message);
        }
        finally
        {
            if (streamReader != null)
            {
                streamReader.Dispose();
            }

        }
        return string.Empty;
    }
}

Can any one help me to test the api using my server details please?


texts:
I want to develop an explorer for coins(BTC,LTC,BCH,...), like blockchair, or blockchain. I've searched a lot and I have found different answers. Finally, here is my solution. First, I use RPC to retrieve all blockchain data and insert them in a Mongo database. After retrieving all blocks data, I use the ZMQ feature of the core, to retrieve realtime blocks and transactions. Transactions will be saved in a separate (in memory) table which is the mempool table. Whenever a new block is found, I delete the mempool transactions which exists in the new block. I have some problems. The first problem is in finding UTXOs of addresses. The utxo query is complicated and takes a long time to respond(I've indexed the fields that uses in utxo query). My solution for this problem is preprocessing data before inserting them in DB and mark the spent outputs. There are other solutions too. One of them is parsing chinstate/levelDB files and extracting utxos. Should I change the schema of the DB for performance? I am confused. The second problem is mempool transactions. They will be lost when I reset the core(for mainteneance). So I lose the unconfirmed transactions. How should I handle them? I don't know whether my solutions are optimal or not? Any suggestions for solving the mentioned problem?
My MongoDB has two collections: blocks and transactions.


texts: Recover keys from legacy blockchain wallet's mnemonic?

texts:
I have an old blockchain wallet that is worth trying to salvage

It seems the old password that the 18 word mnemonic originally had isn't working and another password I had listed also doesn't work.

I used their tool and it shows the original password.
I also have the wallet backup json file.
I have the email address for this account (I see all the notifications)

Can I derive the keys from either the mnemonic or json with the original password or perhaps with no password?

And has anyone be able to get blockchain to 'backup restore from an earlier date' like it says they can on their legacy mnemonic page?


texts: Redeeming OP_SHA256 hash OP_EQUAL (Testnet) Tx


texts: I posted a question on here about my bitcoins being stuck, they are no longer stuck but someone has taken all of my bitcoins from that wallet and I don't know how


texts: How to BIP38 existing private keys offline

texts:
How do I go about encrypting some existing private keys using BIP38 in an offline manner?  I have looked at bitaddress.org and that site only lets you BIP38 keys which the bitaddress.org site itself created.

I basically want to generate my own bitcoin private keys using bitcoin-core, and then BIP38 encrypt them in an offline manner so I can have a copy of my private keys in paper form just as an extra backup to my existing digital encrypted backups.


texts: Who would accept confirmations of invalid transactions in a 51% attack?

texts:
My understanding is that honest nodes work on the longest valid block chain.

Suppose a dishonest node confirms an invalid transaction.  If that node manages to continue producing confirmations at a rate slightly higher than the rest of the network, as in a 51% attack, they may succeed in maintaining the longest block chain.  However, as that block chain is invalid, why does this matter?

That is, if all honest miners are only accepting only valid confirmations, how it is bothersome if a rouge miner is industriously hashing away at an invalid chain?


texts:
Hi I am looking into a secure donations wallet for the RCK - Refugee Community Kitchen. http://refugeecommunitykitchen.com/
 Theyre doing great work to provide a humanitarian response to the humanitarian crisis in Northern france. The founders are happy for me to work on setting up a secure wallet for donations which will open them up to support from the cryptocommunity. I just want to make sure its as easy to manage as possible as although I am totally confident that donors will know exactly what to do, the donations link will be added to their main webpage and ideally needs to be as maintenance free as possible.
I've been over on the SAFEnet forum and been given alot of good advice and pointed in the direction of Copay.
I understand from help on the forum that because its open source and multi sig Copay is a great option.
What I cannot seem to grasp is if a Copay wallet is suitable for donations of other cryptocurrencies as well as Bitcoin? I know my questions are very basic - so is my understanding so I really appreciate your expert opinion.
I looked at Coinomi as this seemed to readily support donations for lots of different coins. Am I missing something basic here? Can a Copay Wallet readily accept multiple types of cryptocurrency?
Thank you very much for your help with this!


texts:
I'm reading through bitcoin manuals and I got this question, please help me to correct my understanding.

I'm aware that changing the transaction output amount value can make the transaction unusable. What happens if the mining nodes lowers the output value to get more transaction fee, in such scenarios how the bitcoin protocol counterfeit that?

Thank You.


texts: How can i trace a transaction where my bitcoin has been withdrawn from my paper wallet?

texts: My bitcoin has been stolen from my paper wallet, can I track where its gone and is it possible to do so with my paper wallet?


texts:
Can anyone explain me any clearly answer or code in python with examples how we can calculate Z value from r and s and inputs outputs order ?? I search in google and youtube and i not saw any correctly answer i just see scam posts or video in youtube.
I tried different methods in python and i can’t get right results. 2coin.org is closed and I want to know how to calculate manually.

thank you in advance


texts: What happens if a mimblewimble transaction gets combined into two different transactions before being posted?

texts: Let's say a couple people create Transaction A and instead of dandelioning it to just one person, they dandelioned it to 2. Let's say further than transaction A then gets combined with transaction B (creating transaction AB) AND gets combined with transaction C (creating transaction AC). If a miner receives both transaction AB and transaction AC, can they be safely combined into the blockchain, or can only one be chosen?


texts: Which iPhone bitcoin wallets let you scan a watch only address and sweep addresses?

texts: Currently Mycelium on Android lets you create watch only addresses by scanning the public key QR code and import paper wallet private keys. But the iPhone  iOS version doesn't. What apps are there for iOS that lets you do watch only and import from a paper wallet?


texts: Can anyone explain this simply? I am not finding enough explanation exactly on this type of attack. If possible, add some additional reading to your answer so that I can understand more.


texts: How to monitor Bitcoin address for new transactions?

texts:
I have some generated Bitcoin addresses which I want to monitor for newly received transactions, I have a full node but I don't want to import those addresses to the node's wallet. I don't want to use any external service API like block.io or blockchain.com, I am working on my own code.

