texts: Can one tell which way the market goes from sell and buy orders?

texts:
Among other open access (i.e. public) data available in exchange API's are the open order books. They are given on exchange websites sorted by coin value. Is there a way to tell which way the market is going, as in up or down for a given pair, from sell and buy order books?
If the only way is by taking two snapshots of these data, would that be a good way to do it, or is there a better way, using public API's?


texts: Security and recover issues in blockchain.info wallet

texts:
I have a wallet in blockchain.info. I'm quite new to bitcoin and would be happy if someone would explain me :

(1) what should I do in order to save my bitcoins if something happens to blockchain.info. Can I access to my bitcoin with ANY wallet, if I know my address and private key, or if I know my address and password? if so, how do I find my private key?

(2) I've also noticed a backup option in blockchain.info wallet. If I use it, can I get access to my bitcoins with this backup, with every wallet? should I save a new backup after every transmission of bitcoins from my blockchain.info wallet?

(3) Wha'ts the best way to prevent a situation where a malware "reads" my password when I enter it?

Thanks!


texts: What does this mean? RPC_CLIENT_NOT_CONNECTED = -9, // Bitcoin is not connected

texts:
I'm building a service which does some automatic Bitcoin transactions and balance checking. In the system I now created some logging, which told me that my bitcoind daemon (running on Ubuntu 14.04 server) gave an error code -9 when running the following command bitcoind getbalance. In the bitcoind source I found error code 9 described as:

RPC_CLIENT_NOT_CONNECTED = -9, // Bitcoin is not connected

About this I have 3 simple questions:

First: what does this mean? I'm running the command on the same machine where the daemon is running, so no remote connection needed.
Secondly; how can this happen? Why does a stable running bitcoind daemon suddenly gets disconnected?
And most importantly; how can I prevent this from happening?

All tips are welcome!


texts: safely delete the blockchain from .bitcoin directory

texts: I have bitcoind installed and I'd like to free up space by deleting the blockchain from my .bitcoin directory. What set of files and directories should I delete such that the next time I start bitcoind it will recover gracefully by downloading the blockchain again?


texts: So, I installed Bitcoin miner from an app store already built into my HP computer. I've downloading blockchain to keep my bitcoin wallet but havent really used it all that much to know when im recieving this payout. I went to pay out address and put in my wallet code at the bottom and of course my barcode came up but i havent gotten any kind if confirmation yet or any enter button after entering my address.. Is there anyway i can know that the satoshis I am mining are going in my wallet? Please help


texts: How to identify a transaction in Bitcoin

texts:
I have a webshop, and I would accept Bitcoin payment. I have a Bitcoin address where I accept payment.
Is it a procedure to pass an id or ask an id to / from the transaction? When I query the received transactions I nee to know to which program it was bought. Who is the user, what is its email.
At other payment providers that create a paymentId and return it to the shop, and that paymentId will be also in the payment I can fetch later. How could it work with Bitcoin?


texts: How do I reduce the loglevel on rippled?

texts: By default, rippled seems to log at the NFO level, which spits out many megabytes of log files each day. How do I reduce this level? According to the Ripple wiki, we can edit pass arguments to rippled when starting it, or edit the configuration file via [rpc_startup], but neither of these methods had any effect for me (on v0.23.0).


texts: Is it possible to spend bitcoins from private key 0?

texts:
In [1]: from bitcoin import *

In [2]: privtoaddr(0)
Out[2]: '16QaFeudRUt8NYy2yzjm3BMvG4xBbAsBFM'

On blockchain.info, there is 0.01 BTC unspent in this address. Is it possible to spend the bitcoins? If not, why?


texts: Are there any downsides to banning node crawlers?

texts:
There are multiple entities and open-source software that crawl the Bitcoin P2P network to discover and monitor nodes for various purposes (statistics, surveys, academic papers etc.)
Some of those I am aware of:

btc_node_scanner
dsn.tm.kit.edu
nodes.multiven.io
bitnodes.earn.com
bitnodes.io

Banning such nodes would free my connection slots for real useful nodes that actually provide consensus sourcing.
But, is there any downside to banning such crawler nodes?

Also, what about banning btc-seeder nodes? Would that affect negatively the health of the P2P network?

I think the ideal answer could provide the effects to two cases:

banning done by one user and how they are affected
banning done by a grand/meaningful number of users and how the overall network would be affected

Thank you


texts: how can i get rid of a zombie channel in LND?

texts:
My LN-Node: 023bf99414b3e93ab7463ce60f44cd691f8be3c1ae33a2015fe784c85c36e770cf
bitcoind 0.17.1 // LND 0.5.2-beta commit=v0.5.2-beta-rc7

Channel: 598078250466476032

Problem: lncli feereport returns:
 rpc error: code = Unknown desc = no policy for outgoing channel

edit:
more of the same?
lncli fwdinghistory returns:

{
    "forwarding_events": [
    ],
    "last_offset_index": 0
}

related?
trying to edit a recent channels policy..

"channel_id": "620981077780267008",
    "chan_point": "e388cce2698c0406985af2fce27ee47c5f02b04e8fbda0523975b71246e66d77:0",
    "last_update": 1551629972,
    "node1_pub": "023bf99414b3e93ab7463ce60f44cd691f8be3c1ae33a2015fe784c85c36e770cf",
    "node2_pub":
 "03efccf2c383d7bf340da9a3f02e2c23104a0e4fe8ac1a880c8e2dc92fbdacd9df",
    "capacity": "500000",
    "node1_policy": {
        "time_lock_delta": 144,
        "min_htlc": "0",
        "fee_base_msat": "1000",
        "fee_rate_milli_msat": "1",
        "disabled": false
    },
    "node2_policy": {
        "time_lock_delta": 14,
        "min_htlc": "1000",
        "fee_base_msat": "485",
        "fee_rate_milli_msat": "1",
        "disabled": false

lncli updatechanpolicy --base_fee_msat 419 --fee_rate 0.000001 --time_lock_delta 14 --chan_point e388cce2698c0406985af2fce27ee47c5f02b04e8fbda0523975b71246e66d77:0

[lncli] rpc error: code = Unknown desc = Channel from self node has no policy


texts: How were the first 169 blocks mined if no transactions occured before block 170?

texts: My guess is that there is that you are able to leave the transaction parameter empty, but I have not been able to find confirmation.


texts: How to derive the private key associated with a Coinbase multi-sig vault address

texts:
When I created a multi-sig vault on Coinbase, I obtained:

A master public key in BIP32 extended format, of depth 0, parent fingerprint 00000000 and child index 0.
A private key in WIF format ("user seed"), which I don't know if it has been hardened, derived from a public key, nor the depth or index.

I am trying to prove ownership of an address derived from the master public key at index 14. So using bip32.org I have been able to derive the public key in BIP32 extended format at index m/14, that corresponds exactly to the address for which I need to prove ownership.

My objective now is therefore to derive the private key for which the address is the same as the address of the derived public key at index m/14, based on the information I have. If possible with pybitcointools.

I tried asking a more general question here, but it was a good case of XY problem (I asked about my attempted solution rather than actual problem).


texts: I mine at Eligius pool and sometimes a new transaction appears in my bitcoin client labeled 'Generated'. Why does this happen? Do I also get these 'Generated' bitcoins if I use an e-wallet's address for mining?


texts: i lost my password and 12 word can i recover my password?

texts: I am new user  i crate my bitcoin wallet on zebpay   then my friend tell me  to creat bitcoin wallet on blockchain.info   as he suggest me i creat new bitcoine wallet  and send  40000 INR in new wallet after a week i try to open my wallet but  i forgot my password  when i try to recover it  system says to 12 word  but i have no knowledge about 12 word   now how i recover my money  please anybody help me


texts:
http://lightning-wallet.com/using-lightning-wallet#receiving-lightning-funds

This link states that:

  Nothing can be received once a fresh channel is created since a room for incoming funds should be first made by spending.
  A payment channel can be thought of as a full bottle of water: in order to pour something in one first has to pour something out.

If correct, how can you ever receive anything?


texts:
Error Message at server 2 / 3 (peers trying to connect to main server)

root@ubuntu:~/dogequark/src# cat ~/.dogequark/dogequark.cterminate called after throwing an instance of 'std::runtime_error'
      what():  CreateNewBlock() : ConnectBlock failed

This is what happen when I try run my daemon at another server, I try run at another few server same issue.

This is my main server node debug.log

1 addresses found from DNS seeds
dnsseed thread exit
addcon thread start
msghand thread start
dumpaddr thread start
init message: Done loading
GetMyExternalIP() received [198.204.236.50] 198.204.236.50:0
GetMyExternalIP() returned 198.204.236.50
AddLocal(198.204.236.50:8008,4)
accepted connection 198.204.228.10:57360
send version message: version 70001, blocks=0, us=198.204.236.50:8008, them=198.204.228.10:57360, peer=198.204.228.10:57360
Added time data, samples 2, offset -11 (+0 minutes)
Added 198.204.228.10:8008 from 198.204.228.10: 0 tried, 2 new
Moving 198.204.228.10:8008 to tried
receive version message: version 70001, blocks=0, us=198.204.236.50:8008, them=198.204.228.10:8008, peer=198.204.228.10:57360
getblocks -1 to 0000000000000000000000000000000000000000000000000000000000000000 limit 500
socket closed
disconnecting node 198.204.228.10:57360
trying connection 198.204.228.10:8008 lastseen=0.0hrs
connect() failed after select(): Connection refused
trying connection 198.204.228.10:8008 lastseen=0.0hrs
connect() failed after select(): Connection refused
trying connection 198.204.228.10:8008 lastseen=0.0hrs
connect() failed after select(): Connection refused
trying connection 198.204.228.10:8008 lastseen=0.0hrs
connect() failed after select(): Connection refused

My conf file for main server

rpcuser=username
rpcpassword=password
rpcallowip=*
port=8008
rpcport=9008
listen=1
server=1
daemon=1
gen=0

My conf file for alternate server

rpcuser=username
rpcpassword=password
rpcallowip=*
port=8008
rpcport=9008
listen=1
server=1
daemon=1
gen=1
addnode=198.204.236.50

Hope to get some help, I trying to learn how to launch my own coin and practice my cpp coding.


texts: How long does it take for a transaction to be included in a block?

texts:
If I understand it correctly, a transaction must be included in a block and broadcasted to other nodes before the transaction is accepted as valid. But it takes time to create such a block which only miners create.

How much time does it take before the transaction is registered as valid?


texts:
If you can please me more.

bitcoin/src/test/miner_tests.cpp

Here is an example code.

https://github.com/bitcoin/bitcoin/blob/master/src/test/miner_tests.cpp#L43-L72


texts: what prevents from address generation to accidentally use an existing one?

texts: How come bitcoin addresses are created in a split second on my wallet app? what promises the address doesn't override a current existing address? I guess the same question applies for a private key...


texts: Can Cryptocoins be spent through payment services?

texts: can Cryptocoins be spent through payment systems like Paypal? i.e. instead of linking to  a credit card, linking to the wallet address. or do they have to explicitly accept bitcoins/crytpocoins?


texts: How to get an average bitcoin to USD price from different sources

texts:
I created a very simple php function to get the current price of bitcoin to USD here,

    //get from coin market
$getCoinMarketPrice = getPrice('https://api.coinmarketcap.com/v1/ticker/bitcoin/?convert=USD');
$btcValues[1]= $getCoinMarketPrice[0]['price_usd'];
//get from bitstamp
//
$getBitstampPrice = getPrice('https://www.bitstamp.net/api/v2/ticker/btcusd/');
$btcValues[2] = $getBitstampPrice['last'];
//get from blockchain

$getBlockchainPrice = getPrice('https://blockchain.info/ticker');
$btcValues[3] = $getBlockchainPrice['USD']['last'];

//get from cytptonator
$getCtyptonatorPrice = getPrice('https://api.cryptonator.com/api/ticker/btc-usd');
$btcValues[4] = $getCtyptonatorPrice['ticker']['price'];

$total=0;
for ($i=0; $i < count($btcValues[$i]); $i++) {
    $total +=$btcValues[$i];
}
$average = $total/count($btcValues[$i]);
return $average;

This Code here above will get bitcoin prices from different sources and add them together and divide them by the total number of the source it got them from e.g

  bitcoin from source from blockchain and bitpay and Xapo are
  6000,5689,5997 respectively, so to get the average result we add these
  results and divide them by 3.

