texts: Working example of raw transaction utilising Boolean (OP_IF, OP_ENDIF) scripting REQUIRED

texts:
I recently posted this Testnet TX (TxID 2d0daa01da8294a54178f8111eb2a02010c425fd15957d8baee8717edcfbe105) which successfully spends an output (TxID 8d897ca91774a7fafa086a3275e679248d6bffee015d3b2efefd5dab00df152d) of form:

OP_DUP OP_HASH160 ##HASH160_KEY1## OP_EQUALVERIFY OP_CHECKSIGVERIFY OP_IF OP_DUP OP_HASH160 ##HASH160_KEY1## OP_EQUALVERIFY OP_CHECKSIG OP_ELSE OP_HASH256 ##HASH256_OF_SECRET## OP_EQUAL OP_ENDIF

Where ##HASH256_OF_SECRET## is sha256(sha256(3ceb50edd0282cd99dc59351f513dcdf)) and ##HASH160_KEYx## is the ripemd160(sha256(public key n)).

I have been trying for days using Python (pybitcointools library, Pycoin library, raw tx construction) and Bitcoincore, however I consistently cannot duplicate the Tx myself.

EDIT: added keys, code

Here's a duplicated Tx on Testnet: ed99a9d3c8da943c5140790349d000450209367c7cf24d1627df6b43ece8b9d4:1

Keys (from pycoin):

input                        : 98a6776b00481d69147af4f19982816d24b21f1e45bd6b9b6612969a805dff5d
network                      : Bitcoin testnet3
netcode                      : XTN
secret exponent              : 69045673789968930636498185430340997034503775217197653543201755869784347377501
 hex                         : 98a6776b00481d69147af4f19982816d24b21f1e45bd6b9b6612969a805dff5d
wif                          : cShS7YocDNMfpxHPd1iWbXX6eTFPQoNTJSw6W4sQY5BVimvvw6FY
 uncompressed                : 92k9QgqAnrFCWtwvA4neyJnngkZG3g43ne9BJuzBmeeirPHXtu3
public pair x                : 66609190448066768097937392847179714582119540337817974512409209527265330917500
public pair y                : 13690920648454078566739109880631240403596673427366917192400893160542072726114
 x as hex                    : 9343773d05d5a07f103914d5294ca742db124babd2c2cac5f84e6114f192f07c
 y as hex                    : 1e44c956c737a60369fbf4f5e6324dc005ba38d156f61232f9251fec8ee3e262
y parity                     : even
key pair as sec              : 029343773d05d5a07f103914d5294ca742db124babd2c2cac5f84e6114f192f07c
 uncompressed                : 049343773d05d5a07f103914d5294ca742db124babd2c2cac5f84e6114f192f07c\
                                 1e44c956c737a60369fbf4f5e6324dc005ba38d156f61232f9251fec8ee3e262
hash160                      : fd00f9fd452fee2214e8b0f9acf4c53496bd5636
 uncompressed                : 23dfc9ad6d857c92ad2b99004354067492cf464c
Bitcoin address              : n4aiRSJEm2gT9QrZTFJ7DJy3KPGnDHxybf
Bitcoin address uncompressed : mine2pMKAyoA6CBimPd1ZdFVi5kvhTM7TT

script = 76a914dd6cce9f255a8cc17bda8ba0373df8e861cb866e88ad6376a914e900510876cb689f1db6fa982376c301362b740c88ac67aa20644d79d87e0907833e888e272e5d7b925deb261a8499a65cbc0bf26797a15e8e8768

[118, 169, '23dfc9ad6d857c92ad2b99004354067492cf464c', 136, 173, 99, 118, 169, 'fd00f9fd452fee2214e8b0f9acf4c53496bd5636', 136, 172, 103, 170, '0757152190e14e5889b1270309d7c8e40219d45e04096fcb97d1b4c5a99064e1', 135, 104]

*mysecret* = '12345678'.decode('hex')
sha256(sha256(*mysecret*)) == 0757152190e14e5889b1270309d7c8e40219d45e04096fcb97d1b4c5a99064e1

I'm looking for a working guide on constructing a Testnet & P2SH Tx which utilises Boolean scripting. Specifically:

A working testnet example of the question posed above (detailed further here) (I'll offer a bounty for this)
Constructing a multisig Tx of form: (1 KEY1 KEY2 2 CHECKMULTISIG) OR MASTERKEY


texts: Replace-by-fee and re-sending to another address

texts:
In Bitcoin Core (or Electrum)
When sending a transaction with "Enable Replace-by-fee" checked, is it possible to resend the transaction (before it was mined) with a higher fee AND to another address?


texts: Transaction Puzzles, Awareness and Questions

texts:
I was just reading about the two following scenarios:

My understanding is that we have two transactions here that don't follow the usual scriptSig/scriptPubKey situation, and I think transactions like these are sometimes called "contracts". In both cases, some funds were sent to a bitcoin address, so they are valid UTXO's floating around in the UTXO set, but instead of the usual situation where someone just needs to provide 0-knowledge-proof that they have private keys associated with that address, something else needs to be done to "unlock the funds". (find the data, or find a collision).
I have some questions:

How would people (likely power users) even be aware that these funds were out there, and available to be redeemed if they solved the puzzles. Did the creators of the transactions likely announce somewhere (via forums or internet), or could someone with full node / full blockchain build a tool that watches for these types of special PKscripts?
What does it mean in the second photo when it says "Note that while transactions like this are fun, they are not secure, because they do not contain any signatures and thus any transaction attempting to spend them can be replaced with a different transaction sending the funds somewhere else.". It seems to me if someone solved the puzzle they could immediately  send the funds to themselves with the standard PKscript. What does it mean the transaction could be "replaced"?
What kind of wallet or software would a power user claiming these funds be using? Certainly one couldn't just hop on a ledger s and try to claim these funds with the solution to the puzzle. It seems you would need more freedom to provide the puzzle solution.


texts: How are Bitcoin Signed Messages generated?

texts:
Ledger Nano S and other pieces of Bitcoin software and hardware can sign messages using the private key associated with an address.

Doing this, I get the following output:

-----BEGIN BITCOIN SIGNED MESSAGE-----
Test
-----BEGIN SIGNATURE-----
1BqtNgMrDXnCek3cdDVSer4BK7knNTDTSR
ILoOBJK9kVKsdUOnJPPoDtrDtRSQw2pyMo+2r5bdUlNkSLDZLqMs8h9mfDm/alZo3DK6rKvTO0xRPrl6DPDpEik=
-----END BITCOIN SIGNED MESSAGE-----

What exactly is being signed? How is the signature generated? What is the hash preimage that goes into the ECDSA signing algorithm?


texts: Have any cryptography experts vetted the bitcoin source code?

texts: Theoretically, bitcoin's open source nature makes it more resistant to bugs and exploits. However, due to the specialized nature of the code, even many programmers don't fully understand the cryptography pieces. Have any well-regarded cryptography experts done an analysis of the code and published their thoughts anywhere?


texts: How can I import Electrum addresses into a Core wallet?

texts: I have been running all my BTC transactions through Electrum, but recently installed the 0.14.0 Core client and would like to move to that. I managed to export my ~40 private keys from Electrum, but how do I properly import them into the Core client?


texts: Is it possible to get already-sent bitcoins from a corrupted wallet?

texts: I bought some bitcoins on LocalBitcoins then downloaded Bitcoin-qt then instantly sent it to my wallet and now the wallet is corrupted... Is there a way to get them back?


texts: can not access bitcoin in an address that belongs to a discontinued wallet, although i have the 12 word phrase?

texts:
I am still a Rookie regarding bitcoins and therefore apologize beforehand if I might use some words wrong.
I started a bitcoin wallet through a provider some years ago and bought some bitcoin. The wallets they provided were in the cloud and the didn't want to continue with that solution after some time so they discontinued their wallets. At that time I transferred my bitcoin to a new wallet.
This week I transferred the bitcoins back from the new wallet to the old wallet as I still had the old address written down and I thought that I could sell the bitcoin through my old provider (had forgotten about that they discontinued their wallets). I can see the public key or address which contains the bitcoin.
I have the 12 word recovery phrases for both wallets. I tried to recover my wallet with the 12 word phrase but the balance is 0. When I log on to the blockchain app i can see the old address under "imported addresses" but it says "not payable".
Is there any way to access these bitcoin on the old address or are they burnt?
I tried the steps in I have my 12 word seed from @Abdussamad, even with different import methods but unfortunately it can't see the balance.
Really appreciate your help.
br


texts:
First, to make sense to me. It sounds like I need a personal wallet first and then go to a place like coinbase to purchase bitcoin. Now what's the difference between bitcoin and cryptocurrencies?
So if the above is right, I purchase bitcoin and the transfer to my wallet for safer keeping. If anyone can answer these questions that would be great.


texts: What is the longnest blockchain fork that has been orphaned to date?

texts:
On this thread, the user asked what is the longest unintentional fork that Bitcoin had suffered. From the answers present, Bitcoin never had a >4 block fork until 2012.

It has been 6 years though, and I wonder if there is a more up-to-date statistics on that question, and if any study has been done so far.


texts: How does the blockchain.info shared receive work?

texts:
I understand the concept of a mixer and have succesfully used Blockchain.info wallet's shared send feature. The shared receiving address however confuses me. I assumed that one needs to click "new shared address" and then send the coins to the new address that is created. However after testing with tiny amounts I got really weird results, such as coins disappearing, mixing not working etc.

I am asking for a detailed step-by-step guide on how to use the feature as well as an explanation of the mechanism behind it. Thanks!


texts: Is it true that if I buy Bitcoin and plan to hold it for 10 years and sell, then Coinbase, Robinhood, or Gemini can prevent any theft?

texts:
It is said that Bitcoin can be subject to being stolen if I have it in my wallet on the smartphone, and is more secure in the Ledger.
However, if I buy it using Coinbase, Robinhood, or Gemini, and just hold it in my account for long term, such as 10 years, and suppose the account itself is not hacked, does that mean it is quite safe against theft?  (that is, not much different from some stocks in my Robinhood account?)


texts: what happens to UTXOs when a transaction output script is satisfied?

texts:
As per my understanding from the book "Mastering bitcoin", a transaction output contains three things

Amount - Bitcoin Value in Satoshis
Locking-Script-Size - Locking-Script length in bytes, to follow
Locking-Script -A script defining the conditions needed to spend the output

Now let us say a transaction input points to UTXOs mentioned in one of the transaction output through transaction hash and a validation software is able satisfy the scriptPubKey(locking script) using script‐
Sig(unlocking script).

Questions regarding this case

What would happen to the UTXOs mentioned in the output of parent transaction? Would it get vanished in the transaction or any change would happen?

  Only a valid transaction that correctly satisfies the conditions of
  the UTXO results in the UTXO being marked as “spent” and removed from
  the set of available (unspent) UTXO.