I want to keep this list of addresses in an external DB (MySql or Mongo) and I want to keep track of them until they receive let's say n confirmations.

I know I can user -blocknotify to receive information of newly mined blocks and with this new block I can scrape the transactions and look for the addresses I monitor. But how can I guarantee I will have all the UTXOs?

If the address is newly generated with the last block I can create my local DB with addresses information. But what should I do if I import (on my database, not Bitcoin Core wallet) an old address which had already been used, how can I check for UTXOs?

Also, how can I check if any of these monitored addresses have unconfirmed transactions?


texts: Anyone able to run Bitcoin-Qt 0.8.6 on Mac OSX 10.9.2?

texts:
I ran the Mavericks update today, putting me at 10.9.2 and now my Bitcoin-Qt stops responding after it notifies me that it is "verifying blocks". I am using it for ongoing research and am in a bad spot now. I realize I should have thought about the possible ramifications of running the update.

At any rate, is anyone able to get it to run? I've tried running it from the .dmg via the gui and via command line. I get the same results in both cases. As soon as it goes to verify blocks, it stops responding.


texts: zk-SNARKs vs. Zk-STARKs vs. BulletProofs? (Updated)

texts:
zk-SNARKs, Zk-STARKs and BulletProofs are three major zero knowledge proofs to provide privacy for the blockchain technology.
If we can compare them,

(1)  Bulletproofs and Zk-STARKs require no trusted setup.

Unlike zk-SNARKs that requires a trusted setup that creates an uncomfortable situation for it.

(2) Zcash using zk-SNARKs can hide amount address along with sender and recipient.

It is not yet clear to me if it is possible to hide sender and recipient by Bulletproofs and Zk-STARKs.

(3) Apparently, Zk-STARKs is faster than zk-SNARKs is
faster than Bulletproofs.
(4) Bulletproofs is shorter than zk-SNARKs and
Zk-STARKs.

In general, what are the main differences (advantages and disadvantages) between these 3 main zero knowledge proofs techniques ?
Note: The references are used for the above comparisons:
https://crypto.stanford.edu/bulletproofs/
https://blockonomi.com/bullet-proofs/
https://nulltx.com/mit-review-acclaims-zk-snarks-but-zk-starks-may-steal-the-show/
Note 1: The following article compares SNARKs with STARKs:
https://medium.com/coinmonks/zk-starks-create-verifiable-trust-even-against-quantum-computers-dd9c6a2bb13d
Note 2: I compared zk-SNARKs vs. Zk-STARKs vs. BulletProofs in following figure. Any comment on this comparison is appreciated:


texts: getrawtransaction asm returns with [ALL], should it be?


texts: Connecting to Bitcoin wallet outside of LAN to 'Solo' Mine

texts:
For educational purposes only...

Scenario:
My friend and I want to solo mine on 1 wallet. But, his computers are not on\in my LAN network.

The wallet has been set to server mode:
-server

bitcoin.conf
rpcuser=user
rpcpassword=pass
server=1

cgminer settings:
-o localhost:port -u user -p name

This works fine for solo mining on just my computer. But how can I change it so that he can connect to my Bitcoin wallet from another state which is obviously outside my LAN?


texts: If I sell something for bitcoin can I then use the bitcoin I receive to buy something else?

texts: I hear a lot about double spending of bitcoin. Can a single bitcoin be spend twice, as a dollar can. For example, I give dollars to 7 eleven for gas, they then use that money to pay their suppliers. Can bitcoin be used in the same way?


texts:
When trying to implement OP_CHECKSIG, I am unable to figure out how to do the actual signature verification in python (python3)

I obtained the signature, public key, and hashed message digest of a transaction, and now I want to verify the signature.

message = '692678553d1b85ccf87d4d4443095f276cdf600f2bb7dd44f6effbd7458fd4c2'
pubkey = '042e930f39ba62c6534ee98ed20ca98959d34aa9e057cda01cfd422c6bab3667b76426529382c23f42b9b08d7832d4fee1d6b437a8526e59667ce9c4e9dcebcabb'
signature = '30450221009908144ca6539e09512b9295c8a27050d478fbb96f8addbc3d075544dc41328702201aa528be2b907d316d2da068dd9eb1e23243d97e444d59290d2fddf25269ee0e'

Since python-ecdsa requires 64 byte input for creating the verifying key, I removed the first byte myself.

pubkey = pubkey[2:]

I also extracted r and s from the DER encoded signature, and concatenated these to create a 64 byte signature as python-ecdsa requires.

r = '9908144ca6539e09512b9295c8a27050d478fbb96f8addbc3d075544dc413287'
s = '1aa528be2b907d316d2da068dd9eb1e23243d97e444d59290d2fddf25269ee0e'
sig = r + s

However when I try to verify the message, I get a BadSignatureError signifying that the verification failed.

from ecdsa import VerifyingKey, SECP256k1
vk = VerifyingKey.from_string(bytes.fromhex(pubkey), curve=SECP256k1)
vk.verify(bytes.fromhex(sig), bytes.fromhex(message))

I am looking for a way to verify signatures that I have extracted from bitcoin transactions.

Thank you.


texts: Limited, but not fixed multisignature transactions, is that possible?

texts:
Is it possible to have a multisignature transaction where N signatures are required and their inputs are limited in value, but not fixed?

The use case would be for a pooled acquisition, where the total amount to be spent is just roughly estimated, but not know. Every participant wants to just specify a maximum value to be used (probably the same for everybody).

