texts:
Apparently I am not alone in feeling foolish regards this.
I think things are safe, but would so much appreciate advice.
When using Coinbase, I had some small change in my Bitcoin Cash wallet, don't know how it got there, as I always use standard Bitcoin.
Anyways I deposited into my Bitcoin CASH wallet.
I then sent the Bitcoin Cash to a standard Bitcoin address, of which I have access to.
So it has been sent to a one off address which is mine.
Can any of you kind folk tell me what will happen?


texts: Can't we use all the mining/processing power to calculate useful stuff?

texts:
When computers are mining now, they're actually trying to break nonsense codes. Can't all that processing power be used to do better things with like
gridrepublic etc.?


texts: In stratum mining pools, are most miners working on the same set of transactions?

texts:
When miners connect to the server, they get a "job" message back with a merkle_branch field that has hashes that correspond to transactions that will be included in the block being worked on.

What I'm wondering is, does the pool server bother changing that transaction set very often, or do they just wait for a block to be solved, and only then broadcast a new job with a different list?

In other words, in between block solvings, is everyone in the pool generally working on the same set of transactions?


texts: I imported my private key into blockchain.info but it says 'no free outputs to spend'?

texts: After two days of researching I finally got my private key! However when I import it in Blockchain, it says 'no free outputs to spend'. How do I fix this?


texts: Can miners collude to bypass the penalty based revocation system of the lightning network?

texts: The core lightning security assumption relies on a punishment mechanism called “Justice Transaction”. However, how can you prevent a malicious user from colluding with a miner, and producing a block with old state transactions without the rest of the network (watchtowers/honest nodes) realising it pre-mining?


texts: NXT uses transparent forging to detect who will solve the blocks. How can DDOS be prevented?

texts: Since NXT does transparent forging and it select a node to be the main one to solve blocks. How does it prevent a DDOS attack? And if a ddos was sucessful on the node during forging, what happens then? does it solve blocks half way only?


texts:
I'm quite new to this. I have transferred coins to a wallet 4 hours ago and I'm still stuck with no confirmations. I do have a Bitcoin wallet on blockchain.info. I transferred from Bitcoin market website straight to another wallet if mine and now its stuck. How can I reverse it or get it moving again? I have tried looking for the trusted peer option and all that, but can't get my head around it. This is my block number on blockchain.info: a8abd5243ac486822577208f87e46f6864baeb1250c1434b3a1811a017ce6e2f

Any help would be appriciated.


texts: What's the maximum possible utxo growth rate now? Can that be turned into an attack?

texts:
Now bitcoin unspent transaction output growth rate (not total size) can be, 260k utxo/day (3×60×60×24). With 8MB blocks, that's 2.8 million.

Single 1 bitcoin output can be split into 1000 x 1 mBTC outputs, within 100 minutes (10 blocks). Then, those 1000 outputs can be moved individually, as required..

Does this kind of utxo bloat attack work? Anything wrong with my calculations?


texts: Bitcoin Address can't be found of client?

texts: So, I'm a total noob to Bitcoin and have just finished installing it and have looked under all of the settings and cannot find the address. This is a little concerning. If I am missing something PLEASE correct/help me. I have seen in older versions that the address is right there on the GUI but I still can't find mine. I'm on version 0.7.2 if that helps.


texts: Do Bitcoin miners verify validity of merge-mined Namecoin blocks?

texts:
I've been reading a little about merged mining as used in Bitcoin and Namecoin.

It seems like merged mining effectively eliminated Namecoin-only mining pools, right? Since Namecoin-only pools are mostly 'out-mined' by the Bitcoin merged mining pools, it seems pointless to start one.

In this case, I had a concern about the incentives of Bitcoin merged-miners to verify Namecoin blocks (i.e. check Namecoin transactions, name updates, etc.). So my question is: Do Bitcoin merged-miners verify the Namecoin block before starting to mine on the merged block? I assume they do.

I suppose if they don't verify the Namecoin part, they save some computation-time but they stand to lose the Namecoin reward, which is not that high anyway. Is the saved computation time ever worth losing the Namecoin block reward?


texts: Security of online Electrum wallet after deleting wallet file

texts:
I just created an Electrum wallet using my computer which is connected to the Internet. Suppose I send my bitcoin from an online exchange to that wallet, then delete the wallet file. Are there any risks that my bitcoin will be stolen if the computer is hacked?
Suppose I've stored the seed phrase on paper or using some metal engraving device. And after deleting the wallet file, I've also used some disk utility to truly wipe it from my hard drive. At this point, unless my computer had already been hacked before I deleted the wallet file, everything is safe, right? Obviously, the drawback is usability, in that now I'd need to restore the wallet using the seed phrase (rather than wallet file + password). But suppose I don't plan on performing any transactions in the near future. Is this solution safe for hodling?


texts: How does Stellar multi-signing happen practically?

texts:
In Blog we read, that Government & NGO came together to sign the transaction, and in docs we read that transaction is invalid if it includes signatures that aren't needed to authorize the transaction and that a transaction envelope wraps a transaction with a set of signatures. But how does the multi-signing process is intended to happen practically?

Let's say I make a transaction that required my and friend's signature, I sign it and publish it. Does it fail because of missing signature? Is my friend notified through stellar that there's a transaction that requires his signature, thus "inviting" him to take a look at it? Can my enemy find it and sign it to deny me contracts? And in case of 20 signers? And in case someone doesn't sign, when does transaction fails? Can he not-sign it in a way to fail the transaction before set expiration time?


texts: Is there any tool to index ALL bitcoind UTXO?

texts:
I've got a full bitcoind node with txindex=1.

listunspent command is useful only if node is in possession of a private key for address.
So, if I want to check UTXO for random address, it will not work until all of that UTXO is indexed properly.

So, are there any tools to do that simultaneously with bitcoind?

Of course there is an option to import that private key to bitcoind. But this question is larger - to get unspent for any address.


texts: I am struggling to find a simple explanation for how to create a multisig address. For single sig, it's clear: double hash function applied to the single pubic key in base code 59. I just can't find any clear explanation for the multisig. Help please.


texts: Detailed overview over old exchange rate

texts:
I would like to create a detailed overview about the exchange rate of bitcoins over the last months. Unfortunately, all I can find are lists with one value per day, but I would like to have much more detail (one value per hour at last).

Is such a detailed list available somewhere on the internet?


texts: Script: How to check if the top item on the main stack is numeric or not?

texts:
I'm looking for the clearest way to check whether the top element of the stack is numeric or not.
Thank you in advance


texts: Transaction still pending after 12 hours

texts:
About 12 hours ago I sent BTC 0.06304568 to my test wallet... and the transactions is still pending:

{
  "receiveAddress": "1KU9VwJ992UisoAYiPbRdSXDRVUCq4wdW1",
  "balance": 0,
  "net": "prod",
  "version": 0,
  "encrypted": true,
  "raw": "Wallet containing 0.06304568 BTC (spendable: 0 BTC) in:
    1 pending transactions
    0 unspent transactions
    32 spent transactions
    0 dead transactions
    Last seen best block: 377306 (Sat Oct 03 13:59:53 EDT 2015): 00000000000000000c07ea569a4be298ff78b6f5ab5df17775649dcd1bc8b68f
    ...
}

If if look at address 1KU9VwJ992UisoAYiPbRdSXDRVUCq4wdW1 in btc.blockr.io I get the following result:

Hash:           1KU9VwJ992UisoAYiPbRdSXDRVUCq4wdW1
Balance:        0.00000000 BTC
Total received: 0.00000000 BTC
Transactions:   0
Unconfirmed:    0.00000000 BTC

I'm a bit confused... it looks like I got a ghost transaction. Am I missing something? I don't know if it is relevant... but I use bitcoinj to receive bitcoins.


texts: How can a seed generate the wrong addresses?

texts:
What happened:
I created a wallet with my backup seed.
Then I sent to the generated wallet addresses:

BTC: bc1q70shswq68tx5p2e2mms34up5jpxeqfyzp3let6

Everything was ok and I had access to my funds in the Coinbase Wallet App.
Then I wanted to send BTC back to Coinbase to trade it.
But I got the same error as the guy on twitter: https://twitter.com/scottyboi78/status/1357378323270291457/photo/1
Calculating the fees was actually not the problem.
Then I restored the wallet with my recovery seed multiple times on my iPhone. I also tried Android Emulator with Android Studio and the official Coinbase Wallet App.
The result is always the same:

BTC: bc1qgdw5aqhd8uz7rl4cxkkk66u33swsnmzl6aeaqg (something wrong)

How can it happen that the SAME seed results in DIFFERENT addresses for BTC!
That should not be possible!
Please help me I lost all my money and it is there in the Blockchain but I can't access it because the seed generation has a bug (I think at least)!


texts: Blockchain.info wallet json created device name

texts:
I have a blockchain info wallet. From this I got a json file. Looking at the unencrypted file there are all my addresses and private keys. However there is one strange address with the following parameters:
"created_time": 0,
"created_device_name": "external",
"created_device_version": "0"

what does this mean?
Also the address has lots of transactions on it even though I never used it.
(All other addresses are of type:
"created_device_name": "javascript_web"

)
Anyone know what this is?


texts: What are the most notable cases of coins or wallet thefts?

texts: What are the most notable cases of coins or wallets being stolen from Bitcoin users or services? When did they occur, how many coins were stolen and has any of the thieves been identified?


texts: Cannot seem to recover my privatekey Or import my wallet on blockchain why? help

texts:
Help, i was running bitcoin and i saw this error message popup saying...f.cloud.github.com/assets/4311082/448597/… what could be causing this and how can i fix it?
*Update*I fixed it by backing up the files uninstalling and reinstlling.

but now im trying to figure out my privatekey because i heard you can transfer coins from your address with it. but everytime i go in debug window and type in

00:42:22
￼
dumpprivkey <...>

it says

00:42:22
￼
Invalid Bitcoin address (code -5)
i replaced my address with three dots but why is it saying that? i go check my wallet in blockchain and it works there it says i have money and everything...

Also when i try to import my wallet.dat file in https://blockchain.info/wallet/import-wallet it keeps saying Wallet decrypter returned empty response when i dont enter a password

and it says Unexpected end of file from server when i type in the password at the end...what could be causing this? why cant i find out my privatekey? help please!!!


texts:
I'm curious what the purpose behind having a word list for BIP39 HD wallets?

Are you required to use these words to create a wallet seed?

What would happen if you chose random words not on the list, or instead a long continuous string?


texts: How can Blockchain.info wallet send unconfirmed bitcoins?

texts:
So i just opened a Blockchain.info wallet after years of using Bitcoin-qt.

My Blockchain.info wallet had an empty wallet, i sent some bitcoins to it and right after that without waiting for confirmations i sent some bitcoins to satoshidice just to test. To my surprise the transaction went through, how is this possible if my bitcoins didn't even have 1 confirmation?