This was a statement from the book, now is there any seperate pool of UTXOs or it just meant the transaction lying at the leaf nodes of merkel tree?
And what does

  removed from the set of available (unspent) UTXO.

mean?

Would the output of the child transaction contain the same transaction  ids as the its parent'output contained?

Assume when the spender tried to see what all he can spend i.e the transactions directed to its bitcoin address then these were the transaction output which he got

[<7dbc497969c7475e45d952c4a872e213fb15d45e5cd3473c386a71a1b0c136a1:0 with 25000000 Satoshis>, \
<7f42eda67921ee92eae5f79bd37c68c9cb859b899ce70dba68c48338857b7818:0 with 16100000 Satoshis>, \
<6596fd070679de96e405d52b51b8e1d644029108ec4cbfe451454486796a1ecf:0 with 16050000 Satoshis>]

Please enlighten me if I am missing out on something.


texts: If newer versions of bitcoin and or bitcoin cash don't allow 0x04 uncompressed public keys, what do you do if you have an address based on one?

texts: So if you have an address with coins in it that uses an uncompressed public key (preceeded by a "04") then how can coins from that wallet be utilized with a network that doesn't allow such public keys?  Compressing the public key changes the relevant wallet address and would prevent one from being able to access one's coins at that point.  Does bitcoin still allow the "04"?  I've read, it seems, that bitcoin cash does not.


texts: What is the 6a[...] hash in OP_RETURN transactions?

texts:
I've been looking up OP_RETURN transactions on http://coinsecrets.org/ and I noticed that they all contain hashes that start with 6a, for instance:

6a28f7377a2065897e429287682bd2ed67ed7d0f5ebfc35cf4b1575756c3bebf0000b84002004b4d4400

Followed by their actual data:

÷7z e~Bh+Òígí}^¿Ã\ô±WWVÃ¾¿¸@KMD

Is that hash the encoded data?
If not, what is it?


texts: Trustworthy url address for bitcoin download?

texts:
I would like to download install some bitcoin software and create a wallet. I know there are some programs like Bitcoin-QT or Multibit. There are more sources to download these programs. I want to be sure, I downloaded the right one.

Which software from which url is trustworthy? Can I check the checksum of the downloaded installer of specific version against some MD5 from a list somewhere, that it is safe?


texts: Dont understand how to buy Bitcoin. Looked at sites but makes no sense to me

texts: I can see prices and do not understand how you buy Bitcoin. I was told you could buy as little as $1 worth.  What would you get for $100?  Nothing really helps me understand this.


texts:
How do I restore a c-lightning node from  a backed up hsm_secret ?
I have tried running lightningd by replacing the generated hsm_secret with the backed-up one. It shows no output and no channel.
How can I retrieve the funds in the node from there ?


texts: How can I create a tronix (trx) cold wallet? I see no info on the Internet. Both a link to a key generator script and website with wallet creation would be ok. Thanks.


texts: Can mining pool participants customize the coinbase of the block they're mining?

texts:
If a participant can customize the coinbase, how would that be done?

Pool participants make certain decisions about how they mine. Some of those decisions are apparent in each block solved by that participant.  The entire bitcoin community could provide extra rewards to one of that participant's bitcoin addresses if it could be positively identified.

A pool participant could compute the hash of "My bitcoin address is 1..." using their address (and any hash algo they want).  Could they put the last eight bytes of the hash into the coinbase?  If they solve a block and they know that there are bitcoiners willing to provide them with extra rewards, then they can prove they made that block by providing the "My bitcoin address..." message and the hash algo used.

Then I could donate some of my bitcoin usefully, and relatively anonymously, and so could everyone else.

This mechanism would help decentralize mining decisions (at least those that pool participants can make) in favor of those with bitcoin who are willing to push their agendas and help individual miners.  Individuals could then send extra rewards to block creators whose blocks reflect desirable decisions.


texts: What is the difference between ripple blockchain and bitcoin exchange?

texts: What is the difference between ripple blockchain and bitcoin exchange ? I was reading this blog the other day but wanted to understand in simple language.


texts:
I just wanted to ask If it makes sense if I want to print out my wallet.dat to encode it with base64?

I also read that the backup would become useless, if I get any receivements or make deposits and I would have to print out the wallet.dat again?

I would like to encode my wallet.dat with base64, print it and hide it in safe.

when my laptop breaks down and my other backups are also damaged (why every), i could scan my printed wallet.dat with OCR, decode it with base64 and just load it into the normal bitcoin client?

does this sound correct?
or are there any things I'm missing?

I dont want to rely on other software, no other web apps or key/password generators...


texts: Which software can I use to setup an e-wallet site?

texts:
I am relatively new to Bitcoin and I have a very simple question: what wallet software is behind "online wallet sites" like http://www.blockchain.info? I would like to set up a mini-site to store my/friends online wallets and I guess I would need a daemon-shell-based Bitcoin wallet software.

Where should I start to do so?


texts: Is there some trusted website that maintains a list of Bitcoin-related websites and their reputation? For example, if I wanted to check if betsofbitco.in is a legitimate websites (it pays rewards fairly, etc.), where should I turn, asides digging through the forum?


texts: Let's suppose that a miner mines a block and adds it to the blockchain. When it gets the reward ? I suspect that first of all the other nodes have to verify that its proof of work is correct and it's not cheating. Right ?


texts:
I am having some trouble understanding the following. Lets say Alice, Bob and Charlie all sends me 1 BTC each to the same address. I want to transfer 1.5 BTC to Dennis, would it then take Alice and Bob's UTXO and send it, or would it take Alice, Bob and Charlie's unspent transactions send it and then resend me the 1.5 BTC as change?

I understand that is how it works with wallets, but I am unsure if an address aggregates UTXO, or whether they still remain separated.


texts: Is there any format change in block #498557

texts:
I wrote some python code to parse the block data, all the result are fine, until block01095.dat, block #498557.

The code to deal with Transaction is:

class Tx:
  def __init__(self, blockchain):
    start_pos = blockchain.tell()
    self.version = uint4(blockchain)
    check_pos = blockchain.tell()
    # For segwit
    # https://en.bitcoin.it/wiki/Transaction
    dummy1 = uint1(blockchain)
    dummy2 = uint1(blockchain)
    if dummy1 != 0 or dummy2 != 1:
      blockchain.seek(check_pos)
    self.inCount = varint(blockchain)
    self.inputs = []
    self.seq = 1
    for i in range(0, self.inCount):
      self.inputs.append(TxInput(blockchain, i))
    self.outCount = varint(blockchain)
    self.outputs = []
    if self.outCount > 0:
      for i in range(0, self.outCount):
        self.outputs.append(TxOutput(blockchain, i))
    # For segwit
    if dummy1 == 0 and dummy2 == 1:
      for i in range(0, self.inCount):
        num_op = uint1(blockchain)
        for n in range(0, num_op):
          op_code=uint1(blockchain)
          _ = hashStr(blockchain.read(op_code))
    self.lockTime = uint4(blockchain)
    cur_pos = blockchain.tell()
    blockchain.seek(start_pos)
    self.raw_bytes = blockchain.read(cur_pos - start_pos)
    self.tx_hash = hash_tx(self.raw_bytes)
    print(self.tx_hash)

Full code is in:
https://github.com/keviny/bitcoin-block-parser/blob/master/block.py

The last transaction in #498556 is https://www.blockchain.com/btc/tx/0baa42c9852b4edd9437e8c3fd38bd0dd89d977fe80ac7648961cf8ff33a2dbf
which is ok to parse.

But in #498557 I can never create the right tx hash anymore.
The first tx hash I get from block #498557 is
https://www.blockchain.com/btc/tx/2da60422e1de3e8e64742bb16db5d1e3b2a9813f754cff416e549d570b2ad0e8
which is not a valid tx hash in blockchain.info.

Actually, the first three hash I got are:
2da60422e1de3e8e64742bb16db5d1e3b2a9813f754cff416e549d570b2ad0e8
e0a7e07ccb9b126bd20b5b134d41ec5f8b70bdb5408a263619ca3b8b3a90512d
6c695c567d14bce39a8e58359a2a5d26dc2bcbd9a83f043b5dbc1800c56f84c8
None of above can be used in blockchain.info.

I suspect there is some format change from this block.

Does Anyone here know any background about this issue?


texts: how to earn a transaction fee for transactions originating from my client

texts:
I am working on an online litecoin wallet system. For every transaction originated from our site, we need to charge say x% of the amount as fees and it'll be sent to Admin's address ? How can I do that ?

I guess paytxfee is what we are willing to pay others for a particular transaction, right ?

I didn't found any parameter to set the address to which the transaction fees should go ?

Looking for some help...


texts: How exactly does BIP11 work, and how can it be used, particularly with/without P2SH?

texts:
I'm trying to write a BIP11-compliant C# client that creates a 2 of 2 or 2 of 3 transaction.

I'm also trying to understand if a 3 of 3 transaction is supported as well.

This example says they are creating a PS2H address, but I'm unsure of exactly what script is being signed, and the meaning of the parameters "2" in addmultisigaddress, and what happens when addmultisigaddress is called.

I have researched the BIP, the RPC documentation, and the forums.  I'm getting confused where if and when the P2SH is needed.


texts: Bitcoin.conf not being read by Bitcoin Core

texts:
My issue is I cannot get RPC working with Bitcoin Core. I do not know what I'm doing wrong! When I first installed Bitcoin Core it did not come with a bitcoin.conf file so I created one with the following details:

server=1
rpcuser=root
rpcpassword=password
rpcconnect=127.0.0.1
rpcport=8332

That's all I have in there. And yes my Bitcoin Core client is in sync with the bitcoin network.

I've also checked my router and it is UPNP enabled and I literally see the port in my router's configuration open. The port is: 8333

And it is the only port open. Do not know if I need 8332 open. Please shed some light on this for me. What I am trying to accomplish is to get PHP to interact with bitcoind such as generate a new bitcoin address.


texts: What is correct way to count LN node stats

texts:
I am running a LN node. Set up monitoring to collect stats. Now i am wondering, how can i get correct conclusions about what collected information actually is.

My question is about forward (transaction?) count. According to my stats i had 14 settled forwards.

There are ~8350 nodes over there, my node according to 1ml.com is ~#450 in channel/capacity rank. so we can assume that i am average active node i think. so then 8350*14=116900 settled forwards over network?. i am not sure what this number mean and can we compare this to 409570 on-chain transactions for last 24 hours.

I had also some 2-3 offchain pay and 1 paid invoice which was my own node made, do i need to add the to calculation above or not?