The exceeding money, if any can go to a shared account or be returned to each of the "bakers".


texts:
Help me to understand this code, spend all day to understand this code, and learned python from scratch, now I understand what operators do, but still some parts are complex to me.

import hashlib, struct

ver = 2
prev_block = "000000000000000117c80378b8da0e33559b5997f2ad55e2f7d18ec1975b9717"
mrkl_root = "871714dcbae6c8193a2bb9b2a69fe1c0440399f38d94b3a0f1b447275a29978a"
time_ = 0x53058b35 # 2014-02-20 04:57:25
bits = 0x19015f53

# https://en.bitcoin.it/wiki/Difficulty
exp = bits >> 24
mant = bits & 0xffffff
target_hexstr = '%064x' % (mant * (1<<(8*(exp - 3))))
target_str = target_hexstr.decode('hex')

nonce = 0
while nonce < 0x100000000:
    header = ( struct.pack("<L", ver) + prev_block.decode('hex')[::-1] +
          mrkl_root.decode('hex')[::-1] + struct.pack("<LLL", time_, bits, nonce))
    hash = hashlib.sha256(hashlib.sha256(header).digest()).digest()
    print nonce, hash[::-1].encode('hex')
    if hash[::-1] < target_str:
        print 'success'
        break
nonce += 1

In this code does the

  prev_block
  "000000000000000117c80378b8da0e33559b5997f2ad55e2f7d18ec1975b9717"

is in SHA256 and then later it's decoded in to hexadecimal by using

  prev_block.decode('hex')[::-1]

?

I just want to create a full "header" using the data I already have.


texts: block explorer, just a parser and database query?

texts:
I am thinking about the 'science' of block explorers

When I go to a block explorer and view an address, I see a list of transactions in that address and current balance

Is this technically just the contents of each block being stored as they are created (or retroactively parsed) and assigning a database entry for each new element found in that block?

Or even storing every unconfirmed transaction's data as well?

Writing this out, I think I answered my own question, but maybe there is some more efficient or clever thing going on here


texts: How to get the "BTC" abbreviation via command line?

texts:
I'm writing a module that connects to multiple wallets at once and I would like to have a way I can simply query the coin daemon for its coins abbreviation (not the "microcoins" as asked in a comment below, just the 3 character currency identifier).

Since my module also reads the coins config file, my only solution thus far is to add a parameter in the coins config file:

abbr=BTC

But I was wondering if there was a cleaner way to do this. A simple rpc command that I can pull the abbr from?


texts: Can I mine with CGMiner or BfgMiner with both an AMD and NVidia GPU on the same MOBO?

texts: I cannot find any good articles or webpages on this, is it possible to run CGMiner with both an AMD and a NVidia graphics card installed? I think I can remember reading something way back that said you shouldn't but can. Does anyone know any concrete information on it?


texts: I use Bitcoin Core v.0.17 on the server. I want to only be able to receive, and prevent sending. How can I turn off sending of bitcoins through bitcoind, bitcoin-cli or bitcoin.conf?


texts: How to avoid contagious media stories affecting Bitcoins?

texts:
There is an integral connection between fiat currencies and shop prices.

Can crypto's achieve the same shop use?

If a crypto has a giant user base, It can be less physical than Fiat. It needs to have some physical coin, institutional and material equivalence, how can that be achieved?


texts: What happens if I send bitcoins to my private key instead of my actual bitcoin address?

texts:
I recently used the website https://www.bitbrothersllc.com/Bitbrothersllc/Welcome.html to obtain my bitcoins, but when I was asked what address to send my coins to, I accidentally put down my wallet's private key, not my bitcoin address.

I'm wondering if the coins are lost forever now, or if they will still appear in my wallet because the private key is attached to my address.  I'm really hoping they are not lost forever, and I would greatly appreciate any assistance anyone could provide.


texts: Why do my 'sign message' not work on Bitcoin core

texts:
If I choose a freshly generated address in Core, and I then choose to sign a message with it, it returns the error message "The entered address does not refer to a key".

Why is this? There should definitely be a key considering that it's an address generated by my seed. It is also the correct address as I checked it multiple times.


texts: Extremely slow syncing speed while starting bitcoin-qt on HDD

texts:
I'm sorry for adding dupelicate question (e.g. How to speed up initial block chain sync using SSD without wasting space?), but I observered a dramatical speed increase while using RAMDisk or some disk cache enhancement software (like PrimoCache).

I've enlarged database cache size up to 2048MB, it didn't seem to help. (about
only 2blocks/min, HDD active time 100%)

I created a 5GB ramdisk (vs 16GB total RAM on my PC) using ImDisk, then chainstate was moved into this ramdisk by creating NTFS junction (mklink /j). After such operations, bitcoin-qt seemed to be boosted up quite a bit(about 60 blocks/min, while HDD seemed to be quite idle).

I wonder if there is any smarter way to do this? Using RAMDisk to accomplish such "boost" seemed to be too awkward.


texts: When a block that has a transaction with change in it is successfully mined, is the change transaction included in the newly mined block?

texts: If not, how is the change transaction processed?


texts:
I'm trying to understand how exactly does the Bitcoin client communicate initially with another client, as I'm making my own client and learning new things about TCP protocol. As I understand, the Bitcoin client uses the standard port (8333) as a server port that is listening to other clients' communication, and the client opens up new ports as it is trying to communicate with other clients. As I'm not sure if I understand the communication correctly, I made this chart:

My question is: is this diagram and my assumptions correct, or did I make some mistake in understanding how the protocol works?


texts:
How does the concept of premining coins work?

For example, bitcoin gold is said to have 16,000 blocks premined. Well, at the current block reward of 12.5 bitcoins, 16000*12.5= 200,000 coins will premined for the developers which sounds sort of like a scam to me.

Anyways, how is this possible? Miners get rewarded for transactions they process. How do coins get premined on future blocks before being released?


texts: Current block vs whole block chain attack

texts:
If an evil computer network wanted to attack Bitcoin, would they need to have more computing power than the present Bitcoin network and then attack a current block, or would they need even more to go back and recalculate all the checksums in the block chain since day one?

