texts: How can I simulate ProofOfStake (PoS) for a testnet (clone of Pivx)?

texts:
After the end of PoW blocks, I am unable to mine using PoS. Here is my setup.

1) Server with the following config file.

server=1
daemon=1
listen=1
rpcuser=user
rpcpassword=password

2) Two clients running from 2 different VPS with individual unique IPs pointed to the server using the following in config file.

staking=1
addnode=<ip of the server>

3) A Mansternode installed on a separate VPS configured to one of the client VPS above.

4) I set the last block for PoW as 200. After that it must use PoS.

5) I start the mining using the server.

6) I send 100,000 coins each both to the client wallets. In one of them I lock 10,000 coins for Masternode, which works fine.

7) The mining continues and all are updating the blocks properly without any issues.

8) However, I see that none of the wallets report that their coins are enabled for staking. when I check the status using "getstakingstatus", this is what I see.

"validtime" : true,
"haveconnections" : true,
"walletunlocked" : true,
"mintablecoins" : true,
"enoughcoins" : true,
"mnsync" : true,
"staking status" : false

Everything is true, but, "staking status" alone is false.

9) PoW stops at 200 blocks. After that, no blocks are produced and none of the clients are active for staking (PoS).

What am I doing wrong? How do I solve this so that I can test PoS and understand it better? Is there any code that I need to look at and chance some setting in the code? Please let me know.


texts:
I've heard anecdotally that the ability to find nonces is much harder than it once was. This implied that there was a fixed number of nonces in the Bitcoin system, and a large number of them have been found.

My question is: Is there a way to estimate the number of unfound nonces?


texts: Can bitcoin core verify a third party blockchain download?

texts: If you were to obtain a copy of the bitcoin blockchain, i.e. a copy of someone's data dir excluding his wallet files on a removable drive or other storage medium, could bitcoin core verify that or not? This would be useful in developing countries where the initial blockchain download is hard to do but keeping up with the chain is easy.


texts:
What is the expected response for a getmemorypool RPC call to a standard client, when calling it with data field? I'm mainly interested in such factors as:

Will the call return true if a sent block is not at the end of a block chain (for example, creates a fork or otherwise invalidates some other blocks)?
Will the call return false if the client is BitcoinQT, not bitcoind?
Will the call return true if the same block is submitted more than once?
Will the call return true if the block does not contain all transactions sent earlier, or contains some transactions that the client does not know about?
Are there any other specific cases one should know about when coding for this call?


texts:
I read the following article:

Bitcoin surging higher after mystery trader buys $344mn in cryptocurrency, Russia Today, February 19, 2018.

Where could the man buy such a large amount of Bitcoin? On an exchange?


texts: how to be a maker for either bid or ask orders on bitcoin exchanges?

texts:
Using a random coin as an example, if the last price is 1.08999944 how can i chose either a buy or sell price that will be a valid 'maker' price ? Can i just bump the price by one Satoshi i.e. 1.08999945 and put a buy.. making it a maker order and take advantage of lower fee ?

Looking at various coins order books there seems to be a lot of open orders so to make a valid maker order do i need to first query the order book for open orders and then find a gap at a price i like and then place the order ?

I understand the maker is

 ... maker fee if the trade order is not matched immediately against an order already on the order book, which is adding liquidity.

I'm just not sure how you know in advance of placing the order that it will not match an open order ?

Thanks
fLo


texts: Bitcoin market hours (open/close prices)

texts:
If Bitcoin trading never stops then what does it mean when news sites and others talk about bitcoin opening or closing at a certain price, and why is this terminology used?

Could two people mean different things when they talk about the closing price at the same date? (apart from price differences between exchanges)


texts: Create a transaction from addresses A and B sending to address C

texts:
Related: Using bitcore to create a transaction with two addresses and change address

I would like to create a transaction from addresses A and B sending to address C

In the above question I get a little confused (it looks like hes doing one transaction that sends from addresses A and B to addresses C and D receiving change at address E) because it looks like he is signing it with the two receiving addresses!

Usually when I create and sign a tx with Bitcore I sign it with the sending address's private key not the receiving address (in my case the receiving address would be a user I do not personally know)

The bitcore docs say:

  To send a transaction to a multisig address, the API is the same as in the above example. To spend outputs that require multiple signatures, the process needs extra information: the public keys of the signers that can unlock that output.

var multiSigTx = new Transaction()
.from(utxo, publicKeys, threshold)
.change(address)
.sign(myKeys);

var serialized = multiSigTx.toObject();

The two parts to this that confuse me are:

Bitcore quote - To send a transaction to a multisig address...

Is this different from a regular address? I notice that the example is lacking .to(address, amount)

Why is Richard from the related question signing with the receiving address's private keys?

Logically shouldn't my desired action look something like this?:

var transaction=new Bitcore.Transaction()
.fee(fee)
.from([output_A,output_B])
.to(pubkey_C,satoshis-fee)
.change(address_A)                    //don't loose the change
.sign([privatekey_A,privatekey_B]);

output_A is from address A and output_B is from address B (both my addresses)


texts: How are per-day statistics computed on MtGox in the middle of the day?

texts: MtGox trades 24 hours a day, 7 days a week. Yet charts show daily charts and volume stats, especially intraday, when does the trading session begin and end on Mt. Gox, for reporting purposes? Also, what time zone.


texts: How can coinbase transactions be created?

texts: How can a coinbase transaction be created and what would happen if there was more than one coinbase transaction in a block?


texts: How does electrum interact with the underlying bitcoind service?

texts:
I am a bit confused regarding the bitcoind peers and Electrum X peers.
From what I understand, the electrum X protocol is built on top of the bitcoin blockchain, but I cannot quite wrap my head around on how exactly they interact.
I get it that electrum needs to have access to a bitcoind process in order to sync up its database, but what happens after the sync? Does the electrum client receive notifications about new transactions from other electrum peers, or does it still use underlying bitcoind mempool? Or both?
Can somebody explain on how exactly these 2 services interact?


texts: Send or receive bitcoins with bitcoin-cli without downloading full blockchain

texts:
I have successfully downloaded, compiled and installed bitcoin-cli from github.

I can send or receive bitcoins with sendtoaddress and getnewaddress methods.

It works great and i am happy to do that without install third party software (i do not trust them)

But i have a problem: I need to download the full blockchain files (with bitcoind) on my computer.

Is there a way to run sendtoaddress and getnewaddress methods with having only wallet.dat file on my computer ? I do not want to download the full blockchain files. Is it possible ?

How works ledger wallet key ? This small key does not contain a copy of the blockchain. And it works !

Thanks


texts:
What are the steps to withdrawing from a MtGox account to a bank account in USD?

Mt Gox's Dwolla account is currently (Aug 2013) frozen or shut down.

Are there international transfer, money order, wire transfers that can occur be used?

Can the steps be better defined?


texts:
How can I forecast the date Bitcoin will hit a certain blockheight?

Are estimates for future halving and other important blockheights just based on the current height plus 1 for each 10 minute period between not and that date/time?

Are there any better formulas that also that take into account difficulty changes just after block halving or release of a new powerwide ASICs mining chips?


texts:
Not part of the protocol, but rather a 3rd party?

A directory could be built starting from this thread, where a lot of known Bitcoin figures posted their Ripple address (myself included).


texts: Is it a threat if top mining player merges?

texts:
It just strikes to me that if top 2 bitcoin miners which would own more than 50% mining, merges can they control bitcoin.

In hypothetical scenario if have bad intension can they control the price etx of bitcoin ?


texts: What is the block verification procedure, and will it ever become too expensive?

texts:
I'm trying to get a grasp on which items the network is responsible for validating / enforcing.  If I understand correctly, when a new block is received, the recipient needs to verify the following:

the block hash - i.e. that the hash of the header, including prev. block hash, Merkle Root hash, time, target, and nonce is correct, and that its value is less than the target.
the target - needs to equal the current (difficulty) target.
the hash of the prev. block - must be correct, and must "point to" the end of the currently "longest" (most difficult) chain.
all the transactions in the block.  This seems like it would involve:  looking up the input txn's of the current txn's by their hashes, and running the appropriate sigScript + pubKeyScript pairs.  Also verifying for each txn that sum(inputs) >= sum(outputs).
the coinbase transaction. sum(outputs) >= the "change" left by all the other current txn's.
hash of the Merkle Root.

Questions:

Have I missed anything?  (timestamp?)
This seems like a lot of work!  Particularly scanning through the entire blockchain to find the input transactions. (Though I suppose the client could build an index once on start-up.)  My understanding is that at least #4 is optional - a node could choose to assume that it's been done by somebody else.  As the blockchain grows larger & larger, wouldn't it become less feasible for individual nodes to do all this work every 10min, resulting in fewer verifications being done?
Does a node have to verify every block (and thus every txn) when it first downloads the chain?  It's one thing to verify all the block hashes, but a new node without any history wouldn't know if the contents were valid - only that X amount of work had gone into solving the blocks.


texts: How can one realistically model the distribution of the network's unspent transaction outputs?

texts:
I am working on a simulation to explore the usefulness of a patch for the CoinSelection behaviour of BitcoinCore. To that end, I am looking for statistics on the distribution of unspent outputs respective to their value in satoshi.

So far, I haven't found much on the topic beside an outdated number of unspent transaction outputs, as likely search terms collide with a lot of unrelated topics.

Are there any papers or other sources that discuss:

How can one realistically model the distribution of the value (in satoshi) of all UTXO (unspent transaction outputs)?
What type of curve best approximates the distribution?
What are mean, standard deviation, and variance of the network's UTXOs' values?
Bonus: How did the distribution of UTXO' values change over time?

Clarification: I am interested in modelling the number of satoshi held in UTXO.


texts: How does one prove total turingness of the bitcoin script using the Ackermann Functions?

texts:
In this Medium Article (https://medium.com/@craig_10243/bitcoin-a-total-turing-machine-5a6c3c68f5a7#_ftn2), C. Wright states:

"...It is known that all primitive recursive functions are total and computable, in this paper we also demonstrate using the Ackermann function that the Bitcoin script constructs include the ability to extend to total computable functions that are not primitive recursive. This demonstrates that Bitcoin can incorporate total computable functions that are simply “recursive” as well as primitive recursive."

What does this mean in mathematical terms?


texts:
I'm trying to scale getrawtransaction calls from bitcoind, without manually parsing the .dat files.