This code is working perfectly, but it's making my app very slow and sometimes Timeout.
Please I need it to be refined and better than this , Thanks


texts: Can Bitcoin and Bitcoin Cash potentially have the same address?

texts: Because Bitcoin Cash is forked from Bitcoin, what happens if two separate users create a wallet, could their address potentially be the same? Let's call that address xyz. Then if someone sends money to xyz which blockchain would it go to?


texts: How to Install bitcoind 0.7.2 Server on Ubuntu for bitcoin-testnet-box

texts:
I am trying to setup a private test net with the source at:
https://github.com/freewil/bitcoin-testnet-box

However, it requires bitcoind 0.7.2 (the latest version is 0.8.0).

I tried installing 0.7.2 with the following:

wget http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.7.2/bitcoin-0.7.2-linux.tar.gz/download

but then get the following errors when I install:

sudo dpkg -i bitcoind_0.7.2-3_amd64.deb

Selecting previously unselected package bitcoind.
(Reading database ... 65728 files and directories currently installed.)
Unpacking bitcoind (from bitcoind_0.7.2-3_amd64.deb) ...
dpkg: dependency problems prevent configuration of bitcoind:
 bitcoind depends on libboost-filesystem1.49.0 (>= 1.49.0-1); however:
  Package libboost-filesystem1.49.0 is not installed.
 bitcoind depends on libboost-program-options1.49.0 (>= 1.49.0-1); however:
  Package libboost-program-options1.49.0 is not installed.
 bitcoind depends on libboost-system1.49.0 (>= 1.49.0-1); however:
  Package libboost-system1.49.0 is not installed.
 bitcoind depends on libboost-thread1.49.0 (>= 1.49.0-1); however:
  Package libboost-thread1.49.0 is not installed.
 bitcoind depends on libdb5.1++; however:
  Package libdb5.1++ is not installed.
dpkg: error processing bitcoind (--install):
 dependency problems - leaving unconfigured
Processing triggers for man-db ...
Errors were encountered while processing:
 bitcoind

Following with

sudo apt-get -f install

Still gives these errors:

dpkg: dependency problems prevent configuration of bitcoind:
 bitcoind depends on libboost-filesystem1.49.0 (>= 1.49.0-1); however:
  Package libboost-filesystem1.49.0 is not installed.
 bitcoind depends on libboost-program-options1.49.0 (>= 1.49.0-1); however:
  Package libboost-program-options1.49.0 is not installed.
 bitcoind depends on libboost-system1.49.0 (>= 1.49.0-1); however:
  Package libboost-system1.49.0 is not installed.
 bitcoind depends on libboost-thread1.49.0 (>= 1.49.0-1); however:
  Package libboost-thread1.49.0 is not installed.
 bitcoind depends on libdb5.1++; however:
  Package libdb5.1++ is not installed.
dpkg: error processing bitcoind (--configure):
 dependency problems - leaving unconfigured
No apport report written because MaxReports is reached already
                                                              Errors were encountered while processing:
 bitcoind

I can't seem to figure out how to install these packages with apt-get even though they are listed here:

http://packages.ubuntu.com/quantal-updates/libboost-filesystem1.49.0

Edit: This may be of help, though I haven't gotten it completely working yet:

http://askubuntu.com/questions/168053/how-to-install-all-the-boost-development-libraries


texts: Handwritten paperwallet or hardwarewallet to store Bitcoins?

texts:
Most people I talk to are convinced that a hardware wallet is the safest place to hold your Bitcoins. But I'm not so sure if it's not safer if I create offline on a non compromised fresh system the keys and write it down on a paper (two copies at two safe places). Of course somebody could steal the keys. But looking on hardware wallets, I see those risks:

Seed words have to be written down - subject to theft
If I or anybody else wants to use the stick in 10 or 15 years the firmware will be outdated, the solution might be hacked or I could run into the problem not finding a safe computer with USB port or accepting the stick. This remembers me when I want to get the films from the 20 years old cameras.
The stick itself plus seed is more difficult to hide than a seed/key alone. If a criminal finds the stick he could force me to hand out the seed.
If not open source I need to trust the manufacturer. E.g. the selection of keys could be not random. If the manufacturer selects just out of fix selection of 10 Mio private keys I wouldn't realise but he could take over all Bitcoin credits from the clients after a few years.

What do you think, what's the best hodl strategy to store the coins safe?


texts:
How does Ripple charge fees for XRP-only transactions to compensate nodes?

I've heard of what I can only describe as a "network fee", that some XRP are burned per transaction.  What is the motivation for that?

I'm also unsure of how the node types are compensated.  There seems to be consensus builders and some kind of set of miners, but I can't be sure.  Are they also compensated through BitCoin type fees?


texts:
I am new to cryptocurrencies.

I want to transfer coins to multiple exchanges, how can I do it?
Can I split coins from one wallet into the exchanges?
Do I need a specific kind of wallet?
And when I withdraw coins from an exchange, can I withdraw only a part of my funds(and leave the rest in my exchange account)?


texts: In NXT, which files store the contact addressbook data?

texts: When upgrading NXT, which files do I need to copy over that contain the NXT address book contacts? What other vital files should i copy over from the old version?


texts: I've noticed that compressed public keys are always either 0x02 or 0x03, but what exactly determines whether it's 0x02 or 0x03? I can go look at the OpenSSL code to answer this, but I'm hoping someone already knows the answer and can tell me :P


texts: Does bitcoin core node relay those child-pay-for-parent transactions?

texts:
I am trying to understand how the relay mechanism works in bitcoin?

I understand how CPFP transaction works, but how those transactions get relayed to miner nodes in the first place? the reason is that some inputs of those transactions are not in UTXO. Should standard nodes discard it in the first place?


texts: Bitcoin - Error message every time I open wallet please help! Win 10

texts:
Windows 10 system.

Every time i open Bitcoin Core version 0.15.1 I get this message.

Cannot obtain a lock on data directory C:. Bitcoin Core is probably already running. The system cannot find the file specified..

I have checked Task manager and nothing is running, I have even deleted the lock file as someone else previously mentioned else where, I have turned computer off and on still no different.


texts:
This is regarding using cpuminer v2.3.2 to do Litecoin mining.

I recently upgraded my minerd from version 2.2.3 to 2.3.2  on both my win7(x64) and Ubuntu(x86) machines. Using the old version, minerd would run using  a "cfg.json" file by default if it was present or you could specify one with "-c myCfg.json". Now with the new version, it no longer "sees" or parses the config file even if it is explicitly told to.

To get 2.3.2 to run I had to specify all parameters directly on the command line.

The question is: has cpuminer changed its use of the old JSON format or is there a bug in that component?

On Win7, I now resort to a batch file for each mining site.

Thanks


texts: What if any proposed blockchain enhancements that require hard forks would require new ASIC hardware?

texts:
From what little I know about ASIC they are not flexible with regard to the tasks that they can execute. Some of the proposals for scaling bitcoin up require hard forks in the blockchain. I read about one proposal about replacing the ECSDA signing algo with Schnorr that made me think of this question.

I'm wondering if any of these hard forks would actually mean that some or all current ASIC miners are rendered incompatible and worthless? This would of course have an impact upon which solutions are likely to go forward.

I expect it depends on the design on the chip, if only the core hashing power is offloaded to the ASIC but everything else is done on a more general CPU. Are most of them designed like this?


texts: Is there a sandbox in bitcoin for testing?

texts: Is there a sandbox in Bitcoin for testing, so that I can create sample bitcoins without mining and do transactions for testing purposes?


texts: Double spend transactions flag the node as "bad"?

texts: I'm playing with raw transactions. It's easy to send two signed valid transactions at the same time from the same output to different addresses (making a double-spend attack). My doubt is: if I make tests like this, will the bitcoin p2p network will flag my node / IP as "bad" or I can do it normally without any consequences? Of course I am not attacking anyone else, I want to make tests with my wallets / system to see the behavior.


texts: im planing to buy BTC miner but the place im keeping it in suffers of power cuts everyday for approximately 15 minutes. will it operate?

texts: im buying bitmain s9 for the 1st time and i have 0 experiences. if the power cut off for like 15-20 min everyday and come back will the miner operate by it self ? or i have to do it my self everyday. also will this affect the miner performance ?


texts: Hybrid Bitcoin web wallet for performing multi-sig transaction on an e-commerce site

texts:
Two participants in a transaction, a buyer and a seller, need to interact financially. For security, they themselves keep their private keys and sign transactions on client using JS.

I want to create a 2 in 3 multi-sig address, i.e: "3...", and have the buyer pay to this address. When a confirmation is received for the acceptance of BTC I will tell the seller to ship product. When it physically arrives to the buyer - he will approve getting the product and sign the multi-sig transaction. In case any dispute site admin will have the third private key to resolve any issue.

My question is how to implement this on my site. There are many open source JS Bitcoin libraries supporting multi-sig out there. There is copay/bitpay api, bitgo, gem.co, coinb.in outcast3k, bitvault, coin kite. Not much online about how to properly go about doing this.

The best implementation I have seen is taking place on http://www.coincola.com/

Anyone can help clearing the fog here?


texts: Transaction fails to validate (Error running script)

texts:
I've created a transaction on the TESTNET and am trying to push it via BlockCyphers facility at:

https://live.blockcypher.com/btc-testnet/pushtx/

when I make the attempt, I get the following error:

  Error validating transaction: Error running script for input 0
  referencing
  261190892daa2c9aaaf25c20624f7f2941d2ad58dec883b0c929d1fa9306fd57 at 0:
  Script was NOT verified successfully..

here's the transaction.  I don't see what the matter with it is and not sure I understand the error.  can anyone help?