I am thinking that as history continues the work required grows and therefore the need for more computing power makes an attack of this sort less feasible.


texts: How much does the weight of 2-of-3 multisignature inputs differ between P2SH and P2SH-P2WSH?

texts:
I'm trying to calculate the weight of a 2-of-3 multisignature P2SH-P2WSH input. I found the related question Predict multi signature transaction size, which I've calculated with m=2, n=3 here:
pubkeySize=33
sigSize=72

SizeOfRedeemScript = 1+n*(1+pubkeySize)+1+1
// 2-of-3: SizeOfRedeemScript = 1+3*(1+33)+1+1 = 105

SizeOfScriptSig = 1+m*(1+sigSize)+SizeOfPushDataFor(RedeemScript)+SizeOfRedeemScript
// 2-of-3: SizeOfScriptSig = 1+2*(1+72)+2+105 = 1 + 146 + 2 + 105 = 254

sizeOf(input) = 32+4+SizeOfCsuintFor(SizeOfScriptSig) + SizeOfScriptSig + 4
// 2-of-3: sizeOf(input) = 32+4+3+254+4 = 297

The size of 2-of-3 input in P2SH has 293 to 297 bytes1. Thus, this  would correspond to up to 297*4 bytes = 1188 wu.
How would I calculate the corresponding weight for a 2-of-3 multisignature P2SH-P2WSH input?

1Note that if both signatures are 71 bytes, the scriptSig is 252 bytes which as a length can be encoded in 1 byte, but in the worst case both signatures are 72 bytes and the length of the scriptSig needs 3 bytes.


texts:
Not sure if this is the correct forum to ask, but I couldn't find a general one for all cryptocurrencies
I wanted to get an idea on how the whole cold-storage private/public key generation works for different cryptocurrencies. So I was playing around with BIP32 deriviation path on: https://iancoleman.io/bip39/#english

I noticed that for example BTC, XRP, PIRL all have the same BIP32 root key and BIP32 extended private/public key, but DOGE was completely different. Why is that? BTC hashing algorithm is SHA256 and PIRL uses Scrypt, their root seeds are the same, while DOGE which uses Dagger has a different seed and private/public key.

The second part that I don't understand is the generation process of addresses for different cryptocurrencies, is there a web site where I could look up on how it's done? The only one I found is for bitcoin here https://www.mobilefish.com/services/cryptocurrency/cryptocurrency.html#refMethod2


texts: Some general questions about blockchain consistency

texts:
I basically understand the principles of a blockchain, nodes and miners. I also basically understand how transactions are hashed/calculated to be added to the chain but i doesnt understand the dezentralized part.

For example bitcoin has a huge amount of nodes so its impossible to
be connected to all nodes. Is there some kind of
connection broker, root node thats always online or broadcasting that holds a list of nodes?
If a transaction is sucessfully hashed and published, how does it
reach all nodes so that nobody will work on an already added
transaction because he think its not finished yet? Ii think in some businesses its like on the wall street to fight about milliseconds.


texts: Using a wallet generated from an out of sync client with a synced client

texts: So I wanted to move my wallet from laptop to computer, and the Bitcoin client on my laptop is out of sync but I still generated a wallet.dat from it. If I then use this wallet.dat in an up to date client, will everything be fine?


texts: Bitcoin-based Distributed Donation Systems, whichs do you know?

texts:
I've heard that Tor Project constructed such system:

Everybody who are participating in the Tor Network, creating Exit Node or even Middle Node, would simply paste his Bitcoin address into the "Nickname" field.
All donates are clearly transparent and divides by the fair mechanism.

Now, I'm thinking, How is really great this Experiment.

And wondering, such mechanism with only one address to Donate and available blockchain.info would give fair Donation to any open-source project. For example Linux Kernel Developers or other GNU projects would simply install such daemon/system by similar # apt-get install command.

Github information would give percentage of job for each person, daemon will split Bitcoin input according to this data and it will be fair and easy controllable by blockchain.info's data.

Thereafter, I'm wondering, Is there anything else, except Tor Project.

I'm meaning "Global", Distributed, Bitcoin-based Donation System. Not only for closely-knitted group, where one person taking all donations and as a General commanding to his army who gonna getting what.

Probably such list will be good adding to bitcoin wiki and this site too.


texts: Eclair Lightning network node is not public

texts:
I'm using Eclair and have a conf file with content:

eclair.chain=testnet
eclair.node-alias=mynodename
eclair.node-color=ff0000
eclair.api.enabled=true
eclair.server.public-ips=["<ip one>","<ip two>"]
eclair.api.password="my-eclair-api-pass"
eclair.bitcoind.rpcuser=aqaqaqaqaq
eclair.bitcoind.rpcpassword=aqaqaqaqaq
eclair.bitcoind.zmq="tcp://127.0.0.1:29000"
eclair.gui.unit=sat

still I can't see my node in https://explorer.acinq.co/
I can open channels

[Edit 1] My pubkey is 03125205d1b5ae747064491d2b3b30b41fd7ec4e96e0ccede2f71c55891995f675


texts:
Why does mining profitability tend towards zero?

Is it different for short term miners than it is for long term miners?

  Example: if I mine now and sell them next year, they may be worth more as next year they'll be harder to mine

Thanks


texts: Please explain network propagation with unconfirmed transactions (blockchain.info)

texts:
I am wondering if someone could explain why two transactions have different network propagation values... and what does it even mean considering they are both unconfirmed transactions.
Do the transactions propagate through the nodes without being confirmed?

