texts: Do all Cryptocurrencies uses same Public key Cryptography algorithm?

texts:
I have been trying to read about how Public key cryptography works and I have just understand what public key cryptography is and how it differs from symmetric key cryptography.

I have also just read that the bitcoin uses "Elliptic Curve Digital Signature Algorithm (ECDSA)" to generate Public/Private key pairs, and then

  the public key is hashed several times until it looks like the
  familiar Bitcoin address.

I then read here, https://ethereum.stackexchange.com/questions/3542/how-are-ethereum-addresses-generated that Ethereum also uses ECDSA to generate key pair and then the Keccak-256 hash of the public key is taken.

My question is, do all the cryptocurrencies in existence uses the same algorithm to generate key pairs ?, if that is true, can a single Public/Private key pair be used to store multiple currencies given that the public key is hashed according to each cryptocurrency standard ?


texts: Would it be possible for an 8-bit microprocessor to create a bitcoin keypair?

texts:
Context for question: With the latest security breaches around modern CPU's (Spectre / Meltdown) I was wondering if we could generate ECDSA keypairs on cheap, small and/or simple air gapped (micro)processors.

I have found GitHub repository Bitduino attempting to make an Arduino (an 8-bit microprocessor) create a bitcoin address, but in fact it simply leverages a connected computer that creates the actual keypair with Python. The Arduino merely creates the (possibly true cryptographic) random bytes.

I also found GitHub repository micro-ecc implementing ECC for 8-bit microprocessors, which looks very promising.

Then I guess additionally all that is needed to generate a keypair, are some hashing algorithms; RIPEMD-160 and SHA-256.
And then simply use Base58 encoding, which can be found as C-code in the actual Bitcoin client implementation (so it could be used for a microprocessor).

So to sum it up, my question comes down to: would putting these parts together enable the generation of ecdsa / bitcoin keypairs on a microprocessor, or am I missing something?

If let's say it's not possible simply because of memory limitations, what amount of memory would make it possible? Or if the 16MHz of an Arduino (for example) would be too slow, would an ESP8266 do, or an STM32F4? Or a Raspberry Pi?

Personal context: I would very much like to create a full implementation of exactly this entire process. Starting with a press of a button (on an embedded device) which will result in a string containing base58 encoded private and public keys, while using strong true cryptographic random values. I'm just trying to prevent unnecessary work targeting a platform that cannot ever make something like this work.

I would be happy to write it in 'cutting-edge' Rust on a 64-core machine, but I also realise that would set the threshold so high, the 'average' user couldn't reproduce it. (Also it wouldn't solve my main issue with modern-day CPU vulnerabilities.) Whereas if the end result would be an Arduino library you can simply download using Arduino's board manager, flash the example and it spits out keypairs, that would suddenly make it accessible for a (very) large audience.

I know hardware wallets exists, I am much more interested in creating something like this myself for learning purposes. Also, if the resulting software can be used by other people on very inexpensive and easy to come by hardware, that would be a plus.


texts: Bitcoin block maturity and block reward rules

texts:
According to the Bitcoin wiki:

"When a block becomes an orphan block, all of its valid transactions are re-added to the pool of queued transactions and will be included in another block. The 50 BTC reward for the orphan block will be lost, which is why a network-enforced 100-block maturation time for generations exists."

Ok, so let's say at block height X, two miners produce separate valid blocks - block A and block B. The miners compete with each other to mine on top of these two blocks. Eventually, the chain with block A becomes the longest chain, and thus block B becomes orphaned. However, the chain with block B is more than 100 blocks long (despite it being the shorter chain). Does this mean that, despite block B being orphaned, the miner who mined block B can still spend the block reward?

In addition, consider another scenario: a miner goes back to a previously orphaned block (a block that was orphaned in, say, 2 months ago) and starts mining on top of it. He produces a chain that is 150 blocks long. Although this chain is still shorter than the main chain, according to the 100-block maturation rule, the miner can spend the block rewards of the first 50 blocks of this 150-block orphan chain, right?

I know the scenarios I suggested above are very unlikely to happen in reality, but I'm just curious.......


texts: how do i backup private keys of user address which are generated by getnewaddress?

texts:
i am working on website which receives and store bitcoins
each user will credited with newaddress for deposit BTC how would i take backup of their privatekeys with bitcoind
i think bitcoind generate address from key pool which is limited to 100 after that it will generate new key pool
what are the best practices to maintain backups


texts: What would happen to my mobile bitcoin wallet if something happens to my phone? If it breaks, or I want to replace it or it gets stolen?


texts: Generating addresses on the fly or pre-generate and store public key?

texts:
When running a service that needed a bitcoin address, would it be better to generate a new address to use at that moment and store the private key on your server, or would it be better to pre-generate say a million addresses and have the private addresses already stored offline?

The later would be combined with a backup option to generate on the fly if its address pool dried up.


texts: lost bitcoin on electrum - wallet closed after transaction went through?

texts:
i'm noob to bitcoin and lack advanced knowledge of how these wallets work. i followed guides on how to buy bitcoin and seemingly the transaction went fine, until my electrum wallet suddenly closed and when i opened it back up i could not find my transaction in history, my recieving address changed and the address i used to buy  bitcoin can not be found anywhere.
here is a link to the transaction https://blockchain.info/da/address/157gZExbGA27R33AFHmQS41EzFxXoUpBjP

and an image of the receipt after purchase
did i screw this up completely or can i still get my bitcoin into my electrum wallet?


texts: Can you "undo" an nlockTime transaction by spending a single UTXO of it before lockTime's block happens?

texts:
Let's say I have a wallet X with money from 3 unspent outputs (UTXOs) A, B and C.

I make an nlocktime transaction to spend 2 of my 3 UTXOs (A & B) to wallet Y, 1 month in the future, sign it, and give it to someone (actually the owner of wallet Y) so that this person can broadcast it later.

Now, let's say a week later, before the nlocktime's block happens, I go and spend one of the UTXOs of the nlocktime transaction (A), but not the other (B).

Will the person that receives the 1st transaction be able to spend the UTXO B in the end? Or would my 2nd transaction render the entire 1st transaction invalid?

Thanks


texts: Raspberry Pi 3 / Bitcoin Node / No space left on device / Link Database to External Hard drive /

texts:
I was following @meeDamian Bitcoin node guide on a Raspberry Pi 3 and could get almost everything to work except that it stores the Blockchain on my USB Harddrive. Its mounted and I have disk space but it puts everything in my root folder.

Where and how can I specify that it gets stored on my USB Drive and can I just the delete the files in folder "blocks"

Thanks for your help

IMG: Node Logfile + Filesystem


texts: How can I participate in a mining pool that is mining Litecoins?

texts:
To date I've only participated in mining GPU-optimised crypto currencies. I wondered what happens when I pointed my GPU miner to a Litecoin mining pool worker, Litecoin being designed to be optimised for CPU mining.

I tried do this for just three shares on coinotron.com and according to guiminer (running Phoenix) two of them were rejected as stale and one was accepted. However, my worker on coinotron.com registered no shares submitted at all (which is probably correct, since it's likely a GPU miner won't work at all for Litecoin).

If I can't use Phoenix, then what do I use to participate in a Litecoin mining pool?


texts: Calculate Any Address Balance Using Bitcoinn RPC getrawtransaction

texts:
I'm trying to use getrawtransaction to get transaction details (for any address) from my local blockchain. What I have is an address in readable format, "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa" but the input to getrawtransaction is a hexadecimal string. I found the following solution that does not change the string at all.

let address='1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa';
address=address.toString('hex')
console.log(address);
client.getRawTransaction(address, function(error, o) { console.log(o); });

Any ideas?


texts: Do payment processors who convert bitcoin to dollars (like Coinbase and Bitpay) devalue bitcoin?

texts: My understanding is that Coinbase and Bitpay process payments made in BTC.  They receive BTC from a buyer (for example someone buying patio furniture) and send USD to merchants who don't want to keep bitcoin (for example Overstock.com).  In order to get the USD to send to the merchant these companies must be constantly selling BTC on an exchange and thereby devaluing bitcoin.  Is my logic correct?


texts: How to deploy BTC blockchain on my Ubuntu17 VPS

texts:
I would like to setup Bitcoin nodes on my VPS so we can call balance API unlimited time. Actually we are launching ICO for that we are in need of this we have previously deployed ETH and NEO node on our VPS.