If this completely incorrect way to count and compare transactions, please describe a correct one.


texts: My first Bitcoin wallet was with OKPAY in 2013 but they have been taken over by Moneypolo and I cannot access my wallet anymore

texts:
I have 12 words, a username and password for my OKPAY wallet but they were taken over by Moneypolo in 2018 and I cannot for the life of me get hold of anyone there so as to access my bitcoin
Does anyone have any suggestions as to how I can get hold of my bitcoin
I have the full string of digits/letters that make up my bitcoin printed on a piece of paper


texts: Is it ok and safe to import master public key from electrum wallet into bluewallet to be a watch-only wallet?

texts:
I want to use my iPhone (Blue wallet) to be the watch-only wallet for my offline wallet generated on electrum. So that I can generate unsigned transaction on the bluewallet and send it back to my offline wallet to be signed on electrum. And then send the signed transaction back to bluewallet to be broadcasted.
Is it safe to do so? Is there any better way to do it so I don't have to send the unsigned and signed transaction back and forth?


texts: Can Bitcoin technology be leveraged to implement a decentralized trust system (i.e. a replacement to SSL)?

texts:
Like Namecoin is intended to replace / augment DNS, can the Bitcoin principles / protocol be extended to support a distributed "trust" mechanism, in a way that no central authority will need to be trusted in order to verify public key authenticity?

This post is inspired by the recent hack of a Certificate Authority.

Clarification - I don't mean for this technology to be integrated within the main client or blockchain, just for the underlying technology to be used.


texts: What prevents a miner from faking nonce hash

texts:
What exactly prevents a miner from presenting a random nonce hash of the block with enough zeroes at the start to get chosen?

How is the new hash verified by the other nodes? Since as I understand there is no 1 valid hash outcome, but multiple? What are the conditions other than having a number of zeroes at the start?

Instead of incrementing the nonce, could you intelligently pick a random higher nonce and see the amount of leading zeroes increase? Or is there never any direct relation between the nonce value and the resulting hash? (Probably, but I need to have this confirmed)

Mainly, what prevents a miner from having a pre-calculated database of sufficiently difficult but random nonces/hashes that could be presented instantly and could be accepted?

If the new hash only has to be equal or lower than the target? How do you verify that work has been done, without doing the same work yourself?


texts:
As we know there are scores of mining pool around the globe but some are pretty big ones such as Antpool, Poolin, BTC.com etc. with majority of them lying in China https://www.buybitcoinworldwide.com/mining/pools/. I have few questions in the broadcasting regard:-

If a solution is found by a miner, does the miner have the control to which nodes is it broadcasted?
If it is broadcasted based on the location of miners, then won't all the miners in the pool have an intrinsic advantage of their pool peers validating the solution?
Let's take a case when there are two solutions being broadcasted at the same time, one from the USA and another from China. Since, a lot of miners are there in China, Mongolia, Russia etc. doesn't miners in China have a better chance of getting consensus?
Also, what do we mean by consensus in the above case? Let's say the USA solution reached 20% of the active miners and the Chinese solution reached 80% of the  miners. As per my understanding even the USA solution could reach more than 51% consensus(more than 10% of globally active miners agreeing with the solution). Shouldn't there be a threshold on the minimum number of global miners agreeing with your solution given this large pools existence?

Thanks in advance! :)


texts: Cannot check balance with blockchain.info API

texts:
I tried below code and gave valid credentials, but we could not get the response of balance check. What would be the solution?

<?php

$guid="xxxxxxxxx";
$main_password="xxxxxxxxx";

$json_url = "https://blockchain.info/merchant/$guid/balance?password=$main_password";

$json_data = file_get_contents($json_url);

$json_feed = json_decode($json_data);

$balance = $json_feed->balance;

echo $balance;


texts: Can a blocksize limit be a sustainable way to introduce scarcity?

texts:
Some people feel that it will be important in the future to introduce some scarcity into the mining market by having a block size limit.  The idea is that this will force transactors to bid up transaction fees in order to get their transaction into the block.  This may be necessary as the freshly minted BTC subsidy becomes less and less significant over time.

If this idea is going to work, it's safe to assume that the size limit will be hit every 10 minutes.  otherwise, it's not effectively forcing transactors to bid up the fees.  But if that is the case, won't a backlog of transactions start accruing such that the average wait time grows infinitely?  For example, if the limit is (more or less) 2000 transactions per block but the protocol puts a limit at 1500 transactions per block, it seems like there's no way around building up a stock of unconfirmed transactions that grows unbounded at a rate of 500 transactions every 10 minutes.

So it seems to me that a limit on block size can serve the original purpose of preventing some kinds of one-off spam attacks, but it can't be a long term solution to the tragedy of the commons problem.  Please confirm or correct my understanding?


texts: How might I reduce the percentage of rejected shares using an Avalon 741 with NiceHash?

texts:
I have an Avalon741 running on NiceHash with CGminer and I'm new to mining. The command I'm running is as follows:

sudo ./cgminer -o stratum+tcp://sha256.eu.nicehash.com:3334 -u <address> -p d=4096

When I run with this, I end up getting usually between 25% and 50% of shares rejected. Why is this? How can I improve the situation and contribute more effectively?

Here are some representative CGminer run statistics:

[2017-06-07 12:57:08.511] Started at [2017-06-07 02:20:49.716]
[2017-06-07 12:57:08.511] Pool: stratum+tcp://sha256.eu.nicehash.com:3334
[2017-06-07 12:57:08.511] Runtime: 10 hrs : 36 mins : 18 secs
[2017-06-07 12:57:08.511] Average hashrate: 5032956.9 Mhash/s
[2017-06-07 12:57:08.511] Solved blocks: 0
[2017-06-07 12:57:08.512] Best share difficulty: 140M
[2017-06-07 12:57:08.512] Share submissions: 7258
[2017-06-07 12:57:08.512] Accepted shares: 5335
[2017-06-07 12:57:08.512] Rejected shares: 1923
[2017-06-07 12:57:08.512] Accepted difficulty shares: 44435456
[2017-06-07 12:57:08.512] Rejected difficulty shares: 15138844
[2017-06-07 12:57:08.512] Reject ratio: 26.5%
[2017-06-07 12:57:08.512] Hardware errors: 11355
[2017-06-07 12:57:08.512] Utility (accepted shares / min): 8.39/min
[2017-06-07 12:57:08.512] Work Utility (diff1 shares solved / min): 94093.46/min

[2017-06-07 12:57:08.512] Stale submissions discarded due to new blocks: 7
[2017-06-07 12:57:08.513] Unable to get work from server occasions: 12
[2017-06-07 12:57:08.513] Work items generated locally: 274339
[2017-06-07 12:57:08.513] Submitting work remotely delay occasions: 6
[2017-06-07 12:57:08.513] New blocks detected on network: 1960

[2017-06-07 12:57:08.513] Summary of per device statistics:

[2017-06-07 12:57:08.513] AV7 0 (5s):32.99G (avg):5.032Th/s | A:44435456 R:15138844 HW:11355 WU
[2017-06-07 12:57:08.513]


texts: I sent bitcoin and put low tx fee (4sat/b). Unconfirmed for 3 days. Can it be forever?

texts:
I just want to withdraw bitcoin and put a low fee.
It's been 3 days and nothing happened with it - Unconfirmed.
So, can it be forever? Or how much time it may take to be confirmed? Or what should I do to make it faster?
I used a simple web blockchain wallet.
I've read about CPFP but I don't know how to find a private key in the blockchain wallet.
My tx: 347c25f1fb17fa0375f02268733910fe1ba1a94f28a61089fca754774c8cb0da


texts: What could be the reason for one loop being significantly more power hungry on an SP20?


texts: What does the MiniWallet class currently do and need to do in the Bitcoin Core functional test framework?

texts:
I tried to run the Taproot functional tests after building Bitcoin Core with the wallet disabled (as I knew there was no Taproot code in the Core wallet at the time of writing, December 2020).
However, they were skipped because a number of the functional tests currently rely on the Core wallet to create and sign transactions. (Thanks to Marco Falke for pointing this out on IRC.)
The introduction of MiniWallet though raises the prospect of being able to update these non-wallet functional tests so they no longer rely on the Core wallet.
There is a good first issue open on the Bitcoin Core repo to do this for all non-wallet tests. As Marco states in that issue:

This is an open-ended issue. You can find candidate tests via
git grep self.skip_if_no_wallet(). Exclude the tests that start with wallet_, as those are tests that are meant to test the Bitcoin Core wallet.

So what does the MiniWallet class currently do (and perhaps need to do) so that all non-wallet functional tests can be rewritten to no longer rely on the Core wallet?


texts: Is it possible to run two nodes with the same public key?

texts:
Is it possible to run two nodes with the same public key on the Lightning network? The reason is reliability -- two different servers run different instances of node software with the same setup (incl keys) -- if one fails -- the other one continue serving. Possible?

thank you.


texts: What does the main.cpp source-code file do? I know what main.cpp files are for in general, but specifically in the case of bitcoin?


texts: Which currency (crypto & fiat) to use to measure profits?

texts:
Lets say you have added enough USD to trade with so you pick BTC to trade altcoins with.

You buy Altcoin X for let's say order total 0.5 BTC
BTC goes up in value but Altcoin X in USD has jumped big time in value
In BTC terms you have lost as BTC's value increase is more than Altcoin X
You sell Altcoin X but you get less BTC, in USD terms you happy, profit both up
BTC drops in value to the USD, you got less than you started with now what?

Do you ignore the USD value and measure only in BTC to get your base currency/crypto currency to use for measuring profits trading Altcoins?

I just cannot get my head around it. Any advice and help/direction will be appreciated.


texts: Specifics on "Race Double Spending Attacks"?

texts:
Hi guys I am doing some research on double spending in the bitcoin network several ideas have been confusing me:

In prevention of Race attacks, merchants are advised to "connect to a large random sample nodes in the network".

First of all, What do they mean by this? How is it done?

Secondly, how do attackers initiate the attack? All I know is they make 2 transactions of same reference, one to themselves the other to the merchant who recognizes only the latter and surrenders his goods.

In an article on prevention, it states "We assume that the attacker may connect to an arbitrary number of nodes in the network to broadcast any number of transactions claiming outputs to its possession."

What exactly does this mean?

Thank you guys, I know this question is very condensed but I appreciate any help.

EDIT: Does it mean that I can go out and send X amount of bitcoins to myself and immediately spend the same amount, X on a merchant to defraud him?

Isn't that just too easy?


texts: How much ASIC power has been, or is being, shipped in 2013?

texts: Where can I verify how much ASIC mining power has been shipped, how much has been pre-ordered, when it will be shipped, and at what rates and time frames more units will be shipped?


texts: LiteCoin Wallet balance does not match block-explorer.com

texts:
My Litecoin wallet version v0.8.6.2-beta is showing a balance of 26.579 ltc
When I query http://block-explorer.com/address/LejrG23b2HcjqPRbZU8UWFxZhdJTUc75pS it is showing 0 balance.

I just sent 2 ltc to another address from my wallet successfully on 19 Feb 2014. This tx did not show up in the block-explorer.com (currently 20 confirmations), yet it did show the new balance correctly.

http://ltc.blockr.io/api/v1/address/balance/LejrG23b2HcjqPRbZU8UWFxZhdJTUc75pS is also showing a 0 balance.

