texts: Overview of the fee structure and strategy to minimize fees?

texts:
What are the current rules regarding transaction fees?
What transactions are broadcasted by the QT-Client?
How to the big pools act - what kind of transactions do say include in their blocks?

The background of the question: We are building a site where people can deposit bitcoins. Interact with the site to increase or decrease their balance and finally cash out to a Bitcoin address. (Like any Exchange, oder Just-Dice)

Obviously, we want to pay as little transaction fees as possible but still have reliable cash outs.

What is the best strategy to minimize fees?


texts:
I have a question about an implementation detail - when are old blocks verified by each full node? I.e. when will I be "caught" if I change the contents of an old block (and thus break the hash chain)

From what I've seen, the possible answers include: when it's downloaded and when you do a -rescan.

However, does a full node regularly verify the integrity of the chain from start to finish?

(I'm aware that changing the history on my node doesn't do any good, as those verifying my future transactions will have the correct chain and thus refuse any attempts to double spend)


texts: What happens if I mistype the address when making a payment?

texts: I sent bitcoins to an address, but I think I made a typo when I copied it. Where did these bitcoins go. Can I get them back?


texts: Problem generating the Genesis block for a PIVX fork

texts:
I am trying to create a PIVX fork,
I updated chainparams.cpp as you do, new pchmessages, port, address prefixes, checkpoints, etc. However I am running into a bit of trouble when it comes to generating the Genesis, I heard somewhere that PIVX uses the quark algorithm, so I used the https://GitHub.com/nasa8x/genesis-block tool to generate a quark genesis block, but when I compile the code and run the daemon it aborts, I’m wondering is there a rule that needs to be changed in the PIVX code or was quark removed when they upgraded to PoS.
Any help is greatly appreciated


texts: How often does Bitcoin connect to the fallback nodes?

texts: Does the standard client have a preference for connecting to fallback nodes (for example, by trying to have at least 1 connection to such node at all times), or are they treated like any other nodes?


texts: Litecoin transaction never reached my adress

texts:
Hi I did a Litecoin transaction from Mercado Bitcoin to Bitstamp and it never reached the destination.

The platform mercado bitcoin says my transaction was completed and it doesn't and when I click on the transaction code it the website blockcypher and Blockchai.info, both say the transaction wasn't found. In the meantime I have no more litecoins in mercado bitcoin and no litecoins appear on Bitstamp.

Here is the transaction code: 68b9ba2f30afc3eca80ba36df298f5e1d91f9aa5b282306233d6d767ca1acddf

Did I loose my litecoins?

Thank you for your help.


texts: My husband died, I have lots of codes and words... help

texts:
I will not post any of the codes here so please don't ask.

So, my husband has a number of apps in a folder -

Tronwallet
Telegram
Guildchat
Coinbase
Biance
Google authenticator

He kept going on about tron etc, I never paid much attention. He gave me codes etc cause "if anything ever happened and you didn't have these it would be lost"...again..I didn't pay much attention... he was 43 and perfectly healthy.

Now I have his phone, these apps and these codes and no clue what to do.

I can't log into tron wallet... he didn't give me a 6 digit pin.

Don't blow my mind too much but I'm clueless here.

I guess the first step in getting into the wallet?


texts:
Stateless wallet are wallets that do not store any information locally on the device.

Stateful wallets are wallets that store  information such as index of unused address.

According to my understanding

Stateful wallets are more efficent as compared to stateless. As stateful wallet store unused address index locally, whenver a user request to generate a new address. They know right unused index, whereas stateless wallet generates addresses from very first index and queries full node whether a address is used or not.
If stateful wallet lose all his locally stored data, it needs to work from very begining. It is acceptable in case of blockchain that keeps history from very first transaction. But in case of cryptocurrency like iota that prunes history, if stateful wallet lose stored information, it is going to be big problem.
Stateless wallet needs to do too much computational cost. As if user last unused address is at index = 1000, it needs to generate all address from index 0 until 1001.

My questions are

Which wallets are better stateless or stateful?
Which wallets are currently common stateless or stateful?
Example of stateless and stateful wallet?
If stateless wallet generates address from index 0 until unspent address index is found, and queires from full node, is it compromise privacy of user. As full node came to know what address a user own?

Note that here i am mainly concern about information of unused index.


texts: when does an address shows on blockchain?

texts: I have a ledger wallet which generates several public keys/addresses. Without having used any of them, some of them are shown in blockchain.info whereas other produce an "Unrecognized search pattern" error. Why does that happen? All these addresses come from the same master key.


texts: Viewing truly raw but decoded transaction data

texts:
I've previously been using bitcoin-cli decoderawtransaction to get human readable bitcoin transaction data but am just learning that it's not only decoding the raw transaction but also adding extra derived fields (e.g. txid, hash) that aren't explicitly stated within the transaction held in the blockchain.

Purely as a means of education I want to be able to interact with exactly the transaction data that's stored by bitcoin in blocks/mempool with no extra extrapolated data.

What's the best way to get this data?


texts: Profit by programming a Bitcoin service (wallet) in an "only-now" bc adopting country?

texts:
A country where I am from appears to take Bitcoin into an interest right now.

I am a senior programmer at one company and have done several projects, but right now I am mostly interested in the opportunities that might appear from Bitcoin to a programmer at my small european country.

I appear to have a domain bitcoin.abc and bitcoins.abc, where abc stands for my country tld name.

I went to freenode chat #bitcoin, #startups, asked out several people, but could not find any helpful information about an opportunities that one might get in my case.

I wonder if there is anything I can use such domain names and a programming knowledge, with interest in such a decentralized system and get on a way to profit.

I don't really know, but, perhaps building a new wallet, or such? I would really appreciate any ideas, thoughts or resources to read for me on my case. Thanks.


texts: what is math behind elliptic curve? (duplicate)

texts:
I have seen many videos regarding the math behind the bitcoin elliptical curve but none of them showing the public key generation they are just defining few steps. i need complete math behind the elliptical curve in which the generation of public key is defined. actually i want to see visual calculation for public key generation, someone give me the link which was defining the math behind elliptical curve
what i understand that is k * n times G is equals to public key but question is remain same if kn times G (where every point of G we get from point multiplication and point addition ) then at every multiplication of kG will result a different value then how can we combine them get the public key.


texts: How to properly use PreviousTxnID in a Ripple Transaction?

texts:
At the moment I am implementing a transaction overwriting with NOPs in Ripple. I want to store information about a transaction I am overwriting inside of the NOP. Looking at the PreviousTxnID field it appears to be ideal for this purpose. However, when I try to use it I get an error of:

{
  "id": 11,
  "status": "success",
  "type": "response",
  "result": {
    "engine_result": "tefWRONG_PRIOR",
    "engine_result_code": -184,
    "engine_result_message": "This previous transaction does not match.",
    "tx_blob": "1200032200000000240000F69555DA10915AA58303872299078F4CD9AD81D4771219C38764BE84B3AB3D6763977268400000000000000F7321025D9E40A50D78347EB8AFF7A36222BBE173CB9D06E68D109D189FF8616FC211077446304402204710D875B7DFC0F9A9F2101F67E0043AE255258BF9F6F21BCF7D42BC19B3A41E0220554CAB999EF43FD3EF720C6869D63F2E324AD774662B51AE4599F50B60E9B4DA8114448BD3912AA0E86A18B17784E7177B262FC38D73",
    "tx_json": {
      "Account": "rfESTMcbvbvCBqU1FTvGWiJP8cmUSu4GKg",
      "Fee": "15",
      "Flags": 0,
      "PreviousTxnID": "DA10915AA58303872299078F4CD9AD81D4771219C38764BE84B3AB3D67639772",
      "Sequence": 63125,
      "SigningPubKey": "025D9E40A50D78347EB8AFF7A36222BBE173CB9D06E68D109D189FF8616FC21107",
      "TransactionType": "AccountSet",
      "TxnSignature": "304402204710D875B7DFC0F9A9F2101F67E0043AE255258BF9F6F21BCF7D42BC19B3A41E0220554CAB999EF43FD3EF720C6869D63F2E324AD774662B51AE4599F50B60E9B4DA",
      "hash": "B1932085BA94FEBE7A360D71359752A1666C48CCBBD97DFF16FFFA8626EDA253"
    }
  }
}

What is the correct way to use PreviousTxnID to overwrite a prior transaction in Ripple? (say, a transaction we submitted that never got into a ledger due to the use of LastLedgerSequence).


texts: How does the bitcoin transaction fee be calculated? And who guide this?

texts:
https://en.bitcoin.it/wiki/Transaction_fees

I learned that the transaction fees is given by sender to bitcoin miners to ensure that this transaction be confirmed.

But I notice that, in most exchange websites or clients, the default transaction fee is 0.0005BTC, so Could It be possible that the transaction fee will be guide by the exchange websites or popular client software providers?

Because if a person don't accept the transaction fee in main stream, his transaction will probably not be accepted and appended to the block.


texts: What positive effects can Quantum Computers have on the Blockchain technology and hence Bitcoin

texts:
Quantum Computers
We always fear what we do not know. This statement has been proven right throughout the history of mankind and has resulted in significant evolution, even though there was always speculation of singularity (existential crisis).
Not hopping the "Quantum Computers will destroy Bitcoin" wagon; I'd like to explore the positive outcomes or the use cases that Quantum computers could be used for, in blockchain technology.
Edit 1:
Just to clarify, this is not a duplicate question as it discovers only positive impacts that quantum computing can bring to the technology.


texts:
I'm working on a bitcoin block explorer in golang, in which I'd like to gather as much informations as possible about transactions.
I am able to extract addresses from every type of output, and mostly every type of input, except I am struggling to find clear P2SH documentation.
BIP16 doesn't say much about non-SegWit P2SH byte structure. I read many examples where OP_0 is the first byte, as opposed to P2WPKH in P2SH and P2WSH in P2SH where the first field is scriptSig's total length followed by 0x0/OP_0.
From what I understand, a non-SegWit P2PH address is obtained by hashing the redeem script, but I'd need something to anchor to, like for example 1st byte is OP_0, then comes the size of the data (probably a signature), loop until finding OP_TRUE followed by OP_PUSHDATA1?
But is this the unique, standard format?


texts: Has the Timestamp Server from the original whitepaper ever been developed?

texts: In the original whitepaper Satoshi proposes a creation of a timestamp server to authenticate that Bitcoin blocks were not created later than at a given time. Has this feature been ever implemented or planned to be implemented? Why would the timestamp server be useful to the Bitcoin client/protocol/community?


texts: bitcoind API sendrawtransaction error 500

texts:
I'm getting an error 500 from my web server when I try to send a raw transaction through the RPC API.