See below:

https://blockchain.info/tx/aec00216dfad6100638580bdc17a52d62e9c5687d9a981aaa2ece769d1f305c3

https://blockchain.info/tx/bda711e375d32b70b9fe65f4e4ceba041c6d2bdcfdaa03c5cfaff02de5445539

A number of my transactions are still unconfirmed after 10 hours of waiting.
All transactions included a fee.
I am trying to work out what has happened to them and what this whole network propagation thing means.


texts: I have got some USD balance with a Bitcoin exchange. I intend to buy stocks for these USDs. Is there an online broker that accepts Bitcoin as a deposit option for stock market trading? I mean the usual stock market where items like Google, Microsoft etc. are traded. Or do I have to go the usual way of withdrawing my USDs from the exchange to my bank account and then invest from there?


texts: Is there an online wallet service that will allow me to access an rpc server?

texts: Let's say I have an online eCommerce solution running with a plugin that is designed to connect to a bitcoin daemon running on the same server, but I am too cheap to hire a vps or dedicated server, so instead I want to use an e-wallet service. Is there one operating that will give me a server address, username and password?


texts:
I am interested in storing some bitcoin, etheruim, altcoins a year or some years.
I know hardware or paper wallets are the best choice, but as an absolute newbie, I decided to use a software offline wallet for simplicity( advice is welcomed).
Searching, I found Jaxx, Electrum, and Exodus as best choices.
As I read, I preferred electrum, but it supports only Bitcoins.
I need : (opensource offline-online user-controlled private keys, software wallet)
I am asking support for deciding on one of the following choices:
1. use an equivalent for electrum for multiple cryptocurrencies. And what to use multiBitHd, Jaxx, ...
2. start with bitcoin, when get some knowledge, create a paper wallet for multicurrencies?


texts: Accidentally sent BCH instead of BTC to a BTC address (Block chain)

texts: I've accidentally sent BCH from Coinbase to a BTC address of Block chain. Both accounts belong to me. Is there any way to recover it? Please help me.


texts: Private keys importing in format got by dumpprivkey

texts: I backed up my private keys this way: Opened my peerunity wallet (bitcoin-qt fork), opened Debug window, issued dumpprivkey  and I got my private key. Then, I wrote it on a piece of paper (!). Now, I would like to recover it. The wallet was encrypted at the time of dumping priv key. I have the key I used to encrypt it. Is privkey on my paper encrypted somehow? Peerunity is not accepting it when I'm trying to importprivkey. (tried it repeatedly)


texts: Where can one find the Bitcoin core roadmap?

texts: Is there a site where it shows the current Bitcoin core roadmap on what features will be implemented in the future?


texts: Antimer L3+ - Approximately How Many Coins In 30 days

texts:
I am about to receive one L3+ LiteCoin miner with
A hash speed of 4TH/s.

Approximately, how much litecoin could I
reasonably expect to mine in 30 days with my L3+
running at full operating speed 24/7, with unlimited
bandwidth up/down for my internet connection to
the miner? Approximately??

Thanks in advance for any response!


texts: What makes Bitcoin transaction secure against attackers/hackers?

texts: Wanted to know what is it that makes bitcoin transaction secure and make it less vulnerable to attackers and hackers


texts: I see there are hundreds of coins in the market. Can I use one program to mine all of them?


texts: How can I transfer bitcoins from a MultiBit wallet to another computer?

texts: I had bitcoins on MultiBit 0.12 on my old computer. I have moved the old computer's hard drive to an external hard drive. How can I transfer my bitcoins from the old hard drive to my new computer's MultiBit 0.15?


texts:
I've noticed that BCI's Wallet version has been updated to version 2 in recent times (and also employs key stretching, amongst other security features).

I've referred to BCI's Wallet Support Page and it says Version 2 wallet data is of the following format:

{
"version" : "2.0",
"pbkdf2_iterations" : 10000,
"payload" : "ENCRYPTED VERSION 1 PAYLOAD (SEE BELOW)"
}

What about the below JSON object (which can be accessed via URL of format https://blockchain.info/wallet/INSERT_GUID_HERE?format=json&resend_code=false)? What version does this correspond to?

To be clear, the difference is my JSON data is missing:

the pbkdf2_iterations variable
the version (=2) variable

For the data in question, here is the (edited) JSON object which is taken from the aforementioned link (replacing GUID with the actual GUID):

{"initial_error":"For Improved security add an email address to your account.","auth_type":0,"real_auth_type":0,"symbol_local":{"symbol":"$","code":"USD","symbolAppearsAfter":false,"name":"U.S. dollar","local":true,"conversion":442752.14734791},"clientTimeDiff":26055161055,"war_checksum":"c8c296cf351e7691","language":"en","symbol_btc":{"symbol":"mBTC","code":"MBC","symbolAppearsAfter":true,"name":"MilliBit (mBTC)","local":false,"conversion":100000.00000000},"extra_seed":"89e4807b343acfed576c474a675da1daac3ddb76691d05963a9e0a76533ca7ad4cd12ff058b40a1dd2f57a40759bb484a3708c3545ccfd995913964f148d405f","payload":"PAYLOAD DATA","guid":"GUID","serverTime":1423127480609,"payload_checksum":"8f8e16d79e7528e9725bef006a9752894e5d344d0324ba4ac6f6e4d804e02971","sync_pubkeys":false}

Compare this to current JSON data (for a wallet created for this purposehttps://blockchain.info/wallet/1d39195b-d918-4b7b-acae-d47db3324454?format=json&resend_code=false

{"initial_error":"For Improved security add an email address to your account.","extra_seed":"92a5d897af5c491e9e36dfad95f72b616553b23e02777859729c49b934ebbe1a575aa31a8ce0ba9978b9901caae649dd112d1759da5e48117379fbab0a91b083","auth_type":0,"real_auth_type":0,"payload":"{\"pbkdf2_iterations\":5000,\"version\":2,\"payload\":\"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\"}","symbol_local":{"symbol":"$","code":"USD","symbolAppearsAfter":false,"name":"U.S. dollar","local":true,"conversion":443419.65235899},"guid":"1d39195b-d918-4b7b-acae-d47db3324454","payload_checksum":"030de1efb09ee9485eaf009095b02b5ec8536432fa3ccc5588e8831b9c9983ea","war_checksum":"c8c296cf351e7691","language":"en","symbol_btc":{"symbol":"BTC","code":"BTC","symbolAppearsAfter":true,"name":"Bitcoin","local":false,"conversion":100000000.00000000},"sync_pubkeys":false}


texts: bitcoin-cli commands like createrawtransaction not working with json on command line

texts:
I am trying to create raw transaction using the createrawtransaction api on testnet using the Windows7 command line. I always get an "error parsing JSON":