Thoughts?


texts: How to get fee in a transaction with unconfirmed inputs in bitcoinj?

texts:
I am trying to get the fee of incoming transactions in a wallet with bitcoinj. At times it was the commission using Transaction.getFee(), but this was throwing NullPointerException. I got to do a little more research and I realized that it happens when the transaction has unconfirmed inputs. I've tried adding the value of all the inputs and subtracting the value of all the outputs, so you would get the fee, but on these occasions the sum of the inputs is 0 BTC. Is there any other way to get the commission?

I leave an example of the output of one of the transactions (testnet):

04f570fdd0cb8c973d8c9b3adf09b803ef70941ec239685d479a93b089e4d621: Seen by 1 peer. Pending/unconfirmed.
   in   PUSHDATA(72)[3045022100fe750e43c3bc46eddb390dad98acd6ef0646e00386770de542e7e5c581f8118102206924cd243b459645ae8626e948e1d33404d29c651a8a59c24ed5cd902d7e939201] PUSHDATA(33)[02a40db91b59058375fe7f13810beb6609e63a8974ce355b76d01692058eaac9f9]
        outpoint:7cd4378560d2b36f53b3d492afa815c5ae615d18bff9611c3081f591a1c0c156:0
   out  DUP HASH160 PUSHDATA(20)[49d2661baf33597c6dc3dbdbb9e7a8835fdb76b4] EQUALVERIFY CHECKSIG 0.00126081 BTC
   out  DUP HASH160 PUSHDATA(20)[372fb0d8affe634b369af9722cc48c63ad90e9df] EQUALVERIFY CHECKSIG 0.001 BTC
   prps UNKNOWN


texts: technical question: receiving wallet.dat error

texts:
I have ~5 BTC on an old laptop (Windows 7) and I tried moving the balance to another client. At first I tried moving about 0.1 BTC just to see what would happen. The client debitted the balance but it never "took" (that is, I never received the 0.1 BTC, and I know it is a good address). The client informed me I should update immediately so I updated to the latest version (v 0.8.0). The client would not load the wallet so I googled around and found a solution that said try to move all the files out of this directory EXCEPT for wallet.dat:

c:\Users[Me]\AppData\Roaming\Bitcoin

I made a copy of this folder elsewhere and emptied all the files except for wallet.dat, and I am now downloading the blockchain. However, intermittently I get this error:

System error: CDB(): can't open database file wallet.dat, error -30974

The error is thrown by this part of bitcoin's code.

ret = pdb->open(NULL,      // Txn pointer
                        fMockDb ? NULL : pszFile,   // Filename
                        fMockDb ? pszFile : "main", // Logical db name
                        DB_BTREE,  // Database type
                        nFlags,    // Flags
                        0);
// snip 7 lines
throw runtime_error(strprintf("CDB() : can't open database file %s, error %d", pszFile, ret));

Which causes the client to close. Right now I am simply re-opening bitcoin, where it will run for awhile (download a maybe a few hundred blocks or so) and then close again.

So the current issues are:
1. The 0.1 BTC I mentioned above is still showing as being debited from the total inside the local bitcoin client though there is no receipt at the receiving address, and this is confirmed by blockchain.info
 2. I cannot create a new address to send coins
 3. The client will not load the blockchain without indicating the error above and closing


texts: How to prevent specific method calls to bitcoin node

texts:
I have setup a bitcoin node and can access RPC methods via curl or bitcoin-cli.

Now I don't want to share the node with multiple parties and in such case, I want to restict some functions from being executed, like listwallets, getbalance etc.

How can I restrict some method calls?

In Ethereum we have different rpcapi and we can remove personal if we don't want others to play around with it unsafely.

My first guess will be to wrap the wallet functionalities in an application server and allow users to access the blockchain node via that application server and hence we can put any restrictions we want. Is there any better solution?


texts: How are difficulty level and block reward determined and stored in decentralized fashion in Bitcoin?

texts:
I know the difficulty level and block reward are periodically adjusted in Bitcoin to keep the block time approximately to 10 minutes.

I guess these are not determined by a central authority but rather are determined in decentralized fashion. If so, what are the exact steps involved here? Each node independently computes on their own, propagates and will it be verified?


texts: I need help to unlock my passphrase. I don't remember setting up one, but now there is a pasphrase. Eitherway I am unable to send out coins from my LitecoinQt to the exchange.


texts: Can one trace a criminal with his Pubkey?

texts:
Say FBI arrested a guy who bought some drugs using bitcoin. Then, is it possible for FBI to trace a drug dealer using the arrested guy’s PrivateKey and his transaction histories?

If my understanding of bitcoin algorithm is correct, this is impossible since PublicKey only shows that “there is a user with this public key” and it does not give any more information about a user who owns that PublicKey.

Moreover, transaction that the dealer and the arrested guy made only shows public keys.

Can one trace someone using past trasactions?


texts:
How can I find API (json data) for cryptocoins current ask/high/low/average price. Is there any website that provides that ticker information for all coins.

For example BTC/LTC ticker info is available in
https://btc-e.com/api/2/ltc_btc/ticker


texts: How to calculate R,S,Z for bitcoin raw transaction with many inputs and outputs?

texts:
How to calculate R,S,Z for raw bitcoin transaction ?
I try many methods and all of these not work for me/
For examle this transaction cf1905de5336258673e1bfc5d25c7de0f701f745d5dc2429006fafe37077d89a (this not raw transaction, but this is example )) )
transaction - cf1905de5336258673e1bfc5d25c7de0f701f745d5dc2429006fafe37077d89a
https://2xoin.com/getRSZfromRawTX/ NOT WORKED FOR MY TRANSACTION LIKE THAT.
ANY HELP PLEASE
Big THX.


texts:
The last transaction in blocks 219882, 219888, and 219892 don't have a timestamp.  And by last transaction I mean the last transaction shown in the json file.

219882
219888
219892

I find this to be a bit odd.  Does anyone know why this has occurred?


texts: Why on bitcoin client sender address is 'undefined'

texts:
Despite the fact that bockexplorer allows to navigate through transaction details and discover the sender address,
why via bitcoin client the sender address remains 'undefined'.

Is it possible to discover sender address via original Bitcoin API?


texts: How to list all the HD address in Electrum?

texts:
I tried to restore all my HD address by importing my xprv in new wallet file but it only shows 20 addresses.
How can I make it show all the child addresses of my xprv?


texts: Why is the block header 80 bytes, not 128 bytes (= two SHA-256 blocks)?

texts:
According to the Bitcoin Developer Reference, the block header is 80 bytes total:

BYTES   NAME
4       version
32      previous block header hash
32      merkle root hash
4       time
4       nonce

As I understand it, the midstate (1st SHA block) contains 64 bytes of the block header (which fields in particular I do not know, but I do know it doesn't contain the nonce), and the 2nd SHA block contains the rest, only 80-64 = 16 bytes. Does this mean the 2nd SHA block is padded with 64 - 16 = 48 bytes? If so, why not make the nonce field, for example, 48 - 4 = 42 bytes larger (i.e., 52 bytes instead of 4 bytes)?

That way, extranonce doesn't have to be in the generation transaction, thereby speeding up hashing, no?


texts:
I am writing hd wallet following bip44.

After each transaction, should I create a brand new change address each time?
Or can I use the same change address multiple times?
What is the recommended practice here?


texts: Is it possible to create an address from a predefined private key?

texts:
I was not sure how to formulate the question title. What I want to achieve is the same as VanityGen and many other tools do to create an address starting with a predefined part, but with private keys.

So basically I want to create a Bitcoin public/private key pair of which the private key begins with a string I define.

Are there tools that already do this? If not, is it possible? How should it be done theoretically?


texts: How do you do point multiplication in bitcoin associated with the ecdsa algorithm?

texts:
I have posted a similar question recently, but not this specific.  I have found that a lot may ride on the idea of "point multiplication" yet all explanations I have found lack explanation or are in code that not everyone (especially myself) can decipher.

Supposedly you "add point G to itself k times". Most examples of point addition or point multiplication show multiple x,y coordinates in the same equation but in this situation, I only have an integer to apply to the equation.  Secondarily, many equations that show this also show that you do something such as "Qy - Py" (aka: Q's y-value minus P's y-value).  This is a problem if the only x,y value I'm working with is Q.  If I subtract Q's y-value from Q's y-value I get zero, thereby nullifying the value of the equation.

I think the criteria for the correct answer to this question are as follows:

It is explained such that anyone who has mathematical experience less than Calculus can at least stumble through it by cutting, pasting, and using a basic calculator that can handle exceedingly large numbers,
Programming experience/understanding is not needed (code can be used but must not require pre-understanding/experience thereof by anyone reading it),
Must show or enable people to show themselves how a K value of 18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725, and a Gx value of 79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798 and a Gy value of 483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 equals x and y values of 36422191471907241029883925342251831624200921388586025344128047678873736520530 and 20277110887056303803699431755396003735040374760118964734768299847012543114150.  (Note: whether the answer is in Hex or Decimal is not significant as converters are readily available on many websites),
Criteria 4 is applicable such that the point multiplication is truly applicable to the question (IE:  that I have asked the proper question in the proper manner).
Whomever meets criteria 1 through 4 must also post their Bitcoin address to permit a donation.

I know this seems complicated and perhaps odd (what with me adding actual answer criteria when I'm essentially a beggar) but I want to be clear such that others who read my post and may be wondering the same thing have a better chance of understanding what I'm asking and the answer.  I also want to filter out, as best I can, answers which don't truly answer the question (as I have seen too many of them on this forum and others).  I am not promising any particular amount of bounty but if someone meets all these criteria I will be sufficiently grateful that I would feel guilty if I failed to provide them with some value.  If your answer to my question meets the criteria, please do not hesitate to leave address for alt-coins you may have as well.


texts: When an IP address in *new* table is overwritten?

texts:
I'm reading the address management of Bitcoin core implementation. There is one thing I couldn't understand is in which condition an IP address in the new table of a node is overwritten?

In particular, when the node hears about a new peer, it adds that IP address into a slot in the new table, if that slot is occupied, it checks if the existing isTerrible: https://github.com/bitcoin/bitcoin/blob/master/src/addrman.cpp#L309

if (infoExisting.IsTerrible() || (infoExisting.nRefCount > 1 && pinfo->nRefCount == 0))

What is nRefCount? What is the idea behind this check?


texts: Blockchain.info "Too Many Requests" - Alternative solutions that can be hosted by myself

texts:
I'm trying to build out a Bitcoin service that requires me to query address balances and other data. So far I've been just using blockchain.info to do these request, but lately i'm hitting the too many request error. I've looked into alternatives, but many of these just went belly up over the years. Blockchain.info seems to be best long standing one that is free up to a point. Even blockstream.info has a limit.
Is there some type of locally hosted service I can just use it for the same type of query data like blockchain.info? I understand I'll need to install bitcoind and download the entire blockchain.


texts: Create an arbitrary script with two locktimes and p2sh

texts:
Alice, Bob and Carol create a p2sh address that initially requires 3/3 signatures. After some time (lock1 using OP_CHECKLOCKTIMEVERIFY)  only Alice and Carol can spend and Bob is permanently forgot. After more time (lock2 using OP_CHECKLOCKTIMEVERIFY) Alice can spend alone.