PHP message:

PHP Warning:  fopen(://...@IP:8332/): failed to open stream: HTTP request failed!
HTTP/1.1 500 Internal Server Error
in /usr/share/nginx/html/common/jsonRPCClient.php on line 132

PHP message:

PHP Fatal error:  Uncaught exception 'Exception' with message
'Unable to connect to://bitcoinrpc:PASSWORD@IP:8332/'
in /usr/share/nginx/html/common/jsonRPCClient.php:140

Stack trace:

#0 /usr/share/nginx/html/tools/do_sendBTC.php(131):
jsonRPCClient->__call('sendrawtransact...', Array)
#1 /usr/share/nginx/html/tools/do_sendBTC.php(131):
jsonRPCClient->sendrawtransaction('010000000115d34...')
#2 {main}

This is the line that crashes:

$result = $bitcoin->sendrawtransaction($tx_data);

Every other API call works, for example validateaddress.

Any idea why this fails? The same raw transaction works if sent through the bitcoind command line.

Thanks


texts: sendtoaddress not deducting from account

texts:
I have two accounts called "hot" and "cold" and have few address and transactions in each of them. I am trying to move some funds between "hot" to "cold" and using sendtoaddress like this

  bitcoin-cli sendtoaddress "one-of-the-cold-wallet-address" 1.23 "" ""

If i check the balances using

  bitcoin-cli listreceivedbyaccount

The balance in "cold" has increased by 1.23 and the balance in "hot" is still the same.

Q1: by default, which account does sendtoaddress uses if i dont have the default account?

Q2: Why did the balance in the "hot" is still the same while the balance in the "cold" increased.


texts: Copay wallet transaction history unavailable?

texts:
Ever since updating my Copay wallet to the newest version to resolve the vulnerability issue, it won’t show my transaction history. Recent transactions will show on the main screen for about 30 minutes, but if I try to open them up to view the details I get an error message. This is especially frustrating since I should have a little more BTC sitting in my wallet than I actually do, but I can’t see where the funds may have gone since the transaction history won’t load. All it shows is an error message saying “Could not update transaction history”. Help?
Using iPhone 6, iOS 11.4.1, copay for iOS v5.4.0
Thank you!


texts: Where does MultiBit keep its data directory? What is the wallet inside called?


texts: Why does a larger block size infer a bigger attack vector

texts: I have read this in several articles that larger block sizes makes adversarial attacks easier. What I wonder is why is that so obvious? is it because in a larger block the number of transactions could increase to a number that it becomes hard to validate each one of them?


texts:
According to https://en.bitcoin.it/wiki/Hash,

  BitCoin uses the SHA-256 hash algorithm to generate verifiably
  "random" numbers in a way that requires a predictable amount of CPU
  effort. Generating a SHA-256 hash with a value less than the current
  target solves a block and wins you some coins.

Here is an example for web logs; https://code.google.com/p/logstalgia/

Obviously solving the hash takes many iterations. I'm curious if there anything that currently lets you visualize a miner hashing?


texts: Noob questions about transfering and offline security

texts: I created a wallet on a USB and one with coinbase.  I bought a bunch of bitcoin on coinbase and transferred .01 bitcoin to my USB wallet to make sure I transferred it right before I transfer everything and lose it all.  Than I transferred .04 bitcoin.  The next day I transferred .01 and than .04 again, because of buying limits while my bank account autherizes.  I checked the balance each time on blockchain.info and the money was all going in there just right.  I than was getting paranoid being new to this that I set up my USB wallet wrong and decided to plug it in to make sure I wasn't throwing my money away.  I plugged it in and it had the funds.  I wanted to do another test and transferred .01, than .05 to my coinbase wallet.  the .01 went and the .05 went but I lost .04 after transferring the .05 .  I understand that transferring can have fees and am wondering if that .04 lost is all in fees?  Would the fees for all the transfers be taken out at the same time?  I listed every transfer I had done up to that point in this and am curious if .04 is normal for fees for that many transfers.  Also, while on blockchain.info I see the addresses I have sent bitcoin to, but their are usually 2 addresses, one says "spent" and the other "unspent", or both will sometimes say unspent.  I recognize one of the addresses usually but not the other one.  Is the unrecognized address the address of the miner who performed the transaction and the number next to it the fee?  Finally, is my offline wallet now compromised and at risk of someone having the keys to it?  Should I keep using it and not plug it in anymore, or should I create an entirely new USB wallet?  thanks!


texts: i made transfer of BCCto my trezor walltet from an online exchange, but by mistake entered my BTC address of trezor, exchange shows transaction is completed. how to recover the same.


texts: Is it possible to run Bitcoin on Google App Engine? / alternatives?

texts:
This question is cross-posted on bitcoin.stackexchange, stackoverflow and bitcointalks.

I'm planning to build an application on Google App Engine that will heavily make use of Bitcoin trading. I've been Googling along a little but I couldn't find whether it is possible to run Bitcoin itself on App Engine (with Java). I have some experience with App Engine, but limited to a pure web-app centered usage.
I've read about a few people that have made applications using Bitcoin with App Engine as well that are hosting Bitcoin separately on an Amazon EC2 instance.

So, does anyone here either has experience with running Bitcoin in App Engine for Java or would anyone have an idea how this could possibly be done?
I know there are a lot of Bitcoin applications out there, I'd like to know how these manage their Bitcoin traffic.

I'm trying to avoid needing a separate Amazon service running all the time next to App Engine.

In fact, receiving Bitcoin can easily be done by using passive APIs like blockexplorer or blockchain, so I'm considering to find a reliable API to handle my outgoing payments. But this approach causes extreme dependency on this API service, which I actually want to avoid as much as possible.


texts: How do I ask other nodes for their stale blocks?

texts:
I want data on as many stale blocks as possible. Is there a way to ask peer nodes to run "getchaintips" and get their results?

Previously, I used Blockchain.info's API call for this, but it seems like they deleted their data on stale blocks (even when I directly search for a known stale block's hash, no results are found).

I've also heard of using merged mining data to find extra stale blocks, per Stifter et al 2019. This method was used to find many stale blocks that weren't propagated to nodes run by certain websites; the paper looks at stale blocks from Decker and Wattenhoffer 2013, Blockchain.info, Bitcoin.com, and ChainQuery.com. However, this method misses many stale blocks that those websites picked up.

My current best idea is to ask as many peers as possible for their "getchaintips", but I don't know how to do this. Can someone help, suggest an alternative method, and/or provide some of their own data?


texts:
Getting senders account

Say we got txid by listtransactions:

"txid" : "2ca54b92338e52bbb16562dd7a91e8670d9362bb255e21fb568acc13e732b6b7"

then

getrawtransaction 2ca54b92338e52bbb16562dd7a91e8670d9362bb255e21fb568acc13e732b6b7

and

decoderawtransaction 0100000001b2314a1f3d2552d781836cbf266b558eea31fb9f6b0e6da9340ab12e8760df0b000000006b483045022100dab5b2ef5e5be67fc0421c637c60a3d21064bcc7afe69f86909d0a7f91ae99440220762ad9a1d9c20a22378136e5653c2e7134499d1ac0ed86aba883faa7fbf6753f012102f342968588796d7214e189a6fef024bad4f29e7a155c93182a8b6f579b2c1fb2ffffffff02172e0100000000001976a914dc05a2f50f5ae09df42f584f5a5582891a41665088ac2e2f4100000000001976a914380e50d59602e9f9960f893f6f2c0f6eb7791b6088ac00000000

out of which we finally receive:

"asm" : "3045022100dab5b2ef5e5be67fc0421c637c60a3d21064bcc7afe69f86909d0a7f91ae99440220762ad9a1d9c20a22378136e5653c2e7134499d1ac0ed86aba883faa7fbf6753f01 02f342968588796d7214e189a6fef024bad4f29e7a155c93182a8b6f579b2c1fb2"

So far so good. Last part is publickey, if understand correctly:02f342968588796d7214e189a6fef024bad4f29e7a155c93182a8b6f579b2c1fb2, which can be translated to address

Then I do following in python to get senders address:
    import hashlib

pkey="02f342968588796d7214e189a6fef024bad4f29e7a155c93182a8b6f579b2c1fb2"

ripemd160 = hashlib.new('ripemd160')

ripemd160.update(hashlib.sha256(pkey.decode('hex')).digest())

but ripemd160.hexdigest() returns 8cdd1b71d32e53a9fe326212281a4a99a1c093a8, and thats not what i want.

It should return valid address, and result seems a bit off to me. I think .hexdigest is wrong way to do it, should be converted to base58.

How properly convert ripemd160.digest into account address?

Thanks a lot


texts: How to determine the coin amount needed for vin?

texts: At first I believed the coin amount of vin just based on what the send thinking. but after read some source code, it seems the coin amount of vin calculated from vout. Is anyone clear about this and please explain how the determination process is in source code. Thanks.


texts: My trezor worked fine until the other day it wouldn't connect.  I tried myehterwallet, trezor app in Chrome, and the trezor.io site--nothing.  I've tried using different cables, different computers, different usb ports and even followed the trezor instructions for emergency reset.  Nothing is working to open my Trezor and allow access to my currency stored on it.


texts: Bitcoin system with payins and payouts using bip32

texts:
I want to build an automated system, that can accept payments from users in bitcoin and can make payouts to addresses, specified by users, as well.

BIP32 says, that the best way to accept payments is to use HD wallets. But what about payouts? How can I make payouts using funds from account's external chain addresses with received funds and not introduce security leaks?


texts: I have BTC in a paper wallet. Will that wallet also have BCH (a.k.a BCC) after the UAHF? Should I move the BTC to my blockchain.info wallet or another type of wallet to ensure I also own BCH after the fork?


texts: I cannot access my copay app because I forgot my PIN number. My app is locked with the PIN number. How can I recover it?


texts: Can I actually profit from bitcoin mining on my PC?

texts:
My PC is kind of power hungry but it's also quite powerful too I was wondering if I might be able to profit from bitcoin mining without a mining rig, even if the profits are small.

Relevant Specs:
GPU: AMD RX 480
AMD: FX 8320e
PSU: 450w Thermaltake 80+ Bronze PSU
OS: Ubuntu 16.04 LTS


texts: Why are the fee value and modified fee value always the same?

texts:
I do not see any transaction in the mempool having differing values for the fee and modified fee fields. Does nobody modify or accelerate their transactions?
How do transactions with modified fees show up in the mempool?


texts: Bitcoin config file to setup bitcoin node in testnet network in ubuntu

texts:
I am new to blockchain, I want to setup my node in testnet network in my ubuntu machine.

I am using this below mentioned bitcoin.conf file. Is this the correct format to sync the node faster?  Or I need to do the changes in this config file.

testnet=1
dnsseed=0
upnp=0
setgenerate=1
blocksonly=1

port=12000
rpcport=5000

server=1
prune=1000

rpcallowip=0.0.0.0/0

rpcuser=someuser
rpcpassword=somepass

I am referring this link to setup my bitcoin node https://www.codeooze.com/blockchain/bitcoind-running-in-docker/


texts: Is it possible to calculate a public key from the message hash and signature?


texts:
In a pay 2 script hash transaction, does the redeem script get checked for valid public keys before a transaction can be signed? I have noticed that if I have a redeem script with one invalid pubkey out of 3, even if I sign with a valid private key for the multi-sig transaction, the "scriptSig" is blank and the hex returned for the signrawtransaction is small/incomplete.