{
    "addresses": [
        "mjGtZWXgPdbLUZYWtDqVTfbFieVzXFfSEj",
        "2N7nSZjfqikj4oVkCqaLB3CNMY3TA72PbNY",
        "msp7depXvcjLqykZxYVrWNG9QgKqLWWKEN"
    ],
    "block_height": -1,
    "block_index": -1,
    "confirmations": 0,
    "double_spend": false,
    "fees": 12375,
    "hash": "463372d7a8f456c882179635aabbeca4146396b1f81c05699a2e885e3f84d6e6",
    "inputs": [
        {
            "addresses": [
                "mjGtZWXgPdbLUZYWtDqVTfbFieVzXFfSEj"
            ],
            "age": 1657999,
            "output_index": 0,
            "output_value": 5000000,
            "prev_hash": "261190892daa2c9aaaf25c20624f7f2941d2ad58dec883b0c929d1fa9306fd57",
            "script": "48304502210093b8ff9180a8a31a5ee7b0fb6c560aef888a3d53576e530cb4601dce2d3c51da02204fd8a28743f1d1100a2f56428e743501091e833550df6cf540bad4f5248a6d3c012102d794c7e1a8068782ef6ee68acf9f6ad9c84c78349671c1a7bf60418a8e1ed108",
            "script_type": "pay-to-pubkey-hash",
            "sequence": 4294967295
        }
    ],
    "outputs": [
        {
            "addresses": [
                "2N7nSZjfqikj4oVkCqaLB3CNMY3TA72PbNY"
            ],
            "script": "a9149f792783320ffb5a4f3ee4c69525d4932ac0497087",
            "script_type": "pay-to-script-hash",
            "value": 500
        },
        {
            "addresses": [
                "msp7depXvcjLqykZxYVrWNG9QgKqLWWKEN"
            ],
            "script": "76a91486e0602ab38efd1811ff4db76f7d58c717c8598888ac",
            "script_type": "pay-to-pubkey-hash",
            "value": 4987125
        }
    ],
    "preference": "high",
    "received": "2020-01-10T05:09:49.945289619Z",
    "relayed_by": "54.197.194.161",
    "size": 224,
    "total": 4987625,
    "ver": 2,
    "vin_sz": 1,
    "vout_sz": 2
}

- Addendum I -

to help narrow down the solution, here's the code I'm using to produce the transaction:
I first produce an address where to receive some coin:

const btc = require('bitcoinjs-lib');
const bip39 = require('bip39');
const bip32 = require('bip32');

var mnem = 'my-12-word-bip39-seed-phrase'
var root = = bip32.fromSeed(
  bip39.mnemonicToSeedSync(mnem), bitcoin.networks.testnet
);
var p = "m/44'/1'/0'/0/0"
var pubkey = root.derivePath(p).publicKey;
var {address} = btc.payments.p2pkh({pubkey, network: btc.networks.testnet});
console.log(address);

which yields mjGtZWXgPdbLUZYWtDqVTfbFieVzXFfSEj.  I then send some coin to that address and attempt to create my transaction:

const CS = require('coinselect');
var feeRate = 55;
var env = 'test3'
var src = 'mjGtZWXgPdbLUZYWtDqVTfbFieVzXFfSEj'
var url = `https://api.blockcypher.com/v1/btc/${env}/addrs/${src}?unspendOnly=true`;
var o = await fetch(url).then(res => res.json());
var utxos = o.txrefs.map(o => ({
    txId: o.tx_hash,
    vout: parseInt(o.tx_output_n),
    value: parseInt(o.value)
}));
var targets = [{address: '2N7nSZjfqikj4oVkCqaLB3CNMY3TA72PbNY', value: 500}];
var {inputs, outputs, fee} = CS(utxos, targets, feeRate);
if (ret.outputs) ret.outputs.forEach(o => {
    if (!o.address) o.address = 'msp7depXvcjLqykZxYVrWNG9QgKqLWWKEN';
})

// builds the transaction
var tx = new btc.TransactionBuilder(btc.networks.testnet);
inputs.forEach(o => tx.addInput(o.txId, o.vout));
outputs.forEach(o => tx.addOutput(o.address, o.value));
tx.sign(0, root);
console.log(tx.build().toHex());

from which I get a numerical string that converts to the above transaction.  as can be seen, I'm using the same root to sign the transaction that was used to create the source address


texts:
I am fairly new to bitcoin and was attempting to setup a local test network in my machine. I am using the regtest network to create the local network. Is there a way in which I can initialize the nodes (using a genesis block or something) to hold bitcoins (without mining)?
I was going through the developer docs but I could not figure it out. Pardon me if it is a simple solution as I am fairly new to bitcoin.
Something like an initialfreecoins=10000000 in the elements/lightning network.


texts: Same private keys, address started with 3 in electrum, but address started with 1 in electron cash

texts:
I have a electrum wallet with 2fa. The addresses in this wallet all start with 3. When I export private keys and import them in electron cash to get Bitcoin cash, the addresses start with 1 instead. And the balance shows 0.

Why? What should I do to get my Bitcoin cash?


texts: aftet sending btc with bitcoin core can i exit after wards?

texts:
I have bitcoin core installed on windows with full node running.
If I send bitcoin do I need to wait its confirmation before exiting bitcoin core ? can I exit in seconds afterward will it be confirmed ?


texts:
What is the relationship between a Bitcoin Private Key / Public Key / Address?  I see that a private key / public key pair is generated, but is there a possibility of generating a private key already in use?  And, also I'm assuming that a wallet address is a bitcoin address?  Does each wallet address have a one-one relationship with a private key?
Thanks


texts: I just recently sent two transactions at $2,500 a piece to a wallet I was given to transfer the money to. The money was transferred and the person has disappeared. I'm wondering how to find out where the money was picked up at.


texts: Can miners insert transactions into the block from wallets they do not own?

texts:
Since Bitcoin blockchain is shared, everyone knows the balance of each Bitcoin wallet. Is it possible for a miner who hashed a block to insert transactions that transfer funds from a wallet to another wallet, without authorization? Of course, given the original wallet has enough funds.

If not, what's the authorization mechanism?


texts: How to turn my bitcoins into legal money

texts:
For a while now I have been mining and have now got 5 Bitcoin which I'm ecstatic about as it means once I have the money for it, I'll be £13k richer and can put a deposit down on a house.

Whilst I can mine and know how to sell the Bitcoin, I don't know how I'd do these legally.

If I simply just sell them, surely I'd need to put tax on them or something to comply with UK tax laws?

If I was to use the money to put a deposit down, they're going to want to know where the money has come from and whether it's legal money and no doubt the bank will go through my accounts very precisely.


texts:
Bitcoin qt says my computer time needs to be correct for it to work properly. My time is right to the minute, but not the second.

Will this cause a problem?


texts: BitcoinJ how to understand receive Address?

texts:
I need to receive bitcoins from the customers, and then add to theirs virtual account some credits. I use BitcoinJ wallet and I want to give each customer the unique Address created by

walletAppKit.wallet().freshReceiveAddress()

But when I receive coins I can't define customer who send me them.

walletAppKit.wallet().addCoinsReceivedEventListener((w, tx, prevBalance, newBalance) contains all information but I don't see any Address info to define customer.


texts:
I'm sure this has been asked many times before, but I've recently gotten into the whole cryptocurrency thing starting with Dogecoin, and I now want to use Bitcoin as well. I am on Windows 7. I found out the hard way that downloading the blockchain through bitcoin-qt takes forever, so I went to https://bitcoin.org/bin/blockchain/ and downloaded the torrent rather than waiting ages. I now have bootstrap.dat ready, but I don't know where to put it. I have two storage drives - a 120GB SSD and a 1TB hard drive. Because of the SSDs small size and the amount of small writes that bitcoin will do I opted to store the client and blockchain on my HDD. According to https://en.bitcoin.it/wiki/Data_directory I need to place the file at %appdata%\Bitcoin. Since appdata is located on the C drive, there is no bitcoin directory there. The rest of that article is for other operating systems.

Where should I place the bootstrap.dat file?


texts: Best place to read about the algorithms and protocols underlying bitcoin?

texts: I haven't been able to find a whitepaper or technical spec detailing the bitcoin algorithms and protocols. Google is flooded with too much hand-wavy nonsense. Can someone point me in the right direction?


texts: How do I compose a transaction with OP_RETURN in Python?

texts:
Currently trying to figure out how to use Python to construct a transaction with OP_RETURN. I tried to encode the message myself, and had no luck. I found a function, OPReturn(), on the internet, but when I attempt to use it, I get the error (from the Blockchain.info broadcast API): Exception: None Standard Script Output OP_RETURN 594f4c4f53574147

Code:

# coding: utf-8

from bitcoin import *
import binascii
from test import *

priv = sha256('brain wallet')

pub = privtopub(priv)

addr = pubtoaddr(pub)

inputs = unspent(addr)

message = "YOLOSWAG"
FullLen = format(len(message)+2,'x').rjust(2,'0')
MessageLen = format(len(message),'x').rjust(2,'0')
ID = binascii.hexlify(str(message))
snd = "6a"+MessageLen+ID

outputs = [{'value': 50000, 'address': addr}, {'value': 0, 'script': snd}]

fee = 10000

tx = mksend(inputs, outputs, addr, fee)

dt = deserialize(tx)
ins = dt['ins']

#print addr
#print ins

for ind, elm in enumerate(ins):
    print elm
    tx = sign(tx, ind, priv)

#print tx

print(pushtx(tx))


texts:
Here we read:

In the Bitcoin network, only blocks with certain hashes get accepted and included in the official list. The criteria for which blocks "count" is that their hash has to be below a certain number called the target. The network adjusts this number up and down according to how frequently blocks are passing the test--this is how it's able to keep the rate of block production at an average of 10 minutes per block.

This calculation is expanded on here:

The Bitcoin difficulty started at 1 (and can never go below that). Then for every 2016 blocks that are found, the timestamps of the blocks are compared to find out how much time it took to find 2016 blocks, call it T. We want 2016 blocks to take 2 weeks, so if T is different, we multiply the difficulty by (2 weeks / T) - this way, if the hashrate continues the way it was, it will now take 2 weeks to find 2016 blocks.
For example, if it took only 10 days it means difficulty is too low and thus will be increased by 40%

But who does this? Is it a collective property of the cluster? Is it the server? What gives the server the authority to determine this?
My question is: What is the mechanism by which the 'system' adjusts the difficulty of finding blocks so one is found on average every 10 minutes?
EDIT:
I don't believe the question ("How is the difficulty of bitcoin mining propagated?") is a duplicate - because it doesn't explain the implementation issue - which is the essence of my question.


texts: What does the frequency of my miner mean?

texts: What does the clock frequency of my miner mean. I can change it but how does it affect performance? For BFGMiner when I start my Gridseed I can press 'C' to change it.


texts: bitcoind reloads blockchain from scratch when it starts up?

texts:
I have had my bitcoind turned off for a couple of months and I just turned it on again (bitcoind -daemon), and it seems to be reloading the entire block chain from scratch. Shouldn't it be loading only the blocks I am missing from the last two months? Why is it starting over from the beginning? Is there any way to get it to remember the blocks it already downloaded from before?

UPDATE

It seems to be increasing in blocks very rapidly, so possibly it is just reading through the blocks on disk and updating its memory?


texts:
Whenever I connect miners to pushpoold (connected to litecoind), it's not updating the shares table in MySQL (which in turn means the stats on mmcfe isn't updating). I'm pretty certain the database settings are correct as pushpool can read the users table to authenticate the miners and it's not an mmcfe config because I've inspected the shares table independently of mmcfe.

My pushpool server.json file is as follows:

{
    "listen" : [
            { "host": "domain.com", "port" : 8336 },
            { "host": "domain.com", "port" : 8337, "protocol" : "http-json" },

            # HTTP JSON-RPC protocol, port 8339,
            # with trusted proxy appserver.example.com forwarding
            # requests to us
            #{ "port" : 8337, "protocol" : "http-json",
            #  "proxy" : "appserver.example.com" },

            # binary protocol, localhost-only port 8338
            { "host" : "127.0.0.1", "port" : 8338, "protocol" : "binary" }

    ],

    "database" : {

            "engine" : "mysql",

            "host" : "localhost",

            "port" : 3306,

            "name" : "db",
            "username" : "user",
            "password" : "pass",

            "sharelog" : true,

            "stmt.pwdb" :
              "SELECT password FROM pool_worker WHERE username = ?",

            "stmt.sharelog" :
             "INSERT INTO shares (rem_host, username, our_result, upstream_result, reason, solution) VALUES (?, ?, ?, ?, ?, ?)"