How would a script like this look like?


texts: How to recover my funds from electrum wallet with privatekey and redeem script?

texts: Hey I think I know the answer already and I kinda screwed up I think I just want to verify. so I send BTC to my electrum wallet and I forgot the seed. I could not find it. but I have the private key and redeem script. is there any chance to restore or gain access to the funds or do I have to say goodbye for ever? thanks in advance if anyone has an idea otherwise I will have to accept my faith and add a learning experience to my repertoire. thanks in advance.


texts: What can cause the chainstate database to become corrupted?

texts:
I have written a tool that accesses the chainstate LevelDB database to get a list of UTXOs.

https://github.com/in3rsha/bitcoin-utxo-dump/blob/master/utxodump.go

The tool would originally corrupt the database every time I accessed it, forcing me to run bitcoind -reindex-chainstate to fix it. I was able to get around this by adding a no compression option when accessing the database, which seemed to fix the problem.

However, using this tool will still occasionally corrupt the database, but not always, and I am not sure why.

I'm not looking for a review of the code, but I was wondering if there might be any common reasons why the chainstate database might become corrupted after another program has accessed it (whilst bitcoind isn't running)?


texts: Error code -3 when signing message from gui?

texts:
I tried to sign a message from gui v18 and the debug console without success:
With the popup it shows red text:

  "the entered address does not refer to a key. Please check the address
  and try again"

With the console:

  "Address does not refer to key (code -3)"

the approach was:
- get a fresh public address from the wallet (new receive address)
- paste it into the address field
- type 'foobar' into the message field
- click sign message

in the console i unlocked the wallet (for long enough!) then
`signmessage "pupaddr" "foobar"
both with no success. I double checked the pubaddr (taken from the address field on the right button).

the throw happens here in the sourcecode. The addr. starts with 3... .


texts: The cost of restarting a lightning channel

texts:
I have some questions about the cost of maintaining a lightning channel between two people. For this question, let's assume that the blockchain mining fee is $1 per transaction.

Question 1: Suppose Alice wants to send Bob 1 mBTC per day, for 100 days. Without lightning, this would have cost $100. With lightning, she has to open a channel to Bob, and after 100 days, close the channel. Is it true that opening the channel and closing the channel each costs $1, so that the total cost is $2?

Question 2: Suppose Alice wants to send Bob 1 mBTC per day, for 200 days, but, she does not have all 200 mBTC now - she only has 100 mBTC (she will get the additional 100 mBTC after 100 days). So, she has to open a channel to Bob, after 100 days close the channel, open a new channel, and after additional 100 days, close the second channel. Is it true that the total cost now is $4?

Question 3: Suppose Alice from question 2 wants to reduce the cost of channel restart, so she says to Bob: "Instead of closing and re-opening the channel, I'll send you 100 mBTC through the blockchain, and you will send me 100 mBTC through the lightning channel. So the restart will only cost us $1 and the total cost will be only $3". Can this trick be done securely, so that neither Alice nor Bob can cheat?


texts: How to instantly give people a pre-filled wallet to introduce them to Bitcoin?

texts:
As a Bitcoin evangelist I like to introduce Bitcoin to my friends, and if possible even get them involved by having them own a few coins themselves.
The settlement of a personal debt through Bitcoin would be the perfect excuse to give someone their first coins. Who hasn't balanced expenses with their friends after a night on the town? Why not gain some new Bitcoin users in the process!
So, is there a way to securely set someone up with a new wallet and transfer some BTC to that wallet at the same time, without requiring any action from the receiving party?Ideally, the BTC.USD exchange rate is taken into account because such debts are unlikely to be denominated in BTC already.
Imagine the following conversation taking place:

Alice: I've paid the restaurant $100. So Bob, you now owe me $50.
Bob: Is it OK if I pay in Bitcoins?
Alice: Sure, but how does that work?
Bob: Don't worry, I'll just [PERFORM_MAGIC] so you'll have the equivalent amount of BTC in a brand new wallet straight away.

I can think of the following (slow, complex, frustration-prone) process to substitute PERFORM_MAGIC with:

Bob emailing some custom instructions telling Alice to install a
Bitcoin client
Alice following these instructions and possibly
having problems with the process
Alice emailing Bob her receiving
address
Bob transferring the coins to Alice.

Is there a way that requires less interaction, preferably accessible from my phone?


texts: Is it possible to check if a bitcoin address "belongs to" a master public key from a deterministic wallet?

texts:
Let's say I have a Master Public Key (MPK) and have a derived some addresses from it.

How can I check later if a given address was derived from my MPK?


texts:
When you install Bitcoin client, how does it discover the nodes to get a copy of the blockchain?
Are their seed nodes ? Are they vulnérables? SPOF ?


texts:
I'm starting up a new bitcoin based commerce site and am wondering how many transactions per second the bitcoin JSON-RPC API can accept? A user can have an account balance in bitcoin and I was initially thinking of storing all transactions in a database and then querying that to determine their account balance, but after reading up on blockchain reorgs and whatnot decided against it.

So is it feasible to just use the bitcoin API directly, or should I implement some sort of caching/load balancing?


texts: How can you operate a fractional reserve e-wallet?

texts:
There are topics about the possibility of e-wallet providers operating like fractional reserve  banking. How it can be done in theory and practice? Did it ever happen on any meaningful way in Bitcoin's short history?

Edit: does this practice involve any real lending of bitcoins just like the case with real banking:

Edit 2: is it a prerequisite for e-wallet operators that they store all clients' funds on a shared bitcoin address or is it only an added benefit for them?


texts: OP_PUSHDATA1 is not allowed inside redeem script of P2SH?


texts: Is this pattern a tracking method or just a Bitcoin wallet making change to itself?

texts:
While following a particular transaction from a donation received in 2011 I noticed a pattern in the block chain.
The entity donating would send .001 to an address and the remainder of the wallet would go to another address.

A few min later the wallet with the remainder would send .001 to someone else and the remainder to yet another address, when that address would again separate and send .001 to a recipient and the remainder to, what I would presume, an address under their control.

Once in a while the sender would send .001 to two or three others but the remainder would always go to a separate address they control.
I followed the chain forward and backward with the typical results.

I am wondering if this is a method used to track individuals, or is this a result of the wallet sending “change” back to itself.
I have followed other donations and usually the address shows multiple transactions without emptying the contents completely.

I have used walletexplorer.com and blockchain.info to follow the history but it seems the trail goes back further then I have time to click and wait for a web page to load.

Is there any software available that can filter through my offline copy of the blockchain ledger and make following these kinds of links easier / quicker?

How does blockchain.info displays user names from bitcointalk embedded somehow with the addresses. Were those identities listed associated with the address by the sender, or was it designated by the recipients wallet?


texts: How do I identify my IP address on bitnodes?

texts:
I have supposedly successfully setup a node using the Bitcoin core, but when I go to bitnodes to remotely see if the node is communicating with the network, bitnodes says i am unreachable. Bitcoin core disagrees. How can I find my node's unique address? Using cmd to run a netstat query shows me an ipv4 address that is also unsearchable with a fluid port range (49800-49950).

Something tells me I know just barely enough about networking to be dangerous.


texts:
consensus.nRuleChangeActivationThreshold = 6; // 75% of 6
consensus.nMinerConfirmationWindow = 8; // nPowTargetTimespan / nPowTargetSpacing * 4

For what this rule exit ? How to calculate this rule for find valid
value for altcoin.
What can be happen if it's value to low or to high ?

Is this value attached to the nPowTargetTimespan / nPowTargetSpacing * 4

Or is it completely unrelated to them?


texts: Why are transactions separate in a block?

texts:
I'm just getting started looking at bitcoin and it's protocol, so this might be an incredibly stupid question. Why does bitcoin have a separate concept of transactions? Wouldn't it be better for each block to have a bunch of inputs and a bunch of outputs without separating them as individual transactions? This way it's more anonymous and private, since anyone trying to track an public key is stopped since their transactions are mixed with hundreds of others?

I guess technically, you could do that right now, by making one transaction with hundreds of inputs and outputs and mining that. I'm not asking why transactions are propagated by the nodes, I'm asking why are they stored separately in the final blocks?


texts: How do you start the Ardor funding account monitor via the command line?

texts:
I want to fund accounts I tag via account properties using the account monitor, but I want to understand how it can be started.

The ardor account monitor can be started via the gui: https://ardordocs.jelurida.com/Account_Monitor

When starting the monitor via the GUI, do you have to leave the browser open?
What about starting it via the command line?
Also how does fee-ratio work? Is there an example?


texts:
I received the following after trying to make a USD deposit to Mt. Gox from Dwolla today.  Does anyone know more information about this or if the court order may apply to other methods of deposit/withdraw?

  As of 12:13 PM on 5/14/2013:

  You’re receiving this notice because our systems have indicated that
  you’ve processed and completed a real-time Dwolla-to-Dwolla payment to
  Mutum Sigillum LLC (“Mt. Gox”) within the last 24 hours.

  Due to recent court orders received from the Department of Homeland
  Security and U.S. District Court for the District of Maryland, Dwolla
  is no longer legally able to service Mutum Sigillum LLC’s account.

  This is a courtesy email encouraging you to follow up on any
  uncompleted orders with Mutum Sigillum LLC as Dwolla is now unable to
  move money to and from Mutum Sigillum LLC’s Dwolla account.

  Dwolla is not party to this matter nor does it have any information or
  further insight into the situation. We strongly encourages those with
  questions to contact Mutum Sigillum LLC

  Note: Dwolla requires a court order before honoring requests such as
  seizing funds or revoking access to an account.

  On behalf of Dwolla, we apologize for this inconvenience.

UPDATE:

Here's what I got back thus far after contacting Mt. Gox to ask about the situation. Looks like they will make a formal announcement about it:

  Hello,

  Thank you for the email. We can see that the Dwolla transactions are
  not getting processed right now. We will contact Dwolla and post an
  announcement regarding this. Your patience is appreciated till then.

  Thanks, MtGox.com Team

Update 2:

The balance that I transferred in on the morning of 05/14 was added to my MtGox account that evening, so it appears they are still honoring the transfers that went through before the lockdown.

Update 3:

Here's the current statement from Mt. Gox (still waiting for the real reason for the court order):

  TOKYO - JAPAN - May 15, 2013

  MtGox has read on the Internet that the United States Department of Homeland Security had a court order and/or warrant issued from the United States District Court in Maryland which it served upon the Dwolla mobile payment service with respect to accounts used for trading with MtGox. MtGox takes this information seriously. However, as of this time MtGox has not been provided with a copy of the court order and/or warrant and does not know its scope and/or the reasons for its issuance. MtGox is investigating and will provide further reports when additional information becomes known.