Can any share URL or document that can help me to deploy bitcoin Nodes on my VPS and it allows to RPC Call for getting balance of any address.


texts:
https://blockchain.info/ip-log

shows the ip:port for bitcoin nodes

where can I find nodes for testnet?

Google is coming up dry!

After many hours spent; I tried what seemed the logical approach: use a main-net nodes ip but change the port from 8333 to 8332 (but, no luck, not connecting to testnet!)

also tried 18332   :/

I am a new company, I want to test!

I am using this https://github.com/sebicas/bitcoin-sniffer to realize new-transactions and new-blocks real time on main-net but I am failing to do so on testnet (where do I connect? please)

This information should be instantly available and easy to find!

Then we wonder why bitcoin is not adopted!

The information is no where on the net!!

While literally the whole planet (99% of everyone) is a newbie (why is this not readily accessible info!??)

I am at a loss for words ...

I currently connect successfully to bitcoin main-net using:

{host:'109.123.116.24',port:8333}


texts: Will a zero-fee transaction get processed faster if I send it straight to a miner I am running especially for that purpose?

texts:
Is it possible to get a transaction with no fee attached processed faster by sending it directly to my own bitcoind running with mintxfee=0?

Does the speed of my hardware play a role?

Is there anything else I need to set in bitcoind?

Is there another way of achieving the same results (fast zero-fee transactions)?

Thanks!


texts: How do I compute a private key, if I have two messages signed using the same nonce?

texts:
If I sign two messages with the same private key and nonce, it compromises security, making it possible to calculate the private key.
I'm implementing a system (outside of bitcoin) where a message, with a unique property, must be signed only once.
In order to enforce this, I'm making it mandatory to use a hash of the unique property as the nonce.
This means that signing a two messages, having the same unique property, will give away the signer's private key.  (Which is not something they want to do, in this system.)
How do I use the secp256k1 functions to obtain a private key from two signed messages which use the same nonce?  (This is alluded to in this question.)


texts: How do mining pools connect to the Bitcoin network and miners connect to pool?

texts:
I couldn't find the answer anywhere so I start a thread.

How do mining pools connect to the Bitcoin network to propagate transactions and blocks? Do they run their own full node? If yes, how many of full nodes?
I presume it's hard to run a mining pool with only one full node because it's IP will be exposed to some network attack like DDoS.
How do miners connect to a pool? Is there any server running by mining pools so miners can connect to?


texts: How to extract raw script from tx messages when the output script starts with 0xA9?

texts:
I'm working on extracting output addresses from tx messages in BITCOIN packets.

Currently, I extract address from output scripts which starts with 0x76(OP_DUP)
like this :

76 a9 14 6d 1d 74 58 95 6e 80 cd b4 c3 3f 1e d5 8e 91 c4 92 1a 85 d0 88

but i don't have any idea about some output scripts which start with 0xA9(OP_HASH160).

As an example, i don't know in below example, what is the raw script, which is used to generate output address?

a9 14 16 52 33 02 f2 ee d0 e0 aa 6a 4c 1d 0a 41 39 6f c2 6f 53 6e 87

How i can extract output address from output scripts which start with -xA9?


texts: No sign of my private keys in Electrum wallet ... where do I find them?

texts:
I recently downloaded an Electrum wallet (version 1.7.3) and made two Bitcoin purchases. The wallet shows the public receiving addresses (including those receiving addresses which I used to receive the coins) and the amount of coins received in these transactions. My problem is that I can't see the private addresses anywhere and don't feel confident that the coins are still in my possession (of if they ever were).

I am guessing that when (in the Classic Gui) I click on the 'Send' tab, enter the address for the intended recipient in the 'Pay to' slot, the 'Amount', 'Description' of the transaction for my own benefit, the 'Fee', and subsequently click on 'Send', the client might then perhaps disclose a private address along with an address for any change to go to. Is this correct? If not, can someone be good enough tell me how it does work?

I feel uneasy that I cannot see the private addresses anywhere. And, of course, I can't spend the coins until I have the private addresses. (I would like to commit my private keys to paper.)

In the 'Settings', there is a tab labeled 'Import/Export' and one of the options there is to 'Export' / 'Import' Private Keys. Does this mean to 'Export' the private addresses from the wallet to somewhere else (another file which one might create, perhaps), or to 'Export' them from somewhere else into the wallet? Does 'Import' the Private Keys mean to bring them into display somewhere in the wallet? I just don't understand and am afraid to try out either of these commands just in case I somehow lose my Bitcoins.

As you can see, I'm not exactly tech savvy and would really be grateful for help here from any Electrum wallet users on this forum.

Terrylei


texts: Wallet backup in heterogenous environment

texts: Can we restore a windows environment .dat backup file into linux environment?


texts: i did a search in my email for "bitcoin" and i came up with a bitcoin address sent from me to me looking like this "bitcoin:1AQhW**************" is that bitcoin money and if so how do i get it ?


texts:
I'm trying to create a BTC transaction with one input and two outputs, one for change and one OP_RETURN to anchor data. And I'm doing all of that on my regtest backend. The raw unsigned transaction is

01000000018be9d0e99e74d69d915e105db1328707f713d42a894909b18a78fe68e1d8290c0000000023210340165231215a98e7a32abce9d410ecd09ac505938b25f9451defa051d591ebf8acffffffff0218ee052a010000001976a9143eb52fb0be4be87edc74848b371547f663e26c7e88ac0000000000000000226a408973d6b447bdda5312b1ef1b5509668672296301dd328d4e55317def98f165d200000000

I can then use the bitcoin rpc to sign it and it works, so I'm pretty certain that this part is correct. When I however try to sign it manually I get the error

500: {"result":null,"error":{"code":-26,"message":"16: mandatory-script-verify-flag-failed (Non-canonical DER signature)"},"id":2}

I've followed the steps outlined in How to redeem a basic Tx? as well as Signing a raw transaction with Python ECDSA (or OpenSSL) as well as attempted to use pybitcointools to sign the input without success.

The address and private key I use are

addr: "mmEXEzUGcMmmiLsfxxM8gB8TQSTkuR1drf"
pk:  "cTyF9pebH3kwwzUt5gzaxSDQ1DbqYfx4P1i4d1TyjtSDEeUFgYsk"

and stragely, even though the PK is the one given to me by ./bitcoin-cli -regtest dumpprivkey <addr> does not seem to match the address and I'm not sure why or what it is I need to do to it (it's in WIF format and compressed, i.e. 0x01 appended to the end

The original TX includes the scriptPubKey of the utxo. I then double sha256 the whole raw tx (shown above) and replace the scriptPubKey part with the sigScript | pubkey using the following code:

private_key, compressed_pk = wif_to_private_key(private_key_wif)
tx = bytearray.fromhex(raw_unsigned_transaction) + int(1).to_bytes(4, 'little')

double_sha256_tx = hashlib.sha256(hashlib.sha256(tx).digest()).digest()
signing_key = ecdsa.SigningKey.from_string(bytearray.fromhex(private_key), curve=ecdsa.SECP256k1)
public_key = bytearray.fromhex(privtopub(private_key_wif))
signature = signing_key.sign_digest(double_sha256_tx, sigencode=ecdsa.util.sigencode_der) + int(1).to_bytes(1, 'little')
scriptSig = to_varstr(signature) + to_varstr(public_key)

to_varstr simply prints [len]|[data] and privtopub is the function from pybitcointools as I couldn't figure out how to go from the compressed private key to the address manually. It's worth noting though that the public_key here that privtoaddr from pybitcointools does not return the correct address either which might be the root cause of the issue?