I've tried:

rpcworkqueue=512 (no difference)
rpcthreads=128 (no difference)
par=8 (no difference)
passing the blockhash with every call to avoid searching the txindex (big difference)
using JSON rpc batching (big difference)
having two separate instances on the same pc and rotating requests (double speed, but costs 200GB)

It seems that a bitcoind will only ever devote 1 core of the cpu to JSON RPC, so when it gets to 100% the only way to scale is with another instance. Unfortunately my server has 24 cores at 2.1GHZ.

Does anyone know if it's possible to have two instances of bitcoind running in the same folder. I.E. one instance is connected to the network and the other instance is running in a read only mode.

Or is is possible to allocate multiple cores(not threads) to JSON rpc

Any help is appreciated, thank you.


texts: Is it possible to limit bitcoin wallet balance?

texts: I'm not sure if this is a right question, but is it possible to create  bitcoin wallet address with specific amount of limit?


texts: How do I find the hash "market share" of P2Pool?

texts:
P2Pool is a peer to peer mining pool, offering some advantages over centralized pools:

There is no central node to take down (assuming the pool is indeed fully decentralized). Pools have suffered from DDOS attacks in the past.
An open source P2P pool should theoretically be able to operate with zero fees.

How can I find out how many people are using P2Pool?


texts: How can I connect to the Lightning Network on Litecoin's testnet?

texts: I installed the software but cannot find any nodes to connect to on testnet. There is a website with mainnet nodes but not testnet. Does anyone know where I can find some testnet nodes?


texts: We can spend balance of an address if we have private key. is it true for master private key too? I mean, we could spend spend balance using master private key? or we should use child private key?


texts: Do i have to run full node to receive unconfirmed transactions?

texts:
i want to query unconfirmed transactions by using getrawmempool.

do i have to run a full node ?

or if i set prune in bitcoin config, will i still get the newly unconfirmed trsanctions ?


texts: Blockchain Parser not working on blockchain generated in regtest mode using bitcoind. Any help?

texts:
Has anyone used this blockchain parser for Bitcoin https://code.google.com/p/blockchain/ ?

http://codesuppository.blogspot.in/2014/01/a-command-line-interface-for-blockchain.html

I tried to parse blockchain generated by Bitcoin (bitcoind -regtest -daemon) in regtest mode but it is not reading(parsing) it correctly.

I copied the file blk00000.dat (this is the only file generated in regtest mode) to /home/somesh/Desktop/blockchain-read-only/ folder.  I executed the command:   ./blockchain.out /home/somesh/Desktop/blockchain-read-only

output:

Successfully opened block-chain input file '/home/somesh/Desktop/blockchain-read-only/blk00000.dat'
Welcome ...
Commands available: ... (then prints all the available commands)

then I selected scanning option

scan

The following is the message I get on scanning

Scanning block-chain re-started from block 0 up to a maximum of 500000 blocks..

Warning: Missing block-header; scanning for next one.
Failed to open block-chain input file '/home/somesh/Desktop/blockchain-read-only/blk00001.dat'

Finished scanning block headers. Built block-chain with 0 blocks found..

It is working fine for Bitcoin's real blockchain but not for the blockchain generated in regtest mode.

I think the parser is not able to find the block header in blk00000.dat and is skipping to next file.

Warning: Missing block-header; scanning for next one.

what changes do I have to make ?


texts: How's Blockchain like "magical Smart Contract"?

texts:
Please keep everything like I'm 5. I don't know computer science or programming. Please help me understand this ELI5 comment? I simplified names.

Bob opens a candy shop called BCS (Bob's Candy Shop).
He has no idea how taxes and all this adult stuff work so he asks his brother Charlie, a smart IT guy, to write him a magical SmartContract that cares about everything. [Question 1] He just needs a buyer to show the QR code Charlie gave him.
Alice comes by to buy some chocolate. She scans the QR code with her phone and sends the amount to the SmartContract Charlie made.
This contract automatically orders new chocolate and pays for it. The chocolate is already on its way to BCS. The taxes are calculated and stored in the SmartContract. This cares about paying the taxes and tells the taxman some other stuff in order to make taxman happy. The rest gets transferred to Bob's account. This all happens magically and faster as Bob can say "Thank you".
After the first day he buys a ticket for the film "Frozen" from the money he just earned. [Question 2] He only has to copy the address code which the cinema has on their website. He sends the amount of money and the name of the film to this address. The magical SmartContract of the cinema sends the ticket back.
Bob coincidentally meets Alice in the cinema. Both loved the film.

What does this mean?  Buyer like Alice has QR Code. Why Charlie gave Bob QR code?

This is just QR Code and buying movie ticket online What do with Block Chain?

Where's Block Chain in this analogy? Does Blockchain suppose be the "magical SmartContract"?


texts: What happens an order and offer are matched but there is a significant gap between them?

texts:
I wonder the implications of the following scenario.

Let's assume I offered one coin with the price 1k (by mistake or for experiment), while the highest order in the market is 2k. What are the prices I'm going to pay and the matching order is going to receive. How would this affect the current price of the market? Thanks


texts: Is there a chart that shows Mhps mint speed over time?

texts:
My BitMinter client says that my approximate mint speed is 0.0078/per day on a MacBook Pro Retna.

I assume that this value decreases as the speed of the network increases, and therefore my contribution per block is less valuable.

Is there any chart that illustrates how Hhps diminishes value over time?
Would this chart correspond with the difficulty value/over time?


texts: Generate bitcoin address from public key file

texts:
Is there a way to generate a bitcoin address from public key with openssl command line ?

Thanks


texts: Is it possible for someone to verify that a wallet is theirs wallet, without providing their private key?

texts: I need to know with 100% certainty that someone can tell me "this is my wallet" and prove it to me.  I could of course simply get their private key/brainwallet phrase, is there any other way to do it?


texts: balance of sub-wallet not in main wallet address (blockchain.com)

texts:
I'm quite new to bitcoins so apologies if i'm being a noob, but I'm very confused!

I have many sub-wallet which created with pycoin command line.

for example, I created subwallet like this:

ku -a xpub -s 0/77 -a

my main bitcoin address and xpub is in blockchain.com.

after someone send BTC to my sub-wallet. I can check that is really confirmed (wallet and transaction in blockchain.com).

But when i go to my wallet in blockchain.com i can'nt see this balance. where is my mistake and how can I solve that?


texts: Security wise what stops me from canceling an unconfirmed transaction?

texts:
I'm in a restaurant where they serve me my meal without waiting for the blockchain confirmation. Technically speaking I can cancel my transaction before the confirmation according to this

So what stops me from doing the same thing with bigger, riskier transactions?


texts:
I am attempting to set up the PHP bitwasp library from the github repository:

https://github.com/Bit-Wasp/bitcoin-php

The installing instructions suggest I simply execute:

$ composer require bitwasp/bitcoin

I do have composer installed but I am getting the following error message:

Problem 1
    - Installation request for bitwasp/bitcoin dev-master -> satisfiable by bitwasp/bitcoin[dev-master].
    - Can only install one of: bitwasp/bitcoin[v0.0.29.1, dev-master].
    - Installation request for bitwasp/bitcoin v0.0.29.1 -> satisfiable by bitwasp/bitcoin[v0.0.29.1].

I do not practice PHP full time so I lack the experience of installing packages in that language and using composer. I would be grateful if someone could point me in the right direction.

EDIT
The suggestion has been made that the package is already installed. However, the following code sample which I got from another thread:

<?php
// failing to install bitwasp
use BitWasp\Bitcoin\Bitcoin;
use BitWasp\Bitcoin\Address;
use BitWasp\Bitcoin\Key\PrivateKeyFactory;

$network = Bitcoin::getNetwork();

$privateKey = PrivateKeyFactory::create(true);
$publicKey = $privateKey->getPublicKey();
$address = $publicKey->getAddress();

?>

is giving me PHP Fatal error:  Class 'BitWasp\Bitcoin\Bitcoin' not found.


texts:
We have a bitcoin wallet which we tried to update as it was dormantfor some 8 years plus but we were unable to do so as we haven’t got the Bitcoin wallet details.

Is there any way of retrieving my Bitcoin wallet details as we don’t have the wallet ID details.


texts: why not make DIY, upgradeable, ASIC mining rigs?

texts:
being a miner myself, I see one of the big problems in the mining field. ASIC's are very unsustainable at making profit, and quickly turn into scrap as something better comes along. (even though they can be super profitable at first)

What this does is centralize the wealth creation into the very first and wealthiest people who come and to buy, and drains the profits quickly for anyone else trying to get it. After the profits are drained, the equiptment becomes junk.

GPU mining is great because its a lot more doable for the average person (at a cost level) serves multiple uses and different coins, and allows a person to custom build their system, which they can update and upgrade as they move along.

So, why not just sell the parts for making ASIC rigs, and let mining enthusiasts build their own? I bet it would be a lot cheaper, and a lot more people could get their hands on ASIC chips.

it would expand the mining further to more people. more decentralization.

So why is this not being done? Do you think this could be a good idea? What do you project would happen?


texts: How can I reproduce the same binary as bitcoin.org or bitcoincore.org?

texts:
I'm hoping that someone can tell me how to get the same binary that we see on bitcoincore.org/bitcoin.org.
I tried using Ubuntu 20.04
git clone https://github.com/bitcoin/bitcoin
git checkout v0.20.1
sudo apt-get update
sudo apt-get install build-essential libtool autotools-dev automake pkg-config bsdmainutils python3 -y
sudo apt-get install libevent-dev libboost-system-dev libboost-filesystem-dev libboost-test-dev libboost-thread-dev -y
./autogen.sh
./configure --disable-wallet
make
make install

Extra details (git commit I'm going off of)
 git log
commit 7ff64311bee570874c4f0dfa18f518552188df08 (HEAD -> 20.1, tag: v0.20.1)
Author: Wladimir J. van der Laan <laanwj@protonmail.com>
Date:   Fri Jul 31 14:01:56 2020 +0200

produces bitcoind: d46f9ca67562129cb2f0d7ed7e0ae576ab06e616d98d28c2a262d82356f9d87b

bitcoincore.org link I'm going off of:
https://bitcoincore.org/bin/bitcoin-core-0.20.1/bitcoin-0.20.1-x86_64-linux-gnu.tar.gz
produces bitcoind: 4ec74161b2a90293926ae8e20a2efbe952bd23b53aeebf051e6a6285ace18271
I was hoping that someone could tell me how to properly configure/setup my environment to produce the same binary that we see packaged nicely in the tarball on these websites.
The binary files aren't even close in size…
from tarball bitcoind size:
10312344 (10 MB)
from building from scratch bitcoind size:
192814984 (192 MB)
How do I make the super sleek and sexy 10 MB version?
Thanks!


texts: (bitcoinj) How to determine which key/address to use to send funds?

texts:
I'm using Bitcoinj and am confused as to the numerous addresses it's generating. I want to be able to send funds from my wallet (for which I have my private and public key) but I am unsure as to what address I should be using.
For example, I have an ECKey from which I can debug print a private or public key, but the wallet allows me to get four different addresses:
wallet.currentAddress(KeyChain.KeyPurpose.AUTHENTICATION)
wallet.currentAddress(KeyChain.KeyPurpose.REFUND)
wallet.currentAddress(KeyChain.KeyPurpose.CHANGE)
wallet.currentAddress(KeyChain.KeyPurpose.RECEIVE_FUNDS)

I understand I may not need to specify an address when creating the transaction (it seems that bitcoinj handles this?) but what address is associated with sending?
Apologies if this explanation doesn't make sense, I've been in crypto for a long time but the programming side is new to me.


texts:
I am trying to follow the instructions in the following post:
Check status of daemon

When I try to run bitcoin-cli getblockchaininfo I get the following error:

When I look for the configuration file. It looks like it is not even there.