  Regards
  Mt.Gox Co. Ltd Team.


texts: How to determine the balance associated with a given BTC address based on input/output amounts

texts:
I'm writing an application that attempts to calculate the running balance of a given BTC address by looking at data including block height, input amount, output amount, etc. However, I'm not certain about the logic involved here. Would it be possible to create this running balance by checking an input/output address and then tracking the input/output amount?
Here's a quick sample of the data that I'm looking:
BLOCK_DATE | BLOCK_HEIGHT | TRANS_HASH | INPUT_ADDRESS | OUTPUT_ADDRESS | INPUT_AMOUNT | OUTPUT_AMOUNT
01/11/2020    190            15c7853       abc             xyz1             -0.01          0.0001
01/11/2020    190            14v9876       abc             xyz2             -0.50          0.70
01/11/2020    191            19vc842       abc             xyz3             -5.03          0.413
01/12/2020    192            20ff4d3       abc             xyz4             -0.06          0.201
01/12/2020    192            154gf34       xyz1            abc              -0.07          0.18
01/12/2020    192            45f4ti5       ggg             abc              -0.10          0.24
01/12/2020    192            33cv5c5       jjj             abc              -0.08          1.13

So using this dummy data, how would I go about calculating the running balance for address abc? I know that the input/output isn't necessarily 1:1 and there are some nuances here that make it more complex than this. So I'm not sure if I could do something straightforward like sum all of the inputs and outputs for a given address.


texts: Is it normal to get 60 confirmations for a transaction in blockchain and still it is not received and confirmed, can you help I m worrying as this is my first transaction, did I forget anything


texts: Shapeshift + bitcoin cash question. The deposit link expired before the deposit reached it

texts:
At first, the transaction stayed unconfirmed, and then, four hours later, it had one confirmation, and now, two days later, the blockexplorer says it has 247 (?) confirmations, but the wallet still says it has two and is pending.  I figured that when the amount will reach Shapeshift, they will issue an automatic refund although the blockchair says that the main part of the deposit is already sent and spent. I tried to use CPFP while it was still unconfirmed to draft the funds back, but it seems like I misunderstood the function. Can anybody tell me what's the problem, if it's stuck for centuries or how to speed it up? And it is actually a second time in a row I get into this situation. Anyway, would anybody just sort out my confusion?
41cd7bb49bab97d82063f5fde1b2e5b9e8cb2cbc1faba65a938d70c69dbce8a7


texts:
Ok, so my bitcoin node (0.15.1) is running, and fully synced up with the network. I'm using python and the 'bitcoinrpc' package. I want to access the RPC server from outside my network. I have RPC set up on the normal port 8332 which is opened up on my router. I have rpcallowip configured to the address of the computer I'm connecting from.

When I run my python program I get the following error, which I am having a hard time tracking down. (my program is called 'PollForAddress.py')

  File "PollForAddress.py", line 46, in <module>
    mempool = nodeRPC.getrawmempool()
  File "/usr/local/lib/python2.7/dist-packages/bitcoinrpc/authproxy.py", line 139, in __call__
    response = self._get_response()
  File "/usr/local/lib/python2.7/dist-packages/bitcoinrpc/authproxy.py", line 187, in _get_response
    'code': -342, 'message': 'non-JSON HTTP response with \'%i %s\' from server' % (http_response.status, http_response.reason)})
bitcoinrpc.authproxy.JSONRPCException: -342: non-JSON HTTP response with '403 Forbidden' from server

any ideas whats going wrong?


texts: Diffrent transactions in different block sync problem

texts: Consider that miner A and B both try to solve its block, A's block has transactions (T1,T2), B's block has transactions (T1,T3). A solved its block then synced the block to B. Does B will discard its block which contains T1 and continuely create a next block contains T3? and how to check T1 is confirmed but T3 not?


texts: Please help - Bitcoin Conf file in the wrong directory

texts:
I am running a full node using Bitcoin Core GUI on Windows 10. The conf file is in my bitcoin data directory, instead of being in the appdata/roaming folder. But Bitcoin-qt points to it by default and seems to work fine.

But bitcoind and bitcoin-cli are looking for the conf file in the appdata/roaming folder, which I guess is the reason the bitcoind server never appears to start. How do I start bitcoind and check if it is running or not? I need bitcoind to run so that I can use json-rpc commands.

If I run bitcoind on cmd, it appears to start downloading the whole blockchain again, which is unnecessary because I already have all of it.


texts: Is 3D acceleration needed for GPU mining

texts:
I'm new to the mining world and want to start with a typical mining motherboard + GPUs rig setup. I plan to use a 100% FLOSS, GNU/Linux based, operating system (Parabola, from which I'm a dev). The thing is that I'm not sure if the convenient GPUs I may use will work with 3D acceleration (due to the lack of free and open source firmware/drivers), although the rest of the features will. AFAIK, the GPUs are used for computing, calculations, etc., but nothing that would require 3D hardware acceleration, right? I think that's only needed for games and 3D modeling, although I'm not very sure about it. Is it necessary for mining?
Thanks in advanced.


texts: Can I cancel a transaction that has not been successfully broadcast yet?

texts:
In Bitcoin Core, is it possible to cancel a transaction whose status is:

"Status: 0/offline, has not been successfully broadcast yet"

The client hasn't caught up with the network. It looks like it's going to do that first, and then send the transaction.

Is that right, or is the transaction already irrevocable?

If I can cancel the transaction, what's the best way to do that?

I tried abandontransaction but it gives the error:

Transaction not eligible for abandonment (code -5)


texts: Lightning Network's RSMC: what happens if there's no revocation transaction?

texts:
From the Lightning Network's whitepaper, page 19:

  If they do not broadcast their most recent version, they will be
  penalized by taking all the funds in the channel and giving it to the
  counterparty.

  ...

  If they do broadcast their most recent Commitment Transaction, there
  should be no revocation transaction superseding the revocable
  transaction, so they will be able to receive their funds after some
  set amount of time (1000 confirmations).

By revocation transaction, I assume the author implies that one party can prove on the main chain that the Commitment Transaction broadcast by the counterparty was not the most recent one.

Given that's true, will the party receive all the funds in that channel? Conversely, what happens if the counterparty goes offline for a long time (more than 1,000 blocks as per the example in there) and there's no revocation transaction, despite the fact the broadcaster lied about the Commitment Transaction?


texts: BIP 32 Public Parent Key -> Public Child Key

texts:
Reading the BIP 32 section of how to generate Public child key from Public parent key, I got stuck in the following:

  The returned child key Ki is point(parse256(IL)) + Kpar.

As I could understand point(p) is the Elliptical Curve multiplication which will output X and Y coords, so how can I add them with Kpar? Also, it should return me a Compressed public key right?


texts: How much would it cost to do a 51% attack

texts:
how much would it cost to carry out an 51%-Attack?
If there is a place service in the web that you can rent ASIC's than i would rather hear what renting this would cost. If not then buying the asics is fine too.

To keep the calculation KiSS following assumptions:

Attacker chooses the cheapest way of renting/buying hardware. But he is NOT renting/bribing whatever the existing machines from miners from the existing bitcoin network. The gear has to come from outside the network.
Don't worry about that renting/buying such a huge qt would drive the price for the hardware up.
Ignore what the community would do, the cored devs or whoever to counterstrike your attack.
you don't need to include electricity cost in the calculation. If you do include it, please tell what you took for US-Cents/kw/h

Thank you!

P.S. is there a website that does this calculations on a regular basis? Would be cool to check this from time to time..

Update 4 Years later ond June 2019: The Hashrate of the Entire Network is right now (according to Bitinfocharts.com): 55,42 ExaHashes. Most efficient Miner is the DragonMint which has exactly (and realisticaly) 16 TH/s and costs including with power supply 2844USD. One would need 55 420 000 TH/s /16 TH/s =3,46 millin Dragon Mints * ~ 2800USD (included a small rebate)~ 9,8 billion USD. Crazy how the cost increased in the last 4 years from 145 Million to almost 10 billion...

EDIT X Years old answers to this question don't matter at all. This question needs to answered every 6 months. Entirely new generations of Asic-miners, change picture a LOT


texts: When exactly an entry is removed or added to the UTXO's set in the Bitcoin core?

texts:
I do have this implementation question and wanted to know how it's implemented specifically in the Bitcoin core.

1. When exactly an entry is added to the set of unspent transactions outputs?
Is it when a block is persisted (added to the bchain) after being validated and then all the utxo from its txs are added to the utxo set?

2. When exactly an entry is removed from the set of unspent transactions outputs?
Does the bitcoin core remove a spent utxo when validating a standalone transaction ? Or is it done on block persistence ?

3. Whats' the difference between validating  a transaction that is validated in block (case of a relayed block) and a transaction that is validated standalone (case of a relayed transaction).


texts: What is the tradeoff between privacy and implementation complexity of Dandelion (BIP156)

texts:
Dandelion is a new relay protocol for transactions on cryptocurrency peer-to-peer networks. It has been heralded as a huge privacy improvement for cryptocurrencies at the networking level– I'm wondering what costs this comes at.

Does Dandelion introduce more complexity into the code base?
Are there possible attack vectors introduced with Dandelion?
What is the hold-up with implementing Dandelion in Bitcoin Core?


texts: How to specify testnet via curl against json-rpc?

texts:
The testnet=1 option can be (not) specified in the bitcoin.conf file (thus causing it to be on mainnet by default), and this can be over-ridden in bitcoin-cli with the -testnet command-line option.

But, when using the json-rpc interface via curl, I can't figure out how to specify I want testnet in this case. I can put the testnet port 18332 in the url, but I don't know how to use any other "command line" switches when using curl?

Can I do it with curl?


texts: I withdrew some bitcoins from a site and the blockchain is not synced yet. It's taking too long for the sync (more than a day). The payment is still not in my wallet. Can I send payment to another wallet before it's synced ?


texts: Could someone solve for your private keys by sending many transactions to the same address?

texts: I've read that it's never safe to use the same bitcoin address more than once because there is a small chance that someone could solve for your private keys (though I don't have a solid-enough background in encryption to understand all of the implications of this concept). In any case, even if you did generate a different address for every incoming transaction, what would stop an attacker from simply sending many transactions to the first address they see in an attempt to crack your private key?


texts:
I downloaded Bitcoin core wallet a few days ago. It was all going well, it synced just to about 25 weeks ago or something. One day the power went down and it shutdown the computer.

When I started bitcoin core again it loaded up to "loading wallet" and is stuck there. Unfortunately I already send a few BTC's to the wallet. Since I could not access my wallet, I figured that my BTC's are lost but then I start reading about accessing my wallet using Bitcoind, however when I create the bitcoin.conf file with the

rpcuser=bitcoinrpc
rpcpassword=xxxxxxxxxxxx

It wont recognize it and still give me the same error and crash as before I created the file.