If Blockchain.info "lends" me bitcoin, how can it do it?


texts:
I run it like the below.

bitcoind -datadir=/Users/varunvb/Downloads -conf=/Users/varunvb/Downloads/bitcoin.conf -daemon

When I run (Using the user name and password as in the config file)

bitcoin-cli -rpcuser=<USER> -rpcpassword=<PWD> getinfo

I get
error: incorrect rpcuser or rpcpassword (authorization failed)

I see the below in the debug log

ThreadRPCServer incorrect password attempt from 127.0.0.1

My bitcoin.conf file looks like this:

-e
rpcuser=<USER>
rpcpassword=<PWD>


texts: How are thousands of transactions put into a block?

texts: As much as I hate to admit it, I am not very tech savvy, and as such, I am fairly confused about the concept of the blockchain. I understand that the chain holds information about previously approved transactions that are grouped together into blocks. How exactly are these blocks formed? Also, does each transaction have its own hash? If so, how are all of the hashes grouped together into one has for the block?


texts: Where can I find the backlog of Bitcoin transactions?

texts:
I would like to see and track the evolution of the backlog of Bitcoin transactions. Is there a website that does that?

Thank you!

David


texts: Obtaining 12 word mnemonic from Private & Public Keys

texts:
After a recent upgrade to Jaxx wallet my Litecoins and my transaction history are lost.

The 12 word mnemonic opens up a wallet with zero Litecoin balance even though the public key address from the earlier Jaxx wallet shows the coins are available and unspent on blockchain.My mnemonic seed has not changed yet Jaxx wallet is not the same.So apparently there may have been a bug in the seed derivation path or ......

Jaxx support is not able to help and they say I am not using the correct mnemonic. This is not at all possible. Unfortunately I do not have the private key for the public key address where my coins are as Jaxx wallet no longer shows me the same set of earlier public/private keys and transaction.

For most of my earlier transaction I have public and private key. Can I generate the 12 word mnemonic from the set of private/public keys just to confirm?


texts: What is the most recent pushpool version and where to get it?

texts:
I found already the following pushpool versions:

https://github.com/jgarzik/pushpool
https://github.com/ArtForz/pushpool
https://github.com/alexhz/pushpool
https://github.com/CryptoManiac/pushpool

(can't post more than 2 links with my current reputation, so made a block)

All of them seem very old already.

I made a research on how to modify the difficulty in pushpool's server.json and found examples on how to set the following options rpc.target.bits and work.expire, but NONE of them seem to work for the mentioned versions.

So what's the newest pushpool version and where can I download it?

EDIT: Tried as described in the following post, but not working. Difficulty doesn't change and nothing is written into shares. MMCFE Not Reporting Stats from pushpool/wallet


texts: Format of comment parameters on bitcoind sendfrom command unclear. Attempts result in 'error: type mismatch'

texts:
The way to specify comment and comment-to parameters when calling bitcoind sendfrom at the comment line is not clear.

When using sendtoaddress, this format works:

bitcoind sendtoaddress 'sendToBitCoinAddress' '0.42' 'comment' 'comment-to'

The man page specifies sendfrom has this format:

sendfrom <fromaccount> <tobitcoinaddress> <amount> [minconf=1] [comment] [comment-to]

However a similar usage to sendtoaddress results in an error. I've tried various permutations like:

bitcoind sendfrom 'testAccount69' 'sendToBitCoinAddress' '0.69' 'comment 'comment-to'

Thanks for any help


texts: How can I send bitcoins without waiting for at least 1confirmation?

texts:
I'm making a service that is similar to markets so I sometimes need to make users send bitcoins without waiting for one confirmation.
So I'm considering how markets that deal cryptocurrencies solve the problem.


texts: Are there any C# wrappers for the Bitcoin REST API?

texts: Are there any C# wappers that take an OOO approach to the Bitcoin REST API, and encapsulate it in an easy to use format?


texts: statistics on actual "replacement" of blocks

texts:
I'm not sure if I'm using the right terminology but I know that theoretically it's possible for a block to be part of the longest (i.e. "main") blockchain but then be "replaced" by an alternative chain that is longer.  Presumably it would most likely happen that the last block would be replaced in this way but it could also happen that the last 2, 3 or more could be replaced.

Are there any statistics on how often this actually happens?  For example, the last block is replaced on average once a day, the last 2 blocks once every 10 days, etc?

This would have bearing on how confident one should be after a payment has had 2, 3, etc. confirmations.


texts: Bitcoin disconnects randomly in regtest mode

texts:
We are running two bitcoin nodes on two different servers with fixed ip addresses in regtest mode.  We have forked version 0.11 of bitcoind and decreased the time between blocks to simulate various scenarios.

In the config, we use the following:

regtest=1
listen=1
addnode=10.80.233.12:19000
port=19000
rpcport=19001
server=1

After a day or so, or around 100000 blocks, the two servers disconnect.  getpeerinfo shows no connections and the blockchain is forked.  A restart is required to bring them back into synch.

This has happened consistently over the last couple of days.  Does anyone know why and what we can do to fix it?


texts: Price calculation from Binance API trades/get_order results

texts:
I'm wondering how to calculate a price (per unit) for 1 order that was filled in 2 trades.

The 2 trades (GET /api/v3/myTrades):

 {'commission': '0.00002301',
  'commissionAsset': 'BNB',
  'id': 536694,
  'isBestMatch': True,
  'isBuyer': False,
  'isMaker': False,
  'orderId': 23456244,
  'orderListId': -1,
  'price': '0.01023100',
  'qty': '3.00000000',
  'quoteQty': '0.03069300',
  'symbol': 'WABIBNB',
  'time': 1573580584514},
 {'commission': '0.00019020',
  'commissionAsset': 'BNB',
  'id': 536695,
  'isBestMatch': True,
  'isBuyer': False,
  'isMaker': False,
  'orderId': 23456244,
  'orderListId': -1,
  'price': '0.01014400',
  'qty': '25.00000000',
  'quoteQty': '0.25360000',
  'symbol': 'WABIBNB',
  'time': 1573580584514}]

The order: (GET /api/v3/order):

{'clientOrderId': 'vt0wm640c8DFewafYyrqnW',
 'cummulativeQuoteQty': '0.28429300',
 'executedQty': '28.00000000',
 'icebergQty': '0.00000000',
 'isWorking': True,
 'orderId': 23456244,
 'orderListId': -1,
 'origQty': '28.00000000',
 'origQuoteOrderQty': '0.00000000',
 'price': '0.01013600',
 'side': 'SELL',
 'status': 'FILLED',
 'stopPrice': '0.01032200',
 'symbol': 'WABIBNB',
 'time': 1573580483202,
 'timeInForce': 'GTC',
 'type': 'STOP_LOSS_LIMIT',
 'updateTime': 1573580584514}

I used to calculate the price by taking the cummulativeQuoteQty and divide it by the executedQty, leading to 0.01015332.

But honestly, I've never been quite so sure about that and now I saw that TabTrader displays a price of 0.010187.

So my question now is: how exactly should one proceed if the price were to be used to calculate a profit?

PS. Taking the quantity weighted prices from the trades leads to yet another different value:

ipdb> weigted_price_from_trades = (0.01023100 * 3 + 28 * 0.01014400) / 28.
0.011240178571428573


texts: Why API of bitcoin exchanges use HMAC over HTTPS/SSL?

texts:
Pretty all exchanges use private and public key. We sign API request with our private key using HMAC algorithm. What's the point of doing so when there is already HTTPS connection?
HTTPS provides both data integrity and ensures security of the transmission.

Isn't it enough to just POST our credentials like api.exchange.com?key=key&private_key=private_key?


texts: Not getting merged mined coins on p2pool

texts:
I have been able to mine successfully on my bitcoin p2pool. I set up merge mining according to the guide found here https://bitcointalk.org/index.php?topic=62842.0 and everything seems to be running fine. Looking at the screen running p2pool I get messages as such: 2014-01-29 00:18:32.797966 Got new merged mining work!

However, I have been mining and have found at least 15 shares for bitcoin since I have installed, but nothing for the merge mined coins I added:

root@p2pool:~# namecoind listtransactions
[
]
root@p2pool:~# ixcoind listtransactions
[
]

I have been mining to a different address as the user, e.g. cgminer -o mypool.com -u  -p x

Would this be the reason why I am not getting any merged coins? Thanks in advance for your help!


texts: Does mining in a pool with a bigger hashrate mean more bitcoins?

texts:
Will someone with a 800 Mhash/s device earn as many bitcoins in one day as someone with a 10 Ghash/s device?

(I can't add a comment to
Mining pool hashrate effect on a miner's income
so I'm asking here.)


texts: Data for time a transaction spent in a pool before it got added to a block

texts: Is it possible to collect data for when an transaction was added to the pool to when it was added to the block?


texts: modifying bitcoind to include mysql support

texts:
I am modifying bitcoind (working with 0.13.1) to include write the log to mysql db versus the log file.
I have all the functions worked out and compiling outside of bitcoind

The trouble I ran into is when trying to compile it all with bitcoind.
i added my new file (.cpp and .h) into the makefile and linked -lmysqlclient, but im getting
undefined reference to 'mysql_init'

any pointers would be appreciated


texts: What is the key difference between the Proof of Activity proposal and Proof of Stake?

texts:
coblee (Litecoin creator) suggested a new Proof of Activity method, to complement Proof of Work, instead of using Proof of Stake (oh my!)

Can someone provide a tl;dr of what is the key problem in PoS that PoA is trying to solve, and how does it solve it?


texts: How do I use the getblocktemplate RPC command of Bitcoin Core GUI? I tried the following usages but none of them worked

texts:
I tried the following commands, but none of them worked.
-getblocktemplate "segwit"
-Error: Error parsing JSON: segwit

-getblocktemplate ("segwit")
-Error: Error parsing JSON: segwit

-getblocktemplate "rules": ["segwit"]
-Error: Error parsing JSON: rules:

-getblocktemplate {"rules": ["segwit"]}
-Error: Error parsing JSON: {rules:

-getblocktemplate
-getblocktemplate must be called with the segwit rule set (call with {"rules": ["segwit"]}) (code -8)

-getblocktemplate {"rules": ["segwit"]}
-Error: Error parsing JSON: {rules:

How can I use this command correctly?


texts: Update (or is it an upgrade?) from 12.0 to 13.2

texts:
I am currently running 120100 bitcoind. Apparently, the software is now at 130200. What is the procedure for updating? Can I just do:

sudo apt-get upgrade bitcoind

or is it more complicated than that? Operating System is Debian 3.16

(This box does not have a wallet and is only used for getting information from the blockchain, so I do not need any strict security protocols.)


texts:
I am a new BitcoinJ user, I have few questions related about its wallet, can anyone please help:

Is there any way to encrypt the .wallet file? will anyone obtain a copy of the file be able to spend all bitcoin in it?
Is there a chance of damaging the file if I stop my application often or incorrectly?

Thanks a lot.


texts: Using bitcoins JSON RPC, how can I confirm a transaction I published?

texts:
I have created, signed and sent a raw transaction via bitcoind RPC. Now I want to wait for it to have n confirmations.

Considering transaction malleability, I can't just check the "confirmations" field returned by gettransaction, because the transaction with that particular txid may never be accepted, in case an equivalent transaction with some other txid was accepted instead.