I am on Windows.


texts: Why transaction is signed with locking script from the input transaction?

texts:
Finally, I've successfully made a raw transaction with Python and this is the last thing, which is totally mistic for me.

In my case, here's the input transaction and it's locking script is:

OP_DUP OP_HASH160 dab3cccc50d7ff2d1d2926ec85ca186e61aef105 OP_EQUALVERIFY OP_CHECKSIG

Why it's necessary to set up the unlocking script to the input's locking script before signing? In my understanding, all the stuff should work well even with blank locking script, because in fact we're signing only other parameters. Unlocking script and unlocking script lenght will be changed anyway, so what's the reason?


texts:
When I run

bitcoind getaccountaddress

I get this error

error: {"code":-1,"message":"getaccountaddress \"account\"\n\nReturns the current Bitcoin address for receiving payments to this account.\n\nArguments:\n1. \"account\"       (string, required) The account name for the address. It ca     n also be set to the empty string \"\" to represent the default account. The account does not need to exist, it will be created and a new address created  if there is no account by the given name.\n\nResult:\n\"bitcoinaddress\"   (s     tring) The account bitcoin address\n\nExamples:\n> bitcoin-cli getaccountaddress \n> bitcoin-cli getaccountaddress \"\"\n> bitcoin-cli getaccountaddress \"myaccount\"\n> curl --user myusername --data-binary '{\"jsonrpc\": \"1.0\", \     "id\":\"curltest\", \"method\": \"getaccountaddress\", \"params\": [\"myaccount\"] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/\n"}


texts: Why would you rather mine Bitcoins than Litecoin? What am I missing?

texts:
I must be missing something here.

This calculator site says that a 2000 kh/s rig can generate .6 litecoins a day or ~10 USD.
http://www.litecoinminingcalculator.com/index.php?khs=2000&diff=3130.08003568&cdiff=3130.08003568&fee=2

Are these numbers wrong or has mining bitcoins with non asic rigs completely pointless now a days? Why isn't everyone mining litecoin at this rate?


texts: Use bitcoin blockchain as a way to send messages to another address purposely setting a 0 fee or a very low fee?

texts:
Having that bitcoin nodes are all over the world. Is it possible to broadcast a transaction sending to 20 different addresses with a piece of the message embedded into each address?

The goal is to make use of the blockchain unconfirmed transaction mempool to relay this message to the recipient.

The fee would be set to 1 satoshi per byte. We know it will never confirm, but thats not the goal of it.

What are some drawbacks to this?


texts:
Can we consider PBFT (Practical Byzantine Fault Tolerance) as a consensus algorithm ?

And if yes, How does it work?

And is it similar to other consensuses such as PoW, PoS or PoA ? Or it is totally different?

And is it used actually in a blockchain platform? if yes, which one?

P.S. I heard that it is NOT scalable for large network, Is it true? And if so, is its scalability even worse than PoW?


texts: What is the probability of forking in blockchain?

texts:
Is there any general formula that allows someone to calculate what is the current probability of having a chain fork?

I know that the probability of finding a new block is proportional to the difficulty target. Given that it's possible to have 2^256 different hashes (for simplification), finding a nonce that will yield a hash lower than target has probability of approximately P(m) = (2^256 - target)/2^256.

Given that a block will be mined within 10 minutes and considering that a delay of 2 seconds would be small enough for the newtwork propagation not being complete, that is, if two nodes find a block 2 seconds appart, there would be no time to notify the full network.

Here is when it gets complicated to me (statistics is not strong with me). What is the probability of the situation described above occur?

I think this is something related with a normal distribution, but I'm not sure.

My rational to find the probability of forking would be:

P(fork) = P(m1) * P(m2) * P(tdse)

Where P(m1) is the probability of node 1 to find a new block, P(m2) the same for node 2 and P(tdse) is the probability of both mining occur with a time difference small enough to not be propagated to the entire network.


texts:
Thanks to the bitcoin.stack community I have successfully launched a bitcoind docker with an external volume which has the block data

Currently its in 100% sync but I am facing an issue to get information using bitcoin-cli I need to run bitcoind -reindex and then add txindex=1 into bitcoin.conf

As I pulled the docker image from docker hub I do not have any control over its docker file and I have 140GB+ blockchain data that I do not wanna discard and start over

How do I run --reindex on a bitcoin docker container ?


texts:
Cryptsy has a lot of markets. Each market has its own ID. Now markets have an ID in the range [1,220]. Sometimes old markets are deleted. Are the IDs of that markets reused or not?

I have the same question for Bittrex and MintPal


texts: I was wondering if some one could explain to me, in this example what the benefit of the website owner(s) is? It seems to me they do not benefit at all from this contract. There are obviously benefits to the user, namely they cannot possibly lose their bitcoins from what I can tell. In this scenario, what is the 'payment' that the user making besides not having access (as far as I can tell no one has access) to their coins for 6 months?


texts: Building from Source on MAC OSX 10.9 Error

texts:
Hi i'm building Bitcoin from source and am having some problems. Curious if anyone would be able to help me.

When I try to make I get:

In file included from ./json/json_spirit_reader_template.h:9:
./json/json_spirit_value.h:20:10: fatal error: 'boost/config.hpp' file not found
#include <boost/config.hpp>
         ^
1 error generated.
make[1]: *** [rpcclient.o] Error 1
make: *** [all-recursive] Error 1

I try brew install boost and it's saying boost-1.55.0_2 already installed. Any ideas what exatly is going on?


texts:
My transaction stays unconfirmed. I've paid a normal fee I quess. The transaction is here:

https://blockchain.info/nl/tx/b8cacc71fba15b4dfee234cd037ba4729a15e573243440257777044f7ed8f101

What can I do to let it through?

Thanks in advance!

Rick


texts: How should I get all transaction history in a format that I can analyze?

texts: I want to download the entire bitcoin transaction history and store it in a database at my end to perform certain analysis. How do I get from the blk*.dat files to a useful format?


texts:
I know how the process of changing BTC price occur, but I curious as to what gave the  initial value to BTC and whether the price of another cryptocurrency refers to the BTC?

How would I replicate this process using an API or any algorithm?


texts: I searched the bitcoin wiki and found references to coinbase, but no clear cut explanation of what exactly it is.  I know that miners can tag their coinbases (that is how some sites tell who mined a block).


texts: Is there a way to create coinbase transactions with an RPC command?


texts:
Someone just asked me to open the RPC console, as part of debugging something else. How do I do that?

I'm using Bitcoin-Qt.


texts: what is a discrete logarithmic assumption? how does it set-up trustless proofs?

texts: pending proposal of bulletproofs as a zk proof for confidential transactions relies on fiat-shamir heuristic to be non-interactive via creating a digital signature on interactive proof of knowledge and as cited in [bootle, wuille, maxwell et al] "Bulletproofs: Short Proofs for Confidential Transactions and More" paper also rely on discrete logarithmic assumption be a trustless proof (unlike snarks). this led to my question above as im not well-versed on this topic and would like to learn more about this, more specifically in its relation to setting up bulletproofs.


texts:
Has anyone here built their own setup for connecting with the Blockstream satellite network?

I'm still looking for a cheap low-noise block downconverter.

  PLL LNB (linear polarization) w/ < = 200kHz LO stability

The ones I can find range from $100 -> $200..

Seems like 200kHz is not required, broader ranges are acceptable.
"L.O. Accuracy & Stability Within +/-1.5MHz" seems to do the trick and they are considerably cheaper (~15$).


texts: How do I get my Bit coin balance to restore on my new phone?

texts: My phone broke and is unusable and I am new to the whole bit coin service. I switched phones and downloaded the bit coin wallet how do I get my balance back?


texts: BIP 32 Private keys to be imported into HSM

texts:
Could someone explain to me how the import of private key in HSM works? Below is the information from the manual:

Private Key Import/Export
Private keys can be imported and exported
with existing PKCS#11 functions. They can be imported and exported
only if the HSM uses the key wrap model instead of cloning. Import a
key by calling C_Encrypt*() on the serialized key followed by
C_UnwrapKey(). Exporting keys by calling C_WrapKey() followed by C_ Decrypt*(). Use C_WrapKey() and C_UnwrapKey() to store keys off the
HSM, or to move them between HSMs.

What key is used for the wrap?


texts:
In bitcoins, it is possible to check if a private key is valid using the WIF checksum.

Is this also the case for altcoins which use SHA256. And how about the ones that use another hashing algorithm?


texts: Why is my /Library/Application Support/Bitcoin directory missing?

texts: I can't launch the latest update, now it just 'unexpectedly quits' before loading. I tried uninstalling and reinstalling a couple of the past versions, but the directory folder was never created. Strangely, the 0.7.2 version did actually launch, with the right wallet contents, but still no directory folder. When I tried going back to the most recent and the most recently successful version.. it still doesn't work. I even tried creating the folder myself before an install but it still didn't work. ANy suggestions?


texts: Is it possible to Send the total balance of Bitcoin from the Wallet using rpc without having to specify the exact amount?

texts:
I know we can send coins using the move, sendtoaddress and sendfrom commands from the console or commandline.

However these commands require to specify an "exact" amount, meaning you need to check the balance before you execute the commands.

Is it possible to just send all coins to an address or to oneself in the same wallet using just one command.

Hopefully someone understands what I"m talking about here.


texts: Are there any tools to check values in tx validation?

texts: Are there any developing tools that can show values(like the hash of tx to sign or the stack of script execution) in tx validation so that developers can check the correctness of their validation code?


texts: send btc from specific input without running bitcoind

texts:
Is there any third-party API allowing to send Bitcoins using specific transactions as inputs?