    },

    "memcached" : {
            "servers" : [
                    { "host" : "127.0.0.1", "port" : 11211 }
            ]
    },

    "pid" : "/opt/pushpool/tmp/pushpoold.pid",

    "forcehost" : "localhost",

    "log.requests" : "/opt/pushpool/tmp/request.log",
    "log.shares" : "/opt/pushpool/tmp/shares.log",

    "longpoll.disable" : false,

    "auth.cred_cache.expire" : 75,

    "rpc.url" : "http://127.0.0.1:8332/",
    "rpc.user" : "user",
    "rpc.pass" : "pass",

    "rpc.target.bits" : 21,

    "work.expire" : 120,

    "roll.ntime.disable" : false
}

I've already searched through stackexchange as well as the wider web, so I think I've picked up on all the basic mistakes (eg not including stmt.sharelog and the rpc.target.bits), but I suspect this is still a configuration problem and that I've overlooked something really stupid.

Overview specs:

Debian Wheezy 64bit
pushpool (repo: https://github.com/jgarzik/pushpool)
litecoind
mysql  Ver 14.14 Distrib 5.5.31, for debian-linux-gnu (x86_64) using readline 6.2


texts: Who bears the transaction fee for settling HTLC in Lightning Network?

texts: Given a channel that exist between Alice and Bob, where Alice wants to transfer 0.0001 BTC to Bob. Alice makes HTLC payment to Bob contingent to the secret for the payment hash within a timelock of say 100 blocks. So now Alice and Bob will each have a copy of the commitment transaction. Suppose Alice decides to close the channel at the 50th block height by broadcasting her copy of commitment transaction which has two output: HTLC success and HTLC timeout. So she bears the transaction fee of the commitment transaction. Now Bob can immediately spend the HTLC success transaction by using the preimage of the payment hash and his signature. Now Bob in order to guarantee that his HTLC success transaction is prioritized, increases the transaction fee of HTLC success transaction (using Replace-by-fee). So is that Bob has to bear the cost of the increased transaction fee in order to spend his output?


texts: Address no longer shows up in Bcoiner account

texts:
Here is what I did:

Downloaded Bcoiner on my iPad.
Made an account.
Generated a new address, which was 1NEuLDXuBRTYfcbGpzUbpkr4Sg2p7sNLB4.
I sent 4.69 bitcoins to this address.

I logged back into my account an hour or so later. I found that the address which I created earlier above has disappeared. I sent all my coins there.  I can see that they made it to the address but I have no access to them because the address is no longer visible on my account with Bcoiner.

I have emailed support at Bcoiner; they have not replied.


texts: In pooled mining, what is pdiff, bdiff and ldiff?

texts:
In pooled mining, there seem to be three different terms for difficulty in use. Apparently, the Stratum protocol uses bdiff, BTCGuild uses pdiff, and Ldiff is common for various Scrypt pools as mentioned in this bitcointalk thread.

What are the meanings of pdiff, bdiff, and ldiff? In what way do they differ?


texts: How can I configure to solo-mine, and use a mining-pool as failover?

texts:
cgminer can be configured to have multiple pools.

Is there a way, to have as first entry my private wallet, and as second entry a public mining-pool?

Doing so gives strange output:

[2014-01-29 12:40:16] Probing for an alive pool
[2014-01-29 12:40:16] Network diff set to 2.46K
[2014-01-29 12:40:16] Block change for http://xxx.yyy.zzz.aaa:9332 detection via stratum+tcp://freedom.wemineltc.com:3333 stratum

In my case, pool1 is my private wallet (xxx.yyy.zzz.aaa), pool2 is freedom.wemineltc.com. I wonder why pool2 shows up at all. Removing pool2 from cgminer.conf makes my cgminer work fine on pool1 / my private wallet.


texts:
I am trying to build a merkle root which contains only the coinbase transaction from bitcoind
After creating the coinbase transaction i need to convert it to little endian, hash it twice and then put it in the blockheader as it is, or i must reconvert it again before i put it in the blockheader
I mean:
step 1: convert coinbase transaction to little endian
step 2 : double SHA256
step 3 : reconvert to little endian or let it as it's?
step 4 : put it on the blockheader
I am a little confused
Thank you for help


texts: Arguments against Bitcoin using adaptive blocksizes

texts:
Besides the risk of miners artificially increasing the average block size on purpose, what are some of the potential negatives of adaptive blocksizes?

Are there any advantages of human set hard limits? Are there any advantages of requiring periodic human intervention to evaluate and modify blocksize limits instead of codifying that task?


texts:
I'm running the puddinpop rpcminer-opencl.exe that came with Guiminer. I'm running it with crazy settings -gpugrid=128 -gputhreads=256 -aggression=14 on a FirePro 2270 workstation card, and it's reporting about 20 GH/s which I understand is not even remotely possible. I assume something went wrong and all my hashes are broken somehow, but how do I troubleshoot this?

Update: The same miner works fine on one of my other machines. I did find this output on the console:

Build program rval=0
build STATUS:
build LOG:C:\Users\Sean\AppData\Local\Temp\OCLF1AC.tmp.cl(51): warning: attribute "vec_type_hint" ignored
__kernel __attribute__((vec_type_hint(uint))) WORKGROUP void opencl_process(__global opencl_in *in, __global opencl_out *out, const uint loops, const uint bits)
^
Create kernel rval=0
Done allocating OpenCL resources for (128,256)
Finding best configuration step end (128,256) 6ms  prev best=9223372036854775807ms
Done allocating OpenCL resources for (16,16)

So the warning is odd, but also that last extra (16,16) line doesn't show up on my other machine that works.

Update 2: With "crazy" settings I get no shares. If I run with no options, it reports 10 MH/s and seems to get about one share every 10 minutes. So somehow changing the settings makes it generate no shares at all!


texts: Access Bitcoin Blockchain to analyze transfer patterns

texts:
I am interested in analysing patterns in transfers between bitcoin users. Is it possible to extract the following data from the bitcoin ledger:

time
sender
amount
receiver

I don't need the real identity of sender/receiver. I understand that the address can be used to approximate unique users? Is this correct?


texts: How do I make a profit buying cloud-hashing contracts?

texts:
I have tried one of the hashpower selling/buying website (nicehash) to buy hashpower. I have connected my order to a pool where I had one worker.
However, despite all the advertisements, I could not make a profit! I do not know what to watch to know whether my order is profitable or not?

And what makes the profit at all? Is it the fact that the hashpower I buy will become more hashpower if I mine in a pool (I observed that sometimes that is the case, but not for the whole lifetime of the order)?

Thank you!


texts: Which rate is the best rate to go by for Bitcoin prices

texts: There are so many exchanges and local exchanges out there. If I want to buy a bitcoin, how do you decide which value to go by? Some of these exchanges vary from few dollars to $200 difference. I know that it is always fluctuating and many times eventually balances out but how do you determine the price that should be paid?


texts: Can you help me with a puzzle transaction?

texts:
I am hoping there is someone out there that can help me with probably a simple bit coin scripting question...but maybe there is something more to it. I am trying to fully test a custom script on a regtest bitcoind node network. I have worked through some online tutorials and I can create the custom locking script, transform it into a P2SH, and send coin to it. The issue is when I try to unlock the script. I am trying to write the unlocking transaction by hand since this is a basic puzzle transaction...with no luck. Here is the detailed info:

Bitcoin Version: 16.0
Network: RegTest
Locking Script Hex: 0x93016387 (OP_ADD 99 OP_EQUAL)

Here is the base transaction serialized, please note this does reference a previous transaction that sends 1.0 coin to that wallet's address.
0200000001f5bbd0f99f94380cdff45f3eb689e62437df6e6519554a99ae4042b6499afee0000000006b483045022100e2382837f540c03bde1d3aafea0706c358db61b65d85aef9ea29350ecfb7c8dd02204244642b7166529085238527771ead376e1fa69d20dd23b49762014543d407ea0121036397e0c5c226797a1244f5c0736d7874b756cbc11fe39866c2c380403ca5bcdaffffffff0180c6ef050000000017a9143f58b4f7b14847a9083694b9b3b52a4cea2569ed8700000000
If you decode this, you will see a vout to the p2sh address:
 2My2ApqGcoNXYceZC4d7fipBu4GodkbefHD
The next transaction I generated is:
02000000014192c46838cfe8296c9189b7d7e51a57aad2ee31f931d5b9721908f13f87594b0000000000ffffffff0140b9ec05000000001976a914351ef68a632b634cdb63d0e2b58b7f795ba1233f88ac00000000
Which references the previous transaction but does not have a signature and it decodes properly. Then I try to insert the solution to the locking script, by adding: 3e5101620493016387a9143f58b4f7b14847a9083694b9b3b52a4cea2569ed87 in the correct spot...which it might not be makes this transaction:
02000000014192c46838cfe8296c9189b7d7e51a57aad2ee31f931d5b9721908f13f87594b00000000003e5101620493016387a9143f58b4f7b14847a9083694b9b3b52a4cea2569ed87ffffffff0140b9ec05000000001976a914351ef68a632b634cdb63d0e2b58b7f795ba1233f88ac00000000

And that is where it breaks, I try to decode it...doesn't work...I try to send it...doesn't work...I believe the hex is correct and I believe it is in the right spot...but any ideas or help you can provide will be helpful.


texts:
I want to make a multisig transaction but dont how to do it. I am using this site: coinb.in

And what is Txin or N that it also can be called.


texts: How much can you earn by running a Dash master node with 1000 dash as of 2017-May?

texts: Is there any information on how much a person would make from running a Dash masternode that locks up 1000 dash as of May 2017?


texts: How to specify PrivateKey search range in HEX?

texts:
I am trying to generate random bitcoin Private_Keys in HEX format (32bit) but
I want the randomness to have a value within a specific HEX range, say between

18909BDE11F67C97A53C62F45E632EAB58EA0D73A5FAC9EB50295FAD40A57EB5

and

DD10559E1285B3EE0303B159B8D6D8D0B88E6168D1C1D6000000000000000000

The following piece of code in Python 3 is a start but it simply generates random keys for the curve's entire field which is up to

FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141

This is the code:

generate_private_key():
    return binascii.hexlify(os.urandom(32)).decode('utf-8').upper()

How to specify the desired search range expanding on the above code?

Thanks.


texts: Can multiple small graphic card memory collect more mining hash rate

texts:
If I set multiple 3GB GTX 1060 , It can generate more hash rate than single GTX 1070 6GB.
Can I still mining ETH by this 3 Gb cards when the bloCk size of eth is over 3 Gb.
EXPLAIN ME.


texts: Electrum: display redeem script of a P2SH utxo

texts:
I use Electrum with a multisig wallet. I would like to figure out how to prove ownership of a "coin".
I understand that I need to share the whole redeem script so that it's hash can be verified against the UTXO I want to prove ownership off. And then I need to sign a message using at least N of M (as defined when creating the multisig wallets) private keys corresponding to the public keys in the redeem script.
My question is how can I display the redeem script in Electrum, in a human readable way that allows to clearly identify N, M and all of the public keys?
How can I display the data structure encoding the redeem script on the blockchain, whose hash constitutes the ps2h address (without spending the UTXO)?


texts: Electrum only offers online wallet, does it not?

texts:
I am currently using Bitcoin-Qt and have just surfed to Electrum's website.

It seems that Electrum only offers an online wallet, not offline. Is that correct?


texts: Does the OS make a difference for mining?

texts:
I would like to know whether it makes a difference to mine on Windows, on macOS or on Linux?