I'd be grateful for any pointers or things to try

cheers
Chris

PS:
another interesting aspect is that the signed transaction I generate is a lot longer than the one generated by the signtransaction rpc call:

rpc:    01000000018be9d0e99e74d69d915e105db1328707f713d42a894909b18a78fe68e1d8290c0000000023210340165231215a98e7a32abce9d410ecd09ac505938b25f9451defa051d591ebf8acffffffff0218ee052a010000001976a9143eb52fb0be4be87edc74848b371547f663e26c7e88ac0000000000000000226a40ac4f0818b683eeeaa1fbf2f508af2fc22cc814e69025152c70d7c414ebbfc30a00000000
manual: 01000000018be9d0e99e74d69d915e105db1328707f713d42a894909b18a78fe68e1d8290c000000006b483045022100d6e538aa819f3162d5c6a0e4d9ee0323395df89e943c769d96ae939baec5c6920220083a311cb35df3c98d7a6bd0bc80d98a71fbdf8e325ba908ea4b721a4eac8bb301210343395a6e84c7f2b1d50c11f96783664a6f04d66b51befb3befcc57334e2a9abcffffffff0218ee052a010000001976a9143eb52fb0be4be87edc74848b371547f663e26c7e88ac0000000000000000226a40ac4f0818b683eeeaa1fbf2f508af2fc22cc814e69025152c70d7c414ebbfc30a00000000


texts: Can I use root used to create multiple BIP32 addresses, to spend transactions belonging to these multiple BIP32 addresses?

texts:
I want to accept BTC from different clients during an ICO, for this, I'm planning to use a combination of BIP32 and BIP39.

var bip39 = require("bip39");
var bitcoin = require("bitcoinjs-lib");

var mnemonic = 'praise you muffin lion enable neck grocery crumble super myself license ghost';
var seed = bip39.mnemonicToSeed(mnemonic);
var root = bitcoin.HDNode.fromSeedBuffer(seed);

console.log(root.derivePath("m/0'/0/0").getAddress());
//'1AVQHbGuES57wD68AJi7Gcobc3RZrfYWTC'
console.log(root.derivePath("m/0'/0/1").getAddress());
//'1Ad6nsmqDzbQo5a822C9bkvAfrYv9mc1JL'

Can I use this mnemonic to login into some pre-existing wallet and transfer the funds sent to the addresses generated using the root to transfer funds to any other BTC wallet? Or can someone suggest a better strategy?


texts: What does it mean that bitcoins have lower transaction costs than more traditional forms of currency?

texts:
So I recently bought some bitcoins. I just bought a small amount and mainly for education purposes. I bought it from a site called Coinbase.

Before this, I was told that one of the advantages of bitcoin was that it had very low fees. However, I feel like it's the opposite.

First, to buy the bitcoin, I have to pay a 3.99% conversion fee to buy. I understand that's just the exchange trying to make money - fair enough.

But then when I want to transfer the money to my paper wallet, there's another $3 they want to charge. And it seems that's the case for every transaction and every time you want to move your money around from wallet to wallet, that is a transaction.

So I guess the question is, what does it mean that transaction costs are low? Is that to mean that in theory, in the future it's got potential to be low cost? Is that to mean, its cheap but only for large transactions? Cause right now, it feels like it's much higher than any traditional form of exchange.

Even with VISA and MasterCard, they don't charge 4% exchange fee for purchases in another currency. And bank transfers are essentially free and instantaneous.


texts: I have the full client running in a local Windows machine but I want to move it to a VPS with Linux.  Will I need to download the whole blockchain again or can I just upload the copy I have on the pc?


texts: Bitcore = "Error: More than one instance of bitcore-lib found"

texts:
These two lines (and nothing more), create an error:

var exp = require('bitcore-explorers');
var btc = require('bitcore-lib');

Error: More than one instance of bitcore-lib found. Please make sure to require bitcore-lib and check that submodules do not also include their own bitcore-lib dependency.

I could see that this issue has been documented here, as well as here, and here. I read these pages, but I am still unable to overcome the issue.

Can someone please help? How do you do when trying to import different modules of bitcore?


texts: How do I determine the descriptor of a given Extended Public Key?

texts:
I am trying to run the bitcoin-cli getdescriptorinfo on a ypub... extended public key. Every time I do this I receive the message:

error code: -5
error message:
Invalid descriptor

How can I determine the correct descriptor for a given ypub?

I am trying to derive the addresses using bitcoin core and import them into my wallet. I am fairly new to using bitcoin-core so I'm not even sure if this is the best way to do this. If not, what other method might I be able to use?


texts: Blockchain parser for transaction level details

texts:
I'm looking for transaction level data for both inputs and outputs. The znort block parser returns the type of data I'm looking for, however it doesn't seem to detect multisig transactions. Has anyone updated the code?

There's another parser written by John Ratcliff which properly detects the multisig transactions, however this does not return transaction level data. Has anyone modified this code to return individual inputs and outputs?

Are there any other parsers available to return transaction level data for inputs and outputs?

Thanks


texts: What is the difference between transactioninput.getFromAddress() and transactioninput.getConnectedOutput().getAddressFromP2SH(networkparameter))?

texts:
I was expecting that, in the case when getFromAddress() returns an address,
transactioninput.getConnectedOutput().getAddressFromP2SH(networkparameter)) should return the same address. But, sometimes  transactioninput.getConnectedOutput() returns a null value, despite getFromAddress() returning a proper address. What is the reason?

If these two methods are different, how could I return the value of field "addr" of the object "prev_out" of the items in the array "input" in the JSON object returned without the use of blockchain.info-api? (for example, for this https://blockchain.info/address/1LoD9DeUeCfnZueSVPzFaFkfFcx8mG1Add?format=json).


texts: Bitcoin optional fees create transaction ordering problems?

texts:
I've tried to find a solid answer to this transaction ordering question and the practical and technical issues that do not seem solved.

My understanding is that after I create a transaction, I can choose to add a fee for miners to pick up my transaction. I submit it to the network for propagation. Miners look in the unspent transaction pool and choose which they want to include in a new block. I saw this Tweet which seems to confirm a transaction ordering problem - using the same transaction input for two transactions with the latter being a high fee and that one confirmed first. I don't understand why several responders seem to to believe this isn't a problem.

https://twitter.com/alexbosworth/status/1028031387201236992?lang=en

I am near 2 stores that accept Bitcoin. I spend an input at Costco with no or a little fee. It hangs in the mempool like above. An hour later I am at BestBuy and spend the same input but include a fee -- and that transaction gets picked up and processed first by a happy miner.

1) Even if Costco waited an hour, there is no guarantee that my earlier transaction will be confirmed in a block in 10 minutes or 210 minutes. It's still too long for BestBuy to wait 5 additional confirmations after the first.

2) There is no guarantee that even if that the first Costco transaction was picked up by a miner, that a second miner that picked up the BestBuy transaction a little later couldn't complete a block which would eventually be in the longer chain. In that case too, the first in transaction eventually gets bounced off the chain.


texts: I know CPUs and GPUs can't really compete with ASICs anymore but what about FPGAs?  Are they still reasonable?  Anyone have a ballpark idea of what kind of Gh/s (or Mh/s) has been done with something like a Spartan 6?


texts: How are wallets updated with new balances?

texts:
Let's say I have a wallet in my computer and I create an address so another person can deposit bitcoins in it.

Then it is passed to miners and later added to the blockchain. But in the meantime this transaction was not verified.

When does my wallet is updated so the balance in my wallet and in the other person's wallet are correct?

Does my wallet (and the other person's wallet) go check if it is finished and validated?


texts: Recieve Bitcoin value notifications on iPhone

texts: I would like every day at a set time to receive a notification on my iPhone with the current Bitcoin value in Euros. How can I have this?


texts: Just curious can you make $ off the spread?

texts: I noticed there was a 2.5% spread on a certain exchange. Is there a way to make money from large spreads?


texts:
I'd like to get number of transaction's data with API.
I already use API of blockchain.info.

Dose someone know other API?
I want to get number of transaction every a minutes(or less than ten minutes).
It's not one day total average.
I mean BTC.

Thank you


texts: I want to create a game where users can win Bitcoins playing my games I created or perhaps other online games. What APIs do similar applications use to achieve this? how do they host the Bitcoins? do they use their own hosted wallet, bitpay? Bitcoin escrow?


texts: How to generate bitcoin addresses on the command line or with python?

texts:
Is there an easy way to generate bitcoin addresses with a commmand-line tool? I am interested in the following requirements:

Reliable, secure and standards conform, with good entropy
Generates private and public keys for the corresponding bitcoin address
Can BIP38 Encrypt
Can produce in bulk
Runs in linux
Nice to have: python library
Nice to have: can save QR codes as images (png) for private / public keys
Nice to have: fast, and non-interactive (all parameters on command line)

Basically I am looking for a replacement for https://www.bitaddress.org/, for the command line.


texts: I have two encrypted wallet.dat files and I'm looking for a way to uniquely identify them from each other. I started using a md5 hash but then I quickly realized that this hash changed each time the bitcoind client was started and recognized the wallet. Is there a way to uniquely identify two unencrypted wallets?


texts: Got 64: non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation) when submitting segwit transaction

texts:
I got the above error when submitting this transaction:

010000000001013894a4bdcfa20ef5a6cbfe1d22c5fe5041eab586a5ea2b044f969a02dab6b3d200000000171600141a982a7d2712fc33d47c990cd8cde15c87ca2e07ffffffff015e3f01000000000017a914fb2dc3b4dd0731c8f2559506c7d0cb876b0e71298702483045022100c68dac735a3529d84fdbfc3a8a11d313d59a9791b046fc39bbfc55db71d6d2010220028f2bbfba78c393858e3cb7ad51e24e8dfd2260d4a3cbbf8feb4d4c6005967701210371b63ebaa78a70420bc36159bed610b8f788e9a7b953558f06bb40622d9cbfe400000000

A previous transaction from the same P2SH-P2WPKH address was successfully spent but I got this error whenever I try to spend this transaction:

d2b3b6da029a964f042beaa586b5ea4150fec5221dfecba6f50ea2cfbda49438

I already attempted to sign the transaction again a few time but still got the same error.


texts: Combined scrypt/SHA256 mining on one GPU

texts:
Is it possible to mine scrypt and sha256 coins at the same time on one GPU?