Back in 2013 I had to run bitcoind myself and build a raw transaction manually. But maybe it's easier now, after 3 years? Running bitcoind is not so cheap now, but I really want to forward a bitcoin payment from one address to others, also keeping it safe and clear.


texts:
How does an exchange calculate the price of a coin? I know it has to do with the amount of sell and buy orders, but what is the formula to do this?

For example, if GDAX says one bitcoin is $10k on their exchange, how did they calculate that?


texts: What are the analogous steps between transfer of value from buyer to seller with traditional P.O.S. solutions vs. with bitcoin

texts:
Recently I built a site that allows purchase of items with bitcoin, also paypal and credit cards.  In testing I haven been struck by how different the experience of purchasing online with bitcoin is vs. traditional methods. It takes much longer from the point of confirmation of sale to the "acceptance" of the payment (the point after which the workflow can move on to fulfillment).  It also takes more user input and action.  It's difficult on the surface of it to understand how this can be the case when transferring value from one person to another seems so much quicker and easier than traditional alternatives.

It occurs to me that part of the difference may be due to fundamental differences in what is taking place. Is a credit card transaction directly analogous to a bitcoin transaction, or instead does a credit card transaction only match a bitcoin transaction considered along with the bank and other transfers on either end of it? Are there other differences or considerations to make when comparing the two experiences procedurally?  I am unsure.

Coming up with strongly analogous steps between these two procedures of transferring value from a buyer to a seller might reveal choking points/areas of improvement for Point of Sale with bitcoin or highlight the differential value of bitcoin's approach.

So what are the analogous steps between the two experiences?


texts: How to extract all info for a public address from a local full node's db?

texts:
I recently started running bitcoind on a local Debian host, and I am still learning how to use the information in the local copy of the bitcoin blockchain.
I would like to extract all the information for one or more public bitcoin addresses currently available in the full node locally 1.  EDIT 2: I want to do this both from the bash command line and programmatically.  (IOW: no GUI-based tools, please.)
I recently learned that, contrary to my initial expectation, bitcoin core is not suitable for performing this sort of query.
Therefore, I went back to Google, but I've come up empty 3.  Hence I'm posting my question here.
Specifically, I would like to know

what software (preferably in the form of one or more Debian packages) would I need to install on the local full node that would enable me to extract all the information for one or more public bitcoin addresses currently available in the full node locally;
how exactly would I use this software to perform such queries.

1 I want to do this without reference to any specific wallet.  Having to add this requirement feels extremely weird to me (like having to add the requirement that answers to my question should work seven days a week).  This is a clear sign to me that there is still at least one pretty gigantic gap and/or confusion in my understanding of bitcoin, because I don't understand why a wallet should be even relevant to the kind of query I want to do.  I would have thought that a wallet would be, at most, an optional piece of information to modify the query, not an essential input for it.  But the fact is that I have not been able to find any way to interrogate the full node's database for specific addresses that does not require specifying a wallet.  This is just mind-boggling to me.
2 I apologize for not mentioning this critical requirement in my original post.  That was a major oversight on my part!
3 I am beginning to realize that the queries I want to perform on a full node's database (and without reference to a wallet) is something practically no one cares to do, and therefore it is hard to find tools for doing them.  Again, this strikes me as a bit weird, and feeds my growing suspicion that I am totally missing the point about bitcoin, blockchains, full nodes, etc.


texts: Can two bitcoin-qt share the same blockchain data

texts: I have a bitcoin-qt and bitcoin-abc on same computer running, can both share the same beginning of the blockchain data file ? since they both have same history till point in time.


texts: Resources for multisignature transactions?

texts:
I am interested in using multisignature transactions to secure my company's coins and I'm wondering what tools are available right now for use with multisignature transactions? I'm especially interested in solutions that work on keys distributed between multiple wallets (no single wallet holds all the keys) and are not currency specific (would work just as well for Bitcoin as for Litecoin or other coins).

I know that the standard bitcoind API is lacking in multisignature support due to this bug.


texts: Why does the time interval for OP_CSV need to be in the nSequence field when it is already in the script?

texts:
BIP68 prescribes how to put the time interval into the nSequence field but then BIP112 tells you that it is possible to specify it in the script with a notation like "30d".
Why are there two ways of doing the same thing? Are they both necessary, or is only one of the two necessary in the verification phase?


texts: Why is it so difficult to track & recover stolen Bitcoins?

texts:
I have to admit I don't fully understand the Bitcoin protocol. But from what I do understand, transactions are traceable -- it is the main reason decentralization works: the world can watch and confirm that a transaction is legit.

Why then can't we observe when a thief tries to cash out or otherwise exchange a Bitcoin that we know to have been stolen?

As Robert Wagner writes:

  1 out of every 14 Bitcoins is now stolen property, and there are
  plenty of laws governing stolen property.

What am I missing here? With so many Bitcoins identified as "stolen," why can't they be traced, recovered and returned to their rightful owner?


texts: How to avoid conflicts in a peer-to-peer topology (Bitcoin)?

texts:
For example in Bitcoin, if I want a miner to verify whether other miners store a transaction, before deleting it from his mempool.

How can I handle the case more than one miner doing the verification at the same time?

Is it possible to use backoff algorithm?


texts: blockchain.info does not want to import my bcc private key

texts: I imported my BCC private key into blockchain.info. But it does not ask me for the private key and lists the address as 'watch only'. I'd like to import the BCC amount into a blockchain.info wallet. All Tutorials about it do not correspond with the current blockchain menus.


texts: Is it possible to explore the blockchain without downloading the blockchain?

texts:
I'm doing some experiments involving bitcoin and the blockchain, and I need to access some informations about addresses, block, and transactions. The problem is that I need a lot of data, so I can't use online APIs such as blockchain.info.
I know it is possible to do such things by downloading and accessing directly the blockchain, but this solution is pretty impracticable, given its size. Is it possible to access this data without downloading the full blockchain? For example by directly making some kind of request to the nodes?


texts: Is there any recourse if an exchange/wallet service fails?

texts:
I recently used Coinbase to acquire some Bitcoins, my second Bitcoin purchase using their exchange.  The first transaction worked as expected however the second purchase seems to have encountered an internal error inside Coinbase.  After waiting the week for the USD transfer from my bank to change from "PENDING" to "COMPLETE" in the system I tried to transfer a portion of the purchased BTC to a bitcoin address.  The transaction appeared to be processing but the BTC never arrived at the destination address.  The following day there was no indication that the transaction had ever happened and the previously "COMPLETED" BTC purchase was once again "PENDING" with an estimate of 1 hour.  It has now been "PENDING" at the hour estimate for 6 days.

I have attempted to resolve this with Coinbase and I've only received an email saying we'll "fix it as soon as possible".  They have held the funds deducted from my account for some time now.  Is there anything I could do at this late date from the banking side of things?

EDIT:  Coinbase finally resolved whatever their issue was and the BTC was successfully delivered to my address.  Just over 14 days on this transaction where the first one took the advertised 7 day wait.


texts: Is there a guaranteed hash for every block?

texts:
Possible Duplicate:
  Nonce size - Will it always be big enough?

My question may be misphrased, if so, I'll correct it if you let me know in the comments.

My understanding of mining is that the header is appended with some nonce and that is SHA256'd to get some hash, let's say: 7050a40746c695a220acb99c725ef66b29aa863707b17ba939c8bb1f5ec52b67

This happens until there are X number of consecutive 0's in that hash. Is there a guarantee that there will always be at least X 0's in a row for every block header?


texts: What is the cheapest device that can run a proper bitcoin client?

texts: What is the cheapest hardware device that can run a proper bitcoin client that can participate in the P2P network?


texts: Fine tunning a Rapsberri Pi 2 B+ full 0.12 node

texts:
I'm running a 0.12 Raspnode (raspberri Pi 2 B+ full node)

I've made the full node syncing in a laptop to speed up the process. Then, after moving all the files successfully and starting the full node in the rPi I have noted that it cannot completely sync and it is most of the time a few blocks away from 100% height.

The rPi is running only bitcoind and I've modified with renice the priority to its assigned PID.

I would like to know what are the parameters and values I need to change in order to get a fully synchronized node (100% height).

The following options comes to mind:

Increase the relayfee parameter? (current value
minrelaytxfee=0.00005)
Decrease the memory assigned to the UXTO? (current value
maxmempool=150)
Increase or decrease the prune value? (current is
prune=30000)
Decrease the free-tx limit? (current at limitfreerelay=10)

If you need any additional info feel free to ask for it, I would gladly provide it.

Edit: seems that blocks are being produced faster than the processing power of the Rpi 2 B+ can handle.. so it never gets sync'ed.. its always behind the last block.


texts: Relation between bitcoin address/private keys size and number of characters?

texts:
Bitcoin address is 25 bytes long, address = [Version Byte (1)][Hash 160 (20)][Checksum (4)]  whereas number of characters in this string are 34.
Same with private key:  32-byte have almost 52 characters.
I want to know how can I map number of characters to the size(Bytes) of the bitcoin address(P2PKH)?


texts: Is a bitcoin wallet address the same as your public key?

texts:
The service CoSign shows that to create a multisig wallet you need to provide a Senders Address and Senders Public Key.

I thought that they were the same thing.

What am I missing here?


texts: How to generate these bitcoin addresses?

texts:
For the private key KwaZRh42fdQD4iUN6sy2GtEC5gfSAYXrQgp16KPV4Pxsspi5ChRb, I have the following addresses:

1N7jKvQ1fHezb61eNsGEaF4gcj5sQXhb2m (P2PKH)
14MNoFYWheu7sLkj8urvXCpYEdCuL4m2PH (P2PKH)
3G4BoJsFB6N3Eejtovr8PUnvz4LRDhWmxk (P2SH)
bc1qu7s8s2ga69a9068s85e9vpxh7uvneet292wa5n (P2WPKH)
bc1qxr7lhfgnynvw7dk3e0asw2hsxhdvp4cgp7u0z09stm26gaxqn6zqd9muau (P2WSH)

I am looking for a utility (like the ku utility from https://github.com/richardkiss/pycoin) which can generate all these address given the private key (the ku does not generate the P2WSH address). The utility I am searching for can be in C, C++, Go or Python.


texts: Can I synchronize the blockchain on one computer then transfer the files to another?

texts:
Possible Duplicate:
  Would it be possible to provide a downloadable blockchain that is updated and verified by a mass of people?