Performancewise?
Is there a big difference in the quantity of software tools available to mine?
Are graphics card drivers equally available for all those OS?


texts: Issue while using create transaction API of blockcypher?

texts:
I am getting this error "Not enough signatures: 1 for 2 inputs" always while using create transaction API for BTC,LTC,DASH.

Before few days ago its was working fine. But Now I am getting Error After hitting transaction.

Please Help me out from this.

Response from API:-

{
  "tx": {
    "block_height": -1,
    "block_index": -1,
    "hash": "ccfd3d55f02db753ccd29b0a3a648d409bc974dd2f24bbcc3c07e5a9362813bb",
    "addresses": [
      "1vkfV2m6C6r9dbkbXCpv8Fg2jugXJarm1",
      "1EdZpspFLCu6YvcAbtPsQCe2tP2JyhpxTy"
    ],
    "total": 10000,
    "fees": 26300,
    "size": 126,
    "preference": "high",
    "relayed_by": "35.177.118.140",
    "received": "2019-08-02T06:13:34.972349221Z",
    "ver": 1,
    "double_spend": false,
    "vin_sz": 2,
    "vout_sz": 1,
    "confirmations": 0,
    "inputs": [
      {
        "prev_hash": "261be3b9c33523078ca92b67c48d1f1dfb60e37749982a6a965ebae62812bb36",
        "output_index": 1,
        "output_value": 6300,
        "sequence": 4294967295,
        "addresses": [
          "1vkfV2m6C6r9dbkbXCpv8Fg2jugXJarm1"
        ],
        "script_type": "pay-to-pubkey-hash",
        "age": 587750
      },
      {
        "prev_hash": "dc0856ee2eb1c019dbd8b979059c86c448d13fb401c5ba68e190c19d5c112b25",
        "output_index": 0,
        "output_value": 30000,
        "sequence": 4294967295,
        "addresses": [
          "1vkfV2m6C6r9dbkbXCpv8Fg2jugXJarm1"
        ],
        "script_type": "pay-to-pubkey-hash",
        "age": 587872
      }
    ],
    "outputs": [
      {
        "value": 10000,
        "script": "76a914958402d8b99f6a3a3e9a252c3c7e9c07ca9840da88ac",
        "addresses": [
          "1EdZpspFLCu6YvcAbtPsQCe2tP2JyhpxTy"
        ],
        "script_type": "pay-to-pubkey-hash"
      }
    ]
  },
  "tosign": [
    "015327ccd713ab76908cbf5631efe1f3f63a5622abb6bff91e14269cd6252cdb",
    "2daa5d0565e6c1df62705b0b6a34cf38221fca5cd123c2c2cf7e0af866d67ed7"
  ],
  "signatures": [
    ""
  ],
  "pubkeys": [
    ""
  ]
}
stdClass Object ( [error] => Not enough signatures: 1 for 2 inputs )

Please check the code :-

$sell_btcbt = '10000';//10000
$sellbtcadd='1EdZpspFLCu6YvcAbtPsQCe2tP2JyhpxTy';
$btccurrentaddress = '13WMhJwu4FUmz3HjXrB3MWZ3TDstdcHe3L';
    $transact_data = '{"inputs":[{"addresses": ["'. $btccurrentaddress .'"]}],"outputs":[{"addresses": ["'. $sellbtcadd .'"], "value": '.$sell_btcbt.'}]}';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://api.blockcypher.com/v1/btc/main/txs/new?token=1a9daeb78d924879a1d5a84391b6daef&sd=");
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $transact_data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$blockcypher_tx1 = curl_exec($ch);

$blockcypher_tx =(json_decode($blockcypher_tx1));
    if($blockcypher_tx == '' || empty($blockcypher_tx)){
    echo 'Error on creating blockcypher transaction';
    die;
}

$to_sign1 = $blockcypher_tx->tosign[0];
$private_key = '';
$cmd = getcwd()."/signer $to_sign1 $private_key";
exec($cmd,$output);
$esda_sign = isset($output[0]) ? $output[0] : "jhkgdjhkfgkdgsklhsdjkghdfhgjkhdfjghjkdfghhdfjklghjklfghldfhgjkdfhgjkdfhgjkdfhgkfhjgklhfjkghjkdfhg";
if($esda_sign == 0){
echo json_encode(array('resp' => 'Error', 'msg' => 'Error to create signature'));
die;
}
$blockcypher_tx->signatures[] = $esda_sign;
$blockcypher_tx->pubkeys[]= '';
$final_string = json_encode($blockcypher_tx,TRUE);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://api.blockcypher.com/v1/btc/main/txs/send?token=1a9daeb78d924879a1d5a84391b6daef&sd=");
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $final_string);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$push_response = curl_exec($ch);
$push_response = json_decode($push_response);
print_R($push_response);

Thanks in Advance.


texts: Why does bitcoind have to listen to the public internet when supporting lnd?

texts:
I have been part of experimenting with setting up a system to send and receive lightning network payments. The system uses bitcoin-core (bitcoind) and lnd. Initially, the system was set up on a home network, behind a NAT, so neither bitcoind nor lnd could listen for incoming connections from the public internet. In this initial configuration, it was possible to use lnd to send payments, but it could not receive incoming payments.
In the process of troubleshooting, we moved the bitcoind to a server outside the NAT, so it had a public IP number and opened the port 8333 for inbound connections. The lnd server is still behind the NAT, and it does not have any ports opened for inbound connections. Suddenly the system started to work and we could receive incoming lightning networks payments.
So we solved the problem, but I'm kind of baffled as to why this actually works. Was this just a fluke? Or is there a reason why a bitcoin node needs to be able to receive inbound connections in order to properly support a lightning network node?
Edit: For extra context, let me also mention that when using Electrum behind a NAT everything works fine, even though it does not listen to any public port. Which is consistent with the reply I got from @Anonymous.


texts: Can an altcoin be worth less than 1 satoshi (0.00000001 BTC)?

texts:
I have a friend who thinks that it's safe to invest in any altcoin that approaches 1 satoshi (0.00000001 BTC) in value, because there will always be someone who is willing to buy it at that price, and if BTC continues to rise in value, that means the altcoin can only ever go up in value.

Is this a reasonable position?


texts:
how will i be able to get a single value out of BTC-e API.
This is the current API:

https://btc-e.com/api/3/ticker/btc_usd

As you can see, it shows lots of information. What can i do so that i will only get
  --> "last":284.323 <--    this number?

Thank you!


texts: reproduce CVE-2018-17144 (inflation bug) on regtest for learning

texts:
I'm reviewing CVE-2018-17144 inflation vulnerability for learning. I think I reproduced the error on regtest. Is it a correct way to reproduce it? I want to know if I'm missing something about it.

Steps to reproduce:

I have 2 regtest nodes; bitcoindA, bitcoindB. The both version are v0.16.2 and connected each other.

bitcoindA is running as mining node with the following patch to accept invalid transaction.

$ git diff
+++ b/src/consensus/tx_verify.cpp
@@ -181,6 +181,7 @@ bool CheckTransaction(const CTransaction& tx, CValidationState &state, bool fChe
     }

     // Check for duplicate inputs - note that this check is slow so we skip it in CheckBlock
+    fCheckDuplicateInputs = false;
     if (fCheckDuplicateInputs) {
         std::set<COutPoint> vInOutPoints;

[1] generate 2 addresses on bitcoindB. (for receive the invalid utxo)

2NBeTpfn57VpE4e167tFuEtc761jYX7t893,
2N2bb6idv8qsPULP2rqGYoC5yirvVos6YEU

[2] mining 101 blocks on bitcoindA

$ ./bitcoinA/src/bitcoin-cli -rpcuser=bitcoinrpc -rpcpassword=bitcoinrpcpass -rpcport=16591 -regtest generate 101

[3] check the spendable txid from the mined block and a create transaction with the txid. duplicated utxo are set like the following.

$ ./bitcoinA/src/bitcoin-cli -rpcuser=bitcoinrpc -rpcpassword=bitcoinrpcpass -rpcport=16591 -regtest createrawtransaction '[{"txid":"5214dc65e9c9d75550a29e9ef9773452d808c5fd0c56bfe396eb7c2d034f5778","vout":0},{"txid":"5214dc65e9c9d75550a29e9ef9773452d808c5fd0c56bfe396eb7c2d034f5778","vout":0}]' '{"2NBeTpfn57VpE4e167tFuEtc761jYX7t893":99.99}'

[4] sign, broadcast and mining on bitcoinA. And then check utxo on bitcoinB.

$ ./bitcoinB/src/bitcoin-cli -rpcuser=bitcoinrpc -rpcpassword=bitcoinrpcpass -rpcport=16592 -regtest listunspent

[
  {
    "txid": "c885a3f8c0275424401d2793e69aa6bca81f7badbfc1755e18033e8801b74703",
    "vout": 0,
    "address": "2NBeTpfn57VpE4e167tFuEtc761jYX7t893",
    "account": "",
    "redeemScript": "00141c8746e62e30554790f9bd74eeea89f45bdd5e13",
    "scriptPubKey": "a914c9d76124901125aaf2a9b37d8e2d1103a9e5508387",
    "amount": 99.99000000,
    "confirmations": 1,
    "spendable": true,
    "solvable": true,
    "safe": true
  }
]

[5] check if the above utxo is possible to send to the generated address (2N2bb6idv8qsPULP2rqGYoC5yirvVos6YEU)


texts:
Let's say I have 5 copies of my .dat file on individual flash drives. I download the blockchain and run a full node and have the core wallet.  I copy my .dat file into bitcoin core. I type in the old password and then change the password to a new password. Will someone who has 1 of my old .dat files and who knows the old password be able to access my bitcoins?
Follow up- So the easiest solution is delete the old. .dat files once I have btc core wallet running with the new password?
Thanks


texts:
I downloaded coin Miner from Cointellect.com on my PC and I started mining.
I have some questions:

Is the software a scam?
Has anyone gained real money from this software?

When I read forums, some people talk about scam and trojan viruses installed on their machines; others show money gained.


texts: Does my Electrum wallet become less secure if I keep generating seeds until I see one I like the look of?

texts:
Let's say I want to create a new electrum seed... I didn't like the initial seed words, since I want to remember them and these didn't look too appealing. Looking "too random" for my taste. When I repeat this process like 100 times, chances are that I like the combination then more, because it looks "less random" or "more logical to me" (looking like a short story being summarized) which is easier to remember.

Is doing this insecure? Do I increase my risk of randomly creating a not-so-random seed by redoing the seed creation until I get a seed that I like?


texts: How do people know that less than 1000 people own 50% of all bitcoins?

texts:
I read this post on this site:
Who are creating all the alternate cryptocurrencies?

In it, there is a answer saying:

  An article about a month ago was written about the owners of Bitcoin
  and we know that 47 people owned about 1/4 of the Bitcoins and 927
  owned over 50%.

I am quite curious, how do the people know who owns how much? What if the owners are lying?


texts: What version byte will produce a Base58 encoding starting with X?

texts:
What is the Value of X in Base58?