Rationale: Hashrate of scrypt mining is limited by memory bandwidth. That means that some of the processor cycles are wasted because the processors are waiting data from RAM. These wasted processor cycles could be used insted for sha256 mining which needs much less bandwidth.


texts: I have some BTC from grid mining I did 6 yrs ago...all I have now is the bitcoin address. How can I spend it?

texts:
I've changed computers at least 4 or 5 times since then, and didn't keep much SW around when I changed.

I've confirmed that it's NOT SPENT (at least at blockchain.info), but I don't even remember what program I was running to mine it, let alone if I needed some wallet to keep it in (or if I HAD a wallet, it's long gone...)...at the time, all I thought I needed was the bitcoin address (starts with 13Ug6j...).

How can I get it into a wallet (or someplace else) so I can spend it or convert to USD?


texts: Bitcoinica was a very popular service when it was operating. What is the story behind it - when was it started, what did it offer, and what hurdles did it face?


texts: What's the safest way to buy bitcoins in India?

texts: I have came across multiple companies selling BTC, but I’m not sure which one to trust. How can I find a safe way to buy bitcoins in India?


texts: I need to find the location of the code which deals with UTXO, and then implement FIFO on UTXO storage. I aint able to find the location of UTXO code and also where it is stored.


texts: What is the recomended sequence for signalling RBF?

texts:
What is the recommended nSequence for signalling RBF transactions?

BIP125 says:

  A transaction is considered to have opted in to allowing replacement of itself if any of its inputs have an nSequence number less than (0xffffffff - 1).

What is the recommended policy - is it better to send smaller or higher nSequence?

Also, does the sequence number need to increase with newer "versions" of the transaction with higher fees, as was the original semantics of nSequence, or not?

Bitcoin Core itself uses nSequence=0, but only in the RBF tests, AFAIK.


texts: How to get best hashing results AntMiner S4

texts:
Does anyone have any helpful tips on getting the best hash rate out of my miner?

My miner works fine, it just that I'm getting a crummy 1.65 to 1.89 TH/s rate.


texts: Is Coinbase.com combining / commingling transactions or funds?

texts:
In this transaction, I transferred 2 BTC from my Coinbase.com wallet to an external address.

Why are there 3 outputs in the transaction?

I understand the output of 2 BTC, and the 0.0001 BTC transaction fee.  One of the outputs is likely a change address.  But I don't know what the 3rd output is for.

Is/does Coinbase.com

combine unrelated user transactions into a single blockchain transaction?
tracking user's funds or transactions off the blockchain (effectively commingling funds)?
extracting its own fee from the transaction?


texts:
I just realized that I have an old Electrum wallet with a small amount of Bitcoin. I'd like to claim the Bitcoin Cash, but I'm having a hard time figuring out how to do this. I do have the original wallet password & seed phrase. I've also transferred the associated Bitcoin to a new address.

According to the Electrum site, I shouldn't install Electrum Cash on the same computer as Electrum. Unfortunately I don't have another computer to work with. I do have an iPhone & a Trezor, but I haven't figured out how to sweep my Electrum address into one of those devices.

What are my options for recovering the Bitcoin Cash without installing Electrum Cash?


texts: bitcoind rpc interface, generate method deprecated in version 0.19.0 (latest)

texts:
How to generate a block in the new version of bitcoind.

  bitcoin-cli -regtest generate 1

The above command no longer works with the latest bitcoind package

I want to confirm a transaction I have executed under the regtest mode for bitcoind, hence generating a block to confirm the tx.


texts: How can I create an exchange in a foreign country?

texts:
New to stack exchange this is my first post so sorry if its rough.

I'm part of a project interested in bringing BTC and crypto trading to Angola. We aren't sure where to start or what the best route to take is ie: create an exchange or wallet that allows P2P mobile transactions. We have a great team in place and some serious interest + investors but lack the technical expertise.

I'm looking to speak to individuals interested and knowledgeable about trading Bitcoin for AOA in Angola. Also if you have any general / technical knowledge on Africa / BTC we would love to chat or bring you on board.
Thanks so much.


texts: Do サトシ (Satoshi) or ナカモト (Nakamoto) mean anything in Japanese?

texts:
Do サトシ (Satoshi) and ナカモト (Nakamoto) have any special meaning in Japanese?

For example, the last name "Smith" or "Miller" refers to a blacksmith or grain miller, respectively.


texts:
I have an android wallet (The Andreas Schildbach one).
Is it possible to import this wallet into my desktop wallet?

I would like to be able to manage my funds using my mobile or my desktop - both looking at the same wallet.

I have been digging through the files in my phone looking for a wallet.dat / .wallet but can't seem to find one.

I did back up my mobile wallet then tried importing the backup file into my desktop wallet, but this did not work.


texts: Does BIP39 mnemonic construction avoid repeating words?

texts: Will all 24 words of a seed-phrase be unique by specification? Or is it possible for a word to occupy two positions (ie the word "tool" is #8 AND #20 in a valid, securely generated seed)


texts: Bitcoin address does not show transaction/balance from Coinbase purchase

texts:
I purchased a bitcoin using a Coinbase account. When I try to verify that transaction to the address, I can't see any activity or balance for the bitcoin address that Coinbase shows as mine. Coinbase, however, still shows my purchase activity and balance correctly on my account.

Has this something to do with the way Coinbase or such wallet services work? Or is there something wrong? Do I actually have the bitcoin or not?


texts: What is a workaround to fundrawtransaction for watchonly addresses

texts:
I have imported watchonly addresses in Bitcoin and trying to createrawtransaction with input watchonly listunspend which has spendable=false, scriptSig=empty.

after that, I'm getting an error on fundrawtransaction with message "Signing transaction failed"

I know it's unsigned and can't calculate fee but if I put in order
createrawtransaction
signrawtransaction
fundrawtransaction
sendrawtransaction

still, it gives me an error "Signing transaction failed"?


texts: Wallet.dat can contain only 100 private keys even if I back up?

texts:
Considering the Bitcoin client for Windows 0.8.1:

So the best way (if I have already used up 100 keys) is to send bitcoins to different wallet and then to newly generated one?

When I want new keys, can I just delete old wallet from default location and WILL BE THE NEW ONE GENERATED AUTOMATICALY when turning on the client?


texts: How spending same coins both at BCC and BTC blockchains prevented?

texts:
------X--.---------- BTC Blockchain
              \
               .--------- BCC Blockchain

Let's say that we have some BTC coins from a transaction at block X. And, there are two blockchains now. Is spending these coins at both blockcoins prevented? Are there any BTC/BCC cross check for double spending?


texts: Should port forwarding for running bitcoin be done also on the ISP's router?

texts:
Follow up question on What is the NAT traversal technique used by bitcoin.

The network architecture described here https://superuser.com/questions/1109859/2-routers-connected-in-series-and-port-forwarding is something that I (probably) have in my home (and probably 99% of other people):

Internet > ISP router (NAT 1) > My home router (NAT 2) > My Node

So my Node is hidden behind 2 NATs. Therefore I should forward ports on both routers to allow incoming connections to my Node.

But people have no access to NAT 1 and can only port-forward NAT 2, and must probably contact ISP to port-forward NAT 1.

How do people run their nodes with incoming connections enabled when this issue is present?