If I install and synchronize the official Bitcoin wallet, can I backup/transfer it to another computer, so that when I install Bitcoin wallet on the other computer it doesn't have to spend so much time synchronizing?


texts: Just installed bitcoin, but it won't connect

texts:
Total newbie at bitcoin; long time Linux user.

kubuntu precise 64: My first attempt was just to download it (a slightly older version than the one from the ppa below), untar it and run the executable. That worked fine and it was downloading the data (block chain?). Then I played with some settings and it stopped downloading. I tried a bunch of things with no success.

Among other things, I tried encrypting my wallet and changing the network settings in bitcoin about the time things stopped working.

Then, I deleted the whole tarball, the expanded files, and the .bitcoin directory tree and installed from apt using the instructions at:
Installing Bitcoin-Qt on Ubuntu

It still won't download anything. It says "No block source available ..." and debug.log ends with a ton of messages which say
2014-04-19 13:36:21 connect() to 192.168.1.2:8333 failed after select(): Connection refused.

I went into my Actiontec gateway and saw that a port forwarding rule had been created by uPnP for 192.168.1.2:8333 (that's my notebook address with the port added) that says TCP any -> 8333. I have other rules using this IP - without the port on the address - which forward ports 587, 995, 5192.

When I go to http://www.canyouseeme.org/ , it tells me port 5192 is open (I have another application using that port), but it says "connection refused" for 587, 995, and 8333.

Any clues as to what I'm doing wrong (or what I should be doing instead) would be appreciated.

I can't figure out why the original attempt was working and then stopped.


texts: Bitcoin Core Wallet doesn't accept my passphrase

texts:
I am using Bitcoin Core Wallet .21 and have encrypted my wallet.
When I try to send some coins it asks for the passphrase, which it says is incorrect.
I have only ever used one of two passphrases and I have copied and pasted these each time using notepad (upper and lower cases), but it rejects my passphrase every time. There is nothing wrong with my passphrase, I know my passphrase is correct.
Are there any circumstances under which the wallet would behave like this?
I have used old backup files of my wallet, but get the same message.
Could my wallet be corrupt and if so can it be repaired anyway?


texts: Is it important to have an unencrypted backup of the private key?

texts:
Am I correct that in not having our private keys written in paper or otherwise backed up we are implicitly trusting the wallet developers to keep publishing wallet versions that are capable of reading and deciphering our password-phrase? Nobody else can decypher that phrase and give us access to the bitcoins, correct?

I recently had a bad experience with Mycellium wallet: i lost my Android mobile and the backup of my wallet was in a 1-year-old format (encrypted private key in paper, QR format) that the new desktop app, amazingly, would not recognise. In the meanwhile, I had moved to iPhone, where no Mycelium was available. Eventually i solved the issue by installing Mycelium in a friend's Android. Fortunately, the Android version did recognize the old encryption after scanning the QR with the camera, so I could send the money to another wallet. But this made me realise that we absolutely rely on the developers if we do not keep the private keys written somewhere, unencrypted.

In other words: What happens if a wallet app is discontinued and we find ourselves in 2020 with no way to install that old wallet in the 2020 standard devices?

Or am i missing something here?

Thanks in advance


texts:
I want to cleanup mempool.
I googled and knew -zapwallettxes might clean up mempool.

But when I do the following command, mempool is still loaded.

  ./bitcoind -testnet=3 -server -rest -dbcache=4000 -txindex=1 -rpcbind=0.0.0.0 -rpcallowip=0.0.0.0/0 -printtoconsole -zapwallettxs=2 -rescan

In this situation, even if I restart bitcoind, mempool is dumped to .bitcoin/testnet3/mempool.dat and loaded on startup.

how should I clean up mempool?

Any comments and advices are welcomed :)


texts: Is it possible to spend the unspent outputs of a burn address?

texts: If a burn address is created without a private key to prevent access to the bitcoin there, is not possible to create a transaction which would spend the utxos since there is no private key to sign the transaction?


texts: Can contracts programmed in bitcoins be used to scam merchants?

texts:
I've been learning a lot about bitcoin over the past couple of weeks because I have some interesting ideas for websites and I would like to accept bitcoin as payment.

One of my concerns centers around a somewhat more advanced topic that so far I've only skimmed the surface of. And I cannot find an adequate answer to my question online.

I was reading that it is possible to program simple contracts into bitcoins to ensure that the recipient must spend the coin in a specific way, or within a specific time-frame. Here is simplified video that discusses this as a feature but does not go into the security implications of it.

Could this possibly be used to scam merchants, for instance, by returning the bit coin to the sender after a period of time, or to hold the bitcoins hostage? What tools do merchants have available to protect themselves from this type of abuse?


texts: bitcoin transaction spent but not received

texts:
I hope you are well.
I had a weird transaction which was sent a few days ago,
it now says spent, and received but has not changed my wallet balance, sent it from one exchange to another. When it is spent, does it still have to be credited to your wallet somehow?
https://live.blockcypher.com/btc/tx/bddc545bb6963e964d82f6c80b1b8915f6cc94e228ea848818905fbc396a2a88/

Thanks,
Deon


texts: I have a Paypal account and I don't want to give up my ID card. Where could I buy Bitcoin at a price reasonably close to the exchange rate?


texts: Is there any way to anonymize bitcoins? It doesn't need to be AML-proof, or even completely anonymize their source, I'd just like to obfuscate the source of the bitcoins more effectively than sending them through a chain of addresses that would be easy to follow.


texts: What is the difference between a electrum server type F and P

texts:
As I am trying my first steps with Bitcoin, I ask you to ignore my potential ignorance.

With Electrum I have to choose a server of which there seem to be F and P type servers. What is their difference?


texts: Where can I find the current Ripple version number?

texts:
This page contains several milestones - versions 1,2,3.

How can I find what version is currently running on Ripple.com?


texts: why is bitcoind is missing from /usr/local/bin?

texts:
i just followed the instructions from degreesof zero built, made and installed bitcoind, but bitcoind was missing from the location above. What's wrong with the procedures please? thanks

https://degreesofzero.com/article/building-bitcoind-from-source-on-ubuntu.html
https://degreesofzero.com/article/installing-bitcoind-on-ubuntu.html


texts: Who approves my public key in Bitcoin network?

texts:
In a PKI approach a public key is approved by a Certificate Authority (CA) with a centralized manner. However, since Bitcoin network is a decentralized network, how my public key validity is approved? Or in general is there an approving process of public keys? And if not, it does not cause any security issues? And how a public/private key is generated in the Bitcoin network? And is there a way to prevent a user to generate too many public key in the Bitcoin network?

Thanks


texts: Imagine I've got 100 BTC in my wallet, which I accumulated at different points of time. When spending a fraction of my BTC, e.g. 10 BTC, which one of my 100 BTC do I actually spent? The last one I accumulated (Lifo)? The first one I accumulated (Fifo)?


texts: Why can't I get any miner to work on my PC?

texts: I've tried BFGminer, CGminer, and GUIminer. I'm registered on Slush's Pool. I can't get BFGminer.exe to even open though and GUIminer refuses to connect to Slush's Pool even if I manually put in the new address. I have no idea what I'm doing wrong. Can someone please help me? I'm super new to this if you can't tell.


texts: Are multi-sig M-of-N transactions with N > 3 supported?

texts:
BIP 11 makes M-of-N multi-sig transactions standard --- for N <= 3. What is the current support among miners for the multi-sig transactions with N > 3? (say 3-of-6). Also, BIP 11 states:

  The current Satoshi bitcoin client does not relay or mine transactions with scriptSigs larger than 200 bytes; to accomodate 3-signature transactions, this will be increased to 500 bytes.

Does this still hold, and if yes, does this limit come into play for N > 3 or M > 3? What other obstacles are in the way of standardizing M-of-N for meaningful N?


texts: Check if an address is new or has been used already

texts: Say, I have an address. I can check if it's watch-only by calling validateaddress. Is there such an easy way to check it that address is new or has been used already?


texts: Is there a way to access transactions that happen inside exchanges?

texts:
For example coinbase is an exchange and so, their transactions are done off of the blockchain.

They do however expose an API, which I believe should expose their own coinbase "blockchain" transactions, but this does not seem to be the case from my perspective, or maybe I missed something.

Is there a way to submit a "public" key given to me by an exchange, then have all transaction for that key?

Thanks


texts: which was the purpose of changing the signature of a TX? or it was just a bug before segwit?

texts:
Was there any purpose in changing the signature of a transaction?

Or it was a bug before segregated witness?

Does segregated witness disable some wanted feature?


texts: Conflicting transaction info on Blockchain.info and Jaxx compared to other sources

texts:
I sent a batched transaction with 3 inputs pointing to the same output address. The receiver claims they only received 0.00042 BTC when they should have received a total of 0.00128615 BTC.

She is using the wallet Jaxx which shows the amount received as 0.00042 BTC. Also, the "Estimated BTC Transacted" field on Blockchain.info shows a similar value 0.00042815 BTC.

However, Block Explorer shows the correct value 0.00128615 BTC.

So is this an issue with how I constructed the transaction or is it simply a display issue in both Blockchain.info and Jaxx?

I suspect that maybe the blockchain explorer is confused by the fact that I batched several different inputs to the same output address.


texts: Can I reload my node's config from the command line without restarting the node?

texts: I needed to make some config changes to my node and I'd like to reload the config without stopping the node and then restarting it. Is that possible? I don't see any related RPC commands on the wiki.


texts: Convert list of BTC address(base58) to Ripemd16(base16)

texts: Are there online tool or repositories that can convert multiple base58  (BTC address) to base16 simultaneously?


texts: How does the most recently found critical vulnerability (CVE-2018-17144) work?

texts:
If you were a miner, what are the steps you would take to create the extra (21,000,012.5th) bitcoin?

Where in the source code is this exactly (link)?

Why can't this be done by a non-miner?

Also, which forks are/were vulnerable?


texts: How's the blockchain connected to a Bitcoin Wallet

texts:
I am thinking about buying some bitcoin buy first I want to understand some theoretical aspects of the technology behind it.

The wallet holds my private keys right? But how s me wallet connected to the blockchain?

Thanks,


texts: How do miners select which transactions to include in a block?

texts:
Where and how do you view and select which transactions to include in the block you are trying to create?

Do you look on the blockchain?