The Problem is when I referred to this table: https://en.bitcoin.it/wiki/Base58Check_encoding

I in the end come up with D when I used 30, but I want X, so what will be the correct value for PUBKEY_ADDRESS and (if necessary) SCRIPT_ADDRESS

This is my existing code:

PUBKEY_ADDRESS = 30, // The letter X (Version 1 Addr.)
         SCRIPT_ADDRESS = 9,
PUBKEY_ADDRESS_TEST = 56, // The Letter P (Version 0 Addr.)
   SCRIPT_ADDRESS_TEST = 119,

Can somebody give the Value that will give me X


texts: Bitcoin core full node - Should I choose my peers or it's fine to use the hardcoded ones?

texts: I have a full node v 0.17.1 running 12-14 hrs/day and I was wondering if it's helpful, for privacy or for whatever reason, to add peers (maybe from https://bitnodes.earn.com/nodes/leaderboard/) with connect= or addnode=.


texts: There are Argentina's friends?I want to buy BTC with Pesos

texts: I want to try using the ARS to buy BTC in Argentina and selling the BTC for RMB in China, so as to ecnomic losses from the traditional way of International remittance.Is the method feasible?I am in China and want to know about some information related to the deal.


texts: Can I recover my Bitcoins bought in 2009?

texts:
I am a complete novice to the whole Bitcoin thing.  Can someone advise me please? I bought Bitcoin in 2009 when it was first launched. I  had downloaded the wallet(been told it was a Bitcoin qt wallet)to my desktop back then but no longer have the computer now. I do not remember the 12 word phrase, but I do remember the email address and the password. The email service provider shutdown in 2017, so I can’t access the original email. I only did one transaction and that was to buy Bitcoin. My questions are...
Would the transactions be recorded in present day Blockchain? Or are there many different Bitcoin Blockchains at present or just one Bitcoin Blockchain?
Can I recover the Wallet ID just by knowing the email address and password?
Are my Bitcoins lost forever?
I am getting lots of people telling me different things, so confused at the moment. Any help would be greatly appreciated. Many thanks


texts: Checking whether lightning node is online/visible

texts: I just created my first lightning node and already have one active connection. My problem is however, that I do not see my node in any lightning network explorer. Is it possible to somehow check whether my node is truly online/visible?


texts: How to make a pay-to-rawmultisig transaction?

texts:
Using the default client's RPC calls, can I make a transaction that sends to a RAW multisig (not P2SH multisig) scriptPubKey?

If I made a raw transaction, and edited the bytes in the scriptPubKey of one of the outputs, could I manually write in my own scriptPubKey? Hopefully, instead of doing this manually there is either support in the core client or there is a tool out there that I don't know of that can help.


texts: Is a private blockchain better in any sense than a database?

texts:
Since the banks appear to be currently looking into the idea of "blockchains" but don't want to be dealing with "Bitcoin", it seems that there is a lot of hype for private blockchains out there like Eris or Hyperledger. However, a lot of people tend to point out that a blockchain without a currency is essentially "an SQL database".

I'm wondering, does a private blockchain have any advantages over a traditional database solution, or can everything that a private blockchain does be replicated with some effort using a database application?


texts: What are good ways to storing backup of an encrypted wallet?

texts:
What are good ways and places for storing backup of an encrypted wallet?

When somebody open encrypted wallet what all can he do when he does not have a key?
asuming that the key to the wallet is e.g. 73 trilion years far to cracking


texts: Are Micropayment channels still subject to malleability after BIP65?

texts:
After BIP 65, are simple, unidirectional, MPC still subject to transaction malleability?

More specifically:

Is the payee at risk because of malleability? If yes, how? (as far as I understood, the payee is not at risk anymore)

Is the payor at risk because of malleability? If yes, how?  (as far as I understood, the payee is still at risk)


texts: Why is POW/POS absolutely necessary to run public distributed ledger?

texts:
my first question here, so please be patient with me. Thank you in advance.

Q: Why exactly are POW/POS mechanisms needed to secure the blockchain (in bitcoin as well as in other alts)? + what is terribly wrong with my example below and why ? (I feel like I am missing something very important here). Thank you very much.

I mean:
- why the block verifying and signing party cannot be just randomly selected node, that would every X minutes put new transactions into the block, calculate hash of block and sign it by its public key, broadcast it to other nodes for inclusion in the blockchain and collect some the reward ? (provided nodes on the network are able to reach some kind of consensus on selected random node - I know it is not easy task - but let's assume it can be done for a moment)

I mean, possible attacks on the network are still there, but it is same as with POW/POS, but:

if node is selected 'truly randomly' (I know, I know), the attacker would need to have just pure luck if he wants to fork the chain with his crafted transactions, because he does not know when he will have the privilege to sign the block...
Or he would need to increase its share of nodes in the network significantly (same with 51% attack in POW/POS)

Above can be (?) mitigated to some degree with including check points in every N blocks in the best chain and having the rule of including e.g. hash of N-x block into recent transactions. (at least from what I understand, that is what some POS coins do)

Why there needs to be POW/POS? (electricity burning/(locked) coins in wallet staking)

Thank you very much for putting my thought process back on track.


texts:
python code

def inverse(x, p):

    return pow(x,p-2,p)

p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f

#private key 2 -->(x , y) value

xx =  0xc6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee5L
yy =  0x1ae168fea63dc339a3c58419466ceaeef7f632653266d0e1236431a950cfe52aL

#private key 4 -->(x , y) value

x  =  0xe493dbf1c10d80f3581e4904930b1404cc6c13900ee0758474fa94abe8c4cd13L
y  =  0x51ed993ea0d455b75642e2098ea51448d967ae33bfbdfe40cfe97bdc47739922L

a= (x*inverse(xx,p))%p

print "x = " + hex(a)

b= (y*inverse(yy,p))%p

print "y = " + hex(b)

output

x = 0x1d8a71dd4218a520a1f976b6a4f66ed600880baf69d401a73dd010dd60f859ffL
y = 0x8f73b0d00f8d9e262cc230b7a6bee35d44ac898986195e819d68ecafd6b7803bL

normal math 4/2 = 2

but here private key 2 x,y value divided by private key 4 x,y value, not provide correct value of x,y

bitcoin , math learning


texts: How do you reliably estimate mining fees?

texts:
I'm asking this question because sites seem to yield widely different estimates.
For instance, if I want a transaction to be accepted within 6 blocks, this is what I currently have to pay according to various calculators:

https://bitcoinfees.net - 5 sat/vB
https://www.buybitcoinworldwide.com/fee-calculator - 123 sat/vB
https://privacypros.io/tools/bitcoin-fee-estimator/ - 356 sat/vB
https://btc.network/estimate - 230 sat/vB

Why are the numbers so different? Who's right?
For the record: at first, I was convinced that bitcoinfees.net had to be wrong, but then, someone sent me a transaction (4a129199006935cad810f99a41c14b2e2cdc4f8043732fde8f6db3f7aa899dfc) with a mining fee of 5 sat/vB... and it received its first confirmation within 20 minutes. It makes me even more confused because I see many transactions currently paying a much higher mining fee.


texts: Litecoin has had SegWit for one month, what impact did that have?

texts:
Litecoin activated SegWit about one month ago on May 10th (block 1201536). What impact did the SegWit activation on Litecoin have? How many blocks have a witness commitment? How many SegWit transactions are there?

(I assume that there was no impact on fees or capacity, but if there was that would be interesting as well.)


texts: How can I generate a Bitcoin address from a 12 word seed without using a computer?

texts: I have a 12 word seed and I want to generate an address without exposing it to any computers. How can I accomplish this?


texts: What is the best cryptocurrency newsletter?

texts: I need one newsletter that covers all my needs: I want to be informed about all the main Bitcoin industry and the blockchain technology events, but not overflooded by tens of daily links.


texts: What is the status of smart contracts in bitcoin?

texts: Are contracts described here already available for use? This source claims that "Ethereum style contracts" will be available in June. Is this correct? How are Ethereum style contracts different from contracts described in the first source?


texts: Could the "pizza guy" sue now had he not received the pizza?

texts:
Let's pretend the guy that spent 10k BTC on a pizza in 2010 did not receive his pizza back in the day (basically got scammed). He shrugged it off as it was only ~20$.
He forgets about it, and notice now that a single bitcoin is valued at around 60k!
Would he be able to sue now 11 years later to get his 10k BTC back, or could he only hope to get back 20$ ?


texts: What is the expected time until the next block is found?

texts:
https://bitcoin.stackexchange.com/a/3908/659 says:

  Luckily, you'll only have to wait five minutes on average for a block to be found (blocks are one every ten minutes, so the expected delay until the next block is five minutes).

Upon reading it, I instantly felt that this was incorrect, and that the expected time until the next block is always 10 minutes (assuming the network hash rate matches the current difficulty).

If the blocks were generated exactly every 10 minutes, than it would be true that the expected time would be 5 minutes, but they're not.

So what's the real expected time?  Please make a plausible argument for why it is so.


texts: bitcoin testnet is mining about 50 blocks per minute right now - why?

texts:
The bitcoin test network is mining about 50 blocks every minute for the last several hours. What is going on?

You can see here: https://www.blocktrail.com/tBTC


texts: How do you generate a Bitcoin wallet by hand?

texts:
I am interested in the exact process for generating the various components of a Bitcoin wallet by hand. Specifically, the components I'm interested in are:

Private Key
Public Key
Public Key Hash
Address

The kinds of tools I have in mind for doing the necessary calculations to generate each by hand is:

Pencil & Paper
Graphing Calculator
Any Other Non-electronic Mathematical Tool
Your Answer

If the process is not too tedious, I might try and give it go.


texts: Dollar cost averaging approach to Bitcoin investing?

texts:
Are there any services offering a dollar cost averaging approach to Bitcoin investing, i.e. something like an index tracker fund which purchases a set amount on a regular basis? If not, are there any reasons why such a service can't exist:

Are there any theoretical disadvantages, i.e. anything specific about the asset which discourages this style of investing?
Are there technical limitations, e.g. is there some restriction imposed by payment bodies which would prevent making a regular payment from Paypal to Dwolla, from Dwolla to an exchange, then buying coins, in an automated fashion?


texts: What is the most cost effective way to exchange USD for Litecoin?

texts: Also, what risks are involved? Do the service(s) have a long track record?


texts: Bitcoin Core Re-install- Don't want to Overwrite Chain Previously Downloaded

texts:
I have a full Bitcoin chain that I downloaded using Bitcoin Core (v.0.18.0.0, from Ubuntu's launchpad bitcoin ppa).  I've moved to another machine and installed the Snap linked from BitcoinCore.Org, pointing it at my .bitcoin directory.  When I run it, I get the following message.  Before I hit "OK", I want to make sure I'm not going to nuke my already downloaded chain.  Can anyone confirm?

As this is the first time the program is launched, ... Bitcoin Core will download and store a copy of the Bitcoin block chain....  The wallet will also be stored in this directory.
[ ] use the default data directory
[x] use a custom data directory
When you click OK, Bitcoin Core will begin to download and process the full Bitcoin block chain (320GB) ....
[ ] Discard blocks after verification, except most recent 2 GB (prune)

Also, it's been a while since I looked, but the Ubuntu PPA stable channel is now saying:

NOT MAINTAINED. The OS-library linking packages here had a series of issues.
PLEASE DOWNLOAD DIRECTLY FROM bitcoincore.org ...

Is there any chance running that Snap might cause any issues with my wallet and already downloaded blockchain?


texts: Anonymous (no ID, no verification) Payments to PayPal?

texts:
Not looking for a discussion on how Bitcoin payments can be traced and it's not truly anonymous. I'm not looking for total anonymity, I just don't want the merchant or payment processor to identify me.

Prior to their update, you could use BitInstant to send money to peoples' PayPal addresses straight from a Bitstamp coupon. Now, they want you to verify who you are with a name, address, urine sample etc. I'm looking for services like the old BitInstant which allow you to direct-pay to PayPal.

Tor being allowed is a plus but not required. I can pay from Bitcoin, MtGox, BTC-e or Bitstamp. The minimum transaction should be trivial, no more than $25-30.