I am currently running on Windows XP. So since I can't access my wallet, and since the manual way does not seem to work either, is there any other way to withdraw the coins from the wallet? If not can anyone help me with the bitcoind problem. Thanks a lot.


texts: Relation between multi-sig and single-sig addresses (in BCCAPI library)?

texts:
I had a multi-sig address M (starting with 3) that I was trying to send a small amount of coins to. I was playing around with BCCAPI and the coins got sent to an "ordinary" address A (starting with 1)

I had supplied M to the library but somehow the signed tx had the address A

I know who controls M but no one seems to control A. I am trying to see if the funds can be recovered by someone controlling M.

Is there any relation between the two addresses? I'd prefer not to post the actual addresses yet. However, the fact that I used BCCAPI might give some clue.

Here is the code (in Scala) that I used:

val M = "3..." // multi-sig address
val receiver = com.bccapi.bitlib.model.Address.fromString(M, netParams)
val so = new com.bccapi.bitlib.model.ScriptOutputStandard(receiver.getTypeSpecificBytes())
...


texts: Can bitcoin-core wallet be used as the backend for a mobile wallet app?

texts:
my idea is to use bitcoin core and it's multi-wallet capabilities as the back-end of a mobile wallet app. The way I think this could be archieved is by creating an empty wallet with bitcoin-cli createwallet true and then using the importmulti RPC command to upload an output descriptor with an xpub.
Disregarding the privacy issues, the only other thing that worries me about this is that some wallets might cause the node to re-scan the blockchain, and since this can potentially take a while, all other clients will be basically denied their service.
I have not really tested this, but I'm pretty sure this will prevent this architecture from ever working. Am I right? or is there a way around this?


texts: Is there a secret number that is only known by the sender and the receiver after making a transaction?

texts: After making a transaction and receiving all the hashes and ids, is there a number that is secret and only the two people involved in the transaction know?


texts: Are hardlinks responsible for the bitcoin data directory appearing larger than expected?

texts:
I was running bitcoind from my Linux box. I stopped the command when ~/.bitcoin size was about 5.8GB.

Today I started the daemon again. ~/.bitcoin size is now 7.2GB. Here is says that the blockchain weight about 6GB: http://blockchain.info/charts/blocks-size.

Is that webpage wrong? Maybe bitcoind is downloading everything again and mixing both downloaded block, thus increasing the size to more than the stats at blockchain says.

A call to getblockcount returns: 225531

EDIT: I've found the total blocks count here: http://blockexplorer.com/q/getblockcount (228972). I guess blockchain.info is not updated.


texts: Benefits of bitcoin as national currency?

texts:
As Bitcoin is crossing total M1 money of few countries, how could a country by adopting Bitcoin as national currency, mutually benefit Bitcoin and the country itself?

https://bitcointalk.org/index.php?topic=154954.0


texts: In a discussion about private channels, Conner Fromknecht mentioned a concept called Link-Level Multiplexing. What is this and what is it useful for? How does it work?


texts:
I am trying to understand what problem in bitcoin proof of work solves and came to this somewhat helpful quote:

  So, for instance, if a miner controls one percent of the computing
  power being used to validate Bitcoin transactions, then they have
  roughly a one percent chance of winning the competition. So provided a
  lot of computing power is being brought to bear on the competition, a
  dishonest miner is likely to have only a relatively small chance to
  corrupt the validation process, unless they expend a huge amount of
  computing resources.

Does this mean that proof of work prevents say double spending because of following reasons. Imagine attacker introduces 100000 rogue nodes in the network and their goal is to send false information about transaction validity - but since these nodes need to do proof of work, in total, when all 100000 nodes are doing proof of work this is too costly for attacker. Is that right? So because of this proof of work keeps attackers at bay.


texts: How to interact with bitcoind using C++?

texts:
I know that bitcoind is written in C++, but I cannot figure out how to use its API within my program. I have been using a Python wrapper effectively, but I need another process running that is as quick as possible. Is there a library somewhere for bitcoind? Thanks.

Or could you just point me to a good Json-rpc library?


texts: Do all wallets use specific explorers? If so, is there a way to identify which explorer the wallet is using? Most of the major-mid tier wallets seem very ambiguous or don't seem to mention this at all.


texts: Can you use an external PCI expansion box for mining?

texts:
I'm wondering if plugging cards into something this external pci expansion box would be effective in a mining setup.

I guess it depends on how much bandwidth is used, but I don't know how bandwidth intensive the mining process is. Has anyone here used a setup like this for mining?


texts: Classic - I´m a newbe in Bitcoin and Bitcoin core offered me a fee and I accepted it. It was very low (see details)

texts:
The transaction has not been confirmed for over 14 days. Is it normal? Am I going to see my BTC ever again? :( Thank you all very much for any help!
Details:
Stav: 0/nepotvrzeno, v transakčním zásobníku
Datum: 21.12.2017 16:38
Pro: 18hSgrZD5CpPftpjPZMhWy9K7hFmmCZUop
Výdaj: -0.03419607 BTC
Transakční poplatek: -0.00000340 BTC
Čistá částka: -0.03419947 BTC
ID transakce: 3857e01084275a0259efee900b30ecd985a81b7e8a30ed53a5853ff9a73d670e
Celková velikost transakce: 339 bytes
Pořadí výstupu: 0


texts: How to verify that the recipient received a payment?

texts: I sent a Bitcoin payment using Circle Pay. According to my Circle Pay the transaction is completed. It's been two days and the person on the other end is claiming they have not received the money. How can I check to see if he is telling the truth. From what I read, all transactions are public, correct?


texts: Why can't we set fees to a fixed amount say 0.005 BTC?

texts:
The current fee mechanism is confusing and difficult to implement.

The current fee system uses transaction size and the size of the block the transaction is due to appear in to calculate the fee. If you're writing a Bitcoin client such as a web wallet or android app this is not easy to implement.

Is there any reason we couldn't have a well documented fee mechanism along the following lines ?

Fixed fee, or
% of transaction amount, or
% of transaction amount capped or floored.


texts: How to verify if a transaction is signed correctly?

texts:
Given an arbitrary signed raw transaction, how can we easily verify if all inputs are correctly signed (assuming all inputs are existent/unspent and the fee is higher than zero)? Bitcoin core's RPC command testmempoolaccept will check if all inputs are available to be spent in the mempool/blockchain so it's impossible to test transactions that have parents not yet broadcasted.
I am aware that for this kind of check, the scriptPubKeys of all inputs needs to be known and therefore only the signed raw transaction by itself is not enough for this kind of check. Still, the scriptPubKeys could be passed to the transaction instance or verify method. I was looking for some nice way to do this in python/javascript but was surprised how difficult this task is:

Peter Todd's python-bitcoinlib requires each input to be validated manually with some flags indicating the type of ScriptPubKey.
1200wd bitcoinlib, has a transaction.verify() method but it seems to only verify the basic transaction types: coinbase, P2PKH, P2SH(P2PKH), P2SH(multisig), ...
BitcoinJS has a method for this, psbt.validateSignaturesOfAllInputs() but converting a raw transaction to PSBT is not possible/easy.
Bitcore's transaction.verify() does mostly some basic sanity checks and doesn't verify the signatures.
BitcoinJ's transaction.verify() does also basic verification and the script execution, as python-bitcoinlib, has also to be done manually with verification flags.


texts: How can I process bitcoin payments from a hidden service on Tor?

texts:
I had a very simple question for which I seem unable to find an answer. I want to set up a Tor hidden service and on it allow Bitcoin transactions. How can I make this happen? The server would be running Windows IIS and is mostly for personal use.

I had a look around at BitcoinD and Blockchain.info but somehow the information there does not resonate (or I am just too daft to grasp what they are saying)


texts: Why are blk*.dat files ~134200000 bytes?

texts:
I understand that blocks are stored on disk across multiple blk*.dat files, but why is the maximum file size roughly 134,200,000 bytes?

What's the reason behind this file size?
Where can I find this setting in the source code?
What's the exact maximum size?


texts: Lost Transaction from Blockchain.com to Electrum

texts: This link, https://www.blockchain.com/btc/tx/a081d03519bc0f1dcf4ac391da6f54d4d6091c458530b620f96eca5c1c5a3511, shows the transaction was delivered to the address "1Mv4fi8UdVhbfm9iLx2Bf8xhDrMv9sZSyD" of my Electrum wallet, but my Electrum wallet doesn't show the transfer. Please teach me what is wrong. how I can find the truth? Thank you for your help in advance


texts: Is it okay to run regtest for dev purposes while simultaneously running a node on mainnet (bitcoind)?

texts: Hope it won't mess anything up on my mainnet node.


texts: Will merge mining patch make Bitcoin network mining power available to anyone?

texts: I think Namecoin has a good value, but while I think Vladimir overestimates the inflation effect of merged mining, I still mostly agree with his post, which is negative towards uncontrolled merged mining. It requires small patch for bitcoind to make it "parent" for Namecoin blockchain, is the patch exclusive for Namecoin? If yes, what makes it exclusive, and if not, is there a way to design a merge mining patch, so it would be exclusive for a particular blockchain? That way bitcoin community would have a choice, when downloading a new version of bitcoin, if it wants to adopt a new blockchain.


texts: Are there any existing tools to measure the time required for block and transaction validation？

texts: The validation time of transactions and blocks has a great impact on the performance of the Bitcoin network. Are there any special measuring tools that can be used?


texts: Understanding transactions in orphan blocks

texts:
This is in regards to Testnet.

I found a transaction that was confirmed in two blocks that were 106 blocks apart (923,255 & 923,149).

Block 923,149 is part of the main chain and 923,255 was orphaned.

My question is, how can a transaction be in two blocks so far apart and the latter being orphaned?


texts: Is cryptofree.casa genuine plateform to earn free BTC

texts:
As O recently login to Cryptofree.casa website, someone told me that after once it reach to 0.2 BTC then I can withdraw my wallet BTC
so is it correct information??


texts: How to monitor large number of public addresses

texts: I have created 10K addresses with vanitygen to deal out for transactions, Now how do I watch all those addresses for transactions and balance?


texts: Why was the time between these two blocks not approximately 10 minutes?

texts:
A new block will be created in approximately 10 minutes, but I saw on blockchain.info that these two blocks were found only two minutes apart!