So, what is the canonical way, using bitcoind JSON-RPC, to check if an equivalent transaction was accepted in place of mine? What calls are better suited for the task?


texts: Can I import my wallet from my bitcoin core for electrum?

texts:
Bitcoin-qt, now bitcoin core is insane. It consumes 40GB hard disk space. It hogs network. I am thinking of using Electrum or something like that.

I want to use another bitcoin client.

Electrum is one of them. However, I got asicminer stocks that send me dividend. I want to import my wallet.dat file into Electrum.

Can that be done?


texts: What is "Script Hash" address exactly and how does it work?

texts:
I found out this address playing with blockchain

https://blockchain.info/address/3NukJ6fYZJ5Kk8bPjycAnruZkE5Q7UW7i8

I found out it's something called "scripthash". How does it work exactly? How does it differ from a normal address?

I found out this - https://en.bitcoin.it/wiki/BIP_0016 - but I still don't get it and I don't get the point.

  The benefit is allowing a sender to fund any arbitrary transaction, no matter how complicated, using a fixed-length 20-byte hash that is short enough to scan from a QR code or easily copied and pasted.

How does it differ from what is possible today - scanning just the address of the reciever?

edit: And adding one more question - why exactly is this transaction with the mentioned address as input

https://blockchain.info/tx-index/3618498

included in 94 different blocks? How does that even work?


texts:
i tried to replicate code in this git
https://github.com/tongokongo/bitcoin-basics/blob/master/HD_wallet/bip32.py .
I'm not familiar with python but the xpub is correct (this is the Test Vector 1 from BIP32) while the xpriv is:
b'Har3K3MhV5fiuEp6ztqjoMJejPsfnrLHAzSWDpkzLGomKaoUPLkSrwPxsdKMbzgsi6eegKG5BMwPyk8RMbDEe6zpHSUnRZMNJkX2HEhDzo41ds7qJVyRkhb3jsGezXb8XB4hW12QKUuxc3pDstNHMuYwEyV'
b'xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8'

what's the mistake?

Below the code:
import binascii
import hmac
import hashlib
import struct
import ecdsa
import base58
from ecdsa.curves import SECP256k1
from ecdsa.ecdsa import int_to_string, string_to_int

#chain m
seed = binascii.unhexlify("000102030405060708090a0b0c0d0e0f") #generiamo il seed, importiamo la stringa del test vector
#calcolaiamo ora I come HMAC-SHA512 (seed key="Bitcoin seed" Data = seed) - occorre importare hmac e hashlib
I = hmac.new(b"Bitcoin seed", seed, hashlib.sha512).digest()
#il risultato ottenuto va diviso in 2 stringhe da 32bytes (Il & Ir)
Il, Ir= I[:32], I[32:]

#il risultato va serializzato come descritto dal BIP32
#priv=xpriv+depth(1byte)+fingerprint(4bytes)+chaincode(32bytes)+chiave(33bytes)
#pub=xpub+depth(1byte)+fingerprint(4bytes)+chaincode(32bytes)+chiave(33bytes)

secret = Il #parte sinistra ottenuta dal HMAC
chain = Ir #parte destra
xprv = binascii.unhexlify("0488ade4") #è la version di default per la mainnet di Bicoin
xpub = binascii.unhexlify("0488b21e") #è la version di default per la mainnet di Bicoin
depth = b"\x00" #come da guida a livello della master  "0x00 for master nodes"
fingerp= b"\0\0\0\0" #come da guida a livello dalla master "(0x00000000 if master key)"
index = 0 #index del child al livello della master
child = struct.pack('>L', index) # L = big endian, the way of storing values starting from most significant value in sequence

#importare ECDSA dopo averlo installato. Occorreranno inoltre le librerie:
#from ecdsa.curves import SECP256k1
#from ecdsa.ecdsa import int_to_string, string_to_int
k_priv = ecdsa.SigningKey.from_string(secret, curve=SECP256k1)
k_priv = k_priv.get_verifying_key()

#bisogna ora serializzare la chiave privata come 32bytes con 00 davanti
data_priv = b'\x00' + (k_priv.to_string())

# serialization the coordinate pair P = (x,y) as a byte sequence using SEC1's compressed form
if k_priv.pubkey.point.y() & 1:
    data_pub = b'\3' + int_to_string(k_priv.pubkey.point.x())
else:
    data_pub = b'\2' + int_to_string(k_priv.pubkey.point.x())

raw_priv = xprv + depth + fingerp + child + chain + data_priv
raw_pub = xpub + depth + fingerp + child + chain + data_pub
#print(raw_priv)
#print(raw_pub)
#a questo punto abbiamo ottenuto due strutture da 78 byte che possono essere Codificate base58. Occore però prima trovare e concatenare
#il cheksum da 32 bits (4 bytes). Il Checksum si ottiene con un doppio SHA256

hashed_xprv = hashlib.sha256(raw_priv).digest()
hashed_xprv = hashlib.sha256(hashed_xprv).digest()
hashed_xpub = hashlib.sha256(raw_pub).digest()
hashed_xpub = hashlib.sha256(hashed_xpub).digest()

#vogliamo aggiungere a raw_priv e raw_pub gli ultimi 4 bytes dei digest ottenuti

raw_priv += hashed_xprv[:4]
raw_pub += hashed_xpub[:4]

#codifichiamo ora base58 - importare prima il pacchetto
print(base58.b58encode(raw_priv))
print(base58.b58encode(raw_pub))


texts: An online wallet service could "lose" my bitcoins?

texts: At bitcoin.org, there's a prominent notice that an online wallet service could "lose your bitcoins."  As I understand it, all bitcoin transactions, and therefore wallet balances, are stored in the block chain, on the peer-to-peer network, so they would not be lost in the event of a service failure.  I suppose that the notice is meant to warn against loss of bitcoin addresses/keys, right?  As long as I back up my keys locally, I can always recover my bitcoins, right?  (Nevermind the case of an untrustworthy wallet service that doesn't protect my keys, or uses them to rob from me.)


texts: What is the point of comparing sha256 of downloaded file with published on the same website code?

texts:
Some websites publish sha256 to check authenticity of downloaded file.

I suppose this is to protect against man-in-the-middle attack - that my file was not altered during download.

What prevents man-in-the-middle from altering web traffic and fix hash code that I see to match malicious downloaded file ?

Those sites often do not provide SSL, so capturing and fixing HTTP traffic is easy, all it takes is to work with my ISP or some backbone router.

There are even sites that allow to calculate sha256 by uploading file over unsafe HTTP with no SSL - ridiculous isn't it ?

Not only I have to trust that this website does not work for government, I also have to trust my ISP by connecting without SSL.


texts: Consequences of sibling keys when xpub and xprv are leaked

texts:
Let's say the following keys are leaked:

44'/60'/4'/0 extended private key
44'/60'/4'/0 extended public key (you can just derive this from the above private key)

Now using the above information can we derive the private or public key of this path:

44'/60'/4'/1

I don't think we can derive the private key because to get the private
or public key of 44'/60'/4'/1, we need to know the private key or
public key for the path 44'/60'/4'. But that's not something which
we can calculate from the above information. Is my understanding right ?


texts: bitcoind - how to find out what is affecting the verificationprogress

texts:
Problem

Bitcoind verificationprogress continues to go up and down around .99999xxx and never finish verifying

Background

Looking for any insight here, had a node that went down and upon bringing it back up it spent about 18 hours between .999992 and .9999998 and just keeps bouncing up and down there.

I'm assuming there is some verification or validation and as blocks are coming in the number goes down slightly but I can't find any stats to help me figure out what is remaining or if there are any issues.


texts:
Does each bitcoin has a unique identifier, like currency notes have serial numbers? If so, could you trace a particular bitcoin's ownership chain (ie find the current owner of a particular bitcoin by its identifier)? The answer I'm finding is no:

  There are also specific features of Bitcoin that make this difficult. Transactions put all the input Bitcoins into a big pile which they dole out as outputs. There's no concept of particular output Bitcoins corresponding to particular inputs. Bitcoins don't have a serial number that can be traced through the block chain. So any such tracking rules would be basically arbitrary.

  https://bitcoin.stackexchange.com/a/2139/894

Is this accurate?


texts: How can I find a digital forensics expert to help trace stolen bitcoins?

texts:
Are there any professional organizations that have lists of blockchain analysis and digital forensics experts by location?

I know some of this work can be done online but a directory of experts by location would be helpful, since I prefer to work with someone locally.


texts: (Why) is it difficult to merge and split wallet.dat?

texts:
It is a common question, how to sync a wallet across different devices.

As far as I understand, a wallet is just a collection of private keys. Each private key can be uniquely identified using the bitcoin address associated with the key. Thus, why don't we think of wallet.dat as if it was a directory:

Filename     File Content
=Address     =Private Key

1HB5XMLmzFV  8ALj6mfBsbifRo
...          ...

Now, syncing such a directory is trivial. If the filename (address) matches, the file is identical and does not need to be synced. If a filename is only present on one side, just copy the file, it's a new address.

Is something like this going to be implemented in a future client version? Or is my idea faulty?


texts: Is there a good website or resource comparing how all exchanges are structured under the hood?

texts:
So one of the issues I am running into is that there are competing definitions for things like: exchange, broker, trading platform, exchange platform, centralized, decentralized, P2P trading, etc. And also the websites often don't come out and say exactly how the operation is structured.
Regardless of what words you use to describe them, there is a difference between how things like Coinbase vs. Binance vs. Uniswap vs. eToro vs. LocalBitcoins are owned, organized, and operated. Is there a good resource that explains the differences in unambiguous language between all the services you can use to trade Bitcoin?


texts: How is Simplicity better suited for static analysis compared to script?

texts:
Quoted from the whitepaper, one of the design goals of Simplicity is:

  Provide  formal  semantics  that  facilitate  easy  reasoning  about  programs using existing off-the-shelf proof-assistant software.

How does Simplicity achieve being more static-analysis-friendly than script? Is it the read-write order in the bit machine?


texts: Bitcoin protocol / algorithm scalability

texts:
I have been looking into the Bitcoin protocol / algorithm a bit. I have the basics down, I think, but there are a lot of questions about how the whole thing is supposed to scale. For example,

Each client currently downloads the entire block chain, right? How is this scalable? They are supposed to be able to prune the Merkel trees, but I haven't gotten a good insight into how this works in P2P.
What was the thought process behind tracking transactions the way they are? You kind of have to traverse a lot of that tree to validate new transactions? Right?
Because of how a transaction ALWAYS needs to be confirmed (at least 6 times?) over P2P, the transfers are effectively far from instantaneous. There is a built in delay. Isn't this a problem? There is some delay already because of the nature of the algorithm that accepts the transaction into a block (solving the reverse hash).


texts: If yes, is this how a node decides that the peer has the best chain for headers-first download?


texts:
I'm new to this community and a Bitcoin novice.

I believe to have understood the concept and purpose of proof of work but also, that the high energy consumption of proofs of work is a major problem of the Bitcoin (and other blockchain based) systems.

The puzzle that need to be solved for the proof of work has to be complex:

computing the cryptographic nonce (as used in the Bitcoin system)
solving complex differential equations
operations on dense matrices

I wonder if my impression is correct that these puzzles' only purpose is to provide authentication, esp. for the right to mine new bitcoins -  and that they are otherwise "useless".