EDIT: In discussion with lenlord it seems that his ISP's router does not perform NAT and that his home router has (dynamically) assigned public Internet address. Is this the standard configuration ISP's provide for homes.

EDIT2: After contacting the ISP and reading some forum posts I found out that I'm indeed behind their NAT (NAT 1 in picture, so called CG-NAT), but that they can remove it for me for free.


texts: Why does the Bitcoin conversion rate change wildly?

texts: I don't understand why the conversion rate for bitcoin changes wildly. Why does it?


texts: If Cryptocurrency offers anonymity, why is it considered by forensic professionals to be the best currency for fighting illicit transactions?

texts: A paper by titled An Analysis of Bitcoin’s Use in Illicit Finance discusses how Cryptocurrency is considered by forensic professionals to be the best currency for fighting illicit transactions. In terms of it being digital this makes sense, and of course the public ledger would showcase all transactions, but aren’t the identities of those transacting hidden cryptographically?


texts: How it is possible to create coins only with the proof of stake system?

texts: Nick Szabo comes 2011 with a alternative proof system wich he calls proof of stake POS. This system was used later by varios coins ( NXT, Peercoin, Blackcoin etc.)  but all of them had the genesis coins premined or have them created in the beginning with the proof of work system. But how it would be possible to create coins only with the proof of stake system from the beginning ?


texts: How to generate random addresses from public key such that they're recoverable later using pub key only

texts:
I head that from a public key, you can generate random addresses just by adding a nonce to the public key. Then, you can regenerate all these addresses again when you need, right?

If my wallet has knowledge of my public key (of course it has), it can generate lots of private/public key pairs just by adding a number to it. For example, suppose the private key is x and its public key is y. If the wallet deleted the private key x for a while, it can generate the address y+1 and be sure that when it does x+1 it will get the private key for this address in the future when it needs to spend those funds. This is a property of elliptic curve cryptography, because there's a homeomorphism between the sets of private and public keys.

I've heard that if I give someone my public key, he can derive a unique address and send to this address being sure that I'll be able to spend it because I can find the private key for that address just by adding the same nonce he used to generate its public key. The problem is:

He has to tell me which nonce was used, otherwise I'd have to try random ones till I get to the one he used. BUT, if that's how its made, then anyone can pick my public key and find all my addresses. If he really has to tell me the nonce used (suppose it's really big and random so I couldn't guess by brute forcing), then there's the risk that I'll lose it, because I'd have to keep track of all these nonces.

So how is this done? How can I, given the public key of someone, generate a random address for him such that he'll be able to get the private/public key for it later, but such that he does not need to store anything that was used to generate that address?


texts: Looking for feedback on (Browser-based) Blockchain Simulator

texts:
I have created a Blockchain 'simulator' in JavaScript, for the purpose of helping explain how the technology works. It is complementary to a website I have set up years ago, where I attempt to explain blockchain technology in laymen's terms (I use the same coloring and design of elements, to stay in line with the design of the website).
It is made up of three basic components:

A Memory Pool
A Miner
'The Blockchain' (an overview of the blocks mined)

It features:

SHA256 mining (with optional MD5 hashing, more of an experiment to see which is faster in JavaScript)
32-bit string noncing
Adjustable hash rate (with a clock-multiplier boost)
Difficulty adjustment
Auto-replenishing Memory Pool (generates random transactions to prevent running dry, unless paused)
Actual individual transactions (represented as SHA256 hashes)
Miner and Memory Pool are individually pausable (or both at once, using the master control)

Everything is 'to scale', in that I have chosen a block target time of 10 seconds, as opposed to 10 minutes*. Furthermore, difficulty adjustment occurs every 5 blocks, and blocks only contain 9 transactions + 1 coinbase transaction. All this is done to benefit the comprehension (obviously no one is going to wait 10 minutes for a block to complete).
*Still working on/experimenting with these values, as hashing seems to be too erratic to reach a good constant 10 seconds.
Here's the link to the simulator
What I'm looking for
I am looking for any feedback on its basic workings, mainly to see if/where I made mistakes, and what I can do to make it even easier to understand. Besides that, I'm very curious as to what you think!
If this is not the place to ask for feedback, I do apologize and will remove asap.


texts: Can I import my wallet while my btc core is syncing

texts: I'm upgrading my btc core to v0.18.1. I'd like to export my wallet to electrum. Is it possible while syncing? How?


texts: Insufficient money, need xxxxxx Satoshis

texts:
Trying to process a transaction out of my Multibit wallet, entering the key & the error message 'insufficient money' appears on the screen. I know that I need to add a transaction fee, which I am doing, however the number of Satoshis required increases at every attempt! For instance, the transaction will require 100250 Satoshis, so I will amend the amount being transferred to 100300 to compensate & allow for any fluctuation.

The warning then reappears stating it now requires 100500 Satoshis.
This cycle is continuing, I can't find a figure beg enough to get
ahead of the curve, without literally throwing my money away! Any help
would be appreciated, this has been frustrating me for some time now!


texts:
Can I be the transaction processor and take in transaction fees as income without mining a Bitcoin?  Would the fees be so low that it is not practical?
Or is it true that I have to be a miner in order to process any transaction? However, after year 2140, when all Bitcoins have been mined, then will people only use the computer to process transactions without doing any mining?


texts: Is a Bitcoin address guaranteed to be unique?

texts: I may have misread this but apparently every time you generate an address it is not checked against any other addresses generated? The reason being the sheer scale of the amount of possible addresses that could be generated makes the probability of generating two of the same addresses almost impossible. If that is the case, that would mean the same for the private key. What would happen if by some chance two addresses were generated equal?


texts: Does anyone know how to get a hold of a human being on the phone at coinbase? Or the contact info of a good crypto lawyer? Their customer support is lacking. I have a stuck transaction going on two weeks with them. I'm worried they are going to change my coinbase receiving address on me and just steal my transaction.


texts: Privacy of sending CoinJoined UTXOs from wallet with unCoinJoined UTXOs

texts: If I use something like Wasabi to CoinJoin my UTXOs and then send the outputs to a wallet with addresses containing UTXOs that haven't been coinjoined does this present a privacy risk?


texts: Query Blockchain: Reference previous transaction in "txin"

texts:
I'm currently working with a postgresql database I've downloaded here which has the following schema and has probably been parsed using Bitcoin-ABE (I added some indexes and redundant columns):

Now I'm stuck trying to make a connection between a transaction input and the previous output. According to the API that belongs to the sql dump, the field prev_out references "the output that this input spends". My problem is, that I can't find any of the txin.prev_out values in tx.hash. Is this line of thinking correct, or am I connecting the wrong fields?

FYI: As you can see both fields are of the type bytea. I was able to use the function encode(hash, 'hex') to get the actual transaction hash and find it at blockchain.info. For the field txin.prev_out however, the hash cannot be found at blockchain.info.


texts: Is the block nonce predictable in any way? It seems to be a proof of work on his own just like the block hash, but may a miner force a mined block to have a specific nonce? (if his hashrate allows him to)


texts: Install Copay on Windows 7 64 bit desktop

texts:
I have windows 7 64 bit.  I need more information.  Step by step, please.

I have reviewed the previous answers but do not understand: (New copay on Windows 7)

1) Exactly what to download from where
2) How to install/ run the download

The windows app store says the download requires Windows 10 + one has to have/ create a Microsoft account. (https://www.microsoft.com/en-us/p/copay-for-windows/9mzgt30hl9df?rtc=1&activetab=pivot:regionofsystemrequirementstab)

From the previous answers, I tried downloading the zip file but cannot figure out how to install it.
Thank you


texts: Is there a list of existing businesses that have started to accept Bitcoin?

texts:
As opposed to new business that sprung up and accept Bitcoin from day 1.

I believe it will much shorter than the Trade wiki page, and perhaps more valuable in a certain way.


texts: Are BIP39 mnemonics generated with a French list compatible with software that expects English words?

texts:
BIP39 specifies different word lists in different languages. But I wonder if the word list generated by a software that gives me French words (e.g. Copay on iOS) can be used to re-create the same wallet using another software that expects English words.

I looked at the section From mnemonic to seed of the BIP39 specification.  Given that the mnemonic sentence itself is fed through the PBKDF2 function, rather than first looking up the indices of the words in the dictionary, I guess that the answer is no, and a French list can't be easily converted into an English list. Is this correct?