Is there some tool that you can use that allows you to see the fees as well?


texts: Are Bitcoins destined to forever increase in value?

texts: The idea of a currency with a limited number of units seems to me to be fundamentally different to existing currencies.  While other currencies are generally based on permanent inflation - more 'units' coming into the currency pool - which causes each unit to be worth less, Bitcoin is based on a fixed number of 'units', never changing.  Does this mean that, as usage increases and time passes, each 'unit' will necessarily be worth more and more and have to be split into smaller and smaller amounts?


texts: Is the HashOfThingToSign (used in signature generation) the same for each input of a transaction or is it different for each input of a transaction?

texts: Does a transaction with 50 inputs have 50 different hashofthingtosign, one for each input, or does it just have one that is used for all the input scripts?


texts: What is learned from listening for inventory messages?

texts:
I am reading the paper Deanonymisation of clients in Bitcoin P2P network [PDF] and have some questions about the fourth step in 'chapter 5: Deanonymization'

I don't understand the emphasized part:

  Step 4) Mapping transactions to entry nodes:
  The attacker listens for
  INVENTORY messages with transaction hashes received over all
  the connections that she established and for each transaction
  T she collects RT — the first q addresses of Bitcoin servers
  that forwarded the INVENTORY message.

What information is learned from these inventory messages? I thought it contains only the transaction hash.

Thank you for your answer. I still have some problems to understand the paper.

Step: I'm sending the GETDADDR-Message to all my Entry-Nodes and they answer with the ADDR-Message which contains the IP addresses of their known Nodes. Now I have my set S with IP addresses.
Step: I'm choosing the subset E of S which contains the ip addresses I want to identify.
Step: Now I want to map new connecting clients to the bitcoin network with their entry-nodes (entry-nodes are elements of E).
Step: This runs parallel to Step 1-3. In this step I'm listening to all INVENTORY-Messages. So you said the INVENTORY-Message contains the transaction hash and an enum. How will be one INVENTORY-Message generated? Will this message generated for every transaction and distributed by broadcast to every known node in the bitcoin network? Who creates this INVENTORY-Message?

Did I correctly understand the first three steps?


texts: If 51% of the hashrate was controlled by bad actors mining invalid blocks, this would become the longest chain. Where do nodes come into the 51% attack? The canonical chain is the longest chain. Is this true even if less than majority of the nodes accept it. I assume that the canonical chain is the one which majority of full nodes accept as the canonical chain, but how does this fut into block height. Would a 51% attack have to be 51% of hash power and nodes or just hash power? If so, why?


texts: In order to mine Bitcoins, one needs to start the bitcoind with "-server" flag and later request from it a getwork to solve. Does the Namecoin client operate in the same way, or is there some specific "namecoind" version one needs to use in order to generate coins? Where can one find the communication protocol for it?


texts: Is it safe to store mnemonic seed in the email if I change random 2 words?

texts: If I store 12 word seed in the email like gmail and my phone as well but change 3rd and 7th words in the seed for example with other bip-39 words and remember it, would that be safe? I can't think of a way for someone to be able to efficiently brute-force it.


texts: I'm looking for an api doc for bitcoin gold on testnet to create, receive and list transactions and accounts. so far I've found this https://bitcoingold.org/testnet-v3/. I'd be thankful if someone shed some light


texts: Bitinstant order was processed, but is not showing in blockchain - did I screw up?

texts:
Did I do something wrong?  Here's the output from the order status page:

Quote ID    a086c30f-04a2-491c-b616-88655077ea68
Event ID    8db863ac-c880-45ae-b96e-ed8ece6e1021
Fees (inclusive)    3.99%%
Amount you paid $500.0 USD
Amount you will receive $480.05 USD
Destination exchange    Bitcoin Address
Destination account 1Jhbh2bezGY9GGPtkUdFixvtfrUpBHU55R

Timestamp   Event ID    Event type
Tue Apr 2 03:08:27 2013 8db863ac-c880-45ae-b96e-ed8ece6e1021    Quote for new transaction
Tue Apr 2 03:40:38 2013 44d23e52-d977-4e1c-825b-2dd9166a72d3    New Order
Tue Apr 2 03:41:49 2013 6bb94555-9e73-4d4f-a9bc-a5cc7e93492d    MTGox Connection Error
Tue Apr 2 03:51:50 2013 980e15b8-6c8a-45af-87b7-0fe9427bd818    Order executed - funds deposited at remote exchange


texts: What is the difference between your address and your public keys

texts: I'm beginning to learn about cryptocurrencies, and I'm having a lot of trouble because some terms are used in different contexts. I know that public keys are generated through a private key. So, are those public keys the addresses? And is it possible to generate more than one address per each private key in wallet? Why?


texts: Copying my Blockchain account to Multibit

texts: Please can you tell me if it is possible to transfer my Blockchain account to Mulitibit.I want to keep my bitcoin address but back it up on Multibit.


texts: Multibit transaction is not being confirmed

texts:
I'm using MultiBit version 0.5.16 (is this classic?)
I am trying to get my bitcoins from Multibit to Electrum, but my transaction doesnt get confirmed. The current transaction is 1mBTC to test it first, so it's not a huge deal if I lose this 1mBTC.
I saw here something similar: Transactions seen by peers, but not confirming
The answer there is that the version is too old.

As MultiBit is no longer supported, is it even possible to update safely, to make sure my transaction will be confirmed?

Thanks in advance,

RitchBit


texts: Is there some means by which I could derive symmetric keys using bitcoin public keys or HD Wallet public key which I have shared with a second user.


texts: Cannot recover wallet from 12 word BIP 39 seed generated by Bread Wallet on iOS

texts:
I still have access to my Bread Wallet on iOS, but I'm trying to test my setup and make sure that I can recover my wallet if for some reason Bread wallet didn't work or if I simply wanted to change wallet providers without having to send my BTC to a new address.

Unfortunately, I haven't been able to successfully "recover" my wallet using the 12-word seed that Bread Wallet generated. I've tried Electrum on macOS, Mycelium on iOS and Copay on iOS. I'm beginning to think that I'm misunderstanding something about the wallet recovery process.

My assumption is that I should be able to use that 12-word seed on any BIP 32 supported wallet, which would then regenerate the private keys and "recover" the UTXO that belongs to key hierarchy.

It definitely seems like bread supports BIP 32 according to their docs here

Does anyone know what I need to do to recover my wallet using my 12-word seed phrase?


texts: When is a new block added to the bitcoin blockchain and is it vulnerable to modifications till then?

texts:
I'm a beginner to Bitcoin and blockchain and from what I understand, one block can hold multiple transactions. Until a block is saturated with the number of transactions it will eventually hold, where are all these transactions stored?
Until a transaction is added to a block whose hash is finally computed and the block added to the blockchain, how are the transactions tamperproof?


texts: How do I restore use of my wallet.dat file, last used in 2013?

texts:
I found a wallet.dat file in my backup folder, which I recall last using in 2013. I'm curious to see what the BTC contents are, which I recall being a really small fraction of BTC.

In any case, is there anything preventing me from just installing Bitcoin Core and replacing the default wallet.dat to recover my backed-up wallet? What is the recommended way to recover such an old wallet.dat file?


texts: How many public keys on an average, do the full nodes store, in order to validate/authenticate the transactions they receive?


texts: Am I Being Prodded By A Bitcoin Mining Scammer?

texts:
I had someone approach me via an insta post, because i found his account and liked a photo. He said he was a bitcoin miner and forex trader in LA california, and asked if i was interested in earning returns daily. We exchanged whatsapp numbers and the conversation below happened (hopefully the pictures upload

After this he led me through the process of downloading and setting up a wallet with the app BlockChain (popular trusted app right?) And showed me where the recieving wallet was. I shared my receiving wallet code with him.
He then had me go on the site www.coinmama.com to buy bitcoin for my wallet.

I told him i would do this tomorrow, and am now trying to think the situation over.

Is there a scam around bitcoin mining that involves this process, and what should I be aware of?

I don’t plan on sharing my sending code to anyone, or my bank account. But if he knows my receiving code, is he planning on scamming all the money?

Many thanks for any replies. I have a nominal education on the exchanges but I have a head in me, and a massive scam detector.


texts: Do wallets break trustless character of cryptocurrency transactions?

texts:
My question is, whether lite wallets and wallets in general break trustless character of cryptocurrency transactions or not?

In case of a lite wallet, even I hold the keys, a blockchain itself is hosted at a server of a wallet creator and I have to trust the wallet creator that he provides me, resp. my lite wallet, with accurate information from that blockchain. For instance, I have to trust him, that he will not push to my UI fake transaction to get some advantage at some point.

Also I have to trust that the wallet do not let me hiddenly sign a money transaction to different address compare to what is shown in its UI. However this last example could be an issue in case of core wallets also, as far as I don't inspect the programming code of the wallet and don't build that code on my local machine by myself. I simply have to trust developers of the wallet (both core and lite) that they don't cheat.

From my point of view, at the moment, even a blockchain is trustless, we still have to trust (in most the cases) somebody - in the above example to developers of wallets.


texts: What is stopping a Taproot spend following old Taproot rules (initially treated as anyone-can-spend) pre-activation creating a re-org post activation?

texts:
This question is similar to this Signet question on Signet nodes enforcing different Taproot rules (old and new) pre mainnet activation. Instead it is regarding how a valid Taproot spend on mainnet according to old Taproot rules (that were never enforced on mainnet) initially treated as anyone-can-spend by the network, doesn't create a massive re-org when new Taproot rules are activated on mainnet.
For example, let's say I created a UTXO encumbered by Taproot rules as they were specified in July 2020 (before the Taproot BIPs were changed from a squaredness tiebreaker for the R point to an evenness tiebreaker). I managed to spend from this UTXO by following the Taproot rules as they were specified in July 2020. Of course Taproot isn't activated at all so all nodes would have treated my transaction as an anyone-can-spend and my transaction would easily have made it into a block. Now let's say in June 2021 Taproot is activated on mainnet with the new rules as they were specified post August 2020 (with the evenness tiebreaker). What is stopping my transaction from failing verification against the new Taproot rules and creating a massive re-org back to the block that contains my transaction?


texts: I've forgotten the password to my wallet but can still access it, can I get my Bitcoins out?

texts:
I have forgotten the password that I created for my wallet. I can, however, open my bitcoin-qt software successfully and see my transactions etc.

I know I can't recover or brute-force my password. Can I move my Bitcoins from this wallet to a new wallet (where I'll take better care of my password)? How?


texts: Based on this, it seems like it did http://blockchain.info/p2sh but it seems I can't find a definitive answer.


texts: How much time to re-mine blockchain at current hashpower?

texts:
It has taken 9 and half years to mine all blocks averaging 1 per 10 minutes.

How long would it take to re-mine all current blocks at current hashing power?


texts: Is CheckSequenceVerify only a stop-gap measure?

texts:
The Lightning Paper v0.5.9.2 says that CSV "would permit further
abilities, including allowing a stop-gap solution before a more permanent
solution for resolving transaction malleability. A future version of this
paper will include proposed solutions."