Any ideas?

I saw a comment on here that led me to believe that public keys in redeem scripts could be text or 'anything'


texts: My Bitcoin Transaction is Unconfirmed from last 10 days Please Help

texts:
Tx id

  9c9fb0d1c60f6f59196c9c41c1b9eb7ad9caf32397f5264f54149af6ecfd8003

Please Help


texts: If I buy Bitcoins at Coinbase.com, should I leave them on Coinbase.com, or should I move them into a Bitcoin Wallet? Why?

texts: If I buy Bitcoins at Coinbase.com, should I leave them in my account at Coinbase.com, or should I move them into a Bitcoin Wallet? Why?


texts: How To Traverse Bitcoin Addresses in HD Wallet

texts:
It appears that there are many way to traverse Bitcoin addresses. I am looking best practice, and I am also looking for the documented logic of how common wallets do it so I can replicate their behaviour.

For example, Trezor creates the first address at this location:
m/49'/0'/0'/0/0, and then the next address will be m/49'/0'/0'/0/1, and so on. So, it appears that it would be easy to just use an iterator over the last digit.

But, when you spend from m/49'/0'/0'/0/0, it moves the leftover to m/49'/0'/0'/1/0 . So, suddenly, I not only have to iterate over the last digit, I also have to iterate over the penultimate digit. I could have said "second last", but I said penultimate because it sounds more intelligent.

Is there standard practice for traversing addresses? Something like, keep traversing over addresses until you hit an address with no transactions? Or possibly say three addresses in a row with no transactions? Or is this really the wild west and we just do whatever we feel like?


texts: Does the amount of memory in a GPU influences mining?

texts:
I am really new to this and am willing to give it a go.
I've seen some rigs online and I would probably go for one, especially if I can upgrade the GPUs.
So, I understand the heavy lifting is done by the GPU, so it's only fair to suppose a 256-bit GPU will do better than a 128-bit. But will the amount of memory make a significant difference?


texts: Telegram ICO technical whitepaper - does it exist?

texts:
Telegram provides a "marketing whitepaper" here:
http://ico-telegram.org/files/gram_whitepaper.pdf

The authors do refer to a technical whitepaper but I can't find it on their website. If it sounds like a scam, reads like a scam it is probably a scam?


texts: XAPO's flow from wallet to vault - a different wallet address used for the transfer

texts:
I have a XAPO account and I moved a bitcoin from Bittrex from XAPO. Now, XAPO has provided me with a wallet address a1.

Now when I have moved my bitcoin from my bitcoin wallet to vault and checked the transaction in the blockchain.info, I was kind of surprised that from address was different from original deposit address a1.

Also, looking into blockchain.info, I was surprised to find that my deposit address a1 was used to send bitcoin to other addresses as well which I have never initiated. So, it looks like XAPO has provided the same deposit address a1 to other users as well, which is not good. In that case, I have to be dependent on their internal ledger to claim my funds, no?

Will the withdrawal process be same as well, meaning when I withdraw from Vault to wallet, the from address will be different from what I see now as my vault address, b1? And when I finally move my fund out from wallet to let's say Bittrex, that txn will also show a different from address?

In addition to that, if XAPO regularly moves the fund around, won't it cost them a lot of fees?


texts: BlockNotify/WalletNotify - but without the console window

texts:
I use the walletnotify and blocknotify config options on bitcoind to have the server call two executables on new transactions/blocks. This all works fine. The two executables (Windows executables) are both designed to run without a console window, and they do.

That is, they do when I run them. When bitcoind runs them, I get a brief flash of a console window. As I run these on my development machine while developing, it's driving me to distraction. Does anyone have any idea to prevent this happening?


texts:
Scenario:

You are running a bitcoind node and listening to the incoming blocks/transactions.  You receive TX 1 which is put into your mempool.  Block A is mined, and includes TX 1, which is subsequently removed from your mempool.  Blocks B and C are mined, orphaning Block A.  Neither Block B, nor C include TX 1, so it is put back into the mempool to be included in a new Block

Question:

How exactly does the node find out that it needs to include TX1 in the mempool again?  Is TX 1 broadcast and received in the same way as when it was first broadcast to the node?  Or in other words, if I'm listening for receiving incoming blocks/transactions, will it be relayed to me a second time or does the client "know" just to put it back in the mempool?

Let me know if any of my understanding is incorrect or if you need any more clarification!


texts: How does the wallet know which outputs are available with LevelDB

texts: So, I found that in the original Bitcoin client there was a member variable vSpent in the class CWalletTX, however it appears that this is no longer the case in the new version. I know that the new Bitcoin client uses UTXO DB to store the unspent transactions. My question is that since LevelDB is a key-value database, and the UTXO key is derived from transaction outpoint, how does the client find the Txs that belongs to the wallet owner? Does it iterate over all unspent transactions and find those containing the public key of the receiver?


texts: PlexCard Visa : Would it be legal all around the world?

texts:
Recently, Plexcoin is to come up in the market with very promising future. Directly, citing from their website, the features include

In comparison to Bitcoin (45 minutes), the transactions (deposit, withdrawal, purchase, sale, transfer) of PlexCoin are confirmed faster (30 seconds) and they have increased storage efficiency.

and

With PlexCoin, you will be able to undertake regular transactions and spend money with your PlexCard VISA© anywhere around the world. You will also have the option to send or receive funds from anyone, in a totally private way.

Will the VISA card be legally accepted around the world ?

and

How can they achieve(claim) to have such fast transaction confirmation time ?


texts:
I want to parse blockchain manually and extract the UTXO set (for various reasons). Is there any way to understand how the blocks are stored without going through the C++ code?

Some specs will be great.


texts:
Where can I find the sighash type specified in a script?
Is it included in the scriptsig?


texts:
I'm monitoring The Shadow Brokers wallet out of curiosity on how big it will become, and I've noticed that a transaction with a value of £0.00 was sent. How can this be?

The transaction I'm referencing is: da849be1571092b467da9be31bcb0a43508bde5776173954bdba0d48845bd842

It was my assumed understanding that you can't send a value of nothing (in this case £0.00) as when I try and send BTC0.00/£0.00, my client always asks me to input a value.

Utlimately, my question is how and why would someone send £0.00.

The why may be impacted by the urge to contribute to the wallet funds for NSA 0days.


texts:
I am not sure if this is the right place for this kind of question, but there is no general crypto currency stack ...

I am developing an application which accesses Bitfinex data and also should be able to modify Bitfinex data and I am using the REST API to achieve this.

But all endpoints I see in https://bitfinex.readme.io/v2/reference are only read endpoints and do not modify orders or create/delete orders. Is this not possible in v2? Can I simply use the v1 endpoints for this or is this deprecated? I don't want to use the Websocket which is able to modify /create new orders.


texts: How many transactions are there in one block

texts:
What I understand:
When a transaction is made , miners compete to  validate it and create a hash . If one miner creates the hash and more than 51% of miners agree on the validity .Then the a block is added to the blockchain.
Am I right?
My doubt:
1)When a block is added it contains one transaction that is validated or more?
Thanks.


texts: Friend sent me Bitcoin using Quickbt and it never ended up in my wallet

texts: One of my friends sent me bitcoin so I could buy something online. They used the website quickbt to send me the money. They used the proper address for my wallet because it was copied and pasted in. That was three days ago and I still haven't received the bit coin. The wallet I'm using is bitcoin-core, and whenever I open it on my laptop there's a loading bar at the bottom of the window that says synchronizing to network (it's been doing that for three days as well). I was wondering if anybody could help me or if anyone has had this problem before?


texts: If the "wallet seed keywords phrase" is all that's needed to restore a hardware Bitcoin wallet, isn't backing that up a nightmare security-wise?

texts:
I buy a Trezor. I put all my coins on it. It has me type out the "wallet seed", which is a series of English words in the right order, onto a paper. And maybe I even buy a metallic card thing to fireproof it. And maybe I'll even put it inside my fireproof safe on top of that.
And then somebody steals the paper. Or finds the phrase in the passwords.txt file in my computer.
And now they have my coins.
Reading the manual/intro to hardware wallets, the first thing they tell you is to back up the seed phrase.
But the seed phrase gives you instant and full access to the wallet!
This just makes my head spin. I don't understand how they can give such advice when this completely violates your security. I don't understand the point of having a hardware wallet when you completely bypass the security it gives by "backing it up".


texts: Why participants transact bitcoins use pseudonyms rather than persistent real-world identitie?

texts:
I recently read an article that tries to make reveal the identity of participants which transact bitcoins. my question is why participants use pseudonym instead of real-world identities and cause transaction be anonymous.
what is the use of this anonymity and why is blockchain structure designed in this form? wasn't it more safe if the identity of participants was clear?


texts: What would happen if a private fork several hundred blocks ahead tried to merge back?

texts:
Suppose mining pool has been off the main network for a long time so that they are 100 or so blocks behind, but managed to mine 200 blocks in the period (say, some combination of had 33% before, deliberately selecting easy blocks to extend, and ...).

Obviously, this can happen by choking down the difficulty, but I'd assume there are protections against such an obvious attack as that one. Update: assumption verified; reducing the difficulty doesn't work here as expected.

I found two roughly similar questions, but neither seems right:

Can a double spend attack be obfuscated by mimicking the transactions seen before the fork?

Countrywide Internet isolation, inevitable fork

The obvious answer, if it contained only mined transactions, would be to manually discard it, but I don't think that assumption would prove valid.

I am bothered by the belief that this is a duplicate of longest chain vs. highest difficulty. Marking this as duplicate pre-supposes an entire class of cryptographic attacks on hashes does not exist, and many other things as well.

One possibility, as hinted by Murch, would be to pre-build a long chain, then using an attack on the hash take a few hours to construct a block with exactly a given hash. This may require waiting until an exceptionally vulnerable block appears but that doesn't really matter.

I finally guessed what a no-malice version might look like and I found this: Scenario: disaster splits the Internet into dozens unconnected fragments Basically, bad things happen if the largest connected network is << 50%.


texts: What is the source of initial transactions of bitcoin?

texts:
Sorry, if I am wrong or silly!

It is understood that:

a) Satoshi Nakamoto sent the first transaction to developer Hal Finney on January 12, 2009, the genesis block contains 1,073 transactions and he got 50BTC as block reward, which is non spendable by design.

b) Coins are mined during block publishing.

c) A coinbase transaction must be 100 blocks deep before you can spend its outputs

d) Coins don't merge

e) For each transaction, sender should have group of input coins, whose sum should be greater than equal to sum of transaction amount and transaction fee.