Doesn't this drastically reduce the interoperability of wallets using different word lists?  Specifically, how can I ensure that the word list I have for a wallet can be used in another software than the one it was generated with?


texts:
Is all the data related with the transaction of bitcoin stored in blockchain or the data stored somewhere in the cloud and they are referenced from blockchain. I have this confusion because if we are storing all the transaction information on blockchain then it will become heavy with time. How it will get managed at storage level (if the data is in blocks).

The size of each block in bitcoin is 1 MB, is it sufficient to store all the data (of every 10 mins) in the blocks?


texts: Bitcoin testnet: "Bitcoin is downloading blocks..." and other problem

texts:
I'm trying to setup a local testnet with multiple nodes. Currently I have three nodes, and their mining powers are almost the same.

Things have been quite ok so far, except some problems that I need to ask from you.

When I run the getblocktemplate rpc call (because I later want to run a pool), it returns the message as in the title. For example:

./src/bitcoin-cli -datadir=./localnet getblocktemplate
error: {"code":-10,"message":"Bitcoin is downloading blocks..."}

although there are already 10 blocks in the blockchain maintained by the node. Its the same for other nodes as well. So why does that happen?

The nodes do not sync up very often although they are all connected together (each node has 2 inbound connections and 2 outbound connections). It is so often that one node is 2 block ahead of other and remains so for a long time. Thus, again, why does that happen? I thought after finding a valid block, the node will broadcast that to every connected node and the network will work on top of that block?

Please let me know if you can help answer either one or all the questions.


texts:
I would like to get the full raw data on the latest bitcoin block. I was hoping I could get this from an API.

I looked at blockchain.com's API's but these don't seem to provide the full data for each block including the header and transactions.

Does anyone know of a good source for this? Or should I be looking at alternatives to an API?


texts: create/sign/send raw transaction from specific Wallet account

texts:
I've been playing with the createrawtransaction, signrawtransaction, and sendrawtransaction Bitcoin calls.

Let's say there are two accounts in my Wallet: Account1 and the default "" account. Let's also say account balances are "" = 0.00000000 and Account1 = 0.50000000 and that the only UTXO in my Wallet references a Bitcoin address owned by Account1 as the output address and is in the amount of 0.50000000.

When I create, sign, and send the transaction to another Wallet, the account balances appear as "" = -0.50000000 and Account1 = 0.50000000, and the balance of my Wallet equals the obvious 0.00000000.

Is there any way, when creating/signing/sending a transaction, that I can specify which account to send it from?

I'm familiar with the sendfromaccount call that would accomplish this, but I want to create my transactions manually so I can control the change (when necessary) and the transaction fees.


texts: How does a miner get selected in Proof Of Stake?

texts:
I am trying to understand POS. I get that POS uses currency held analogous to the hash power held in POW system. More the stake we have, more are our chances of mining the block. At various sources I read that, a miner is chosen deterministically.

Can someone please explain, how miner selection takes place. And how everyone agree on the same miner, there has to be some algorithm involved.

Quite a lot is mentioned here: https://github.com/ethereum/wiki/wiki/Proof-of-Stake-FAQ
but, I can't seem to find the answer to my query.


texts: How to make cryptocurrency easier for law enforcement?

texts:
I am researching the topic of cryptocurrency and its impact on society.

It's often said that cryptocurrency is equivalent to cash, but that is clearly not true since cash is very difficult to transport in large quantities over borders and usually requires physical presence to conduct a trade. It is also said that Bitcoin is not anonymous since the transactions can be tracked. However, in reality, its pseudo-anonymity can easily translate to true anonymity when a good laundry service is employed. Thus, cryptocurrency can and does open new avenues for criminals, such as making it much easier to transport and launder the proceeds of crime, facilitating bribery and blackmail by reducing their risks, and many of the bad things cash is associated with since money has always been a central element in crime.

Regardless of what you think of this from a political point of view (and I expect that many in this community don't see a problem with it), I think there is an interesting technical question here:

Is it possible to design a cryptocurrency that achieves a compromise between the relatively strong pseudo-anonymity of Bitcoin and the classic banking system that is disastrous to personal privacy?

Ideally, we should design a system that keeps as much as possible of Bitcoin's strong privacy protection and other desirable features such as decentralization, but at the same time, allows law enforcement to track anti-social actors like the classic banking system allows.

So, I'm asking for ideas of about how to get the best of both worlds. The network should work in a high privacy mode by default, and when the need arises, law enforcement should be able to reduce the privacy in a very visible way, for example by requesting the collaboration of other users. There should be no backdoor, no way to deanonymize the whole network in a surreptitious way like the NSA is doing by tapping all SWIFT traffic.
Therefore, the definition of "law enforcement" is not a magic attribute or key stored by the network, rather it's implicit: the party who can convince nodes to collaborate to deanonymize other nodes.

Additionally, it would be desirable to prevent anonymous laundry services while keeping the network open to join like Bitcoin, without the classic KYC routine of banks. This seems like a contradiction (Sybil attack) but maybe some compromise exists, so your thoughts are much appreciated.


texts: What could be the impact of the distribution of "tainted" Bitcoinica coins?

texts:
The hacker was distributing them in IRC recently, and sent some to the Bitcoin Faucet. Is this a reliable method for evading the "Bitcoin Police"?

Here's a forum thread discussing the distribution and a pastebin of the IRC conversation. Pasted below is just the beginning of the pastebin content:

<BitcoinicaHacker> Who wants free bitcoins courtesy of bitcoinica?
<grepix> who doesn't!
<BitcoinicaHacker> post your btc addr
<nanotube> i think bitcoinica wants free bitcoins courtesy of bitcoinica
<Phraust> oooh, i'll take some: 18LSrqYfUwt4q52CvSWXkSqNiDMGDADAao
<BitcoinicaHacker> d43282f1ec433cb896ddf7d4a88faa4a202c97ac6e60568eaecfd1df53d82ef6
<Phraust> sweet, many thanks.
<OneMiner> 121VuNzJi7ihM6FTv28oruemfw4fp4rvPZ I'll take a piece of that. :P
<BitcoinicaHacker> f87f87a6e053157140bd509952c999e56344fe4fa90eaf47288bbcdda7689514
<BitcoinicaHacker> 74358a453321026b197549a250c3aa65b60187f8d4ba4578de1b1422eec2937d
<OneMiner> Thank you very much.
<b00bsman> BitcoinicaHacker, wie ist der Kuchen?
<brwyatt> 12KTki1xe5xVoQneEZy2CED8Ep87ifubx7 I'll give it a try.
<brwyatt> He really wasn't kidding. o.O
<BitcoinicaHacker> 8694268cfe0aa51d7ecb3749b8f4bc8ebe7c56cc8e920f1b7b34862f9992e004
<OneMiner> Ya, seems legit.
<grepix> the BTC def showed up, but for all we know this is just a lazy trolling :D
<brwyatt> yeah
<OneMiner> The balance of the account suggests otherwise.


texts:
When I run cgminer for run it to mine ltc the parameter --scrypt, cgminer says that is not recognized option. So, cgminer does not work.

What miner can I use to mine litecoin with the scrypt hash function?


texts: How to convert Script hash into opcodes, in Ruby?

texts: I have a script and it looks like this: 76a914af7a4a30243f2301e6a14a4979ae099d52f560d488ac. How can I create an instance of class Bitcoin::Script from ruby-bitcoin? It has to be parsed, I believe, but how? I posted a GitHub ticket too.


texts: Move Bitcoin from account '' to default account

texts:
I am running Bitcoind and Bitcoin-cli for my RPC. When I run

./bitcoin-cli getbalance

it does not return my correct balance, but when I run

./bitcoin-cli getbalance ''

I can see all my funds.

Question

How can I move my bitcoin internally, such that I only need to call

./bitcoin-cli getbalance to see my balance.


texts:
on the testimony of bitcoin champion all the testimonies talk  of an initial investment of 100 usd, and when Iam registrating the inicial investment is 200 usd? why is this?
I whant to register buy I justo want to invest 100 usd.


texts: Do Bitcoins mined in a pool automatically transfer to your wallet?

texts: I've installed the GUIMiner app and the Multibit app.  I am in a mining pool, and I have about 17 shares thus far. Do the Bitcoins transfer to my MultBit wallet automatically or do I need to do it manually?


texts: How to generate xPub Key from public key in java

texts: I am working on a Bitcoin Wallet, i have public key but can't figure out how can i genrate xPub key from this.


texts: ripple-lib is not returning transactions with the getTransactions method

texts:
My code is

const api = new RippleAPI({
  server: 'wss://s1.ripple.com'
});

api.connect();

    let isConnected = false;
    api.on('connected', () => {
      isConnected = true;
    });
      return api.getTransactions(address)
        .then((transactions) => {
          console.log(transactions);
        })
        .catch((err) => {
          console.log(err);
        })

But it doesn't actually return anything. It has an empty array [] for transactions.