Thanks for the help.


texts:
Where to find old versions of bitcoin-qt from 2011-2012 for download? I cannot find anything on the source code repository and all links I've found on forums are dead.
Is anyone able to assist finding the very old windows bitcoin-qt downloads?


texts: What is the motivation for miners to include all recent transactions in a block?

texts:
I think I understand the basic operation of the Bitcoin protocol.

Blocks are the "long-term memory" of the network used to prevent double spending (and the way the network agrees in first place). Proof of work is sort of brute-forcing the nonce so that the hash has at least the desired number of zeros. When a dishonest node generates a new block other nodes will refuse it should it contain transactions that were not seen by them, so the network will "converge".

I guess the transactions need to be included in that PoW (or else it would be simple to alter them afterwards). So every time a new transaction is seen it will require the miner to start brute-forcing "from scratch"? I read some sort of tree is formed, so it actually doesn't mean the input to the hash function gets longer, but still every transaction will change the "root value", won't it?

Why would a miner even bother to include all transactions that occurred on the network (given that transaction fees are minimal)? There is no lower limit on the tx number per block (perhaps in that time there were really no transactions). It would be simpler for them to just include perhaps one and then use their (CPU) time to solve the puzzle and earn the reward.

There must be some sort of thing in the Bitcoin design which I don't get yet...


texts: Possible to create 5+0$ founding transaction in Ligthning Network?

texts: Watching a tutorial on how the Lightning Network works. Is it possible that only one party puts in money in the founding address / transaction?


texts: Can someone give more information on that type of transaction? Why is it useful for the network. Can it be claimed since it has OP_RETURN command?


texts:
I always thought a transaction can be accepted when all its inputs are correctly provided with their unlock script (which usually contains a signature) ——yes transactions may also be rejected with output > input etc but that’s not the topic

Does the transaction itself also need to be signed? If yes, when I am having inputs with different unlock scripts, which one should I use to sign the transaction?


texts: How to get a wallet feerate (sat/byte) of an unconfirmed transaction?

texts:
On block explorers such as blockchain.com, each unconfirmed transaction has a desired feerate set by the wallet such as 58.000 sat/B. This is not to be confused with the actual final fee calculation.
My question is how do they obtain/calculate the feerate desired by the users wallet that submitted the transaction?
Is this possible via the bitcoin JSON RPC api?
From what I understand, getrawtransaction() does not provide any details of the feerate set by the sender. Moreover, you can also get the feerate set by a user by getting their wallet details. If so, how is the wallet feerate set calculated if there are two inputs to the transaction?


texts:
What can I expect using the salvagewallet command?
What is it actually doing?

I am asking specifically about the zcoin fork, if that matters.
How can this help with corrupted wallet?
How can Wallets become corrupted in the first place?


texts: sendrawtransaction creates hash but does not propogate to the network

texts:
I'm on testnet, I've created a raw tx and I'm using bitcoind. I've confirmed that the hex is formed correctly and signrawtransaction returns complete:true.

After I've run bitcoind sendrawtransaction raw_tx I get a hash returned, however when I look at http://blockexplorer.com the hash cannot be found.

I'm definitely on testnet.

Can anyone suggest any ideas?


texts: blockchain.info says my tx is double spend. Which tx use the same utxo?

texts:
My transaction is marked as double spend. I don't remember when I spent it twice. How can I see what transaction used the same utxo?

https://blockchain.info/ja/tx/60821723b93e2ae5ed729e93c22ca824e7e91fe5a16cba3468139657dc953abc


texts: How would a hard fork for a new key-pair/address generation algorithm be implemented practically?

texts:
If an upcoming hard fork entails a switch to new method for key-pair/address generation, how exactly is it going to be carried out? How would all the old addresses going to change to ones that are compatible with the new algorithm and how is the transfer of ownership going to be conducted exactly?
For the blockchain to keep the same state after the fork, there would have to be a new address for each old (incompatible) address that holds the same amount of BTC and has the same owner.
One way I can think of is adding support for both the old and new key-pair/address generation methods temporarily, and then prompt all owners holding addresses generated using the old method to send their BTC to new addresses generated using the newer method, and finally dropping support for the old method. With ~30 million unique BTC addresses as of today, and a current block size capable of processing 2-7 transactions per second, this transition would need between 50-173 days to complete, during which the blockchain is completely incapacitated, and miner fees being higher than usual. I suppose it could also trap any BTC that hasn't been transferred to a new address by owners in a timely manner within the old, incompatible address.


texts: Compiling a statically linked binary for bitcoin core v0.12.0

texts:
I'm trying to compile a statically linked binary following https://github.com/bitcoin/bitcoin/tree/master/depends. But when I run make I got this error:

fcmatch.c:284:63: error: 'PRI_CHAR_WIDTH_STRONG' undeclared here (not in a function); did you mean 'PRI_CHAR_HEIGHT_STRONG'?
  284 | #define FC_OBJECT(NAME, Type, Cmp) { FC_##NAME##_OBJECT, Cmp, PRI_##NAME##_STRONG, PRI_##NAME##_WEAK },
      |                                                               ^~~~
fcobjs.h:54:1: note: in expansion of macro 'FC_OBJECT'
   54 | FC_OBJECT (CHAR_WIDTH,  FcTypeInteger, NULL)
      | ^~~~~~~~~
fcmatch.c:284:84: error: 'PRI_CHAR_WIDTH_WEAK' undeclared here (not in a function); did you mean 'PRI_CHAR_HEIGHT_WEAK'?
  284 | #define FC_OBJECT(NAME, Type, Cmp) { FC_##NAME##_OBJECT, Cmp, PRI_##NAME##_STRONG, PRI_##NAME##_WEAK },
      |                                                                                ^~~~
fcobjs.h:54:1: note: in expansion of macro 'FC_OBJECT'
   54 | FC_OBJECT (CHAR_WIDTH,  FcTypeInteger, NULL)
      | ^~~~~~~~~
make[4]: *** [Makefile:613: fcmatch.lo] Error 1
make[4]: Leaving directory '/usr/local/src/bitcoin-0.12.0/depends/work/build/x86_64-pc-linux-gnu/fontconfig/2.11.1-14f43f3a52a/src'
make[3]: *** [Makefile:474: all] Error 2
make[3]: Leaving directory '/usr/local/src/bitcoin-0.12.0/depends/work/build/x86_64-pc-linux-gnu/fontconfig/2.11.1-14f43f3a52a/src'
make[2]: *** [Makefile:561: all-recursive] Error 1
make[2]: Leaving directory '/usr/local/src/bitcoin-0.12.0/depends/work/build/x86_64-pc-linux-gnu/fontconfig/2.11.1-14f43f3a52a'
make[1]: *** [Makefile:444: all] Error 2
make[1]: Leaving directory '/usr/local/src/bitcoin-0.12.0/depends/work/build/x86_64-pc-linux-gnu/fontconfig/2.11.1-14f43f3a52a'
make: *** [funcs.mk:240: /usr/local/src/bitcoin-0.12.0/depends/work/build/x86_64-pc-linux-gnu/fontconfig/2.11.1-14f43f3a52a/./.stamp_built] Error 2

I'm doing this on ubuntu 20.04 LTS using the source code of bitcoin core v0.12.0. I already compiled the source code and because it is an old version it was necessary to install some old libraries. But I believe the problem is related to the C++ version and I don't know how to set the right C++ version. How can I fix that?


texts: How does the network determine whether to replace a transaction?

texts: Further to this question, how does the network determine whether to accept a new version of a transaction as a replacement transaction? Could an attacker replace transactions maliciously?


texts:
Is there any Python package which will allow me to verify if the checksum of a bip39 mnemonic is valid?  For instance, I have a 24-word bip39 mnemonic, and I might have made a mistake for one of the words.  I want to see which words will result in a valid checksum.

I've seen javscript versions, but nothing in Python


texts: where is the bitcoin's private key saved?

texts:
I'm making a service and I will have to take charge of users' private keys
So I'm really worried about it.how should i take charge of that?


texts:
I'd like to pay people using the following command:

curl --data-binary '{"id":"curltext","method":"payto","params":{"destination":"mwLmd5xMnKkf4bBUa6MDrg4HYQaazoHtkj", "amount":"0.001"}}'

But I don't know what will be charged as fee. Is it possible to set the fee?


texts: Why would I have so many rejected shares while mining?

texts:
I am mining litecoin with give-me-coins and I have the following info on website's stats section

 Valid Paid: 118
 Invalid (Not Paid): 113 (95.76%)

As far as I know this is not very good.

How can I make it better ?

I use cgminer 3.7.2 (used 3.6.6 also) with following command

cgminer --scrypt -o ltc-eu.give-me-coins.com:3333 -u user.pass -p x -I 11


texts: Someone named mr_richard665 on instagram told me he was a bitcoin broker that worked with bitcoingroup and that he could help me make 30% profit everyday from my investment if i let him manage my account by me sending my bitcoin investment to his miners wallet address,is this a scam?


texts: Checks to Verify money sent to any address in a transaction

texts:
I'm using wallet-less bitcoin daemon (it just syncs blockchain) – the purpose is to read blocks and transactions in them, and do some useful things. This particular question is focused on determining the checks to be made to verify the amount received by each address in a given transaction.

Given tx, I call decoderawtransaction(getrawtransaction(tx)) and receive following details (json):

{
"txid" : "691cb3d61192c7325f203fe14d3d5cf6e98e6bd81877b166f6c37fd629aaa4fb",
"version" : 1,
"locktime" : 0,
"vin" : [
    {
        "txid" : "0c0b442e866f007a0da8a2c1abbe8afad8e96217105b561b097aa835b73a6b70",
        "vout" : 0,
        "scriptSig" : {
            "asm" : "3045022100eb01c02b4655c96b08544908bd44d1fbc165971bdc25705ba1b4790c60716dfa022024adeb306f66a72a2a90455035940b89e7c96c8300b6f73f3ae83af605b9c35d01 03ca8ff2ad5114e703d07b3cee962d54609c1de95fd4511e53de91ba0ce35ef4ee",
            "hex" : "483045022100eb01c02b4655c96b08544908bd44d1fbc165971bdc25705ba1b4790c60716dfa022024adeb306f66a72a2a90455035940b89e7c96c8300b6f73f3ae83af605b9c35d012103ca8ff2ad5114e703d07b3cee962d54609c1de95fd4511e53de91ba0ce35ef4ee"
        },
        "sequence" : 4294967295
    }
],
"vout" : [
    {
        "value" : 0.01000000,
        "n" : 0,
        "scriptPubKey" : {
            "asm" : "OP_DUP OP_HASH160 8bab392bcc5cfce30affc16336cdd68e807147a2 OP_EQUALVERIFY OP_CHECKSIG",
            "hex" : "76a9148bab392bcc5cfce30affc16336cdd68e807147a288ac",
            "reqSigs" : 1,
            "type" : "pubkeyhash",
            "addresses" : [
                "mtFTLXKfDxHuJT36cHugYTZw5CVLejqccq"
            ]
        }
    },
    {
        "value" : 0.04000000,
        "n" : 1,
        "scriptPubKey" : {
            "asm" : "OP_DUP OP_HASH160 d86064ea608dd1ceeae690e548979b854ca55360 OP_EQUALVERIFY OP_CHECKSIG",
            "hex" : "76a914d86064ea608dd1ceeae690e548979b854ca5536088ac",
            "reqSigs" : 1,
            "type" : "pubkeyhash",
            "addresses" : [
                "n1F3j5MdfSLSgpUnaQXNVJb8KBMvnfBYPr"
            ]
        }
    }
]
}

I can see each txout record gives amount as a value (scalar) and addresses as an array.