More than that I wonder if there are attempts to define complex proof of work puzzles that fulfill other purposes that are more beneficial/useful/valuable to - let's say society - which would justify the high energy consumption.

You may compare this with Google's ReCAPTCHAs that next to authentication "assist in the digitization of books or improve machine learning".


texts: Stealing Bitcoin Private key using Man-in-the-Browser

texts:
I was reading that Man-in-the-Browser (MITB) is able to steal credentials data, modify html, and modify out going data.
Indeed, MITB is one of the big threat of Bitcoin online wallets
usually, when using online wallet user's private key is encrypted and decrypted using Java script in the user's browser

Now, I am wondering how MITB is able to steal the private key after encrypted it in the browser ?


texts: send bitcoin to mobile number or email address

texts: How I can send bitcoins to someone's phone number or email address. I explored this api but they have documentation only for sending bitcoins to an address directly. But here they have explained how to send directly to a mobile number or email address. I want to implement this idea in php, please let me know how I can do it or where I can find some relevant information.


texts: Reliable method to convert national currency to bitcoin

texts:
I'm relatively new to Bitcoin and cryptocurrency so please excuse my newbie question.

I'm looking for a reliable method to convert national currency (i.e. "normal" money) into Bitcoin. A quick google turns up a plethora of exchanges, but I have no idea how to judge which are reliable.  By "reliable", I have two chief concerns:

That my information will be treated securely and privately; and
That the funds I deposit will arrive in my Bitcoin wallet.

Please give me some advice on an exchange or exchanges considered reliable by the community, or even better, a list of criteria by which to determine this for myself.


texts: How to link a bitcoin address to a wallet address?

texts:
BitGo has a feature where you can have multiple addresses under a wallet. The wallet also has its own address. Now suppose I have two addresses under my wallet. This means for any user to send me BTC, I can give one out of any three addresses which is 2 addresses + 1 wallet address.

How is that even possible to link two bitcoin addresses?


texts:
I have clearly installed Windows 7 and Bitcoin Core.
There is no Bitcoin folder in {User}/AppData/Roaming... Blockchain is dowloading but I cannot find where it is and wallet.dat also. Anybody help?

My OS in Windows 7.

Maybe I am kind of idiot so I'm pasting PrintScreens with steps I have done

1

2


texts: How do devs decide who should have commit access? what is the process?

texts:
Andrew Chow (2020) compiled a great list on when people gained/lost commit access to Bitcoin Core.
Satoshi asked Andresen to take over as Lead Maintainer, and Andresen passed the responsibility to Van Der Laan. The Lead Maintainer appears to be selected by the previous Lead Maintainer (by convention).

Many others have received/lost commit access. How exactly is
this decision made? and by who?

If the Lead Maintainer unexpectedly died (hope not), but if he
did, who would decide upon the next Lead Maintainer and how?


texts:
Im trying to figure out the script and DER

In P2PKH, the "first part (scriptsig)" push in stack (<sig><pubK>) because is it DER?
Instead  the "second part (scriptPubKey)" you can map the byte on https://en.bitcoin.it/wiki/Script

Or even the first part you can map with script?


texts: Old Wallet, Private key and known public address

texts:
This is the scenario
I have an old wallet
This wallet misses a transaction. This transaction was confirmed several times in 2014
I have the public address of that transaction
If I ask to my friend to send the payment again (how?) to my address , will I get my founds back again?
In other words, I have an old backup of a wallet that misses a transaction but I have the pubblic address where my friend sent the coins
Is thera a way to get the litecoin back again without knowing the private key?Consider that I have the original wallet


texts: With JSON how do I know the amount that was LAST sent to a given address?

texts:
I am trying to build a script that will give me the amount a user has sent to a given bitcoin address. Currently this data is in JSON format.

How can I use this JSON data to know the amount that was LAST sent to a given address?

For the moment I have as a return of a submitted form:

$userIDsent = $_POST['userID'];
$adrsBTCsent = $_POST['adrsBTC'];

$bcInfo = json_decode(file_get_contents("https://blockchain.info/address/". $adrsBTCsent ."?format=json"), true);

$nombre_de_transac  = $bcInfo["n_tx"];
$valeur_en_satochi = $bcInfo["total_received"];

If ($nombre_de_transac > 1){
    /* more then 1 transaction for that BTC adds. I need to know what is the amount last sent and NOT the total amount used on that address */

} else {
    /* 1 transaction this address is new so let's get the amount of BTC sent */
    echo "The user ".$userIDsent." has sent ". $valeur_en_satochi . "uBTC";
    echo "bra, bla, bla lets continue";
}

Thank you for your help.


texts: Whats the minimum recommended output for a faucet-like system? (April 2017)

texts:
I am building a software to involve friends. I am testing it.
I made several sendmany transactions with 43478 Satoshi.
I wont be using high fee Bitcoin system man.......

There are better things coming... like Nimiq... still waiting to see the real thing come out in the following months... sure creating a faucet like system.... or mining for movies... or anything...

I would say $0.05 cents a day? total of $10usd daily among different ip's... this could be hacked...


texts: Bitcoin transaction stuck as unconfirmed with no fee

texts:
I could have sworn when i tried withdrawing BTC to my local BTC wallet i set the fee to 0.005
The blockchain shows no fee was paid and the transaction is hanging with 0 confirmations.
I really am trying to get this BTC ASAP.
Any ideas? Here is the transaction link.

https://blockchain.info/tx/0b30583b830a7ee674dd92f0a22b3d4b21c81b5f80687b2ad2e6b951a64ef4e2

Also: the transaction seems to be moving BACK in the queue


texts: While I sending BTC to specific adress, it went to it but also it went to another address. How can i refund it?


texts:
I bought bitcoin 3yrs ago (i did not know so much about it then, i was only playing with it).
I received the bitcoin via a particular address which I still have. How can i track the BTC wallet I used via BTC address?


texts: How many addresses can be in input and output of a transaction

texts:
I have read through this question and i understand that there can be many sender and receiver addresses within 1 transaction(i'm new to bitcoin transaction, previous i was working with ethereum where 1 transaction can only have 1 sender and 1 receiver).
I'm working with blockcypher api endpoint to monitor incoming bitcoin to an address. I need to get all the possible number of address that can happen in input or output.
Here the logic of my monitor system, user can input their addresses to send(save in database), and my system also has an address to receive that amount. The monitor system only detect the incoming transactions to my address from the user addresses in the input addresses (exists in database)
I have categorized it into these to know the correct value that was send to an address:
input | output  | incoming amount to address
1     | 1 or 2  | amount show on receiver(output) of my address
1     | >2      | amount show on receiver(output) of my address
>1    | 1       | amount show on sender(of the system)(input)

Now i need to know can there be more then 2 on the input and more than 2 on the output? i haven't found any example of it yet
Also please tell me if my monitor logic is correct, are there different logic to monitor incoming bitcoin transaction to an address?
Thank in advance
Sorry if i mess up somewhere in my question, i'm pretty new to bitcoin system.


texts: What is the format of coinbase input scripts?

texts:
The input script of the coinbase transaction of block number 1 (right after the genesis block) looks like this: 04ffff001d010b

How do I recognize this as a coinbase transaction?

Do I simply know that this is a coinbase transaction because it is the first transaction in the block?

Does the coinbase script have to have a special format?


texts: Transaction size limit across a single path in a Lightning Network and fee earned

texts: Given MPP is included in the current version of lnd, an arbitrarily large transaction can be processed in the network. What is the transaction size limit across a single path? Is it still bounded to 0.0429 BTC (limited by max_concurrent_htlc)? What is the estimated fee earned (average as well as maximum) by a lightning node per day?


texts:
What are the problems related in using the "normal" ( bigger than N/2) value of the s number in transaction signature and why we use the lower one?
Is it about the math behind the ecdsa?


texts: How does bitcoin functional test framework work?

texts:
Could someone explain how and where in the code the bitcoin test framework calls map to C++ bitcoin core code or RPC calls such that regression suite tests the bitcoin core functionality?

Background and more details
I am writing a blockchain application and was thinking of how I can do regression while I keep developing. I wanted to leverage the design used by bitcoin (or any other blockchain application). I would expect that framework would call either C++ classes in bitcoin core directly or use RPC from python scripts such that features are tested.

I spotted that bitcoin functional tests are written in python scripts whereby test_runner.py calls a bunch of scripts testing specific features But I cannot spot in the bitcoin framework as to where it eventually calls actual bitcoin core c++ code or RPC.

Appreciate your help in spotting the code in python scripts in the framework that does it.


texts: How does blockchain.info get miner revenue?

texts:
In the stats page of blockchain.info, I see the revenue of miners is $1,680,297.91. As I understand, its the total money that people have spent on buying their miners. But, i doubt that since its a bit too small compared to the total revenue of Bitcoin market. So I have some questions as following

What is the meaning of that number?
How does blockchain.info compute it? Will it be updated frequently?


texts:
As I understand it mining provides the security for the blockchain in that it makes it hard to forge a transaction. The incentive for finding eligible hashes is a reward in the form of Bitcoin. As more blocks emerge, the cost of mining increases. But the number of bitcoins is limited to 21M.
Won't that mean that at some point in the future, either all bitcoins will be gone, or mining will not be cost effective anymore?
And in both cases, why would anyone still mine? Then wouldn't the hash rate drop considerably and thus the security?


texts: Is there an easy way to check out the market cap of the alternative cryptocurrencies?

texts:
Ideally, I'd like to see a pie chart with the whole pie being "Bitcoin-derived cryptocurrencies", and each major alternative represented as a market cap in Bitcoins and USD.
Currently, from what I gather we have:

Bitcoin - 7,415,750 BTC = $34,854,025 = 99.7%
Namecoin - 959,150 NMC = 25,897 BTC = $121,716 = 0.3%

I don't know where to get data on other cryptocurrencies right now, and if they even have any significant market cap.


texts: What hardware and bandwidth requirements would a server need to fulfill to run Bitcore?

texts:
What's the cost of running Bitcore on AWS or DigitalOcean? I know I'd need about 128gb of hardrive space, but I'm not sure how much the typical bandwidth costs would be, and how much RAM or cores I would need.

My goal is to create an API for looking up balances. Thanks for any advice!


texts: What is a selfish mining attack MonaCoin suffered from?


texts: How are off-chain transactions handled by bitcoind?

texts:
I'm trying to figure out how transactions are actually handled by bitcoind.

I'm looking at the full list of RPC methods and there are missing documentation for some most interesting methods.

move

I know there are two methods of moving bitcoins between addresses either via direct p2p transaction or via the so-called off-chain transaction. If I believe correctly, the built-in wallet of bitcoind allows us to send off-chain transactions via the move method. Sadly, it's not very well documented, but I want to know exactly how it works.