What is the total amount of all those transactions and how they got BTCs for the initial transactions?


texts: What is the best way to compute UTXO of any address? Do I have to traverse whole block chain each time? Is there a efficient way to compute it?


texts: Someone has sent money to my wallet, then got them back with everything else in a wallet

texts:
I had about 0.02 bitcoins in my wallet for couple of years, but when I've started bitcoin wallet last time I've found out three transactions (two incoming and one outgoing), which I've never authorized:

4/1/18 18:51 Confirmed (2508 confirmations). Sent to (no label) 18wrbpmkwNTCyT6BYNYEenzRXKvf8ZXHHc -1.97508779
4/1/18 18:43 Confirmed (2509 confirmations). Received with (no label) 1HMpg6iHbwWmeezxfczKPH5ZK5NCTx5n5x 1.19001290
4/1/18 18:13 Confirmed (2510 confirmations). Received with (no label) 1HMpg6iHbwWmeezxfczKPH5ZK5NCTx5n5x 0.76083845

I can't fully rule out that somehow I've lost my wallet key. Although it was a local wallet on my PC in a Bitcoin Core client. And PC wasn't even on on that day. But then, they would have just transferred the money out and that's it. But here it seems to be some kind of attack, by first sending money, then cancelling transactions and getting them back with high transaction fee. It doesn't fall under any bitcoin weakness described on this page. So I'd be glad if someone help me understand what has happened.


texts:
What is the safest medium on which to store my wallet/private keys?

I avoid eWallets like the plague.

I have my wallet on my computer at the moment with the Bitcoin passphrase encryption and I have a few backups on different harddrives/USB drives.

But USB drives don't seem to be the most reliable thing to store wallets on, and I want to move my wallet off my computer for improved safety, so I was looking at paper wallets and they seem good apart from if they deteriorate over time, or from things like water damage etc.

CDs seem okay to use but they can also get scratched and can't be updated once burnt.

I'd also rather avoid cloud file services.

A plastic card that I could print my public/private keys on seemed like a good idea, but this would have to be printed by a third party as card printers are expensive, unless there's somewhere I can go to do it myself.

Any recommendations on the safest medium to store Bitcoins on?


texts: Is there a comprehensive list of registered BIP43 purposes?

texts:
Where can I find a comprehensive list of all proposed and/or used "purposes" as defined in BIP43?

So far I could only find these:

44: BIP-0044: Multi-Account Hierarchy for Deterministic Wallets
45: BIP-0045: Structure for Deterministic P2SH Multisignature Wallets
48: SLIP-0048: Deterministic Key Hierarchy for Graphene-based Networks
80: BIP-0080: Hierarchy for Non-Colored Voting Pool Deterministic Multisig Wallets

Is there a comprehensive list? or does anybody know of any other that I could add to this list?


texts: Does Bitcoin have a physical equivalent like US dollars do?

texts: I can send US dollars electronically and they get recorded electronically at my bank. However I can also get a piece of paper to represent different amounts.  For example, my bank will give me a 'hundred dollar bill' to represent 100 US dollars.  This is the largest amount of US dollars that one US bill can represent.  Billionaires would need a lot of them to carry around their US dollars.  However, at least it is possible in theory.  Does Bitcoin also support using physical paper 'bills' or is it strictly electronic?


texts: Where to find logarithmic graph of Bitcoin over time?

texts:
I'd like to find a logarithmic graph of the value of BTC vs the simple USD/time graph. Any suggestions of where to find that?

Thank you!


texts: API for converting currency such as Euro/USD to BTC

texts:
Basically what I'm looking for is a reliable API that allows for the conversion of an imputed currency amount such as USD/Euro amount and a conversion would be made that would  convert the amount to BTC.

I want to also point out that I am not looking to convert hard cash for actual bitcoin. I am only looking to determine the current value conversion of a particular USD/Euro at that particular time period.

I am hoping to use this feature on a current website (HTML/PHP/ETC..) that I am working on.

If anyone can point me to a reliable API that can perform such a task please let me know. Also if you happen to have any guides in regards to implementing/using the API that would also be greatly appreciated.

EDIT:

I want to also point out that I have gathered a few API URLs from numerous websites which can be viewed at the comment section. Now my question is how do I go about choosing the most efficient API and is their any step to step guides, that guides someone in implementing a particular API?


texts: What happens when an encrypted wallet runs out of keys?

texts: Say someone wanted to be evil to the main client and set its wallet to contain one key, lock it, and then start mining. After the first block was generated, the client would traditionally create a new key to use for mining and store it in a wallet. However, as it doesn't have the password in memory, it can't encode the key. How would the client respond in this situation? Use an old key for generation, store the key unencrypted, or do something entirely different?


texts: How Can I import Multibit Private Key into Electrum or Blockchain.com

texts:
I am having trouble importing a multibit private key into electrum and blockchaing.com.  The key is declared invalid.
the key looks like this
U2FsdGVkX1+vNknxxxxxxxxxxxxxxU/KiWdlFKlBCv0y613C+rP2t3JMGnuR2xxxxxxxxk/gNe9S
lvv/OJQGbRJ4qP07m3CII4FLvovMg71F8cXSav15QeIxxxxxxxxf
Is this the entire key?
Or
Do I extract segments from the key above? What segment?


texts: nSequence win OP_CSV in child tx must be equal to nSeq parent tx?

texts:
When I create OP_CSV  transaction I need to set nSequence to the same number (in blocks)
e.g.

3 OP_CHECKSEQUENCEVERIFY
nSequence = 3

But when I trying to spend this tx (after 3 blocks confirmation) I have to generate transaction with the same nSequence as parent.

Otherwise I'm getting error (when I'm trying to spend with different nSequence)

non-mandatory-script-verify-flag (Locktime requirement not satisfied) (code 64)

But I wont set the nSequence to child transaction, because, in this case, I can't spend immediately child transaction.

Do I need to set some flag or something?


texts: How can I verify my wallet.dat file against an older version?

texts:
I recently ran into an issue with an unsafe shutdown corruption on an NTFS partition in such a way that the files all existed, but chkdsk had to be run to verify some non-essential files.

My peers.dat file was the only file chkdsk complained about, but I verified my blockchain to be sure. How can I ensure my private keys in my current wallet.dat match the ones in my backup? I don't believe it is corrupt (At least Bitcoin-QT hasn't complained yet), but I'd rather be safe.


texts:
There are two formats of mini private keys, one is based on SHA-256, other on PBKDF2. In the instructions for decoding the second one, we read:

"The iteration count is determined as follows: 2 ^ (n/4) rounded to the nearest integer, where n is the second byte."

Does the rounding refer to the value of (n/4), or 2 ^ (n/4)? For example, for n=9, we have:

n/4=9/4=2.25
2^(n/4)=2^(9/4)=4.75682846

If we round the result of the second equation, we get 5, but if we round the result of the first equation, we get:

2^2=4

Which is a bit of an inconsistency.

Where should one apply rounding for calculating the proper PBKDF2-encoded mini private key?

EDIT:
Moreover, should the division by 4 should be carried out arithmetically (rounding the number to nearest integer, with 0.5 being rounded up), or by a logical shift (the number is rounded down).


texts: How can I use multi signature addresses with Bitcoin Core?

texts:
Using the instructions on the debug window, I created a multi signature address as below:

addmultisigaddress 2 "[\"Address1\",\"Address2\"]"

MultiSigAddress

My understanding is that one needs the private keys of Addres1 and Addres2 to be able to spend from MultiSigAddress. Is this correct?

I sent some btc to MultiSigAddress, both Adress1 and Adress2 belong to me and I can go to coin control panel select MultiSigAddress as input. It will send the transaction without any problems.

What if one of the addresses belonged to someone else? How could I use the funds on MultiSigAddress using Bitcoin Core in that case?

Thirdly, the address I created in this case is 2 out of 2. What if I wanted to create an address that is 2 out of 3? How can I create that using Bitcoin Core? Or is that only possible for multi-sig transactions?


texts: Who generates the Bitcoin mathematical puzzles?

texts: I would like to know how it is generated and who generates the mathematical puzzles within bitcoin, and how is its generation mechanics and how it also verifies transactions.


texts: For lightning network, can I surround myself with a bunch of nodes to increase anonymity?

texts:
Let's say I'm on a Lightning Network. Can I create a bunch of nodes, and do all my spending through those nodes?
Can you hide the fact that these nodes are likely controlled by the same person?
How often would you need to contact the blockchain? Would doing so compromise privacy?
(You may assume that every network action is done from a different IP address.)


texts: bcoin chainldb Resource Temporarily unavailable

texts:
I'm trying to run a script that retrieves transactions from the blockchain. When I run the script though I get the following error:

Error: IO error: lock /home/bucko/.bcoin/testnet/chain.ldb/LOCK: Resource temporarily unavailable

Here is the JS I'm trying to run:

'use strict';

const path = require('path');
const bcoin = require('../..');
const Chain = bcoin.chain;
const Logger = bcoin.logger;
const util = bcoin.util;

const HOME = process.env.HOME;

// Setup logger to see what's Bcoin doing.
const logger = new Logger({
  level: 'debug'
});

// Create chain for testnet, specify chain directory
const chain = new Chain({
  logger: logger,
  network: 'testnet',
  db: 'leveldb',
  prefix: path.join(HOME, '.bcoin/testnet'),
  indexTX: true,
  indexAddress: true
});

(async () => {
  await logger.open();
  await chain.open();

  const entry = await chain.getEntry(50000);
  console.log('Block at 50k:', entry);

  // eslint-disable-next-line max-len
  const txhash = '7f5990b008a2d0fc006d13b15e25d05ff30fadab656d49a5c6afea0e0d0b458c';
  const txmeta = await chain.db.getMeta(util.revHex(txhash));
  console.log(`Tx with hash ${txhash}:`, txmeta);

})().catch((err) => {
  console.error(err.stack);
  process.exit(1);
});


texts:
Trying to mine using cudaminer but I keep getting JSON error 1, here is the batch file

cudaminer.exe -H 1 -i 1 -l T9x20 -C 2 or -H 1 -i 1 -l T12x32 -c 1 -o stratum+tcp://global.wemineltc.com:3333 -u omarqureshi.1 -p x -I 13


texts:
I see a few different levels here and I want to clarify
There's various levels where your password could be potentially exposed... at least from my mind

Storage (paper wallet, metal wallet, cold storage wallet)
Device (Phone, Computer etc.) i.e. Apple, Microsoft, Google (device makers)
Interface (Mobile App, Desktop App) (how do we know which are safe?)
Internet provider? (if it's https secure do we need to worry here?)
Miner? (is it at all possible for miners to manipulate your transaction?)

On what levels are we the most vulnerable?


texts:
I'm using Bitcoin core v0.15.1 and I am trying to send my BTC to coinbase. I have waited over 72 hours since initiating a transaction and when I right click the "abandon transaction" and "Increase fee" options are still not available.