This means that Thunder is still vulnerable to malleability attacks since it relies on CSV as a solution.

Since the Thunder readme does not mention malleability fixes as a TODO point, I guess the Thunder authors considers it fixed.

The cited Lightning draft is from January.


texts: What if periodic redistribution of bitcoin had been built in the protocol/wallets?

texts:
Imagine if there was a Bitcoin-like currency that had periodic wealth redistribution built in the protocol. For example, every month you and every other wallet would pay 20% of their bitcoin evenly to everybody else.

I know the idea has a lot of technical challenges/flaws, but on principle what do you think of the idea? Would it incentivize more transactions and economic activity?

Early miners/users own most of the bitcoin supply and there is not much incentive for normies to get involved because a small number of whales are controlling the network and there is no way to get access to meaningful sums of bitcoin.

It's just an idea -- what do you think?


texts: Is tighting inputs to specific outputs possible within one transaction?

texts:
For convenience purposes let's say I need to make these payments (and let's pretend that tx fees do not exist):

Address A: 1 BTC
Address B: 2 BTC
Address C: 3 BTC

My balance is 6 BTC that consists of these spendable inputs:

Tx1: 0.5 BTC
Tx2: 0.5 BTC
Tx3: 0.5 BTC
Tx4: 4.5 BTC

It's easy now to create a raw tx using createrawtransaction and since the inputs' sum matches the outputs' sum (and we pretend there are no tx fees whatsoever) everything will work as expected.

But what if I must (for business purposes) use specific inputs for each output?

An example would be:

Address A will be paid inputs: Tx1 and Tx3
Address B and Address C will be paid by inputs: Tx2 and Tx4

These will be batch payments and I plan to be sending batches of 20-30 logical payments per raw tx, so I would like to avoid breaking down the raw tx into small, atomic (per-logical-payments) transactions.

Is that even possible with raw transactions?


texts: What is DrahtBot on Bitcoin Core pull requests?

texts: I see DrahtBot on a lot of Bitcoin Core pull requests (PRs) e.g. here. What does it do? Is it open source?


texts:
So, I want to create a cold storage bitcoin address to store incoming BTCs from donations and payments (I'm a freelance developer so I'm getting used being payed with BTC). Since this address has to be spread among lots of different people, I can't change it so frequently, it's like my gpg public key, it would be a pain to change this address.

This means that I need a way to spend the BTCs stored on my paper wallet in a safe but fast way. The most obvious solution is using the Blockchain.info app, scanning the private key when required (I do not care about privacy in that case, I know I can be traced and such, but I'm ok that change goes back to the same paper wallet).

My question is, how much should I be worried about my private key being compromised by scanning it with my phone? Are there any known reports about this happening? Are there same safe ROMs that could prevent this?

If this is a serious concern, how can I spend the BTCs on my paper wallet in a same way whitout changing the public address everytime?


texts: What exactly is collecting transactions?

texts:
From this post, I get some sense of how bitcoin works:

  What exactly is Mining?

Some dots I can't connect are related to how collecting transaction works:

Where to collect? Are these collected transactions always be
authentic (i.e. the user intended to perform such transaction with
promised transaction fees.)?
I can't see how a block ensures the collected transactions are
faithfully represented. can't they be distort by a miner?

Thank you for shedding some lights.


texts: Is there a signature format, or cryptography has *only one* possible S value?

texts:
EDIT: This question is not specific to Bitcoin.  It's applicable to any other crypto currency that is interested in using a different signature scheme than Bitcoin or the QT reference client.  One reason for this is to reduce complexity (and bugs) in the protocol.

My understanding of malleable transactions in Bitcoin is that two different values are supported for "S" when a signature is validated.

The solution for this is to ensure that S is less than the following

  X9ECParameters ecParams = Org.BouncyCastle.Asn1.Sec.SecNamedCurves.GetByName("secp256k1");

  HALF_CURVE_ORDER = ecParams.N.ShiftRight(1);

Given the plethora of signature mechanisms available to crypto-currency, what algorithms or signature approaches are not vulnerable to Malleable Transactions?

e.g.  What if...

A different curve was selected instead of secp256k1?
A different signature mechanism was chosen?
A different approach entirely, such as a blind HMAC was used to sign transactions?

I'm interested in answers that describe both solutions that are broken, and those that would prevent malleable transactions from ever occurring.

My goal is to flush out an algorithm that produces consistent results with minimal complexity for implementors.  (in other words, even Mt Gox would get it right)


texts: Can someone explain how this person hacked bitcoin?

texts:
I'm trying to fill a few gaps in my understanding how this transaction happened!

It all started with this article

In short, some vigilante/miner was able to scoop up all of the BCH sitting in segwit addresses (namely, the ones for which the public keys were revealed by the owners spending BTC from the same addresses.

See this Transaction that was created, miner
Bitcoin Cash Block Explorer

Step by Step Breakdown

Miner scoops public key of this address 3P9dyU9ga3aJorHAUqKBFCX2NdyuHEVgx1
(this is a P2SH P2WPKH address see this bitcoin block explorer )

Question: what is that public key? Do you see any keys?
("3" is a multisig address & requires 3 addresses, so there must be 3 public keys, right?)
The article didn't explain how and what raw transaction he created using only public keys.
This is the most frustrating part. The article claims that miner created a segwit node and mined on top of that.

How is that even possible? (Bcash doesnt have segwit activated. However even if he mined using his segwit node, his node will not allow him to create a valid transaction because segwit requires a witness or sign with private key of public key of address 3P9dyU9ga3aJorHAUqKBFCX2NdyuHEVgx1.)

However, this article claims

The miner just created a scriptsig (the article didn't explain what "apply a particular hash" means).
Now it's easy, the miner just has to assign a BCH output (address starting with 1)
it gets even more stupid. The article says after making that raw transaction he mined it ..... without broadcasting it. How does that work?

3.1 If you are not broadcasting it then whats the point? How will that transaction go through to the new address/wallet created by miner (in this case 1C4TafndKYFoGkeoHfQAWkZzEYLum31txf)?

3.2 If the miner is mining his own block and then not broadcasting it, wouldn't it get orphaned? So what is going on here?


texts: Where is the incentive to update the Merkle root

texts:
I've just read the following question
Does block size effect Miner's Hashing speed?

and it appears that the answer is no - since miners only need to hash the Merkle root.

However, updating the Merkle root will take a lot of CPU power if/when bitcoin transactions reach a rate of 4000 tps.

What is the incentive for miners/pools to expend effort maintaining the merkle root at this rate?  Obviously if they do not expend this effort the result will be an ever growing backlog of unverified transactions.


texts: How to decode very huge (!) raw transactions?

texts:
I'm parsing the blockchain to extract certain information I need for a script.

One thing I do is parsing transactions. What I do is:

getrawtransaction <tx>
decoderawtransaction <rawtx>

This works on most of the transactions (>99%) but some are very huge and the bitcoin client cant handle them. I wonder what else can handle them if not bitcoind itself. The error I get in bitcoind:

TX decode failed (code -22)

Thats because it cant accept very long arguments. My ruby script dies with

Arguement list too long - (Errno::E2BIG)

How to decode such transactions? Here are some examples:

2f50fdf7adbf58e91d738869948f4b191eb3cafa016c6df7e9182c06e4513852
e7229316b5a5b1f53382ec5a526b842dda2ca96bc891cd02d397a52c4a84dba0
540359af779a510828f0afd3c88562b62c37d0e4eeccb08104a167a3600f7956

Thanks.

Update: I just tried to paste the rawtransaction to this online parser and this one decodes that transaction without any problems. How is that possible programmatically?


texts: After a month, BTC sent from trezor to coinbase never received after 5000 confirmations

texts:
On 12/21, I sent 0.75 BTC from Trezor to a valid BTC Coinbase address. The transaction is stuck. It has over 5000 confirmations but Coinbase.com never received the BTC. Both Trezor and Coinbase have been of zero help. Can someone please help me?

Here is the link of the transaction

Thank you!


texts:
How can I create 50,000+ bitcoin addresses in my wallet?

I will need more than 50,000+ addresses in my main wallet. I use Bitcoin Armory, Bitcoin-Qt and I'm just trying out Blockchain.info.

Is it possible to generate 50,000+ addresses in my wallet? If I use bBitcoin-Qt  or Armory I can create addresses manually, but I need something to automate this system.

Is it possible? Is there some API for this?


texts: What underlying data structure is used to store wallet address on the blockchain?

texts:
I'm curious how websites like bitref.com can determine the balance of a bitcoin wallet very quickly.

I understand that the blockchain stores every single transaction across the thousands of blocks, so it's possible to reconstruct the balance of any wallet with this ledger. But wouldn't it take a long time to scan all these transactions?

Instead, does the blockchain actually store every single address in some sort of map? Would this also contain the balance of each address? If so, I can't find a website where I could view all the addresses on the blockchain. Does anyone know where I can find that?


texts: what is the lowest amount i can transfer using bitcoin ? can i send 0 satoshis?

texts:
i was looking at this bitcoin tx

https://blockchain.info/tx/b4ea693a9d2d7e32b66777964fce13da302bed024bd9fd4651919da650fb1c40

where

Inputs and Outputs
Total Input 0.00003 BTC
Total Output    0 BTC
Fees    0.00003 BTC
Fee per byte    12.821 sat/B
Fee per weight unit 3.205 sat/WU
Estimated BTC Transacted    0 BTC

the user has set total output as 0 BTC so in short all input is given as fee.

Is this common practice or bug ?


texts: Any advice for attorney accepting bitcoin?

texts: I just started accepting bitcoin for potentially anonymous legal consultations.  Does anyone out there have any advice for how to accomplish anonymous yet legally confidential attorney relations?  I firmly believe in attorney-client privilege but know that a court order can force disclosure -- making the reality of confidentiality a question of court order.


texts: Does bitcoin validate transactions against the mempool?

texts:
I want to know whether or not bitcoin checks for the existence of transactions in the mempool as one of the many validation rules it performs for new blocks.

If a transaction most exist in the mempool when a new block is received, how is this rule applied for blocks received during block synchronisation with peers, considering transactions in older blocks will not exist in the mempool?


texts: Is the hash of the previous block included in the block header?

texts:
What the title says above, but for more clarification I am asking whether the hash of the previous block header is part of what is hashed to create the header of the new block? Like what are all the components that are hashed together to get the block header hash?

Thanks.


texts:
I am still attempting to complete the receipt of a payment in BitCoin-QT. The initial synchronization is beginning to be a hassle so I thought I might get my key and transfer my wallet to Blockchain.info.