If addresses array has multiple values, it is a contract (m-to-n transaction perhaps) and I should not consider the money to have been received by any of the  addresses for immediate spend.
Assuming addresses has only one value, what are other checks I must make to verify that the address has received the amount mentioned in the field 'value'?

So I need to know a set of all checks to verify the transaction is confirmed, valid and that a particular address in a particular txout has received the specified amount. confirmation can be ascertained depending on the number of blocks that precede block of this transaction (getblockcount - blockheight).

Thanks!


texts: Is it legal to buy Litecoin and sell those within a few minutes?

texts: In US, is it legal to buy and sell cyber currency within a few minutes?


texts: Can a node broadcast a valid signed raw transaction while still syncing?

texts:
Built and signed a native bech32 UTXO, but when I attempt to broadcast from my testnet node using the command sendrawtransaction it returns "missing inputs". I don't have the private keys in my wallet, and the testnet node is still syncing, but I was able to broadcast it fine with a testnet API service that lets you broadcast signed transactions.

Is it possible to broadcast a raw signed transaction to the network while still syncing?


texts: What can be the reason to change transaction ID?

texts:
I always thought that when my wallet create a transaction, it's transaction id is fixed (it is the SHA256 of the transaction message). Yes, the transaction might not be included in the next block (and can even be dropped completely) but if it will be included the transaction ID is fixed. Apparently this is not correct:

  Transaction IDs are not authoritative until a transaction has been
  confirmed. Absence of a transaction hash in the blockchain does not
  mean the transaction was not processed. This is known as "transaction
  malleability," because transaction hashes can be modified prior to
  confirmation in a block. After confirmation, the txid is immutable and
  authoritative.

Can anyone explain

the reasons why transaction ID can be changed?
Who can change this ID (I assume a miner who mined a block)?
What field in the transaction message can be changed to warrant the change of txId?


texts: I’m victim scammed by criminals online. How I can find what exchange they belong to?

texts:
My stolen money was sent on address: 3MUHxDiY2H6C9sy4ce412HbF953FCn87ZQ, and then on to this address:  1L1xSXttdsBAPVjVfyoyCg3RZbdHinT5G5
How I can find


texts: How can I generate the qrcode client-side that would be compatible with the Ardor Wallet qrcode

texts:
I'd like to generate a qrcode the same way the Ardor Wallet generates it, such that it would be compatible.

I found qrcode related javascript shipped with the Ardor node download in ardor/html/www/js/util and ardor/html/www/js/3rdparty, however I wasn't able to find any documentation.

Thanks for any hints or pointers.


texts: A more updated address clustering method?

texts:
say i have a transaction details of one address from blockchain info. is there a more updated heuristics for address clustering ? i.e. if a transaction has 2 output which address belongs to a different entity and which one belongs to the same entity(if there is any)
thanks


texts:
Is there an up to date and updated chart which tracks the entire energy used by bitcoin mining rigs worldwide?
Looking for the energy used per t-hash.


texts: What is the relationship between the Ripple secret key and the wallet name/passphrase?

texts:
The Ripple client has both a wallet name/passphrase and a secret key, and to the newbie it's not clear why there are two secrets. The client advises the user to write down the secret key and keep it safe so the funds can be recovered if the wallet is lost. If the funds can be recovered using just the secret key, then why does it have a wallet name/passphrase as well?

Is the wallet name/passphrase just for convenience (easy to remember)?

Why can't the wallet name/passphrase be changed?

Why not generate the secret key from the wallet name/passphrase so that the user has only one secret to keep safe?


texts: How to tell if a file is a Bitcoin wallet?

texts:
This question is very similar to this one ("Identifying wallet file among soup of recovered .dat files"), but slightly different.

I ran photorec and ended up with a bunch of files. Per this answer, I ran file and found one that had the exact description mentioned: Berkeley DB (Btree, version 9, native byte-order)

Can I easily tell if this is a bitcoin wallet file or just some DB file used by another application? It sounds like photorec can't find the EOF for these files, so mine is probably larger than the original file was. Are there any tools that might help me here?


texts:
I have only known about Bitcoin for maybe a month now.

I don't know what I need to start mining, but I had these two programs that were said to be needed for the Bitcoins. I deleted these programs and thought maybe I shouldn't mess with all this, but I just can't do that.

Please, any help on starting the process of mining and the way everything works would be much appreciated.


texts: Values for txid and vout for create a coinbase transaction

texts: I want create a coinbase transaction to go with a new block minned by my program. I am creating it with the json-rpc command createrawtransaction. What's the values for txid and vout in this case?


texts: What is the exact difference between a Bitcoin and Bitcoin Cash raw transaction to address sighash_forkid?

texts:
Bitcoin Cash apparently uses sighash_forkid, such that if you don't implement that into your raw transactions, the bitcoin cash network won't accept it.  How would one need to alter (what to add and how to get it) a transaction made to bitcoin tx specifications, to make it work on the Bitcoin cash chain?

It has been suggested that in an answer to this question:

  The SIGHASH_FORKID is an addition to the sighash type and simply means that the sighash type must have bit 6 set.

What is it to "have bit 6 set"?  And set to what?  What is an example of it being "set" and not being "set"?  Instead of "01" can I just type ĹéêŤ or does it need to be a "01" or a "02" or what can it be or not be?


texts: What is the skim call function for PancakeSwap on BSC?

texts:
Can someone explain this transaction for me?  An active trading address managed to extract a significant part of a cake liquidity pool.  I haven't found anything related to BSC skim call function before.  Please, could someone kindly explain how this works and if there is a problem there.  TX: 0x0a2962c6f9788d1cfc922c6492feb622b2048f139cfe8249ef7a0370e8fa7789
https://explorer.bitquery.io/bsc/tx/0x0a2962c6f9788d1cfc922c6492feb622b2048f139cfe8249ef7a0370e8fa7789/calls


texts: Are there any hosted online store solutions (a la Shopify.com) that are compatible with bitcoins?

texts: Are there any hosted online stores that can be set-up easily to take bitcoins?


texts:
Can Armory be used for mining?
I hear it is a wallet, but as it downloads the whole blockchain anyway should not you be able to mine with it, too?


texts: Bitcore-wallet-client "Server response could not be verified"

texts:
I'm getting an error trying to sign a transaction with bitcore-wallet-client.

I create the transaction, publish it and when I try to sign it, I'm getting the error: "SERVER_COMPROMISED - Server response could not be verified"

bws server: https://bws.bitpay.com/bws/api

can anyone point me in the right direction?

ps: using wallet-client (CLI) I can sign the same transaction (created and published from bitcore-wallet-client)

edit: I'm using a testnet account


texts: Why is it more profitable for a node with more than 51% computation power to abide by the rules in the bitcoin network

texts:
The Bitcoin whitepaper states - "The incentive may help encourage nodes to stay honest. If a greedy attacker is able to assemble more CPU power than all the honest nodes, he would have to choose between using it to defraud people by stealing back his payments, or using it to generate new coins. He ought to find it more profitable to play by the rules, such rules that favour him with more new coins than everyone else combined, than to undermine the system and the validity of his own wealth."

I don't quite understand as to why? Can someone explain as to what can an attacker gain if he has more than 50% computing power and how it is outweighed by what he can gain if he plays by the rules.

The question What can an attacker with 51% of hash power do? does not seem to answer my question as it does not clearly seem to explain WHY is it more profitable to play by the rules.


texts: Why is Bitcoin so susceptible to credit card fraud?

texts: I understand that you can't buy Bitcoins with a credit card due to massive fraud problems involving chargebacks. Why is Bitcoin more susceptible to this then the thousands of other businesses that take credit card payments for non-physical products (say, RPGNow, Bandcamp, iTunes and so on).


texts: Wallet as daemon, what's the security-concern about "rpcallowip"?

texts:
When running (btc-/ltc-/whatever) wallet as daemon, I have to set "rpcuser" and "rpcpassword".

There is the option "rpcallowip", it is recommended to have this value very strict, e.g. "127.0.0.1".

I cannot see any danger setting this value to "..*.*" - if anyone guesses my server and credentials, he/she is welcome to mine for my wallet.

So, is there any danger opening rpcallowip?


texts:
I am creating an application which will be paying out some amount of BTC every hour to few  addresses. Is there a service that allows me to program the transactions or a wallet, which offers a feature like this?
Any suggestions ?


texts: What's the status of alternative full node implementations?

texts:
In "Does running an alternative full node implementation benefit the Bitcoin network?", I asked about running an alternative full node implementation for the benefit of the Bitcoin network.

What is the current status of different alternative full node implementations with regard to

maturity (alpha/beta/stable)
performance
compatibility tests
code review
suitability for different purposes:

experimentation
merchants
as a wallet
as a lightweight wallet back-end
solely for the benefit of the network?

Update: Moved the list of implementations into an answer.


texts: Bitcoin over Tor and man in the middle attack: risks mitigated yet?

texts: This paper explains how combining Bitcoin and Tor creates an attack vector. A man in the middle can control the information flow between all users who connect over Tor. This paper is from 2014. Has this sort of risk been mitigated by new engineering yet?


texts: Generating Bitcoin Public and Private Keys

texts:
I managed to write the below code which will create public and private keys

Private Key

$input = "satoshinakamoto";
$sha256 = hash("sha256", ($input));
echo "Private Key: ".$sha256."
";

Public Key

    $step1 = hexStringToByteString("0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6");
    echo "
Step 1: ".$step1."
";
    $step2 = hash("sha256", $step1);
    echo "
Step 2: ".$step2."
";
    $step3 = hash('ripemd160', hexStringToByteString($step2));
    echo "
Step 3: ".$step3."
";
    $step4 = '00'.$step3;
    echo "
Step 4: ".$step4."
";
    $step5 = hash("sha256", hexStringToByteString($step4));
    echo "
Step 5: ".$step5."
";
    $step6 = hash("sha256",hexStringToByteString($step5));
    echo "
Step 6: ".$step6."
";
    $step7 = substr($step6,0,8);
    echo "
Step 7: ".$step7."
";
    $step8 = $step4.$step7;
    echo "
Step 8: ".$step8."
";
    $step9 = bc_hexdec($step8);
    echo "
Step 9: ".$step9."
";
    $step10 = bc_base58_encode($step9);
    echo "
Step 10: 1".$step10."
";
    return $step10;

To generate public key I took reference from https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses

In that link they provided Step by Step process and I followed the same and if
I input from Step 1 in the link then I am able to convert the code to public key but I am not sure how to convert Step 0 to Step 1

i.e.

From:

18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725

To

0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6

Document says

Take the corresponding public key generated with it (65 bytes, 1 byte 0x04, 32 bytes corresponding to X coordinate, 32 bytes corresponding to Y coordinate)

What does that mean? How can I generate this value from Private Key.

Edit 1

This question says https://stackoverflow.com/questions/17672696/generating-bitcoin-address-from-ecdsa-public-key

Joining the Elliptic Public Key and I still don't understand what are they.


texts: I purchased $40 worth of Bitcoin from a btc atm. I use this method to add to the same wallet every time a couple times a week. This time when it loaded to my wallet I needed to send it from there to another wallet on a site to use. It won’t send $32 saying I don’t have enough to cover the transaction fee. I look and see the transaction fee is $117.00??? When I’m sending $32 of btc? Why?


texts: How is Coinbase any different than Mt Gox?

texts:
Apparently Coinbase handles the private keys for your wallet which allows them to easily handle buying and selling.

  As Coinbase is a hosted wallet, we do not provide users with their private keys; doing so would prevent us from taking advantage of our secure cold-storage technology to protect your bitcoin funds.

Isn't this exactly what Mt Gox did before it was compromised?