C:\Users\amjad>bitcoin-cli -testnet createrawtransaction '[{ "txid" : "12b8e7ede
4992f4d30f93idj3085746951d945e39f40becebd7c290af8c2e7ad", "vout" : 0 }]' '{"mxh3
H416KCRoBDiweSESew5YJyAk1nxLrN": 0.025, "mkrzDhhZtzQm8zgckSs4fMNrvtNJ66zaFe": 0.
0245}'
error: Error parsing JSON:'[{

Does anyone have an idea what I'm doing wrong?


texts: How does the scriptPubKey for this test vector work?


texts:
Since UTXOs are required to spend funds, where does Trezor get the unspent outputs from?

Storing them in the hardware requires you to plug it in from time to time to update the UTXO set. You could even run out of UTXOs!
Host-side blockchain scanning for UTXOs from a given deterministic wallet is very expensive (if not impossible since there are infinite addresses in a deterministic wallet).
You can't build a "wallet -> UTXO" index for the same reasons above.

What am I missing? I'm assuming Trezor's primary use case is in PoS. Pehaps I'm wrong there?


texts: Computation expenses of syncing / getting a full node up and running, hardware considerations

texts: Since a full node needs to process the entire block chain from the beginning and it keeps getting bigger this requires more computing resources over time. Does it seem more likely in the near future that this will continue to be processed on a general purpose CPU or will the computation be hardware accelerated through specialized hardware ? Will the computational complexity outpace CPU improvements ? Is hardware acceleration possible for this task?


texts: Are Bitcoin transactions really "frictionless" given confirmation time?

texts:
One of the big selling points for Bitcoin is that transactions are frictionless.  I understand this to mean that there is no middleman to take a cut.  However, there are 2 major frictions I see.

1) Clients are difficult to use for "non-techies".  This can easily be solved with better clients.

2) Transaction confirmation times can take 10 to 60 minutes.  This seems like major "friction" in that it prevents fast transactions - something most people are really used to with cash and plastic.

So is Bitcoin really frictionless?


texts: In which order does the leveldb iterator iterate over utxos?

texts: I would like to know in which order the leveldb iterator iterates over the chainstate entries. I aim to serialize the chainstate and have to make sure that every node can calculate exactly the same serialization (to compare its hash afterwards).


texts:
I'm using NBitcoin and I created an ExtKey object. Now I need to get the Master Chain Code (see page 89 of Mastering Bitcoin for a good explanation) for this HD node. How do I do this?

According to Mastering Bitcoin a root seed is used with HMAC-SHA512 to create a 512-bits output. The left 256 bits are used for the master private key, the right 256 bits are used for the master chain code. When I call GetBytes() on my ExtKey object, however, it returns a byte[74] array. This corresponds to 592 bits. I don't know what the extra 80 bits are so I can't just take the right 256 bits.


texts: Can we experiment on Signet with multiple proposed soft forks whilst maintaining the ability of full nodes to validate the Signet chain?

texts:
One of the goals of Signet is to test proposed soft forks before they are activated on mainnet. Not only does this mean proposed soft forks such as Taproot that at the time of writing (August 2020) are at an advanced stage (BIPs reviewed, PR under review in Bitcoin Core codebase, activation discussion started) but potentially other proposed soft forks that are at a less advanced stage. It is also worth noting that despite Taproot being at an advanced stage there has still been discussion on changing the BIP (340). With less advanced proposed soft forks they could change and be updated at multiple points before either being activated on mainnet or rejected entirely.
How will Signet allow for this experimentation and testing on proposed soft forks whilst maintaining the ability for full nodes to validate the Signet chain from genesis?


texts: Bitcoin wallets- question about control and centralization

texts:
Community,

Just a quick simple question very important for me to understand about the security of wallet types.

Are there bitcoin wallets which can shut down and block/freeze/control your bitcoin transactions in any way shape or form?  I know that direct stealing of coins is not possible (at least not with any "decent" wallet). But what I like to know is if there are wallets or an entire "category" of wallet types, which could "interfer" or "block" transfers/transactions. Not stealing  but just blocking.  Could you please for example name one or two so that I can do more research on such wallets?
Can you reference some wallets which, from technical standpoint, have guaranteed not any (given any circumstances) way to "block" your btc transactions?

Basically I want to know what wallet (types) to use so that the wallet provider can never block my transactions.  I know that the bitcoin core wallet/main btc software would solve my question. But please disregard this, I like to ignore the option of running own btc node/btc software.

Thank you


texts:
Bitcoin core is currently 15 hours behind as I'm writing this and the piph (progress increase per hour) is at a STUPIDLY low speed. There are 95 blocks left but it says its going up 0.04% per hour. I've read that inscreasing the cache helps. Anyone else got some ideas on a fix? Or is this just how it is supposed to be?

Edit: Bitcoin core is also apparently using 50% of my disk which is not true. An application was using 12mb/s of disk and it was only using about 20% of the disk total. Bitcoin core however is using 3mb/s and is using 50%


texts: Unable to send raw transaction: mandatory-script-verify-flag-failed


texts: Since the blockchain is public, how can we see it?

texts: The blockchain is a shared public ledger for Bitcoin. What does that mean exactly? Is it possible to see, publicly, all transactions? For every bitcoin a person owns, is he able to see all the historical transactions? If so, there should be privacy issues, no? If he can't, who can?


texts: Why is the full blockchain required, effectively forever?

texts: I do understand that every block is validated in terms of the blocks before it by way of the previous block's hash, all the way back to the genesis block. However, could the protocol be modified such that the blockchain is a sliding window over the most recent N number of blocks? How likely is it that some block from 1 year ago later turns out to be invalid?


texts:
Is the segwit2x called off for sure for now?
I see there is still 53.9% intention as of 15th Nov for Segwit2x (Source)
I know this is not sure that it is called off forever, but I just want to know whether it will happen anytime soon as the NYA agreement of making segwit2x on block 494784


texts: Where could I find Peercoin's documentation?

texts: The whitepaper hosted in the official page is pretty lacking in "whys" so, is there anything that resembles https://bitcoin.org/en/developer-guide with Peercoin? Any technical papers?


texts: What's the difference between bitcoind and bitcoin-qt? Different commands?

texts:
This is a multi-part question, mainly do to contradictory information from different articles. It's got me all confused.