I followed the directions in How do I export my private keys from my Bitcoin-QT?
to get my private key. All I get back for dumpprivkey[] is:

  Invalid Bitcoin address (code -5).

I thought maybe I had the wrong address so I entered listreceivedbyaddress 0 true.

There are only a couple of addresses since I have a new wallet. All of the addresses returned the same "Invalid Bitcoin address" message. What is going on? I know one of these addresses was used to give to an exchange for my new BC. Is it simply because my blockchain is incomplete and the transaction is incomplete?


texts: In the app "Bitcoin wallet" from " bitcoin wallet developers" you can choose to backup your wallet. It will store this backup on your sd-card. But how can you restore it on another phone? I saved the backup on my PC and send it to my other phone, but he can't open the file and I don't know how to restore the wallet.


texts: Serialized Block doesn't have all the fields of a Block

texts:
bitcoin-cli getblock 000000000003b9c88b8a4bf0bac7059913381bba300cdfddffc54a3d8c6e8105 false

This command will give block related data in the form of Hex. This Serialized data doesn't contain certain fields like confirmations, chainwork nextblockhash. Is there any reason for this?


texts: What are the costs of cryptocurrency fraud?

texts:
I have heard many claims that transaction volumes can be "faked" for cryptocurrencies, but I am skeptical about how this is possible. I want someone to walk me through the math describing what you need to believe in order to make money by boosting transaction volumes.

1) First, assume a constant velocity of money but a positive transaction cost t. Suppose t is relatively high. Is it possible to make money as a market manipulator? What would these profits be? Is there a point where t prevents you from making money as a manipulator?

2) Second, assume it is possible that coin velocity declines because momentum-driven speculators enter on news that prices rose due to "fake" transaction volumes from the market manipulator. What is the required velocity change as a function of the transaction cost t?

I am not sure whether I understand the math here, but I suspect that coin manipulation is possible. However, there is a point where t exceeds the possible change in coin velocity, which creates a limit to market manipulation.


texts:
I've configured the large (8x) GPU image on AWS at 2.60/hour. I ran it goes few hours after setup and mined nothing.

This was my first foray into mining.

Given this setup, am I better placed to join a pool? And what pool should I join? (Some pools reward the biggest contributor and others payout shares.)


texts:
BIP91 forces BIP141 signaling, the blocks that do not signal BIP141 will be rejected by those who are pro-BIP91.
The minority of miners that do not support BIP91 (and by extension BIP141), could start rejecting blocks of those who are signaling BIP141, thereby creating a different chain.
Is that a possibility both in theory and in practice?


texts: Bitcoin -qt or Bitcoind - which one to use for building a trading website?

texts:
I'm building a Bitcoin website that will be fully based on wallet services and also trading. I learnt through my searching in the web that Bitcoin qt is the friendly UI version of the software while Bitcoind is just the headless daemon, but same core functionalities.

Now I was given a project to build a website that provide wallets and exchange service for users and also with trading application. Which of this two software will be the best to download? The website will be on VPS account with Godaddy.

Thanks to Nate and Pieter for warning on the security. I understand the risk but I will still love to have answer to that question.


texts:
Let's assume that I have small crypto exchange site called "MyExchangeWebsite".
It works like this: user creates ETH-BTC order, specifies his BTC address and sends ETH to my ETH address, I exchange it on Bitfinex and send resulting BTC to the specified user's address. Site is very simple and doesn't have accounts (non-custodial model).
By some reason user made a one-character typo in his BTC address for ETH-BTC order and it's impossible now to withdraw BTC, as checksum is bad. User noticed that he didn't receive BTC and contacts me to provide right address.

Am I right in my understanding that it's safe to change user's address and it's impossible to scam MyExchangeWebsite by third person who knows about typo and user's order details?
If it's not one-character, but N-characters typo. At what N it becomes unsafe to change N characters in user's address?
What is the best way to make sure that I'm in contact with the real order creator?


texts:
Let’s suppose i buy some bitcoin on an exchange platform (kraken for example).
This platform Ask me some informations (id card).
Now, if i transfer all my bitcoins to a physical wallet, then to another one wallet: is there a way for the platform owner to say: i Know The identity of this wallet owner.
Please note i do not want to do something nasty. It is just for understanding.
Thanks


texts: Cannot get the same address format from zeroMQ and Bitcoin Core

texts:
I use nodejs with this npm library:

const bitcoinjs = require('bitcoinjs-lib');  // version "^5.1.6"

I received a rawTx from zeroMq, then extract it:

const tx = bitcoinjs.Transaction.fromHex(rawTx);

the txID is 8dba72608cbfca197b55d86aae2817d11f829b9361eb421fb005616f48ce8401

if I take the first output:

let output = tx.outs[0];

then I try to get the address:

const scriptBuffer = Buffer.from(output.script);
const address = bitcoinjs.address.fromOutputScript(scriptBuffer);

I get:

  37XE9EYzix7S42fLMxutrNaPfDbCccLhiT

But from bitcoin core I get:

  2My5SCyV2LQcnFpHt36XmUKZesZoNRQRPa5

My question: how do I convert the address to the same format as bitcoin core ?


texts: Miner modifies unconfirmed transactions and put it into the block

texts:
Is is possible that a miner modified a unconfirmed transaction (like changing the output of transaction to the miner himself) and put it into the local block, and after 10 mins the miner luckily solved the PoW, putting the block on the chain and broadcast it to others?

If a transaction was modified and finally linked onto the chain, how others check whether the tx was valid or not? (others only check if PoW answer was right or wrong, not checking tx, am I right?)

And If modified tx was on chain, how do affected people recover their assets from the loss in modified tx (in which output was modified to the miner himself)?
Could they ask to revoke the block or how could they do?

Thanks


texts: In Bitcoin, what happens if there is no viable nonce?

texts:
I'm assuming SHA is perfectly uniform.
In bitcoin, there are $2^{32}$ possible inputs per block, which are mapped to $2^{256}$ possible outputs. So there is a $1/2^{224}$ chance that any randomly picked 256-bit string is a possible output hash of one of the possible nonce values. So that means there are $2^{32}$ possible output 256-bit strings. In other words, a 1-to-1 mapping from nonce to output is very likely.
The $2^{32}$ possible outputs are distributed uniformly. So that means half of them have a 0 in the first bit, and the other half have a 1. That means there are $2^{31}$ possible outputs with a 0 in the first bit. Each leading 0 bit reduces the number possible outputs by half. So with 76 leading zero bits (the current difficulty), there's a $1/2^{44}$ chance that there exists a acceptable nonce.
Another way to see it is that there is a $1/2^{76}$ chance that any nonce is accepted. But there are $2^{32}$ possible nonce values. So the probability that none of those nonces are acceptable would be $(1-1/2^{76})^{2^{32}}$ which equals $1/2^{44}$.
Either way you look at it, there's an extremely small chance that any 32-bit nonce will work.
So what happens if there are no acceptable nonces?


texts: How can one extract an address balance at a specific height?

texts:
Is it possible to view the balance of an address at a specific height, without using any external web api?

Could it perhaps be done using bx or the Bitcoin client API?


texts: How to start programming your own Bitcoin client?

texts: I want to develop my own Bitcoin client in a language that is not yet supported. Are there any resources that can be referenced to help me, or any other future developer with the task, or is the source code for the official client (and other clients) the only thing to go by? Has anyone made some cohesive documentation of the Bitcoin protocol, that if followed would guarantee the finished client would be able to operate along with the existing clients?


texts: Where can I look to see a revealed public key?

texts: I've read that pub keys aren't exposed until they're spent from.  Can someone show me an example of a transaction prior to the pub key being exposed and then after?  Where do i look?


texts: Where is the AES-256 key/ IV pair stored in wallet.dat file?

texts: I have created an encrypted bitcoin file. I know the password and I see the mkey in the hex dump. I would like to know where the AES key / IV pair are located in the wallet.dat file?


texts: Is having a copy of my wallet.dat file enough to recover lost Bitcoin?

texts:
I have been using Bitcoin-qt to mine bitcoin. I am a little worried about losing my coins on my computer, so I have made a backup of my wallet.dat file and put it somewhere safe.

Is this the right way to keep my coins safe from my computer crashing? Am I completely on the wrong track? What else might I need? I haven't encrypted my wallet.


texts: Lightning Wallet (lnd) - Export Private/Public Keys?

texts:
Is it possible to export keys from a Lightning Wallet, specifically lnd? I started opening my first channels, and most of what I'm reading says that you want to monitor your wallet balance (in the absence of watchtowers, which aren't implemented yet). I was looking to get the public key for my Lightning wallet so I can have a watching-only copy. I suppose I can do that by just having the address with some wallets, but it would also be nice to have the raw private keys for backup.

I know how to get the keys out of a normal bitcoin wallet, but not sure how to do that with lnd, since they're stored in wallet.db.


texts: TX Validation: Can a miner choose specific tx to validate from mempool?

texts:
I have made two TXs few days back and they remain unconfirmed so far.
Can I be a bitcoin miner and validate them myself?
And what happens if it remains as it is?
There are some big amount of utxo locked in those tx.
Thanks in advance.


texts: Are pools share rewards equivalent to the power/hash rate input of a mining machine

texts: I would like to know if I enter a pool and I input a given amount of Hash rate, is my share reward equivalent to my Hash rate input


texts: Fees for Multisig Addreses Twice as High as Standard Address?

texts:
Based on my research the cost to transfer funds from a 2/3 MultiSig address to any other address (be it a standard or MultiSig address) is approx. 2 x the cost of transferring funds from a standard address to another address since it consumes approx. 2 x the amount of data (147 bytes vs. 295 bytes) (pretty costly!).
A single output is roughly 34 bytes per output regardless of whether the output represents a standard address or multisig address. Is this correct? In other words, the higher price for a MultiSig only matters when it's being used as the input of a transaction, not the output?
If so, does the data size grow linearly with each additional signature? (i.e, what would be the approx. number of bytes for a 2/2 and a 3/4 MultiSig transaction)?
Thanks


texts: Blockr.io - how to decode a transaction via API

texts:
I've read through the documentation on decoding a transaction via API on Blockr:

http://blockr.io/documentation/api

I have the hex code, which correctly decodes on http://blockr.io/tx/push

Thus it can decode.

Please show me where I am going wrong trying to follow the API documentation which states:

My attempt includes adding the path to postman (as a post):

http://btc.blockr.io/api/v1/tx/decode?hex=010000000117f244eba4...


texts: Why does this return an ssl error when using pybitcointools?

texts:
Really confused as to why this error persists.
I have upgraded pip ( I believe)
And have installed pybitcointools...