I selected minimum fee under custom and didn't use the recommended. I don't want to further mess things up and some of the answers on here seem kind of technical is there a way I can just right click an abandon transaction if its still unconfirmed for almost 4 days now?

I also only have a mac computer and when I try running bitcoind from the "bin" folder I can't type anything at all in the terminal the commands do any of the commands like -zapwallettxs. I also have never used the terminal before.

All I want to do is gain access to my bitcoin and cancel Transaction ID: 3f749994629bd22808733e98cde83fa9c85d7124b7e616df5c78420f9b573341


texts:
A few years ago I purchased some bitcoins from MtGox and decided to retrieve them to the wallet on my PC.

Now without getting into detail I got sick of the headaches and ended up uninstalling the program before I received ANY coins. In retrospect I could not have been a bigger idiot.

Now these coins are worth a small fortune and I've done everything I could think of to retrieve them. I contacted MtGox and all they could say was that the network says the transaction shows as complete. I have extensively and on a byte level searched the PC in question for remnants of my private key, with no success.

Which brings me to the question at hand.

I still have my public key, the knowledge the coins were never received and access to the MtGox account they were sent from.

What can I do? MtGox simply left it at "the network says it was completed, therefore fuck off"


texts:
I recently tried to get started in Bitcoins, bought some online and received on an armory wallet. Little did i know i needed to download the full blockchain, that i have no space for.
I tried to sweep using armory private keys (wallet/backup this wallet/export key list) into electrum and several other wallet but the wallets can't seem to recognise the keys since the "sweep" button always stay grey.
I also tried to send the bitcoins to another address using omniwallet but armory can't recognise and sign the transaction file.
What can i do ? I feel like i'm out of options


texts: Is it safe to keep ONLY a time-locked tx?

texts: What if the tx become incompatible with future versions of Bitcoin? In which cases it would just stop being compatible? If there is no compatibility guarantee, how can this be useful at all?


texts: Performance and modularity of Bitcore vs Toshi

texts: I have been reading about both, BitPay's Bitcore and Coinbase Toshi, and although they both claim to be highly scalable I could not find information in order to compare them in terms of performance and modularity. Does anybody knows about this?


texts: What happens to transactions included in extinct or invalid blocks?

texts:
I have read that a block contains several transactions.

An attacker can forge fake a block.

The blockchain is safe because the system will choose and keep the longest chain.

So the fake block will be lost.

This is great but what happens if my transaction was included in the fake block?
Let's suppose I am buying a car. Should I wait for 6 confirmations to be sure? That would mean that I have to wait one hour!


texts: My transactions regularly have to be rebroadcast. Why? How can I fix it?

texts:
I run a small Bitcoin related service in which bitcoins get sent out my users regularly throughout each day via my bitcoind node. Once or twice a week some of the transactions don't seem to be properly broadcast, and when pushing manually using Blockchain's pushtx tool, Blockchain will respond with Unable to find inputs: [...] (where the ... is one or more txids)

Pushing the inputs listed will usually solve the issue, but why is this necessary in the first place? How can I fix it? I hope I'm describing the issue well enough; I'm finding it hard to explain.


texts:
This question is similar to previosuly asked question Start a Private Bitcoin Network but since I can't comment there I am asking again.

I am working on a concept specifically for existing bitcoin so the suggested methods of litecoin or regtest are not applicable for my purpose. I need to simulate a bitcoin network over my LAN/Wifi and it would be great if someone could point me towards a method to do it.


texts:
Is there anyway to create an IRA with bitcoins that doesn't involve giving up my keys -- a non-custodial account?

I know, for example, that Bitcoin IRA will create a bitcoin-funded IRA, but I won't actually own the bitcoins since they will set up a custodial account.  I suspect the answer is a flat "no" since the IRS requires IRAs to have administrators.  But maybe administration != possessing the keys...


texts:
I want to know if it is safe to use online wallets? Can we trust online storages which stores our privkeys, passphase and wallet.dat files?

I read that at least one android wallet was hacked so I think this is not safe when private keys stored into foreign remote storage. Maybe I misunderstood something?


texts: Where are the non-scriptPubKey outputs in the chainstate leveldb?

texts:
I read
https://bitcoindev.network/understanding-the-data/
and it explain that the leveldb of the chainstate contain transaction with at least one unspent output.

And it has "The scriptPubKey and amount for those unspent outputs."

But I read somewhere any OPCODE script is possible for an output.
Where are the non-scriptPubKey outputs?


texts:
I am running LN node powered by lnd. Also I have installed on my phone a LN  app - Bitcoin Lightning Wallet. I opened a channel from mobile app to lnd node sucessfully (many confirmations), but I cannot request money from the mobile app with only two 'errors':

Receiving not yet enabled by peer (View channel details screen)
Can't ask for Lightning payments because your peer has not allowed receiving yet, this typically happens once a funding Bitcoin transaction gets
confirmations (Receive funds screen)

In lnd (lncli listchannels) i see the channel as inactive ("active": false) , but the other channels opened from lnd are active.

Could you please advise what can I do before I close the channel ? Or explain what I didn't understand? How to bring the channel to active state? My opinion is that mobile wallet is not working well, because I can't generate invoice (payment request). I don't know.


texts: Gift bitcoin more than the annual limit to a friend overseas without tax implications?

texts:
If I am gifting my friend say $100k work of bitcoins or any other crypto. Do I have to pay tax apart from the annual limit of $15k. Or will it be cut from my life time limit? My friend he live in a different country, so does he needs to pay tax when he sells this crypto?

Please give me information on this to understand the tax laws and to do nothing illegal.

Best Regards.


texts: Segwit change address from Regular address

texts:
I would like to move my bitcoins to a Segwit Electrum wallet, however - I don't want to pay the high fees for the initial transfer.
I though about using the change address, so that when I make payments with the regular Electrum bitcoin wallet, the change will be automatically sent to the Segwit address. Is it possible with the non-Segwit Electrum wallet? How do I set it up?


texts: Is there a Bitcoin exchange which has bank accounts in South Korea?

texts: Is there any exchange, or a website selling Bitcoin, which has a bank account in South Korea?


texts: I am looking for the most basic blockchain technology implementation. What is the simplest crypto-currency?


texts: How can blockchain send my all money without any notification??

texts: Yesterday  I made deposit  in blockchain wallet and  after that next morning  when i chk my Wallet  all bitcoin  were sent to an address  even i didn't made any transaction  how can any one tell me and this was my first  transaction  in blockchain can anyone know jow to recover  my fund


texts: Is there a Bitcoin service that works like Western Union?

texts:
I am very new to using Bitcoin.  I have never actually used it yet.  My goal is to send a payment of $100 to a trustworthy individual in China.  I was given some sort of address by this individual when I asked how/where to send payment.

Is it possible for me to simply go to a physical agent location near my address to make this payment, then have the agent send my payment to the recipient (similar to how western union and money gram work)?

I am very intimidated by how this all works.  I would love to simply do this on my own computer, but even creating a credible "wallet" has been confusing for me.

Any comments or help are greatly appreciated!!

Thanks


texts: How are transactions hashed together to form a Merkle Root?

texts:
In block #59,500 there are 2 transactions

Transaction 1. 6653ad77d695752cff9fe63bbb5702a53807be534c537251d53de06aac5ca093

and

Transaction 2. 72e8781092c01e9eb1c21ba33d52ad6abc42f3807601bcd8b8074d583446346e

Would you double SHA-256 transaction 1 and then double SHA-256 transaction 2 and then combine those and double SHA-256 that value to get the Merkle Root?


texts:
Economies of scale are powerful and Bitcoin growth has been substantial over the past few years. Unfortunately much of the world including those in the 3rd world (many unbanked) who may need it most have yet to embrace Bitcoin.

Could distribuition statistics cause hesitation among later adopters? Some early adopters mined or purchased 10,000+ (even 100,000 in a few cases) BTC when they cost pennies each. Will that be enough to discourage those in the third world who might only be able to afford a fraction of one Bitcoin now?

Even if distribution does bother some people, will the economy of scale Bitcoin already enjoys versus all other cryptocurrencies (with different distribution models) be too much to make any alternative viable?


texts: Why is it important that miners mine at the end of the longest branch?

texts:
In this paper, the authors present a simplified description of mining strategies. The strategy which they call "honest strategy" is to always mine a block at the end of the currently longest branch. They claim that, if a miner has a very large computing power (above ~45% of the total power in the network), he might gain a higher profit by deviating from this strategy and using a "dishonest strategy" - mining at a shorter branch - hoping that at some point his branch will become longest and be accepted by the community.

They claim that this "dishonest strategy" is problematic, but I do not understand why; what can happen to the bitcoin network if some miner will use this "dishonest strategy"?  As far as I understand, he will not be able to create a "double spending", since such a double spending can be easily detected by any other node reading his branch. So what else can happen?


texts: datadir compatible between 0.14.0 and 0.14.1

texts: I have a raspberry pi with bitcoin core (0.14.1, self compiled) and a macOS system with bitcoin core (0.14.0, binary from bitcoin.org). I am storing the blockchain (complete datadir) on an external hard drive. Can I expect to plug this hard drive in my macOS system, sync it and later plug it into my raspberry without having any problems?


texts:
I recently got a new bitcoin wallet from bitcoin core and it is taking fort to sync, during the sync it gave me an address I sent bitcoin to however due to complications syncing, the address is no longer in my recieving addresses, will it still be saved with the wall.dat file with the bitcoin core files automatically? If not how do I add a custom address to s new wallet to receive the bitcoin if not
Thanks


texts: Cannot sign txn with change address using bitcoinjs-lib psbt

texts:
I am having a difficult time figuring out how to sign a spend from a change address. I get Error: cannot sign for this input with the key <value>. The initial transaction works fine, where I generate a transaction with multiple inputs to two outputs, one of them being the change address - it is the same as the spender addresses. Here are the steps:
1) I grab all UTXO for our spending address.

const unspentTx = (await listUnspentTxByAddresses([mainAddress])).data.result;

2) I add all inputs and outputs, sign, finalize, and submit.

  const fee = new BigNumber((await getEstimateSmartFee(2)).data.result.feerate)
    .times(100000000)
    .div(3);

  const output = {
    address: destinationAddress,
    value: parseInt(pullAmount.minus(fee).toFixed(0)),
  };

  const senderBalance = sum
    .times(100000000)
    .minus(pullAmount)
    .minus(fee);

  const change = {
    address: sender,
    value: parseInt(senderBalance.toString()),
  };

  // Adding the output
  psbt.addOutput(output);
  psbt.addOutput(change);

  for (let i = 0; i < txids.length; i++) {
    const transactionObject = await getTransaction(txids[i]);

    const input = {
      hash: txids[i],
      index: 0,
      nonWitnessUtxo: Buffer.from(transactionObject.data.result.hex, 'hex'),
    };

    try {
      psbt.addInput(input);
    } catch (e) {
      console.log('Add Input Failed e =>', e);
      return null;
    }
  }

  const key = bitcoin.ECPair.fromWIF(privateKey, testnet);

  for (let i = 0; i < txids.length; i++) {
    psbt.signInput(i, key);
  }

  psbt.finalizeAllInputs();

  const rawTx = psbt.extractTransaction().toHex();

  const withdrawPendingTx = await sendRawTransaction(rawTx);