Here's the documentation for it:

move <fromaccount> <toaccount> <amount> [minconf=1] [comment]

Move from one account in your wallet to another

So, if account A has one BTC and account B has zero. What will happen if I first move one BTC from A to B using off-chain transaction and then issue a direct transaction of 1 BTC from B to C?
Also, what minconf parameter is for? As far as I understand, off-chain transactions doesn't require confirmations.

sendfrom

Here's the documentation for the sendfrom method:

sendfrom <fromaccount> <tobitcoinaddress> <amount> [minconf=1] [comment] [comment-to]

<amount> is a real and is rounded to 8 decimal places. Will send the given amount to the given address, ensuring the account has a valid balance using [minconf] confirmations. Returns the transaction ID if successful (not in JSON object).

It requires an account to send bitcoins from.

What if I have multiple addresses/transactions for the specified account? What strategy bitcoind uses to determine from which addresses to make a transaction and how much bitcoins to use from each?
What minconf parameter is for?

sendtoaddress

sendtoaddress <bitcoinaddress> <amount> [comment] [comment-to]

<amount> is a real and is rounded to 8 decimal places. Returns the transaction ID <txid> if successful.

The account is not specified for this call. What account bitcoind will use? The default one?
Why there is no minconf parameter for this one?


texts: Should we expect in the foreseeable future a Bitcoin Core release optimised for ARM-based Macs?


texts:
I've not been able to figure out why I can't relaiably get the senders address using bitcoind 8.1 on the json API with php.

foreach ($bitcoin->listtransactions() as $transaction) {
 if ($transaction['category'] == 'receive') {
  $info['account'] = $transaction['account'];
  $info['address'] = $transaction['address'];
  $info['amount']  = $transaction['amount'];
  $info['confirmations'] = $transaction['confirmations'];
  $info['time'] = $transaction['timereceived'];
  $info['txid'] = $transaction['txid'];

  $txdetails = $bitcoin->getrawtransaction($transaction['txid'],(int)1);
  foreach ($txdetails['vout'] as $vout) {
    if ($vout['value']  $info['amount']) {
      $info['sender'] = $vout['scriptPubKey']['addresses']['0'];
    }
  }
}

The result I get is

Array
(
    [account] => Pool
    [address] => n3YgVTznqBCTb5ghWwNUoSmn5z37vfg4VK
    [amount] => 2
    [confirmations] => 7
    [time] => 1368107164
    [txid] => 94a25aac9e26b19cbf3c0afd4e7689047e33f9adbea4bbe9d5bd198cdc918717
    [sender] => mvoiUMUyR5QvX1Z2SYBAqT9eK6rjuQGVCF
)

But the address I get in the [address] does not receive anything I send back to it.

What am I missing?


texts: Bitcoin Core frozen trying to sync and/or connecting to peers

texts: I downloaded Bitcoin Core directly to my laptop and sent BTC to what i believe is my wallet. The BTC is no longer in my senders wallet and I do not see it in my bitcoin core wallet. It was working slowly but now it is frozen at 12 percent.


texts: Will coinbase.com have replay protection for receives?

texts:
According to this, "Bitcoin Segwit2x does not have any built-in replay protection, but Coinbase has implemented our own replay protection system. You can safely send any BTC or B2X from Coinbase without worrying about replays on the other chain."

But will they have any replay protection for receives, as well as sends? I don't imagine they can do anything to prevent a transaction sent to them from being replayed on both chains, but at least they could detect the replay, and credit both currencies to your account.

I'll probably try to avoid this, but just wondering if I have some backup protection if I make a mistake.


texts: What happens when relative and absolute lock times are used in the same transaction?

texts:
BIP 68 redefines the input sequence number field as bit vector that encodes a relative lock time.

A transaction can be encumbered with an absolute lock time by setting the nLockTime field to a non-zero value and by ensuring that at least one input sequence is non-maximal (not 0xffffffff).

What happens if a one-input transaction sets nLockTime > 0 and introduces a relative lock time under BIP 68? For example, nLockTime might expire in 12,000 blocks and the input's relative lock time might expire in 11,000 blocks. Conversely, the relative lock time might expire after the absolute lock time.

Which locking mechanism wins in these cases? Are both locks checked, or only one? If the latter, which one?

The "Compatibility" section of BIP 68 hints that both locks will be checked, but from my reading doesn't state this explicitly:

  The only use of sequence numbers by the Bitcoin Core reference client software is to disable checking the nLockTime constraints in a transaction. The semantics of that application are preserved by this BIP.


texts:
I tried to create altcoin using litecoin source code. I am able to generate genesis block for same. After setup on ubuntu VPS qt wallet connect to server and disconnect within seconds. Please help me to get out of this.

Here is log

trying connection xx.xx.xx.xx:9293 lastseen=113.8hrs
connected xx.xx.xx.xx:9293
send version message: version 70001, blocks=0, us=0.0.0.0:0, them=xx.xx.xx.xx:9293, peer=xx.xx.xx.xx:9293
disconnecting node xx.xx.xx.xx:29293


texts: How much can I earn with AntMiner S7 miner

texts:
I have started to learn about blockchain technologies, BTC and other crypto-currencies and right now interested in mining.
I know that mining of BTC is not very profitable right now, but other currencies can be profitable.

I looked at ETH, DASH and Monero and according to this site I can earn near 150K per day with AntMiner S7, which seems to be unrealistic.

Please help me understand how this stuff works, is it real or have I some misunderstood something?


texts: Using paper based public/private keys in bitcoin-qt

texts:
If I only have a public key string and a private key string written on a sheet of paper.  How do I use those in bitcoin-qt?

If this can be added to bitcoin-qt, will it eventually show me how much funds that private/public key has when the block chain is synchronized on my computer?

I understand this action will cause the cold private key to become a hot private key.


texts: Why do we need two transactions for CommitCoin scheme

texts:
I am studying BitCoin recently.

I noticed a method called CommitCoin for secure timestamping. It requires two transactions to send coins back with the same randomness so that others can compute the private key.

However, isn't it easier to just reveal the private key yourself? The whole point is to prove that at some time in the past, I knew something. If I send some coins to the address and send the coins back, and later reveal my private key and it matches the public key, shouldn't it be enough to prove that?

Thanks in advance.


texts: How can a 24 word seed know when I added or removed wallets at a later point?

texts:
Since I do not have 50 Rep points I had to post my question this way!

This is an answer by "https://bitcoin.stackexchange.com/users/56917/rstack" to the question "How do Ledger Backups get stored?"

"Using words to back up wallets is a process described in BIP 39.

Basically, the mnemonic is converted into a seed. This seed is then used as the seed to a Heirarchical Deterministic (HD) wallet, as laid out in BIP 32. The seed is used to generate a Master Extended Private Key, from which all other private keys can be generated. The child key generation follows the standard of BIP 44 so it is compatible with other wallets too.

Thus, by backing up your mnemonic words, any time you enter them in a wallet, it can recreate the seed, then the master private key, then all your other keys, so your wallet is back."

When I start my Ledger for the first time I get a generated 24 word seed. At this point my Ledger has the default wallets (BTC, ETH, LTC) if any. From Rstack's answer I get how this works or could work so far, BUT how does my 24 word seed know the future when I add or remove wallets? The 24 word seed does not change after I add or remove wallets. Randomly generated public and private keys that are created in the future can no way have ties to a previously generated 24 word seed. Does not make sense!

Unless this can be explained I am going to have to assume that my public and private keys are stored somewhere and retrieved by the 24 word seed.

Can anyone shed light on this?
Thanks in advance and cheers everyone.


texts: How can I recognize a bitcoin transaction from a given person?

texts:
If I ask two different people to pay me a given amount of bitcoin, how can I tell which one has paid and which one has not?

If the amount is different then it's easy. For the same amount? Public key of the sender? If so, shall I trust my local copy of the blockchain? (I know the "balance" can be faked albeit nobody can steal or send bitcoins in your behalf)

What about big merchants which process large amount of transactions?

Of course I'm not asking how to find out the identity of the senders


texts: How to consolidate a large amount of unspent outputs?

texts:
I have tried different solutions to consolidate a large amount of unspent outputs, but I am stuck:
1st option: Create transaction using "coinb.in/#newTransaction". But I need private key to create transaction and I am cant find option to export private key. There are steps given on support site for new and classic blockchain.info wallets. But I do not see option of "Private Key" when I click on Manage - More Options.

2nd step: there are some steps showing transfer/sweep funds - which I have tried but it did not work.


texts: For Anyone Trying to Be Scamed by GlowexCoin Givaway

texts:
I am not 100% positive but I just want to put this out there in case anyone else has info. Pretty sure there is a fake platform called GlowexCoin that will offer you a giveaway win. It "credits" you bitcoin then says you need to add at least .01 Bitcoin in the account for trading.
If you know what I am talking about please, confirm. If not, be weary!


texts: Does Blockstream have a revenue model that can only exist in a small block environment?

texts:
Anyone reading discussions in the Bitcoin scene these days probably has seen the following argument (or similar):

  "Blockstream is preventing a blocksize increase because their products can only turn profit in a small block environment."

What evidence is there to support or refute this statement?

PSA (as per our rules):

Be open-minded. This question will likely generate diverse answers that may not align with your personal opinion.
When answering this question, back up all statements you make with appropriate references and evidence.
Answers will be edited/moderated for tone. Stay respectful and courteous.
Avoid statements solely based on your opinion.
Logical fallacies will be called out.


texts: How did the first 50 Bitcoins come into being?

texts: How was the Bitcoin system initialized? Can one start the system with only a single node (computer)? Please explain it in plain English. Thanks, guys.


texts: Given a list of buy/sell orders and previous trades, compute a buy/sell price

texts:
I'm using the Cryptsy API with a bot. So far, my bot's problem is that when it decides it needs to buy or sell a coin (not just bitcoin), I always seem to compute a price that is way too low or high. The data I have access to is:

The currently outstanding buy orders (though a few seconds old and without timestamps)
The currently outstanding sell orders
The previous 20 trades that were executed on the market

From all of this data, is there an existing algorithm to compute a price that will almost always buy or sell? My bot's priority is to have fast trades(like, less than a minute for execution), even if the price is not the best.

Cryptsy themselves compute a pretty good number in their web UI (the default ask/bid price), but I don't see that value exposed in their API. Where does this ask/bid price come from?

For reference, I've tried a few things with little success

Highest buy price/Lowest sell price -- This tends to catch outliers and results in me placing an overly optimistic bid that only one buyer/seller was willing to pay (and because my data is seconds old, apparently somone else picks it up)
An average of 3 lowest/highest -- This had the same problem with outliers
Lowest buy price/Highest sell price -- This is extremely pessimistic and results in me paying ridiculous prices that are unreasonable

How can I compute a good ask/bid price from this set of data I have?


texts:
I try to understand how Bitcoin handles change or the combination of multiple transactions to provide sufficient funds for a given price.

Bitcoin transactions contain an array for the input transactions and an array for the UTXO outputs (vout).

For example: If I'm Frank and I send Charlie 1 BTC with an input transaction which holds 1.2 BTC, does that mean, that my next TX using the 0.2 BTC and Charlies TX using the 1 BTC form two new TX chains?