If you look at the address I'm looking at: https://xrpcharts.ripple.com/#/graph/rqnfXCcsZRadjoj8tDQWYsP1pVyv3Ro7X

You'll see there are some transactions. So why doesn't the API return anything?


texts: Which precautions should a newbie like me do when exporting keys from an Bitcoin Core wallet to an Electrum wallet

texts:
I have an Bitcoin QT v0.8.5-beta wallet (downloaded in 2013) which it seems that I now have sucsessfully upgraded to the latest Bitcoin Core wallet. The  Bitcoin QT wallet did not disappear with the upgrade, and now I also got the Bitcoin Core Testnet wallet that automatically followed the Bitcoin Core wallet upgrade.

About 1/15 of the blockchain is now downloadet in the wallets, and I bought half a bitcoin in 2013 that I do not have catched in in my wallet yet. So I plan to download an Electrum wallet, and then import the private keys from the Bitcoin Core wallet, to the Electrum wallet, so I faster can get my half an bitcoin.

The Core wallet has now, for some hours, reindexed blocs on disc, so I think I should wait until that is ready.

My Bitcoin Core wallet is encrypted with a password, So should I decrypt the wallet before exporting the keys? The problem then is then that I can not find a place in the  Bitcoin Core wallet to quit the password, but only change the password.

And is it a problem that I do not have catched in the whole blockchain yet to the Core wallet before exporting the keys?

Should I export the keys from the Core wallet, or should I import the keys from the Electrum wallet, and where in the right wallet do I find the option?

Other problems a Newbie like me can stumble upon at this project?


texts: How much does it cost in computing time/hardware to mine bitcoins?

texts: I'd like to know how much the number changes depending on whether it's done using hardware or just in software. I'm curious how long you'd have to leave a computer mining bitcoins for it to pay for itself


texts: Butterfly Labs ASIC for rendering in 3dsmax

texts:
Sorry if my question could be silly, but is there any option to perform 3d rendering on my Butterfly Labs ASICS?

As for now, I don't see any reason to farm bitcons on my 5Ghash ASICs, so I came up to an idea of making a rendering farm.

Thanks!


texts: Is it possible to change to protocol, mine lots of blocks offline, and then change it back?

texts:
Is it possible to make changes in Bitcoin protocol and then start to mine faster than 1 block in 10 minutes?

What happens when someone makes those changes and "mines offline" blockchain that is longer than current one. And after that changes protocol back to "normal" and appears back to online network?

Is it even possible?


texts: Where, or how, can I get a complete history of difficulty?

texts:
I would like to have a complete list of the historical mining difficulty of bitcoin. Preferably it would be a text list or csv, but a webpage that displays the data in any text format will do.

I've been searching for several hours over the last couple of days with no progress. I'm quite surprised that this is so hard to find...


texts:
Currently, the Bitcoin Wiki states:

  A part of the original Bitcoin implementation, nLockTime is a field that specifies the earliest time a transaction may be added to a valid block. A later Bitcoin soft fork allowed nLockTime to alternatively specify the lowest block height a transaction may be added to a valid block.

Is the ordering correct? It appears that the source code as of v0.1.5 used the block height and v0.1.6 extended this to handle timestamps. Also, does this new ordering make it a hard-fork?


texts: Can you send Bitcoins from Bitcoin-Qt without downloading the whole blockchain?

texts: If I have Bitcoins in my wallet and I have downloaded the blockchain far enough so that I can see that I have received them, can I send them without having a fully updated blockchain?


texts: BIP34, BIP66 and BIP65 should have been enforced at unique block heights. Why do different sources claim different block heights for enforcement?

texts:
Inconsistent Consensus/Activation of BIPs

BIP34

Activated Block Height 227,835 (BitMEX Reference)

Activated Block Height 227,930 (Bitcoin Developer Reference)

Activated Block Height 227,931 (Github Reference)

BIP66

Activated Block Height 363,724 (Previous Question)

Activated Block Height 363,725 (Github Reference)

Activated Block Height 363,731 (BitMEX Reference)

BIP65

Activated Block Height 388,380 (BitMEX Reference)

Activated Block Height 388,381 (Github Reference)

Confusing Documentation

BIP34 says it activates when 950 out of 1000 blocks signal for Version 2. It is not clear if this includes the current block or refers to previous blocks

BIP66 says it activates when 950 of the previous 1000 blocks signal for Version 3. However, the client notes say 951 of the previous 1001 blocks. Then BIP66 says it activates using the protocol of BIP34. Now we have three possible methods. They do not match up.

Any advice on what is going on here?


texts: can cryptocoins be put to good use? now or in the future?

texts:
it would be amazing is there was a Cryptocoin that could be put to good use.
Like some sort of protein folding.
Curecoin, CureCancerCoin exists but it doesn't put anything towards computational research projects.
Folding@Home is an example of something that could be integrated to a cryptocoin.

Is there anything other than Curecoin or CCC?


texts: What is the recommended lowest fee for a segwit transaction when sending coins from a bc1 address?

texts: What is the lowest fee for sending 1 btc from a segwit bc1 address?


texts: Help me please, my transaction is still unconfirmed

texts:
Please help me, I have a payment which is not confirmed after 16 hours.

https://blockchain.info/tx/b10e78862f253c967ad588a7e017d75fc8fe85419e3f2506bfb790ddd765712c

What should I do?


texts: Clarification of some getaddr() function inputs and outputs

texts:
In the Bitcoin system to discover new nodes, each node communicates with its peers by sending getaddr() to the peers. Based on the bitcoin implementation:

//! the maximum percentage of nodes to return in a getaddr call
#define ADDRMAN_GETADDR_MAX_PCT 23

//! the maximum number of nodes to return in a getaddr call
#define ADDRMAN_GETADDR_MAX 2500

Based on Eclipse Attacks on Bitcoin’s Peer-to-Peer Network ∗

The peer responds with n randomly selected addresses from its tried and new tables, where n is a random number between x and 2500 and x is 23% of the addresses the peer has stored.

The reason behind this is to eliminate an eclipse attack (aka netsplit), where an attacker monopolizes the environment of a node by sending it compromised addresses.

The receiving node accepts a maximum of 1000 addresses because it is limited to a buffer size that can only hold 1000 addresses.

What is the 23% or the 2500 addresses based on?

Why is the buffer size limited to 1000 addresses?


texts: What are the country-specific cryptocurrency prices on Yahoo finance?

texts: I was under the impression that cryptocurrency prices were set by an exchange's currency volume and buy/sell averages, so what exchanges are used to get the Yahoo finance data with country-specific cryptocurrency prices?


texts: Use hdseedid to give all addresses in bitcoin

texts:
I'm using bitcoin core version 0.18.1 and I'm studying Hd Wallet.
I can see the value hdseedid, and I understand that it's HASH160 of my hd seed.

Can I use this seed to retrieve all my keys?
I tried to put this value in https://iancoleman.io/ like entropia, but I don't find the same address that I can find in dumpwallet.


texts: Ability to Send Bitcoins to an Address over a duration of time

texts: Is there a service or upcoming feature which lets you send Bitcoins to an address over a duration of time? I can write a script myself to send 1mbtc every day to an address and leave it running on my computer/server. But I was wondering if there was a service that does this already? Or can smart contracts do this, if so which one?


texts: How to sign a message using Bitcoin private key?

texts:
How does one create a proper signature for a given message using Bitcoin private keys?