How come that the time between the first two listed blocks is just two minutes?


texts:
Hello everyone
I'm jud3v and i'm searching an api that provide me the same as electrum wallet for creating multisig wallet 2-of-3 for my client to protect there btc with multisignature.
I have already find there compatible api like blockcypher, bitgo, cryptoapi, and many more...
But there api don't have the same as electrum creating multisig wallet, because for example blockcypher provide free api for creating multisig wallet but there api have many bug to fix there are not a stable api like blockchain or coinbase for example.
These api does not compatible with multisig blockchain coinbase btc.com blocktrail (down) blockchair and many more.
So where i can find an api to implement multisig feature from 2 signatory (client, seller) for 3 xpub (co-signatory)
Did i need to download the bitcoin core for creating "only" multisig wallet ?
Thanks you all :)


texts: How to subtract two points on an elliptic curve?

texts:
Please tell me if there is a formula for A-B, (That is, subtraction of two points / minus). I know how two points are added, A + B this addition is described in detail

(Please tell me how you can change the formula to subtract two points / minus) A-B


texts: Peercoin: What is the difference and similarity between the PoW difficulty and PoS difficulty?

texts:
As of now the difficult for PoW block (Block #127803) is 183694752.0, and for PoS block (Block #127804) is 10.4918556213. Why are the two values so different?

Is there any relation between PoW difficulty and PoS difficulty?

"This block reward reduces by half every time the hashing power of the network increases by 16 times". Does this statement apply to only PoW difficulty or to both PoW and PoS difficulty?


texts:
I wanna clear this thing that how blocks are retrieved and created in from the nodes using an end point. The end point is basically centralized and have nothing to do with network if i'm not wrong. Is that end point is also running some kinda setup to keep blocks in sync as well as connected nodes?
In a network we have nodes [B,C,D,E,F,G...] and we have endpoint A. Lets say we have to retrieve a block then on which node the request will be sent?

Take example of STORJ in that request lands on one server(kinda end point) only then it broadcast to all. Isn't the centralized system.


texts: Is there a way to mine bitcoins without installing a client, that is can I do it in PHP or Node.js by adding some libraries etc which replicate what the bitcoin client would do(more or less)?


texts: Explain how to send bitcoins from multiple addresses to one

texts:
Let's assume that user has a wallet with 3 bitcoin addresses:
A, B, C.

The user received 1 BTC to address A,
1 BTC on address B,
1 BTC on address C.

Now the user wants to send 3 BTC to another user. How would he do it?
What about miner fee, will it be more than in case of sending from one address to another?
Please help me understand that question.


texts: Why is my bitcoin node not picking up transactions?

texts:
Im running a very simple bitcoin core node that talks to a client. Whilst running on the testnet everythign works perfectly. As soon as I switch to live, the bitcoin node no longer seems to pickup transactions for payments into addresses it generates. I double checked the payments with blockchain.info and the payments were received and confirmed. Anyone know what is going here?

bitcoin.conf

prune=600
maxconnections=10
rpcthreads=2
rpcuser=#######################
rpcpassword=#############################
daemon=1
keypool=10000
walletnotify=############################
blocknotify=##########################
testnet=0
rpcallow=###############

The same config and was used for test/live with the obvious exception of toggling the testnet value.


texts:
I'm trying to create Bob's first receive (ephemeral) address according to the BIP 47 spec after the Notification Transaction has taken place, which I believe to be:

  141fi7TY3h936vRUKh1qfUZr8rSBuYbVBK

according to these test vectors. I have been unable to calculate the correct ephemeral public key (B') corresponding to this address via:

B' = B + sG

or the correct private key (b') for the ephemeral address via:

b' = b + s

The variables I have come up with so far for this first address include:

// Alice selects the 0th private key derived from her payment code:
a = 8d6a8ecd8ee5e0042ad0cb56e3a971c760b5145c3917a8e7beaf0ed92d7a520c

// Alice selects the next unused public key derived from Bob's payment code,
// starting from zero:
B = 024ce8e3b04ea205ff49f529950616c3db615b1e37753858cc60c1ce64d17e2ad8

// Alice calculates a secret point:
S = 03f5bb84706ee366052471e6139e6a9a969d586e5fe6471a9b96c3d8caefe86fef

// Alice calculates a scalar shared secret using the x value of S:
// x value = f5bb84706ee366052471e6139e6a9a969d586e5fe6471a9b96c3d8caefe86fef
// SHA256(x value)
s = d24366e662da47c0cccca4cc2d2d817af54e4d21039c0cc4fc441624efe273f7

// s multiplied by generator point
sG = 0283850c6835576554261fbab5845a099638859528b2725455e6a48e7566415c02

// Alice uses the scalar shared secret to calculate the ephemeral public key
// used to generate the P2PKH address for this transaction:
B' = 0344b4795e48df097bd87e6cf87a70e4f0c30b2d847b6e34cddde64af10296952d

// Bob's first private key
b = 04448fd1be0c9c13a5ca0b530e464b619dc091b299b98c5cab9978b32b4a1b8b

b' = d687f6b820e6e3d47296b01f3b73ccdc930eded39d559921a7dd8ed81b2c8f82

Are any of these variables incorrect, and if so, how are the correct ones obtained?


texts: How hard is it for an exchange to adopt native segwit? Is it not as simple as updating the address regex checker on the front-end?

texts: Just wondering, maybe I'm missing something. Are there changes on the backend needed to be implemented as well? Not as simple as changing the regex validation on the front end?


texts: How can I generate a vanity Bitcoin address?

texts: I once found a program that was capable of creating Bitcoin addresses with specific words in them, but can't find it now.  Is there a trusted program, in the Ubuntu repositories for example, that can generate these 'vanity' addresses?


texts: What makes the initial download of the blockchain so slow?

texts:
If you download a bootstrap copy of the blockchain through torrents, it will be faster than getting that same data through the Bitcoin network.

Ofcourse the BitTorrent protocol is more optimized for bulk data transfer, but is there any other reason for the huge difference in bandwidth? Is it artificially limited in the client right now, or by design?


texts: Do imperfections in dice make them unsuitable to make really good bitcoin private keys?

texts:
Dice do have imperfections (depending on how expensive ones you get), but would they not still have enough entropy such that a private key generated by them could be considered really safe? I am thinking of paper wallets storing lots of coins, potentially.

It would short circuit the problems with the implementations of random number generators on computers (the recent Android bug, and the Debian bug between 2006 and 2008)

http://www.debian.org/security/2008/dsa-1571

If a die is missing a side one would notice, so they are a lot easier to inspect for big errors than computer code.

So, how much would imperfections in dice lower the entropy? Could you just calculate with a lower base, e.g. 5.765*N rather than 6*N with a perfect die (5.765 then being a measurement of imperfection of a specific die).

Edit: maybe rather 6**(N-x), where x are the extra occurrences of one number.


texts: I'm developing a mining application that switches mining between different altcoins. I'm looking for a mining pool with an API that allows withdraws, so that I can automate the withdraw process for each user. Are there any pools with this feature available? Thanks in advance!


texts: RPCPORT and --rpcport not working in Latest version: 0.18.0

texts:
We are using bitcoin core RPC Endpoint to broadcast transaction over network, It was working perfectly till version 0.17.0 but in latest version 0.18.0 RPCPORT and --rpcport is not working.

Please let us know is there any way to start RPC port on version 0.18.0


texts: Lightning networks revocable commitments: unilaterally closing could cause funds lost forever?

texts: If I understands correctly, A and B will exchange their revocation key once they are ready to move to the next state. What happens if B received the revocation key and decided to close the channel unilaterally without broadcasting the transaction. This way B can never get his funds, but A can never get his funds as well. Because A can not broadcast his transaction since B has his revocation key. Isn't it a huge risk for A?


texts: Electrum Wallet - Is it possible to specify inputs in new transaction?

texts:
In my wallet, I have bitcoins belonging to three different addresses.  I want to send the bitcoins from one of those addresses elsewhere.

This is made easier, perhaps, by the fact that the balance of that one address arrived in a single transaction.

Is there any way for me to do this?

Thanks!


texts:
Is there a reserved Bitcoin address?

It should not be able to send bitcoins to it. But the address should be syntactically valid.

Such an address could be used for examples/documentation, without advantaging the author. Similar to example.com.

Wikipedia and bitcoin.it use bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W. Is this a reserved address or is it owned by someone? (resp.: could you send bitcoins to this address?)

If there is no reserved address, which should we use? Simply take a valid address and replace the first digit with, say, a "9"? (would this be future-proof?) Or use a testnet address?


texts: Does anyone have a formula for dynamic block durations?

texts: I want to implement this, so does anyone have a formula for dynamic block durations instead of a fixed target of 10 minutes?


texts: If all block chain copies get deleted, what would happen?

texts:
What would happen if all block chain copies get deleted at one time?

At first, all clients would try to get the block chain from other clients, right? But this would fail. Would the "network" then (but when exactly?) assume that everything just started, and mine the genesis block again?


texts: Calculating the average bid/ask price when placing orders

texts:
new to bitcoin and trading,

I'm writing some code to analyse cryptocurrency markets and I want to better understand market depth.

For a dummy scenario:

Lets say BTC was at $100 and I have 10 that I want to sell. When I place a market order do I 'consume' the highest 10BTC-worth of bids? Such that my average ask is the weighted average of all coins I just sold?

E.g. if the bids were 5BTC at $100 and 5 at $101, when I place by 10BTC ask, I fill those 10 bids and my return is (5 * $100) + (5 * $101) with an average of $100.50 for each BTC I sold?

Obviously in reality there are any number of bids/asks at all sorts of volumes, but the concept is the same?

I've read about interpreting the order-book but I'm looking for an explicit example of what happens when you bid/ask on a given market.

Thanks,


texts:
I'm very new to Elementary OS and I used the version Freya a short time. There I got Bitcoin-qt easily out of the repositories.
On Elementary OS isn't that that simple - has anyone experienced the same?

sudo add-apt-repository ppa:bitcoin/bitcoin
sudo apt-get update

The tags above aren´t working on Loki.
I just want to know - I have no problem to download the .tar.gz and start it from there.


texts:
this is two weeks

I am trying to crack my MultiBit portfolio, I do not remember my password recorded in July; I have no old file save my wallet, the word must be no more than 15 characters and must be single and I need only 2-3 characters to remind me.

I looked all over the web and bitcoin forums looking for a solution, but being French, the English pages are poorly translated and difficult to understand. My English is not very strong. I asked walletrecoveryservives, but he couldn't figure out my password using the ideas that I gave him.

I have no more ideas; is the island cracker possible without ideas? Could you help me do it if it's possible?


texts: Why didn't the difficulty adjust for the first 30,240 blocks?

texts:
I'm working on showing the difficulty adjustments over time, and I've noticed that the first difficulty adjustment did not take place until block 32,256:

http://learnmeabitcoin.com/explorer/node/difficulty/

Why is this?


texts: blockchain.info receiving address changes - is it OK to put BTC address on the website?

texts:
Wallet from blockchain.info change the receiving address from time to time. I guess the rationale is to protect my privacy or something.

In reality I'd be more secure in my head if I had the same BTC address...

Solution to that would be to create own vanity address, but in the meanwhile - is it OK if I publish the address on the website and will it work in 6 months?

EDIT / UPDATE: Wish the changing addresses were better explained - https://en.bitcoin.it/wiki/Deterministic_wallet - I was quite seriously worried why my address is changing.