Or would I just reference the latest TX in the chain of transactions, containing both parts of the 1.2 BTC and sometimes the 0.2 BTC is referenced as VIN element and sometimes the 1.0 BTC?


texts: When ACTUALLY using bitcoin to buy and sell goods, is there a way to take its current price ($22,xxx) and find an actual value to it?

texts:
Because if i sell my valued item at say, 22,000 worth of bitcoin. Tomorrow, there could be a crash which brings it down to $1000 or less and i've essentially traded my $22,000 item for worthless bubble money.

Is there any term to search or people to talk to who understand bitcoins true value?


texts: Delete a specific private key from an Electrum 3.3.8 wallet via the command line?

texts: I imported a few private keys into my electrum wallet via the command line. Now I want to delete these specific private keys from electrum 3.3.8 - What is the command to delete these keys from my wallet?


texts: Why do the price of bitcoins vary wildly between exchanges?


texts: Sent transaction on 30 march 2021 still unconfirmed in mempool what can i do?

texts:
I made small BTC transaction from my bitcoincore wallet to account of Binance on March 30, 2021. I did set the fee low. But i wait a month for the transaction to back to my wallet. But it said still not confirmed on mempool.(32 days)
what can i do? thanks your help


texts:
if you have a nano ledger, you can access your coins with the ledger live app. Even if the device is not plugged in, I can still see my currency from the app. You are given a 24 word recovery phrase when setting up the nano ledger.
What makes this any different from a software wallet like Electrum? The electrum wallet has a seed phrase just like the hardware wallet, no? If I can access ledger live from either my PC or phone, I don't understand what makes the two any different? Is it the case that you can not trade or transfer coins unless the physical device is plugged into the PC or phone with the app open?
What is the differentiator between the two that I am missing?


texts:
I'm just not understanding what does the following arguments do!

-dbcache : Set database cache size in megabytes (4 to 16384, default: 300)

  which database is that? and what may happen if the file size excessed
  16384 megabytes.

-par=N  Set the number of script verification threads (-2 to 16, 0 = auto, <0 = leave that many cores free, default: 0)

  What is script verifications threads? may this affect performance?

-pid= Specify pid file (default: bitcoind.pid)

  what is this for?

-bind=    Bind to given address and always listen on it. Use [host]:port notation for IPv6

  is this for RPC calls, so bitcoin core listens only to given IP address?

-discover   Discover own IP addresses (default: 1 when listening and no -externalip or -proxy)

  what do they mean?

-upgradewallet  Upgrade wallet to latest format on startup

  what is the wallet formats?

-rpcbind=<addr> Bind to given address to listen for JSON-RPC connections. Use [host]:port notation for IPv6. This option can be specified multiple times (default: bind to all interfaces)

  when we Bind to IP address, will the software listens to this IP address only?

-rpcthreads=<n> Set the number of threads to service RPC calls (default: 4)

  how many connections can a thread afford? and how the connections counted? is it per IP address or command?


texts: What will happend when a certain node is not connected to full node?

texts:
what will happen when there are some full nodes in the network which are not connected to one client-how can he get new blocks updates?

thank you


texts: Zero Hashes Per Second with Diablo-D3 Miner

texts:
I'm trying to setup Diablo-D3 Miner on my computer (I'm aware that there are other solutions available, but I need something written in Java for a personal project) and I see in console I'm getting zero hashes:

mh: 0.0/0.0 | a/r/hwe: 0/0/0 | gh: 0.0 0.0 | fps: Infinity

Why is my hash rate zero when I have NVIDIA CUDA OpenCL 1.2 CUDA 9.1.75 and   GeForce GTX 960M installed on my system and it's being detected by Diablo?

Thanks in advance.


texts:
Technically speaking a full PoW solution is one whose hash value is below a certain threshold value say V. It is not equivalent to saying that the hash value must begin with say X number of zeros (unless the threshold value is a power of 2).

My question is what is the usual practice in mining pools where one needs to submit partial proof of work to give a proof that he has worked on finding the block honestly? Lets say in some 'round' the miners in a pool have got their best (the least) hash values as v= v1,v2,..v_n. Is there a function that takes in v as an input and computes the reward for each of the miners ? Are there are checkpoint sort of system where say if the submitted share has hash value lying in between some range then that miner is categorised in that range. Once all the members are categorised into groups (which would reflect how powerful mining rigs they have), they can then be paid for their service proportionately.  Of course there is no need to categorise, like the way I mention but is it how it works in practice ? If so, how are the level checkpoints distributed ?


texts: How can I choose the address bitcoins are sent from?

texts:
So let's say I have multiple bitcoin addresses (some of them already received bitcoins), created a new bitcoin address, received bitcoins on it and would like to use the very same address to send them elsewhere - how can I do that?

I'm using Bitcoin Core (bitcoin-qt) as of right now.


texts: Have passphrase from bitcoin core circa 10 years ago

texts:
I have the passphrase but wallet.dat gone...
What tools should I use?
I thought about using VS to try to compile it from github in order to see typical phrase word list......
What concerns me is that my phrase has extra large words like vacationers....
Thanks for any leads. I insist on 20 tip paypal...


texts: How to import private key on testnet and verify balance of wallet?

texts:
I have a python library to create wallets and play around with private key generation and stuff like that.

But i can't find any service / wallet - preferably online - where i could import my generated testnet-private-key and check the balance...

I can get coins thru Testnet Faucet and see the balance of an address on testnet via Blockcypher but where can i test importing private keys on the testnet?

EDIT: I don't really want to download the whole blockchain so some online service would really be great!


texts: Does Blockchain.info's "totalbc" API value account for "lost" Bitcoins?

texts:
totalbc - Total Bitcoins in circulation (delayed by up to 1 hour])

Source: https://blockchain.info/q/
https://blockchain.info/q/totalbc
1865520600000000

It seems like it actually gives the value in satoshis for some reason, but that's not the really confusing part.
What I wonder is if this value really represents the "total Bitcoins in circulation", or just "total Bitcoins mined". Does it account for the "lost" Bitcoins which will never again be possible for anyone to use because the private keys are no longer accessible by any human or machine?
If not, is there a source which lets me grab that number? It's pretty useless to know how many Bitcoins have been mined; I want to know how many currently "really exist", as in, are actually in circulation, or can be "circulated".


texts: Bitcoin c++ library that provides the networking

texts:
I want to make a very simple Bitcoin mining software with use of getblocktemplate, my own SHA and block building. Is there any c or better c++ library that would help with the networking part? I am new to Bitcoin and would prefer to focus on the block building and hashing part for now, as I'm starting from scratch.

I'm aware of the difficulty level and I am doing this just for getting to know Bitcoin better.


texts:
It is known that historical database of all bitcoin transactions stored in blk*.dat files. Is it possible for bitcoin-core to change any of this files in any time? Or this database is equal for all bitcoin peers (may be except the last few files)?

I think this files consist non-changable historical data for blockchain. Is it true?


texts: Does getreceivedbyaddress or listreceivedbyaddress or listunspent shows pay to pubkey and bare mutlisig transactions?

texts:
Couldn’t find the answer inside the source code.
If I receive a pay to pubkey transaction to the pubkey of a 1r address, will it shows up using getreceivedbyaddress or listreceivedbyaddress or listunspent? Or will it ignore the coins received that way.
The same question apply when 1-of-n bare multisig.


texts: How can I find out how much bitcoin is in existence with PHP?

texts: I'm running a Bitcoin blog and I'd love to display a ticket of the total amount of Bitcoins in existence. Unfortunately, I'm not sure where I can find a JSON feed for this (now that MTGOX is gone). Is there something like this I can utilize?


texts:
I write free software in my spare time. Some of my softwares are quite popular. Now i'm a thinking of a way to generate a little revenue. Using adware is not an option for me.

Is there a Bitcoin mining library ( maybe a .dll ) that i can bundle into my programs?


texts:
Does there really not exist a web multicoin wallet that has a programmable API that can be used by apps to send transactions? It is common practice to authorize your credit card in an app so that it can make transactions without explicitly asking for it each time, but I can't find any way to do this with cryptocurrencies.

I think blockchain.info wallet allows this, but it is Bitcoin only. Any ideas?


texts: How to sign raw transaction given a private key and SHA hash (in java)

texts:
I have followed the instructions here to build my own bitcoin transaction.

Redeeming a raw transaction step by step example required

Currently my code can create a transaction and compute the SHA hash but I am struggling to sign it using ECDSA.

I have written so code to do it using bitcoinj but it is not working. I need some help signing a transaction using a java library or an API.

Here is what I have so far. Any help you be super appreciated :).

import org.apache.commons.codec.binary.Hex;
import org.bitcoinj.core.*;
import org.bitcoinj.core.ECKey.*;

public class Test3 {
    public static void main(String[] args) {

        //Given private key and SHA 256 Hash, sign a transaction

        String shaHash = "15953935a135031bfec37d36a9d662aea43e1deb0ea463d6932ac6e537cb3e81";
        String privateKey = "private key for the address";

        byte[] priv = Base58.decode(privateKey);
        // Generate ecsda key
        ECKey ecdsa = ECKey.fromPrivate(priv);
        Sha256Hash hash = new Sha256Hash(shaHash);
        // Sign the transaction
        ECDSASignature sig = ecdsa.sign(hash);
        byte[] res = sig.encodeToDER();
        String res2 = Hex.encodeHexString(res);

        System.out.println(res2);

    }
}


texts: What prevent someone to not use the receiver address of one transaction as the sender in another one?

texts:
Title may be confusing you, and to be honest I am also confused how things work and I am new to this crypto world so sorry in advance if I am not using the correct words.
I try to explain :
Let say Alice wants to send cryptos to Bob.
A sends to B
(address of A) to (address of B)

Because blockchains are public, and both address will be known to each one, what process do prevent Bob from not using Alice address as the sender in another transaction ?
B pretends to be A
using A to send to B
(address of A) to (address of B) without A consent

The reason why I am confused right now about this question is because in Dapps you can use a wallet like Metamask to make some transactions, which means you only needs an address. So how is that secure.
If someone code a program using the same logic as Metamask, what prevents him to use another person's address in Dapps and to smart contracts? (Similar to changing the ip field in http requests, which was a popular hacking technique for man in the middle before https was widely used).
Thanks in advance for helping me to understand.


texts:
I am trying to run bitcoind on a raspberrypi.
I started by starting bitcoind on my laptop,downloading and verifying the blockchain. So far so good, bitcoind works as expected.
Then I set prune=600 in bitcoin.conf, and it pruned as expected.
Then I moved the datafiles to my raspberrypi (the whole /bitcoin directory ).
The SD card has ~7Gb of storage.  3.5Gb was available, including the /bitcoin dir.
There was a pause of some days or weeks, so I lack the blocks in between times.
When I ran bitcoind it gave me the 'Error Disk space is too low' report, and the SD card is full
root@mybox:/home/rshn# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/root       7.3G  7.0G     0 100% /

The bitcoind log seems to indicate that it is downloading from the earliest blocks
2021-05-06T08:09:10Z
UpdateTip: new best=000000000000065c0819853ac71bdda8518706b8942f6540079ad079e2dea6e4
height=193539 version=0x00000002 log2_work=68.525890 tx=5868863
date='2012-08-12T12:29:56Z' progress=0.009181 cache=261.0MiB(2279817txo)

The blocks dir indicates that there are about 460Mb of data.
root@mybox:/home/rshn/bitcoin/blocks# ls -l
total 460068
-rw------- 1 rshn rshn 134212156 Apr 30 13:07 blk00002.dat
-rw------- 1 rshn rshn 134205043 Apr 30 13:08 blk00003.dat
-rw------- 1 rshn rshn 134191619 Apr 30 13:10 blk00004.dat
-rw------- 1 rshn rshn  16777216 Apr 30 13:10 blk00005.dat
drwx------ 2 rshn rshn      4096 Apr 30 13:10 index
-rw------- 1 rshn rshn  16271929 Apr 30 13:07 rev00002.dat
-rw------- 1 rshn rshn  16501235 Apr 30 13:08 rev00003.dat
-rw------- 1 rshn rshn  16826540 Apr 30 13:10 rev00004.dat
-rw------- 1 rshn rshn   2097152 Apr 30 13:10 rev00005.dat

How do I run the pruned node in these circs?  Thank you.


texts: Is it possible to mine empty block without downloading entire blockchain?

texts:
As far as I can understand, whole blockchain is required for verifying and discarding double-spend transactions. Also, mining empty block is accepted by bitcoin's blockchain protocol.