This works the first time around, but as mentioned, the second time I call
await listUnspentTxByAddresses([mainAddress]) and follow the same exact procedure, the js library validation prevents signing with the main address key. It doesn't seem to make sense, so I hope there is an obvious error here. I'm pretty sure it's sent as a default P2PKH with SigHashAll.


texts: How to make Bisq open Bitcoin Core as it used to until last version?

texts:
(A few days ago, I asked this on Superuser, but it was one of the many ignored questions, and this category seems more relevant as it actually has a Bisq tag.)
I have used Bisq on Windows for a long time. Starting with the last version, or perhaps two versions ago or so, it has broken in a subtle way. I can still use it, but it's very annoying.
The issue is that the button called Open your external wallet for funding has mysteriously stopped working. Previously, when clicking it, it would open up Bitcoin Core with all the data filled in to make a Bitcoin transaction.
Now, it simply opens File Explorer at "My documents". Huh? I don't get how that can be possible, but it is.
I've:

Looked all over the Bisq GUI for any "settings" or "configuration" to set the path to Bitcoin Core. No such thing exists.
Looked in the ".cfg" file in the Bisq directory. It contains nothing relevant.
Searched online. Found nothing.
Looked in the Windows 10 settings for "default apps" and "protocols". Bitcoin Core/Bitcoin/Bisq is not mentioned anywhere there, and there is no (obvious) way to add one.

I would make an issue on Github or their Reddit if those sites allowed me to register accounts, which they consistently don't. So I cannot ask there.
What to do about this? What could explain that it has stopped working?


texts: How to compile headless bitcoin-qt for Ubuntu

texts:
OS : Ubuntu 18.04
Bitcoin Version : Latest Master Branch
I have installed all required dependencies and compiled bitcoind, and bitcoin-qt successfully. The GUI app runs fine on the system I compiled it. But if I send it to my other Ubuntu 18.04 system and run it, it gives me error dependencies error, example libzmq missing. If I install libzmq5-dev, it give me other dependency error until I install all the dependencies.
As a normal user, I want to use the wallet out of the box without needing to install anything. How do I achieve that ?


texts: Can't get the tx with gettransaction or getrawtransaction methods

texts:
I am running bitcoin-d (probably downloading the prev blocks) in a shell.
In another shell i am trying to get the information of a transaction (0627052b6f28912f2703066a912ea577f2ce4da4caa5a5fbd8a57286c345c2f2) with bitcoin-cli. I can see that tx on blockchain.info but when i tried it with gettransaction and getrawtransaction it didn't work out. Does anyone know why is that?
screenshot below.


texts: Is there anyway I can be notified on my phone when I receive bitcoin?

texts: I am not talking about getting notified on my desktop, but I am talking about my phone.


texts:
I follow the instruction on this post to create bitcoin address from given hex private key

In vanitygen.c
Replace

EC_KEY_generate_key(pkey);

with

  BIGNUM *res;
        BN_init(&start);
        res = &start;
        BN_hex2bn(&res, "3B1BCC5A67F38853810972B1DA8A67148FAD78C6CD6F22B2C823D141BE59C81C"); //Set up hex private key
        vg_set_privkey(res, pkey);

& remove case

if (++npoints >= rekey_at){}else{}

The input key will be replace with hashcat feature like this

"?1?1?1?1?1?1?1"+"A67F38853810972B1DA8A67148FAD78C6CD6F22B2C823D141BE59C81C"

I test it with single key first & notice the function still multiply the key which give a slightly different private key from the original & use my restore function, it only generate few hundreds actual private key & multiply the rest. No matter how i edit the "ptarraysize" value, it doesn't make CPU run on 100% power. Is anybody know to how to adjust the code to check address from mutiple generated key without multiply it. If possible, the performance will stay around like original vanitygen code or at least decline to 1-20 times, i wouldn't mind that. Thank You


texts:
The blockchain consensus seems to be very related to the Game Theory, when each participant tries to achieve their "favorites", where defining "what favorites means" is not very easy, since a participant may ex. intends to gain more coins, while another one tries to destroy the system and decrease its reputation as a "competitor crypto-currency" etc.

However, in the Game theory Wikipedia page, there is a list of "Game types" such as :

Cooperative / Non-cooperative,
Symmetric / Asymmetric,
Zero-sum / Non-zero-sum,
Simultaneous / Sequential,
Perfect information and imperfect information,
Combinatorial games,
Infinitely long games,
Discrete and continuous games,
Differential games,
Evolutionary game theory,
Stochastic outcomes,
Metagames, Pooling games,
Mean field game theory ...

Regarding to above explanations, what types of these Game Theory are more involved in the blockchain consensus?


texts: 10 Days Unconfirmed. Transaction Fr. Blockchain Wallet

texts:
I sent a transaction on Dec 12. It is now the 22 and its still unconfirmed. I paid $17 in miner's fees... and still. 10 days later its still stuck. I've tried ViaBtc, and Antpool accelerator to no avail. Still stuck. PushTx.Btc is $500 as are two other services I tried. Not sure what to do.

tx
24f2df7d517dbf03447a279a1d3f6e5db82fc1760cf78178b0a7bf80a35389d0

Please help

PS> I have written to Blockhain, and they said they do not accelerate nor confirm transactions

PSPS> CPFP: Does this mean that I send more money to the SAME wallet address and pay more on the second transaction?


texts: What will happen when SHA 256 needs to be replaced?

texts:
MD5 used to be the hash algorithm. Everyone loved it, but now, not so much.

What will happen to bitcoin if flaws are found in SHA256 in the future?


texts:
According to this site there are 3,260,162.5 bitcoins left to be mined. Do you know if eventually Bitcoin mining will stop after that? If yes which other cryptocurrency can be mined for ever?

Thank you


texts: Where can I safely sell a Casascius version 1 physical bitcoin (with hologram error) for cash?

texts:
I have one of the Casascius coins (this one, to be exact) that contains an error: the small lettering on the hologram reads "Casacius", without the second 's'. I'm a inexperienced when it comes to all things bitcoin, as well as all things collectable.

I understand that one can sell these coins for a premium over their BTC value. Where can I put the coin up for sale relatively safely? I'm willing to sacrifice getting the highest possible price in order not to get scammed.


texts: How wallets/ miners differentiate bitcoin and bitcoin cash (forks of cryptos)? (technical IT question)

texts:
I could not find the answer by web search. People usually interested in economic differences. I guess it is a question for those who know how mining algorithms works.
Internet is kind of decentralized. But there is single domain servers grid that tells where to find google.com. In a world of cryptos, how do wallets know where to send your BTC / BTC cash transaction? How to differentiate between forks? Is there some list of agreed gateways like for TOR? If so who administers it?


texts: How do they know which chain is the real one?

texts: Basically how are chains kept in sync so that there is only one main chain?


texts: What happens to SHA256 based cryptocurrencies when encription break takes no time?

texts:
There is 49 qbit quantum processor already, there are predicted trends of time to facror.

So what happens to SHA256 based cryptocurrencies when encription break takes no time and all transactions on all blocks are decripted in a day\month?


texts: Why are there so many fake cryptocurrency airdrops?

texts: I started learning about cryptocurrency three months ago and I have come across many airdrops spread by scammers who disappear after many persons have signed up on their platform. Are there ways one can identify the scammers in the crypto space?


texts:
When opening my Trezor Wallet on Chrome I get a message:

  The TREZOR Chrome Extension will be outdated soon.
  Google will disable the functionality required by the TREZOR Chrome Extension during this year.
  To avoid any service downtime, please install the TREZOR Bridge instead.

So I installed Trezor Bridge 2.0.14 on a MacOS High Sierra 10.13.3 but the website is still not recognizing the installation. It still says that it is not installed even though I used the Mac's Installer and everything went fine.

How can I install it properly or make the website recognize the installation?

EDIT: This is what I see after installing Bridge but then when I refresh it still says it is not installed. There are no additional icons like blocked popups or something like that in the url bar.


texts: do i get a new private key for every transaction that I transfer to my cold storage

texts:
If I buy crypto in little bits at a time and I transfer to the cold storage wallet every time I buy some, would a get different private keys for each transfer? how to keep track of all those keys?

For example: If I buy 10 cryptocoins today and I store in my hardware wallet and I get private key A, then I buy 15 cryptocoins next week and I again transfer it to my hardware wallet, will I get private key B for the second transaction?
Thanks
Eve


texts: When monitoring incoming transactions for a web wallet, should I check for confirmations on a timer, e.g. every minute? Or should I check once every block by using blocknotify?


texts:
I was attempting to learn more about LN and came across the post below.

https://medium.com/tokensoft/tokensoft-lightning-node-how-to-connect-for-free-62b9aaec18b8

I also made a picture of my interpretation of the instructions.

In it, the suggestion is made that Nodes 1, 2 and3 connect to the his own (main) Lighning Node.

The purpose of this exercise is for Nodes 1, 2, and 3 to "gain access to the Lightning Network" altogether.

I was wondering if this would not be an exercise of futility (since the channels are funded with such small amounts).

TIA


texts:
Take this Bitcoin transaction:

https://www.blockchain.com/en/btc/tx/bad181b4bf50342e5226982ac5031d8b9ce670053d3b5c7502b0ff349a5f2838

In my Ledger Live, I can see that 0.3881168 BTC left the wallet:

Which is weird, because I actually sent only 0.3878 BTC to 16fPHhrdaBuRNPH1YbEqC4fDE8tCUXNmuM, with the remainder 0.00065121 BTC being one of my newly created UTXO whose value was credited back to my wallet.