From my understanding, bitcoin-qt is just a GUI version of bitcoind - which was the original 'client' or 'node'. Is it true that bitcoind is actually built within bitcoin-qt, and runs in the background as a daemon (when the app is open)?

When I first started bitcoin-qt, it started downloading the block-chain. After that, I was curious about setting up a pool server, so I sought out information about that. I ended up going through a tutorial on installing Eloipool - they informed me that I had to have bitcoind setup and running as a daemon. That was interesting, because I thought that it was already running through bitcoin-qt?

This is where my confusion started. I even tried using the bitcoin-qt debug console; but it didn't have the same commands as bitcoind - specifically the rpc ones.

Where does this leave me? Am I doing something wrong? If I shutdown bitcoin-qt and start bitcoind -daemon, then it starts downloading another block-chain.

Do I really need both of these to make this work, or does the bitcoin-qt have access (somehow) to all the bitcoind commands?

Does bitcoin-qt use bitcoin.conf, the same as bitcoind? The reason I ask this, is for setting up the rpcuser and rpcpassword, amongst other things.

* UPDATE *

I did some more reading, and found out that most people just use bitcoind for more serious stuff. Is there not a way to configure bitcoin-qt to use a currently running instance of bitcoind, instead of spawning it's own daemon (when GUI is open).


texts: Understanding Multi-threading (boost) in bitcoin initialization

texts:
I am not familiar with boost in c++. Can any expert please explain in simple terms what is happening in the below code ? Is it like the logic in ThreadScriptCheck is scheduled to be run in background or how?

This is taken from bitcoin initialization (src/init.cpp). The classes are defined in src/scheduler.h

AppInit2():

// Assume value of nScriptCheckThreads is 4

if (nScriptCheckThreads) {
    for (int i=0; i<nScriptCheckThreads-1; i++)
        threadGroup.create_thread(&ThreadScriptCheck);
}

// Start the lightweight task scheduler thread
CScheduler::Function serviceLoop = boost::bind(&CScheduler::serviceQueue, &scheduler);
threadGroup.create_thread(boost::bind(&TraceThread<CScheduler::Function>, "scheduler", serviceLoop));


texts: Has the bitcoin network ever been "down"?

texts:
I'd be interested to know if the bitcoin network has ever been down. By "down" I mean that a client would not be able to synchronize with the network to obtain data like the txs in the mempool or recently mined blocks.

My guess would be that this would be extremely rare due to the decentralized architecture, but it'd be great to know for sure. If there have been downtimes, I'd be interested to know how frequent these have been and how long they have persisted.


texts: What prevents bitcoin from breaking down in case of a "transaction attack"

texts:
Let's say that I want to kill Bitcoin by means of a transaction attack. What in the bitcoin system prevents the following approach:

I buy a limited number of bitcoin in the market.
Using a small number (say 50) physical computers all running bitcoin clients and accessing the net through proxies, I generate, say, 100.000 wallets - each with their own bitcoin addresses.
(Running a script on the computers) I start sending random amounts (mili-to nanobitcoin range) of bitcoin back and forth between all my 100.000 (or more) wallets - each at a very high frequency. Average flow of bitcoin between wallets average to zero.

This causes an explosion in the number of daily transactions (currently in 1,000-10,000/day) range to millions or billions of transactions.

This makes every block gigantic in size causing an explosion in the blockchain and causing widespread problems with blockchain verification, storage and (worse) synchronization => the network dies.

Can someone explain why bitcoin is immune to this kind of "transfer attack"?


texts: Transaction rejected by our node. Blockchain receive API

texts:
I use the Blockchain.info receive API with great succes.
Yesterday I created a new address: 1MMVp6fzZ6QrVYXg9iRSJb5PsM8crq5iMZ
It received 1.5 BTC and was transferred to my BTC address (unfonfirmed). With transaction hash: 79ff50d749d1d8099e68ac04dba4e64645322e49e671326d74d871bfd0f868eb

Today I logged in on my wallet, the unconfirmed transaction was gone.
Now if I search that hash on blockchain.info, I get following message: Transaction rejected by our node. Reason: Transaction was previously accepted but has been pruned from our database.

Will the Blockchain API retry to send the BTC to my address or are they forever lost on the generated address? Would it make sense to make a small payment to that address so the Blockchain API would resend the whole amount?

Why does this happen?


texts:
When creating a custom route, if you use the queryroutes from lnd it sometimes  with tlv_payload set to either True or False. How does the node figure whether to set this flag?

I cant seem to find it in the source code. Clearly when using RPC calls such as 'getnodeinfo' the feature bit set from the node does not come through. So is this possible that the feature set per node is not exposed via RPC?


texts: What is a UTX 0 Proof? (as discussed in this video)

texts:
This video discusses how off chain transactions can be accomplished as an alternative to increasing the block size.

At the 21:25 marker he discusses "UTX 0 Proofs".  What is that?


texts:
I've found this in the code on Github:

  This pubkey can accept any type of coin, please leave this in
             your config to help support development.