When we want to mine empty block, we don't need to validate transactions, because there are no transactions (except block reward) in our empty block. Is it mean, we don't need to download entire blockchain for mining empty block?


texts: How can I brute force guess the passphrase for a Bitcoin Wallet (Andreas Schildbach) backup file?

texts:
I have a 2013-2014 240-byte wallet backup file from Bitcoin Wallet (by )Andreas Schildbach). I generated the passphrase using a pattern of two English proper nouns and 1-2 numbers.
I cannot positively say I know the proper nouns, or the capitalization. I do not know the overall length. am not positive the numbers are adjacent in the passphrase.
I am aware of Hashcat generally, and have done basic attacks on this passphrase using my best guess wordlist and standard wordlists. What are some more advanced technique ideas I can apply to this?


texts: Were anyone-can-spend transactions valid before SegWit?

texts:
Non-segwit nodes (legacy nodes) see segwit transactions as anyone-can-spend (ACS) transactions. It is clear that such a nodes can (and do) validate blocks containing ACS transactions, because the scripts they run are compatible with the original rules of Bitcoin (this is why SegWit is considered a soft fork). However, I see around the statement that a miner running a non-segwit node cannot include a ACS transaction in his own mining block, because, if he had managed to mine that block, segwits nodes would reject it because digital signatures were missing, resulting in an orphaned block.
Is it correct what I’m saying? If yes, let me consider the following scenario BEFORE the creation and implementation of SegWit on Bitcoin:
Before the creation and implementation of SegWit, when all running nodes were non-segwit, if a miner had included an ACS transaction in his own block and he had managed to mine it, would such a block be accepted by others nodes? I don't see the reason why such a block could be forbidden. From the point of view of the other nodes (which are all non-segwit), they see this new block a one containing ACS transactions, and like any other block nowadays, they should validate it.
What I’m trying to say is that, in the previous version of Bitcoin (before SegWit), there was nothing to "prohibit" a miner from spending/stealing someone else's funds. If the answer is that before SegWit nodes would never accept blocks containing ACS transactions, this means that SegWit is in fact a hard fork, because nowadays they do accept them.
Hence, I see the following three “scenarios”

Before SegWit implementation, miners could include ACS transactions in their blocks and all the other nodes should validate them. The fact that it never happened is because all miners were “honest”.
Before SegWit, nodes did not validate blocks containing ACS transactions. But they do validate them now. This results in a HARD fork.
There is something that I’m missing or I’m misunderstanding.

I hope the answer is number 3. I’ll appreciate if somebody could help me.


texts: Does Bitcoin limit the number of parallel connections from the same IP?

texts: Is there a measure in place to prevent an adversary from connecting to a Bitcoin node many times in parallel, thus saturating its open connection slots?


texts: Do any hardware wallets / hardware platforms that rely on or allow open source firmware?

texts:
There's a reason the safest software wallets are open-source: they can be audited by anyone. With hardware wallets, unless you're manufacturing one yourself, you're all but forced to trust the manufacturer to a certain extent. This trust could be minimized if a manufacturer created a generalized security device that users would upload their own firmware to. This way, the manufacturer would be very limited in the types of security holes it could intentionally add, given that they couldn't know what firmware would be running on it.

So it seems to me that the ideal would be for a hardware wallet to have an open-source design, manufactured by some hopefully (but not necessarily) trustworthy private company, and each user would upload and run some open source firmware on the device.

Are there any devices / hardware wallets that fit this description?


texts: Can gaming consoles be used as a Bitcoin mining platform?

texts:
I'm very new to the concept of Bitcoin (having only just read the wikipedia entry and visited bitcoin.org)

My question is this: why is the mining platform limited to PC/ traditional computing devices? It seems that gaming platforms would also work quite well, having better performance specs than the general user would reasonably have on his/her home PC and they have networking capabilities.


texts: how to see my private key bye decrypted wallet.dat

texts: How to decrypted my wallet.dat (Yes, I know the password) so i can see my private key? if anyone can help there is 1 LTC for them


texts: I want to create bitcoin address from extended public key, without exposing private key but did not get any success till now. Do someone know how to do it? I am using bitcore-lib package


texts: My phones died and can't restore wallet on Copay

texts: My phone recently died and I had to reset it all the apps. I tool the 16 character reference I was given in Copay to reinstate my wallet, but there is NOWHERE to put the 16 characters code. Have I just lost all my bitcoin?


texts: What will be required to increase the "soft" 500KB per-block data limit

texts:
We've alerady hit the point where a block has become 90% full, thanks to the popularity of SatoshiDICE.

The limit can be increased from the 500 KB max per-block in the software to 1 MB per-block limit in the Bitcoin protocol, reportedly.

To increase this to the level allowed by the protocol, is it just a client update for miners, or does it require a new client for everyone who needs to be able to accept blocks with the larger limit?


texts: Proving the margin of error of a block timestamp

texts:
In the Bitcoin wiki:

  Block times are accurate only to within an hour or two.

is a bit vague. Is it possible to prove that an arbitrary accepted block timestamp is within x seconds of the real-world time? How?


texts: How to transmit fraudulent commitment transaction on lightning channel?

texts: I'm trying to simulate a fraudulent commitment transaction on lightning. How would you submit an earlier commitment transaction. It doesn't seem like this can be done with a command. Does anyone know where in the code (LND or C-lightning) you could change it to do this?


texts: Is Lightning Network a blockchain technology?

texts:
Does the Lightning Network use a blockchain?
Is the Lightning Network still blockchain technology or not anymore?


texts: In a Lightning Network who commits to the blockchain the final transaction?

texts:
So let's imagine a Lightning Network made up of thousand of nodes. Transactions are routed until the moment comes where all the channels need to be closed and commited I presume. Which node actually takes care of this?

I'm a bit confused of this process and it's not clear how the final transaction will be built, and more importantly, who will actually pay the fees to the BTC network?

I imagine this huge transaction will have lots inputs-ouputs based on the parties involved in the network for that moment of time.

I'm thinking it's a race game, right? So any node can broadcast this huge transaction to the blockchain, and since all the inputs-outputs have all the right signatures of the participants, all the money and fees will go to the nodes that helped route the transactions around, and of course all the money will correctly go to the right destinations.

Also, I'm thinking this is not something that happens every 10 mins or so. Whoever is listening and has the transactions in hand can build this huge transaction (as long as the timelocks are respected) and soon it will be mined.

But still, if the fee for the this huge tx is higher than what that single node got for routing it, what's the incentive for them to actually broadcast it rather than letting another node broadcast it, and hence put the burden on another node to pay the fees.


texts:
I'm syncing my raspberry pi 4 model B, 4GB and after 4 days I'm less than 50% synced. It seems as though there is something wrong with bitcoind as there are some weird symptoms going on. The pi is running raspiblitz 1.7RC2 (64bit). I have 400mbps internet and it's connected to a new 1TB sandisk ssd.
First I looked at the debug.log file (sudo tail -f /mnt/hdd/bitcoin/debug.log) When bitoind is first started up I see blocks being added at a rate of several per second. After letting it run for awhile it slows down to one block every few seconds. I also get ping timouts and my peer connections are constantly cutting off and don't exceed ~10.
Trying to communicate with bitcoind also becomes slow, bitcoin-cli getnetworkinfo | grep connections at the start is instant but after awhile this command can take 30 seconds to execute.
Finally using nmon the system usage is very low except bitcoind is reading from the ssd at a rate of ~250 mbps but not doing much writing. The cpu usage is blocked by waiting io. The only thing I have tried was lowering the dbcache by 500mb thinking there wasn't enough free memory but it did not help.
bitcoin.conf:
# bitcoind configuration
# mainnet/testnet
testnet=0
# Bitcoind options
server=1
daemon=1
txindex=0
disablewallet=1
peerbloomfilters=1
# Connection settings
rpcuser=raspibolt
rpcpassword=c4w0Mh2q
rpcport=8332
rpcallowip=127.0.0.1
rpcbind=127.0.0.1:8332
zmqpubrawblock=tcp://127.0.0.1:28332
zmqpubrawtx=tcp://127.0.0.1:28333
# Raspberry Pi optimizations
dbcache=2560
maxorphantx=10
maxmempool=300
maxconnections=40
maxuploadtarget=5000
datadir=/mnt/hdd/bitcoin

Edit
After several restarts the sync seems to be going faster than before, even after waiting. The disk reads are much lower with some writes as well. Not sure why lower read speeds results in faster syncing...

Eidt 2
I noticed after "leaving block file" it's operating at about 1/2 speed for awhile now. Look at the time stamps in the attached screenshot. Things slow down quite a bit after that.


texts:
How can someone like an exchange track the Bitfinex hacked coins to make sure the hacker cannot exchange them?
Does a service exist to make it easy for the exchange to call an API with the deposit txid and get back an answer if the input coins are tracked to the hack?
Update
I understand that people don't like the idea of tracking bitcoins, but as an exchange if bitcoins associated with the hack are deposited on your platform and allowed to be converted into USD you are potentially liable for facilitating a crime. An exchange needs an easy way to keep track of these coins so at the very least they can put a hold on the user's account while investigating the source of the deposited coins. This happens with USD all the time, so I'm not sure why people would expect bitcoins to be any different. No exchange wants to be a party of criminal actions.
Hopefully now the question is more clear. So does such a service exist or must the exchange write their own code to handle this?


texts:
Hello,

We, a small team, have implemented about 95% of a breakthrough scientific proposal that is describing the NiPoPoW Non-Interactive Proofs of Proof-of-Work. You can find our source code implementation of the NiPoPoW algorithm on our GitHub

During the implementation, we have got a few questions that we were not able to figure out from your breakthrough paper:

I. The WebDollar uses the Mini-Blockchain scheme ( Ethereum alike ) by using Patrica Merkle Trees to store the Balances of every non-zero addresses and Smart contracts. So, in order to validate a balance, we need only SPV hashes from the Patrica Merkle Tree and proofs based NiPoPoW of the last block (which is the last block from the blockchain)… so we believe we don’t require the infix proofs. Am I right? Or do we need the infix or velvet NiPoPoW algorithm?