Why does Ledger Live not show the actual spent amount but instead the gross amount which is the sum of all used UTXOs? How can I only see the spent amount?


texts: If Bitcoins aren't tied to a conventional currency, how did they get so valuable?

texts: I would appreciate it if  someone could provide me with some insightful information.


texts: Bip39 tool - BIP32 Extended Private Key vs BIP32 Root Key

texts:
In the bip39 mnemonic tool there is three sections :

Mnemonic : we input our words or a BIP39 seed and the tool compute for us the BIP32 Root Key
Derivation Path: there is a BIP32 Extended Private/Public Key
Derived Addresses

Questions :
1- If i want to use Electrum wallet and I have already a wallet. Which key should I have to import ? What is the difference if I import the BIP32 Root Key or if I import the BIP32 Extended Private Key ?
2- Should I use BIP44 instead of BIP32 to import my wallet in an Electrum one ?


texts:
I am completely new to Bitcoin.
I am trying to connect Slushpool using BFGminer, but its showing some USB device not detected?
I am a newbie and don't know which device it needs.
What should I do?


texts: dumpwallet output documentation & explanation?

texts:
Where do I find complete documentation on what the console command "dumpwallet" output means?
Sample of my testnet output:
# Wallet dump created by Bitcoin v0.21.0
# * Created on 2021-01-21T16:59:50Z
# * Best block at time of backup was 1905234 (00000000e26170d0f846a334a1bfdfebe8da906c5),
#   mined on 2021-01-21T17:05:05Z

# extended private masterkey: tpR2efnJMh85ufpQcYSTwrrKrYJ

cTdH4SbvTR 1970-01-01T00:00:01Z label= # addr=mnb8RSpTqvhLh8Q6,2MudYFE2awqc,tbvhpur8zf35ql3yx5h9nu
cRaKzuR9MCVwAxVa3aAZrVh15YbV 2019-08-26T01:19:00Z reserve=1 # addr=tb1q3qc52q hdkeypath=m/0'/0'/222'
cT2ozo5xcj6iCe4dTfywan3qJnib 2019-08-26T01:19:00Z hdseed=1 # addr=tb1qzqtu25qsue0a5pp3hg8lkftclf8ds
cNb2K9tUhQaeXiVz2Jt2Wq9DMLdf 2019-08-26T01:19:00Z reserve=1 # addr=tb14d7lx hdkeypath=m/0'/0'/117'

.....4040 lines
# End of dump

What's "hdkeypath"?
What's "reserve" ?
What's "hdseed"?
Why does "addr" sometimes have 1 address and sometimes 3 addresses?
Why does my dump have 4040 lines?
(for purposes of formatting & discretion, all addrs/keys are mangled)
This is the best I could find. It offers no detail about the output:
dumpwallet


texts: Is there a safe way to use bitcoin based online services?

texts:
Today I've seen new service www.spend-a-bit.com.
Idea is good, however you need to send them bitcoins first and then you get your balance.

Question is: Is there any way to make online services safe to use, without worrying that you send bitcoins, but never get anything back?

Examples, which come to my mind:
1) Some website takes responsibility as dispute system. You send them first, then receive balance, then they send it to merchant. In case of arguments they check if sides kept their promises. It always takes time to figure out, which makes it less attractive for scammers.
2) Just some public ratings for services. Where everyone can report scam


texts: How to generate a valid hash for a bip39 seed phrase?

texts:
I'm trying to prove to myself that I understand how bip39 seed phrases work...  I'm doing most of this in a spreadsheet because I thought it would be easier but I'm having trouble with the checksum value...  These are the steps I'm taking:

I start with a valid 24 word seed
then change each word to its index value
then change those to a single 264 binary digit string
then change that to a 66 character hexadecimal string
I manually enter the first 64 hexadecimal characters into a
binary editor to create a 32 byte file
then I use the linux terminal command 'shasum -a 256' on that 32 byte file to get the hash

However, the leading byte of that hash does not match the last byte of the 66 character hexadecimal string from above...

As I understand it, 24 word bip39 seed phrases have a single byte checksum value at the end.  That checksum is the first byte of a sha256 hash of the first 32 bytes of the number encoded by the seed phrase.  But, so far, I haven't been able to supply a 33rd byte that reproduces a valid seed phrase...  Any suggestions?


texts: What are the implications of BIP 12 vs BIP 16 and OP_CODEHASHCHECK?

texts:
There is a discussion about two different Bitcoin Improvement Proposals - BIP 12 and BIP 16, and probably only one of them is going to be included in Bitcoin 0.6 (miners will decided which by a majority vote of mining power). LukeJr proposed an alternative to BIP 16 called OP_CODEHASHCHECK.

Can anyone summarize the core differences between the three proposals, and their respective advantages / disadvantages?


texts: What were some discussed and current potential issues with pre-forked Bitcoin coins from August 2017 that have never moved since then?

texts:
I was speaking to a friend that mentioned that there were issues with pre-forked Bitcoin coins from Aug 2017 that never moved. He wouldn't tell me exactly what the potential issue was, but what were some discussed or potential issues with these unmoved pre-fork UTXOs?
Is it a potential double spend that could happen on these coins that never moved?


texts:
I am trying compile bitcoin on Debian 7 Wheezy (64bit) but I am encountering the error Fixing libtool for -rpath problems.

I installed all dependencies

sudo apt-get install build-essential libtool autotools-dev autoconf pkg-config libssl-dev
sudo apt-get install libboost-all-dev
sudo apt-get install libdb4.8-dev libdb4.8++-dev (like that http://askubuntu.com/questions/290094/libdb4-8-is-no-longer-available
apt-get install miniupnpc

$ ./autogen.sh
$ ./configure
...
configure: creating ./config.status
config.status: creating Makefile
config.status: creating libsecp256k1.pc
config.status: creating src/libsecp256k1-config.h
config.status: src/libsecp256k1-config.h is unchanged
config.status: executing depfiles commands
config.status: executing libtool commands
Fixing libtool for -rpath problems.

What is the solution to fix this error?


texts: Why can't timestamps be a substitute for blockchain?

texts:
I'm super fascinated by the entire concept of proof of work and how it allows for a trustless, decentralized system. Despite knowing that proof of work (or proof of stake) can be an inevitable necessity to having a cryptocurrency like Bitcoin, I'd like to fully understand where other methods fail.

The first problem Bitcoin addresses from my understanding is signatures with each transaction. To me, this completely makes sense, as it is completely necessary to be able to verify that the sender indeed was the creator of the transaction. But then the next problem is transaction order and validity to prevent double spending. I don't understand completely why a timestamp can't just be included for every broadcasted transaction, and the transaction could have the correct, universally agreed upon time, and each ledger gets sorted chronologically. Is this because it requires a centralized system to prevent people from forging timestamps? Or what am I missing? To me, it seems like if the transactions were broadcast publicly to the entire network, there wouldn't be conflicts in ledgers / double spending.

And how exactly does the main blockchain stay decentralized? Let's say I go offline and miss transaction broadcasts, and now I want an updated version of the main blockchain. I would have to rely/trust others for this main blockchain, which seemingly is centralized now in the way that all new users are pulling from this same copy of the blockchain. I don't quite see how that's different from the analogy with a community ledger with everyone just keeping their copy updated with that, or a main branch on a git repo which everyone continually pulls from. There is no single point of failure, but it seems to still be a community ledger in a sense.

I am completely well aware that the "solutions" I presented above have faults somewhere that I'm missing / scenarios in which these will fail which I haven't considered, and I'd like to understand exactly why a proof of work system is necessary in these scenarios. And, how it can stay decentralized and trustless despite having characteristics described in the above paragraph. This, I believe, will help me understand the true beauty of it.


texts: What happens to old transactions in case of a fork?

texts: I'm confused about forking. What happens to the 'old' version of a blockchain and related transactions/data in case of a fork. Can they still be deleted or does the new branch still depend on them to ensure continuity?


texts: Block Chain length/size may one day get unwieldy to compute

texts: Is it possible that the length of the existing block chain will one day become unwieldy to compute? Would it make more sense that the chain would somehow be rolled up like normal bank ledgers do with opening balance for every account every year?


texts: Does the client broadcast it's version? Is it possible to determine which version of client are in use?

texts:
When the client communicates to other clients does it transmit its version?  If so is it only on certain communications (i.e. originated transactions)?

Can this data be captured?  I would be interested to see if it is possible ot determine which versions are in use and hopefully combine that with geo-location data to map the bitcoin network by client node version.


texts: Trying to understand how bitcore-node stores the data in the DB

texts:
I'm looking into the data and source of bitcore-node ( http://bitcore.io/ ), I'm a bit confused how all the information is stored in the database, probably it's in a similar way to others block explorers, so maybe someone could help me.

In this case for example https://blockchain.info/tx/acb2e895a9b3664cfcfb13dd0321ef0c1205cf2aa082681dc6ba424af6456a42

In the database I found two txo- txo-acb2e895a9b3664cfcfb13dd0321ef0c1205cf2aa082681dc6ba424af6456a42-0

{"prevTxId":"8697331c3124c8a4cf2f43afb5732374ea13769e42f10aa3a98148a08989af5e","outputIndex":1,"sequenceNumber":4294967295,"script":"4730440220106c316c22d4bf8c970f8e4b1af1edd95121397cfe29ab987cb000b478ec8e4302202b77986b89d77ab716da3cf53424efacf35e9097b1c89194df220e99503b8cae01","scriptString":"71 0x30440220106c316c22d4bf8c970f8e4b1af1edd95121397cfe29ab987cb000b478ec8e4302202b77986b89d77ab716da3cf53424efacf35e9097b1c89194df220e99503b8cae01","heightConfirmed":37514}

txo-acb2e895a9b3664cfcfb13dd0321ef0c1205cf2aa082681dc6ba424af6456a42-1

{"satoshis":10100000000,"script":"76a91427d25a1ff9a6da31eeb991c48bb6cd95191a6b2c88ac"}

Clearly different data, not sure why in one case we store the previous txid and in the other just the satoshis sent. It has to be obvious, but not sure what I'm missing here.

Another example https://blockchain.info/tx/00eff263871e6d44abed66d90abb10d5a211441668511dba3146e380360efe4b

txo-00eff263871e6d44abed66d90abb10d5a211441668511dba3146e380360efe4b-0 (from 0 to 5 all have similar data)

{"prevTxId":"6aebb4a764a027436f703ca9d42d0735423798f56973f9f236832a91fc2e9026","outputIndex":0,"sequenceNumber":4294967295,"script":"473044022057801e812f964bcb9e8ff17b37acef55afbb7119a66f24a148ba65e86a7aa1e3022064af657d280068b979ea17a29969976aedee8a664b3f1b575ebb88ef9275302601","scriptString":"71 0x3044022057801e812f964bcb9e8ff17b37acef55afbb7119a66f24a148ba65e86a7aa1e3022064af657d280068b979ea17a29969976aedee8a664b3f1b575ebb88ef9275302601","heightConfirmed":10712}

Also,... they are inputs, not outputs of the transaction.

I'm trying to read the code, but I can't get to understand all the pieces.

As someone points me in reddit, it looks like it's using txo-- to store both, outputs and inputs. So I'm not sure how bitcore manages to get the inputs/outputs separately later (the API allows you to request only the inputs for example).


texts: Security concerns when downloading the block chain from a 3rd party source?

texts:
It takes very long until bitcoin-core has downloaded the whole block chain. So I decided to download the block chain files via a bittorrent published by this website: http://www.getbitcoinblockchain.com

After the download was finished I noticed that the md5 checksums of the files from the torrent were different then of the files from bitcoin-core.

Why could that be?

Are there any security related concerns of using a block chain from a 3rd party source?


texts:
I've been observing the huge increase in the price of Bitcoin over the last month (November 2013) and I can't help but think, is someone with an ulterior motive pulling the strings here?

It seems to me that Bitcoin represents a huge threat to some very powerful people who would like to see the financial status quo maintained. If Bitcoin posed a significant threat to them, how would they combat it?