  22851477d63a085dbc2398c8430af1c09e7343f6

How do I create a similar address?


texts: Is there any chance to check the name by bitcoin hash?

texts: Someone recently wants to sell me an iPhone, but the seller does not want to show me anything about it. It's a second-hand phone, and I'm worried about it a little bit. Is there any chance to see the information about the seller from bitcoin hash?


texts: Purpose of the LN transaction description

texts:
According to Bolt 11, an invoice may contain a short description. However, what I fail to understand is who is sending this information to whom.

Since the invoice is usually generated by the payee, I'd argue that the short description is some information for the payer, like "Purchase: Product A, Product B". However, I've seen Lapps like tip boxes, where it is the payer who creates the message for the payee.

Or is the idea that the payee could propose a description, but the payer could then change it as he wants?


texts:
Armory 0.95.1
Bitcoin core 0.14.1

I am stuck with a payment that has the state "not in the blockchain yet".

I already updated armory and bitcoin core, tried to rebuild the database and did the "clear all unconfirmed" command.

I added a fee of 0.0001 Bitcons to it, never had issues with this. The transaction was initiated several hours ago, it still has 0 confirmations.

According to blockchain.info the current confirmation time shouldn't be longer than 100mins...


texts: Bitcoind --reindex vs starting allover again

texts:
I setup a Bitcoin Daemon on a VM hosted on an OpenStack cloud. VM has 8 Cores and 32GB of Ram and 20GB of storage. I mounted a 1TB volume into the .Bitcoin/blocks folder. I started bitcoind and it downloaded about 139GB of the chain.
I was working on the web stuff when i accidentally restarted the VM.

"error: Could not locate RPC credentials. No authentication cookie could be
found, and no rpcpassword is set in the configuration file
(/home/ubuntu/.bitcoin/bitcoin.conf)"

bitcoind -rescan
: Error loading block database.

and bitcoind -reindex takes really long time and is still processing. The 138GB are untouched but it looks like --reindex is changing the files in /index.

What will be faster? deleting the 138GB of blockchain and starting bitcoind -daemon all over or bitcoind --reindex


texts: P2Pool latency, should I host in a datacenter or at home?

texts:
I read about latency on P2Pool being a bad thing. Is this latency between the miner and P2Pool, or P2Pool and the network, or both?

I am trying to decide if I should host P2Pool pool on one of my servers in a datacenter, or at home where my miners are.


texts: Bitcoin mining on headless Ubuntu 12.04 server

texts:
I've googled a lot and also read threads here but I'm still struggling.
Background:
I'm a eager but novice Linux user
I've an Ubuntu 12.04 webserver sitting pretty and is not doing much.
I would like to use the free processing power to mine Bitcoins - makes cents (sense).

Thus, I have Ubuntu 12.04. I have installed bitcoind and made a bitcoind.conf file as per Ubuntu Linux -- How do I start bitcoind as a service to run automatically?
(Basically, copy and paste)

I've installed bfgminer and I've register an account with Eclipse Mining Consortium (eclipsemc).

Now my questions:

I've read the bitcoin needs to download a large data file (+- 6Gb).
I can't find any log files to tail.  How do I know bitcoind is
working properly?

$ ps aux | grep bitcoind
1000     30080  0.0  0.0   9364   368 pts/1    D+   21:21   0:00 grep --color=auto bitcoind

When I run bfgminer (bfgminer -o http://eu.eclipsemc.com:8337 -u [MyUserName_worker] -p [password] -L bfgminer.log), I have to press "M", then "+" and enter "auto" before it will pick CPU 7 as the device.  How can I ensure that it will pick CPU 7 as the default device? How can I run this as a background process?
I still need a bitcoin wallet?  I'm using Armory on my Windows box, what is a compatible one for Ubuntu webserver?
How do I ensure that bitcoind and bfgminer doesn't kill my server?

Thank you very much!

André


texts: It is possible to serve the Bitcoin Core GUI remotely via a web page running on a server running in Digital Ocean (or any other provider)? If so, where can I find instructions on how to do this?


texts: Can a Mining Pool Force Changes Without Agreement from Bitcoin Core Developers?

texts:
I'm trying to understand a @petertoddbtc tweet about Chinese miners making a controversial stance.
 According to the accompanying article https://www.cryptocoinsnews.com/bitcoin-market-needs-big-blocks-says-founder-btc-top-mining-pool/, the Chinese miners advocate Bitcoin Unlimited.
 Bitcoin Unlimited allows large blocks (>1MB?). In contrast, Bitcoin Core Developers
 are considering limiting to smaller blocks (300KB).

There are quotes from Zhuoer who controls 8% of total hashrate and is rallying the Chinese miners:

  Who goes against the market will be destroyed, unless he can show more money.

In regards to Luke-Jr's (Core developer) threat of hardfork, there is the reaction:

  We have prepared $100M USD to kill the small fork of CoreCoin.

Isn't change supposed to be with the agreement of all developers, miners, and consumers?
 Can the mining pool group force this change on the Core developers?
 Why is Bitcoin Unlimited so different from Core, and what makes it incompatible to Core
 in that now there is a rift between miners and the Core developers?


texts: How does the network know the legitimate chain in a double-spend attempt?

texts:
Apologies if this has been covered, but there's one area of the Bitcoin network that is not clear in my head, and it's intimately linked to the double-spend problem.

Suppose Person A is purchasing an item in a store.  They "pay" Person B 1 BTC for a good and broadcast this transaction to the network, which Person B sees as unconfirmed.  The transaction is included in a block (Block 1) whose Proof of Work is now being found/solved.

Suppose Person A controls 30% of the Bitcoin mining network (arbitrary high proportion), and has his miners instead mine a different block (Block 2) containing a transaction spending the same BTC to a different wallet controlled by Person A.

Suppose the Proof of Work for Block 2 is, against the odds, obtained first, and the "corrupt" miner who finds the requisite hash broadcasts it to the entire bitcoin network.  This is where my understanding breaks down.  What exactly happens when the remaining 70% see this transaction?  Do they stop mining Block 1?  At what point can Block 1 be orphaned?