II.  Algorithm 2 Verify

a)  We guess that the function validChain will validate π and χ in order to check the interlinks that they point to the genesis block and the hashes are correctly calculated.

b) My first technical question is that we were not able to understand what is the Q predicate used in the Verify Algorithm 2. Is it a “function” that checks and validates the χ (validating a PoW blocks based Target (T), interlinks. I am right? ) or how Q predicate will look like ? What else will the Q predicate do differently than validChain (π, χ)

III. MultiLevel Property

We are not very sure we got the order correctly.

We iterate u' from [0 to all u] and we will check that every u' must hold the property that for any C* included in C that has the property   |C∗↑µ'| ≥ k1, C* must have also the last equation. in case C* fails the last equation we return false;

IV. Badness

We were not able to understand the marked C* from the badness function

a. What is the correct order to calculate the expression C↓↑µ−1… first we calculate C↓ and then we calculate based the previous result ↑µ−1?
b. How do we calculate C↓? We couldn’t find any idea of how to calculate  C↓ only C’↓ which is downchain definition C’↓ C is defined as C[C’[0] : C’[−1]].
c. Isn’t it C’↓ and not C↓ ?

Thank you!


texts:
Is there an online record of historical Bitcoin node counts? If so:

When did the record keeping begin?
Are IP addresses available?
Did Satoshi and most early adopters run Bitcoin nodes over Tor or were their real IP addresses revealed to other Bitcoin nodes?


texts: How to get sender address from transaction with JSON RPC?

texts:
I'm using JSON-RPC call to connect to local bitcoin node on my clouding server.
I could get all transactions with wallet name by using gettransactions.
Now I need to get sender's address for each transaction but result contains only receivers' address.
Following is response of gettransactions request.
{
"result": [
{
"address": "bc1qd9mgd4ynryaw2kp0pzfjdxguhz9dzvs5vh0nfn",
"category": "receive",
"amount": 0.001,
"label": "",
"vout": 27,
"confirmations": 1322,
"blockhash": "000000000000000000074551080f954e790edfe6ad810ecebf4691e881175eaf",
"blockheight": 660029,
"blockindex": 106,
"blocktime": 1607147554,
"txid": "07ab59c8d3a204172887085258460d0058c20a9acdb451daa5ad4290cbd461b0",
"walletconflicts": [],
"time": 1607147511,
"timereceived": 1607147511,
"bip125-replaceable": "no"
},
{
"address": "bc1q6dh3h5e3qgku8u9s8y664844fj4fkm08n7cnwt",
"category": "receive",
"amount": 0.0011,
"label": "",
"vout": 9,
"confirmations": 1313,
"blockhash": "00000000000000000000960f4476a8552cac203eec6e0f826886b41fae402bec",
"blockheight": 660038,
"blockindex": 393,
"blocktime": 1607153799,
"txid": "af0885e4c1d10e935de525680c6c33d221ab506742b08e34a0322bba90b56fb0",
"walletconflicts": [],
"time": 1607152236,
"timereceived": 1607152236,
"bip125-replaceable": "no"
},
{
"address": "1L8ZNCibVVpPjJ8VJ1ALLuTjtctA4mzGPw",
"category": "send",
"amount": -0.001,
"vout": 0,
"fee": -0.00008536,
"confirmations": 706,
"blockhash": "0000000000000000000c3230522e267980bb990883cc0b36460ad3efc1f8fed4",
"blockheight": 660645,
"blockindex": 1049,
"blocktime": 1607529332,
"txid": "a2056e7a49bc608435713519bc038ed7da2e65f588495f36c6628f5ca6fe2d7d",
"walletconflicts": [],
"time": 1607528963,
"timereceived": 1607528963,
"bip125-replaceable": "no",
"comment": " ",
"to": "seans outpost",
"abandoned": false
},
{
"address": "1L8ZNCibVVpPjJ8VJ1ALLuTjtctA4mzGPw",
"category": "send",
"amount": -0.0005,
"vout": 1,
"fee": -0.00008536,
"confirmations": 705,
"blockhash": "0000000000000000000994e21412109847caffa2bd990884f49461d53c047055",
"blockheight": 660646,
"blockindex": 844,
"blocktime": 1607529675,
"txid": "ddbe1dce4537926b6cf5bc1e222e5cd32de224cf346ca89251c127ce32226f30",
"walletconflicts": [],
"time": 1607529401,
"timereceived": 1607529401,
"bip125-replaceable": "no",
"comment": " ",
"to": "seans outpost",
"abandoned": false
}
],
"error": null,
"id": "curltest"
}
How can I get sender's address ?


texts: Is there an API to create a Dogecoin Wallet?

texts: Identical to this, but for dogecoin? https://blockchain.info/api/create_wallet


texts:
On 4-Jan 2017, I have made a BTC payment and now,it's been more than 16+hours to my unconfirmed transaction of 0.1313828 BTC through blockchain wallet.

Please help either to revert back this amount in my blockchain wallet or send it to the same address.

URL: https://blockchain.info/tx/5f3088954a3960132bd52438d4b7124bab50d2776c7ce9bdf158d37dc53d8786

Query:
Will it revert back automatically?
Do I need to do something to pull or push it further? Please suggest

I really appreciate if someone helps me as I read certain blogs this is due to low commission fees and nobody picking it during BTC mining.

Thanks


texts:
Why is it giving me this error and not receiving my bit coins?

The system cannot find the path specified ".org.multibit.file.WalletSaveException"
Cannot save wallet 'C:\Program Files\MultiBit-0.5.15\null\MultiBit\multibit.wallet'
Created wallet "C:\Program Files\MultiBit-0.5.15\null\MultiBit\multibit.wallet".
Could not load the wallet file "C:\Program Files\MultiBit-0.5.15\null\MultiBit\multibit.wallet".


texts: What wallets are compatible with Satoshi Dice?

texts:
Satoshi Dice requires wallets to be able to receive coins from the same address they are sent.

What are some notable examples that are compatible and incompatible with this?

What are the technical reasons behind such an incompatibility?


texts: How to detect reorganization from bitcoind via ZMQ?

texts:
I have my own bitcoind server (bitcoin core) and receive transaction data from the bitcoind via ZMQ. Then the transactions are stored into my database for data analytics or statics.

[bitcoind] --> (bitcoin transactions via ZMQ) --> [store into my DB]

Normally, it works well but sometimes blockchain will be re-organized when multiple chains are detected. At that time, I have to update my database as well. My question is how to detect the reorganization event from bitcoind server. Or do you have any good ideas for this.

FYI,

I'm listening new block generation notification via ZMQ.
The main reason why I have my own database is seeing Colored coin transactions and Counterparty transaction.

Update 1

It seems that I can subscribe only four channels; hashblock, hashtx, rawblock and rawtx. It may be impossible to know the reorganization via ZMQ. I may have to confirm when I receive newblock notification wether fork exists or not..

Update 2

I may have to call getchaintips RPC when every time I receive a new transaction notification.

How to detect a fork with bitcoin-cli?

Update 3

My understanding is that I need the following process to reorganize MY OWN Database.

getchaintips RPC's response

{
    "height": 420561,
    "hash": "000000000000000001cb02590846299c91794e9b9f422513cff4b9c1dd5c62a",
    "branchlen": 0,
    "status": "active"
},
{
    "height": 419698,
    "hash": "000000000000000004a3a78750438d0491b6335cbbe9c15099a6e55b6943e51a",
    "branchlen": 1,
    "status": "valid-headers"
},
{
    "height": 418868,
    "hash": "000000000000000000ba1d7d93ad1c7f04fb4a430fdee67c44fbdd3236f2b805",
    "branchlen": 1,
    "status": "valid-fork"
},

Call getchaintips when I receive a new tx notification.
Compare the two hashes. One is status is at "valid-fork" and another is stored hash at the same height in my own database. (As above response, height=418868, hash=000000000000000000ba1d7d93ad1c7f04fb4a430fdee67c44fbdd3236f2b805)
If the two hashes are different, delete all records from valid-fork's height and fetch transactions from the hight to the height of active status(As above response, height=420561), then insert them into to my own database.

Update 4

It seems that Counterparty detects reorganizations in the following source code. I think I can see it as reference.

https://github.com/CounterpartyXCP/counterparty-lib/blob/5498d891ffec270c64a5804a4273962d2c759fa5/counterpartylib/lib/blocks.py#L1074


texts:
Orphan block is a block that doesn't have a known parent in the
longest block chain.

As I understand, this mean that orphaned block does not have a reference on it as "previous block hash" in any newest block. It is correct?

If yes, I make some research and does not understand why I get some strange results.

So, I extract all block hashes from raw dat files. Then I extract all "previous block hash" data from raw dat files. As a result I've got 2 arrays: block hashes (array A) and parent references (array B). Then if I subtract B from A, I would get a list of orphaned blocks.

Is it right way to get orphaned block list, or not?

P.S. I get this results after parsing dat files from blk00000.dat to blk00953.dat (I chose two blocks from the compiled list):

000000000000000003D57B69D1AC77F64287C893C16ADBC1816C6D7386CCC3C0 – orphaned
0000000000000000011523D7477DD274B7E0DCC2C616B2E2F584FFDEC20237D3 - main chain

main chain and orphaned are the status based on block explorer sites.

On this two blocks does not any reference as "previous" in raw dat files. I'am confused – "why?"


texts: Why do transactions send coins to the same address as they spent it from?

texts:
I often notice transactions such as:

364efe5a906de5971e242f9711008e58a5ab79f136a8044b66615e8662d35f09

Where funds from the address 3PU with 1.38 BTC are split to itself (1.35 BTC) and 37Ek (0.027BTC):

3PUui (1.38 BTC) -> 37Ekc (0.0278 BTC)
                 -> 3Puui (1.3519 BTC)

I am wondering why the transaction doesn't look like:

3PUui (0.0279 BTC) -> 37Ekc (0.0278 BTC)

I read from this question that an input must be completely consumed in the transaction, so if I have received 1.35 BTC during the last transaction, if I refer to it, I must consume the 1.35 BTC.

However on https://coinb.in/#newTransaction I can see the amount can be specified for each input. So why should I need to mention the input amount if it is already set by the previous transaction?


texts: OSX Bitcoin Core frozen on login while "Activating Best Chain"

texts:
I recently downloaded Bitcoin Core for OSX, sent a payment to my wallet address, then waited for the client to complete a sync. About 2 days later and w/ only 8 weeks to go, the client froze. Upon restart, it only gets to "Activating Best Chain" and won't open fully.

I've seen related answers to this question in the forum, but I think they're all for Windows machines.

I do have my wallet encrypted.

I'd like to export my wallet to another client, but apparently am not using the correct inputs in console. Any help much appreciated.

cheers

...and when I try to run:
getwalletpassword "pwd" 600
the application crashes and I have to restart. So it doesn't look like the standard way to get my privkey out will work.