I don't think trying to govern or control Bitcoin in any way would work. If I was in that position, I would probably pour a lot of resources into artificially raising the value of Bitcoin, create a mania of publicity around it and get as many people invested into the bubble as possible. Then when it reached a tipping point, I would burst that bubble hard, make sure all those people who invested got their fingers badly burned. Killing Bitcoin by destroying everyone's faith in it...

That's why the sudden increase in value concerns me.

Is it feasibly possible for someone to artificially raise the value of Bitcoin in this way? Given that those who might want to do so would have almost unlimited financial resources, and a whole lot of influence over the media/public opinion. Could they be setting up Bitcoin for a very overt fall?


texts:
I was taking data from the BTC Blockchain with a custom script.
I found something really weird.

Block nr. 24668 was created at 2009-10-09 23:02:57

Block nr. 24669 was created at 2009-10-10 00:15:48

Block nr. 24670 was created at 2009-10-09 23:15:43

Now tell me, how it's possible that block 24670 is 'younger' than the 24669?
I already checked and all the blockchain explorer websites show exactly this data.

Thank you for your attention,

Mattia


texts: Decentralised escrow / distributed private key generation

texts:
Issue

Hi

As many others i am curious in addressing distributed escrow problem (not just for bitcoin). As it stands now there are no decentralised escrows. All escrow services are based on trust in the escrow. Obviously, this has certain limitations to the escrow reputation / other risks.

Contracts

The solution often proposed are the contracts when transaction should be signed by many participants. Consequently, they will be required to find mutually beneficial solution.

However, there are few problems with contracts (btw, they are not delivered for bitcoin yet, right?):
- Pure multi signature functionality will not work as an escrow (one of the parties can simply block the transaction). So, there is reliance on the third party
- This will work only within bitcoin. So, in the example of exchanging bitcoin for other digital asset (e. g. stock) automated / escrow that does not require trust among participants will work only for bitcoin.

Alternatives

E. g.:
Two partipants - Party A and Party B;
Party A wants to buy a stock issued in electronic form (within one of the distributed exchanges) for bitcoins. Accordingly, Party B wants to sell. They do not trust each other and there are no escrow to trust.

In theory we can argue that solution can be something like this:

Party A should transfer bitcoin to the escrow wallet. Otherwise Party A can cancel the coins after pledging bitcoin for stock. Party A should receive coins back assuming that other party have not transferred stock to the escrow (assuming stock represented as crypto asset)
Party B conducts similar actions to Party A
Certain system X (ideally distributed - as there are no trust across participants) - can initiate transaction in bitcoin from escrow wallet and at the same time initiate transaction for stock. In theory this means that system X should have Private key for public address.

Questions

Are there any solutions to come up with private bitcoin key generation on distributed network? At the moment all private keys are generated on the secured PC. Consequently, are there any options on private key generation in hostile environment. E. g. Distributed private key across other participants (http://en.wikipedia.org/wiki/Shamir's_Secret_Sharing)
Maybe someone sees other solution to this problems (outside contracts space for bitcoin)?


texts: Is there a wallet like Multibit for Litecoin?

texts: Is there a lightweight client like Multibit available for Litecoin? If not, is one in development?


texts: Using bitcoin-qt in bitcoin-core: How to tie my wallet to my email address?

texts:
I can send and receive money using listreceivedbyaddress.

How do I get my public address in Bitcoin Core?

However, I would like to connect this address to my email address.

Is this possible?
If this is possible, how to do this?


texts: Derive LTC Segwit (M-Address) private key from Trezor

texts:
So I'm trying to get my head around this!

I've got my 24 seed for my Trezor.
I got my Segwit account for LTC (Address starts with M).
I also have the P2H equivalent for my address (Starts with 3).

How do I derive using the BIP39? I tried, and I ended up with addresses that start with L. (Legacy ones).

m/49'/2'/0'/0    --> this one is for M Segwit LTC
m/44'/2'/0'/0    ---> this one is for Legacy LTC


texts: Will the Bitcoin network discredit a transaction if you do a simple transfer on a multi-sig after you found the collision on that address?

texts:
Let's say you found a collision for an address on the Bitcoin network. You have its private key.
Will you be able to transfer any money around or will the network prevent it or does it get verified?

Here's another way of putting it: Can the address generated by 2-of-3 pv/pk be accessed by a 4th pv(a collision) or the network always looks for 2 of those 3 signing the transaction. Is that clear now?
Is multisig only a way for shareholders of an address, making sure enough of them are present during a transaction, or does the network actually prevents a transfer without all the necessary signatures?


texts: NBitcoin -- How do I just check the balance of my wallet from my seed phrase?

texts:
I've looked through the docs, I've Googled, I've searched here, and it all just seems like Greek to me... I must not be using the right keywords, because I just can't figure out what I think should be the most dead-simple thing...
How can I use NBitcoin to open my wallet from my 12 word seed phrase and look at the balance? I feel like if I can just get some help getting that far, I can probably go from there to do more...
Also, does NBitcoin have an API reference guide?
Thanks all!


texts:
I have been working on Ethereum for years. Now assigned to work on Bitcoin. The way that BTC handle transaction is vastly different and utterly complicated.
After reading for quite sometime. Can I assume that for a simple website to receive and send bitcoin, I only need to handle the scenarios below:

Coin only. No colors, no assets.

Receive coin using P2PK and / or P2PKH only?

For sending I can always stay with P2PK or P2PKH is that correct?

Are the above sufficient for me to handle coins sent to my website and subsequently transfer to another account?


texts: While using Open Transaction as a Decentralized Exchange, how can one guarantee sanctity of the trade carried out by the parties?

texts:
Lets assume Alice holds 100 shares of Twitter and wants to sell those shares on Open Transactions. Bob decides to purchase those shares. They decide the terms of the transaction, price etc and sign a smart contract. The transaction gets completed. Bob pays Alice for the shares either in dollars or bitcoins etc and alice transfers the 100 twitter shares to Bob.

How does one preserve sanctity of this transaction because, Alice can repudiate this transaction at a later date. On a parallel Centralized Stock Exchange the ownership of these 100 shares will still be attributed to Alice and she will continue to get dividends etc as an owner.


texts: How can a reciever verify that transaction data was not altered by 3rd party?

texts:
My scenario:

My web server:
- Generates private and public, and a wallet address from the public key for a user website account
- Server can not connect to the outside (Can not connect to the Bitcoin network)
- Has a page that allows anyone to send money to the user account wallet address

What I need to do:
- The server needs to know when bitcoins were sent to the wallet address, and how many total bitcoins are at the wallet address

Because web server can not access outside internet, I am using Javascript on the browser side to get the wallet address info by getting https://api.blockcypher.com/v1/btc/test3/addrs/miedePxMt4SDQHjWJyfhbCWvXcm33vzDa1/full and/or https://api.blockcypher.com/v1/btc/test3/txs/681b16b4de3676a5865a85e0bba3097afcc195d928f3167e4d5591c388c1e474?includeHex=true  ... and sending that data to my webserver using a Ajax call to check for the received bitcoins.

Note: I have sent testnet bitcoins to that wallet.

Everything works except 1 problem: The browser user can easily change the bitcoin amounts and trick the web server into thinking more bitcoin were sent.

My question is: What methods can I use on the webserver to verify that the transaction data was not changed by the browser user. The web server has the pub/priv key of the receiving wallet. The webserver has the "bx" libbitcoin-explorer program available and I could potentially install other software.

Can I use the cammands in this diagram at all? https://github.com/libbitcoin/libbitcoin-explorer/wiki/Transaction-Commands


texts:
If you have a online site that accepts bitcoin deposits and users can withdraw their balance, Is  it possible to have the deposits go to the watch-only address of a cold storage and the withdraws come from the hot wallet?

If yes, then basically I'll have to give a programmer my private key for the hot wallet and just the master public key for the watch only-address on the server. Am I correct?


texts:
Is there a way I can restore my mycelium Bitcoin wallet if I have forgotten the 12-word list?

I have searched everywhere and no one describes a situation like this.


texts: What amount of hashrate can we estimate Google's 53 qubit Sycamore quantum computer could yield?

texts:
Could Sycamore be programmed to perform massively parallel SHA256 searching?

If so, how much hashrate do you estimate this 53 qubit machine could yield?

Is there enough public information to be able to estimate this or do other factors such as the computer's memory and QPU architecture come into play?


texts: In a bitcoin multi-sig wallet, can i determine which of the m of n keys were used to send bitcoin?

texts: I'm particularly interested in this for large n multi-sig wallets. For example, if m-of-n is 4-of-6, and 6 different people (e.g. 6 non-profit co-directors) hold each of the n keys. If one day all of the wallet is emptied just using 4 (m) keys, will the 2 (n-m) people be able to determine which were the 4 keys and thereby the 4 co-directors that emptied the wallet?


texts: Does the percentage of fluctuation remain the same regardless of the value in all wallets?

texts:
This was initially going to reference this question here

I, as well, have $10 bitcoin in my wallet, I notice the value does fluctuate. However, will the value fluctuate the same in a $100 wallet, as if it were $10?

In other words, my $10 is now $11.72, does that mean the value of a $100 wallet will be $101.72, or will the value be much higher?


texts: How to work out my hardware's hashrate power

texts:
Using my existing hardware, I want to work out which altcoin is still profitable to mine.

I have found this link:

http://dustcoin.com/mining

But don't know which values to enter into the boxes at the bottom of that page.

How do I work out the SHA-256 and scrypt hashrate
For the Power(W) box, do I enter in my computers PSU wattage? I think it's 650w
For the Power Cost ($/kWh) box, do I check my electricity bill to find out how much I am paying per kWh?


texts: Transfer incoming funds from Bitcoin Core to another wallet before blockchain sync is completed

texts:
This is my situation:

I have a Bitcoin-QT wallet on my Mac (Qt version 4.7.4.- yes I know its very old). only recently I've been working out how to operate and exchange bitcoins. well to cut a long story short i went to bitbargain.co.uk and bought an mbtc, managed to completed the transaction with relative ease and saw the bitcoin in my Bitbargain.co.uk account.

I then decided to transfer this purchase to my wallet on my Mac and did so but entering a received address on the bitbargain account page. I waited and waited and have not seen the bitcoin come through on my Bitcoin-qt wallet.

It looks like there is a lot of syncing to do! only 45.65% complete, needs to catch up around 1720 days, this I estimate will be around 2 months if not more? that is if it actually completes?

My question is this, is there a way to move this purchase to another wallet I have, without having to let this wallet sync 100%? as the time frame required is very uncertain?

Can i transfer a bitcoin from bitcoin-qt to another wallet even though it is not showing up in my wallet becuase it is 1720 days out of sync?

Thanks for the help with this guys!

Best
FT


texts:
How to add workers through API?

https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list

I don't see any method to add workers or may be it is there but with some other name?