I have an input address of

5JeWZ1z6sRcLTJXdQEDdB986E6XfLAkj9CgNE4EHzr5GmjrVFpf

or

6d7f6815bd7927423a728db28c5f4ea4032a81ab8dbca06ec41476508de48a6d

I want to sign message:

test

I convert it to hex:

74657374

I feed it to a signing function of ECDSA library that uses secp256k1, and I get two outputs,

r = D16A44BF1095FB7D517C7C4DD6A51E3EFD29548C5CAD8CA4AB763946D02AE0E8
s = 2AB3E674B788804B87CED50619A1EFA267E17D20C016D0779BC3203D40E8105D

If I marshal it with DER/asn1 as a list of Big Integers, I get a result of:

MEUCIQDRakS/EJX7fVF8fE3WpR4+/SlUjFytjKSrdjlG0Crg6AIgKrPmdLeIgEuHztUGGaHvomfhfSDAFtB3m8MgPUDoEF0=

If I marshal them as a list of byte arrays, I get

MEQEINFqRL8Qlft9UXx8TdalHj79KVSMXK2MpKt2OUbQKuDoBCAqs+Z0t4iAS4fO1QYZoe+iZ+F9IMAW0HebwyA9QOgQXQ==

if I marshal them as one long byte array, I get 0WpEvxCV+31RfHxN1qUePv0pVIxcrYykq3Y5RtAq4Ogqs+Z0t4iAS4fO1QYZoe+iZ+F9IMAW0HebwyA9QOgQXQ==

None of them appear to work as signatures when I try to verify the message signature using tools like http://brainwallet.org/#verify .

How do I properly sign messages using Bitcoin private keys to be compatible with BitcoinQT?


texts: How to dump all of addresses from wallet.dat for other alt-coins?

texts:
I'm on binarycoin now, with solo mining. Luck smile to me. I'm found 5 blocks. It is 100.0 binarycoins.

I'm trying to use "aggressive" speed-up, my daemon compiled with -O3.

After last block I caught crash of daemon. And fails of relaunching with err:

Database environment corrupt; the wrong log files may have been removed or incompatible database files imported from another environment
PANIC: DB_RUNRECOVERY: Fatal error, run database recovery
wallet.dat: unable to flush page: 19
txn_checkpoint: failed to flush the buffer cache: DB_RUNRECOVERY: Fatal error, run database recovery

If I'm redownload the blockchain.

-rescan doesn't help.

I'm shutdown the network, clean everything in the .binarycoin/* except wallet.dat and binarycoin.conf. Launch the daemon. My wallet.dat remembered that there were blocks, every block was marked as orphan. I've start to sniffing for my coins. My account named as "" contain only one address. I've found a web-blockchain  www.binarycoin.info:8080/
There was no my address.

By tx ids in my wallet.dat, on this web-blockchain I've found addresses that received the bounties. I've dumped privkeys of this addresses, and cooled down.

My nerve continue playing. What if there is no side web-blockchain. How should I discovery the tx ids and thereafter my addresses, and thereafter dump my privkeys?

There is no option to get every address from wallet.dat, only one (default) address.

I found pywallet. It is for Bitcoin. Nevertheless, I've dump in plain-text my wallet.dat. 117 addresses with their privkeys.

I compare my real addresses with this 117. No one.

I compare privkeys. No one.

How to trully extract all addresses and all privkeys that wallet.dat contains?
( Specially for alt-coins )


texts:
As far as I can tell, my old bitcoin wallet got corrupted. It was created in Bitcoin Core in the 2014/2015s, and I'm trying to recover it. Bitcoin Core doesn't accept it anymore (and doesn't give an error message), so I'm trying another way.
I managed to read the contents using walletools (https://github.com/akx/walletool), and here is what I have :

a long list of "tx" items, containing mostly binary data
quite a few (probably 50 ish) "ckey" items, with the public key and encrypted private keys
a single "mkey" item, with the 'nID', 'encrypted_key', 'salt', 'derivationMethod', 'nDerivationIterations' and 'otherParams' fields containing data
two "name" items containing 'hash' and 'name' fields
a number of "pool" items with 'n', 'nVersion', 'nTime', and the 'public_key'
lots of empty "keymeta" items
a "version" item : 150001
a "bestblock" item, with a "key" field
a "minversion" item : 130000
a "orderposnext" item (empty)
a "bestblock_nomerkle" item (empty)

From there, I imagine the important data is the mkey. What is its encryption algorithm and what Python lib could I use to decrypt it (assuming I remember the password ! ) ?


texts: Is there already reached consensus on network upgrades like Taproot, Submarine Swaps?

texts:
I have read about some very interesting new protocol amendments. I am not asking for their explanations, but would be great if anyone explained  their current status, if they are still considered to be implemented (do you know when?), or if they have been removed from consideration...
Is majority of relevant stakeholders in consensus and for these changes, any struggles to be expected like with segwit?

MAST/TAPROOT

SCHNORR

Submarine Swaps

Drivechain Sidechain, by Paul Sztorc


texts: Currently the best graphics cards to mine Bitcoins are all AMDs. What should be changed in the Bitcoin protocol to make the alternative version of Bitcoins better mined by NVIDIA graphics cards? Could there be a protocol that would support both of the graphics cards produces in more or less equal way?


texts: What is the maximum number of names (domains) that can be registered with NameCoin?

texts:
Is it 21,000,000 / 0.01 (the cost of naming) = 2.1B?
from docs: "The name_firstupdate transaction has a network fee. The network fees represents namecoins (NC) that are destroyed. "

Am I missing something? If not, it seems like quite a small number.


texts:
If each bitcoin has a ledger (Peer to Peer) and contains all the transaction history since it was mined, then how come it can be stolen?
For example, Bitcoins were stolen by hackers from Mt. Gox. If the Bitcoins each have a ledger it would show its owner and the Mt. Gox account. So it would be traceable and hard to trade if stolen.
Maybe I am not fully clear, would appreciate clarification - thanks!


texts:
When I share an request as a link it can look like this:

bitcoin:1474awqSNomvEjS2vPv4Pueq3WkrMaEFfP?amount=1

I've got some basic questions about request link:

Is just my address and the value sent contained?
What software recognizes such links?
When is it displayed as a link?
How to use it without being clickable?


texts: How much hashpower would I require to surely mine one block per day?


texts:
I'm starting a new project that uses bitcoin. I'm afraid some feature can't be done, or aren't safe. I'd like to validate some ideas:

I'll create a wallet/address and publish it on the project's website. All customers are supposed to pay/transfer BTCs to the same address (identify the payment is not a problem).

Eventually, I'll need to refund a customer.

1) Is it safe to refund the customer using the same address he/she used to pay me?
2) Can I continue using the same address for receiving BTCs after a refound?

I know that, when you send money to another address, the change back is sent to another address (still yours).

3) Can I send a % of a wallet to an address and the remaining/change back to a new address (totally different wallet/private key) in the same transaction.


texts: Yes I am a newbie trying to get started with Coinbase. I have created a wallet and it seems there is no way to back-up that wallet for safety reasons. I am still confused, can I send an amount from that wallet to a offline wallet and what would the steps be? Thank you.


texts:
I randomly stumbled upon an example of a channel for which one of the two sides does not have a channel policy. What could be the reason for that? For example, lncli getchaninfo 620048691895336960 returns this (and node1_policy here is null):

{
    "channel_id": "620048691895336960",
    "chan_point": "4857421490e50d3ffed1e31346c8cc56f229f70ad93d800d647db794cc09bb59:0",
    "last_update": 1550695804,
    "node1_pub": "03b9c09d8522d6d6ca3c4fe3e635b65e962fade78437ef2ac46f37df4c0119aa03",
    "node2_pub": "03bb88ccc444534da7b5b64b4f7b15e1eccb18e102db0e400d4b9cfe93763aa26d",
    "capacity": "2000000",
    "node1_policy": null,
    "node2_policy": {
        "time_lock_delta": 144,
        "min_htlc": "1",
        "fee_base_msat": "0",
        "fee_rate_milli_msat": "1",
        "disabled": false
    }
}

If that is relevant, node1 here runs eclair, and node2 runs lnd.


texts: Which derivation paths are used by the Abra wallet?

texts:
Abra have stated in a reddit comment that their non-custodial HD wallet uses custom derivation paths to convert the user's BIP39 mnemonic seed into cryptocurrency address/key pairs. Has anyone figured out what these custom derivation paths are?

If Abra's nodes ever get shut down, users of the Abra wallet will need to know the derivation path[s] — otherwise their funds will be trapped, even if those funds are not being used as collateral in a contract.

In March 2018, the CEO of Abra said “there is no standard structure for reconstituting p2sh based wallets across different apps via the seed”, so I'm effectively asking if there's been any progress since then.


texts: I was unable to fund another wallet since this morning

texts: Hello everyone, I have been trying to transfer some amount from my wallet to another bitcoin address but didn't successful since morning, please I need help on this critical issue.


texts: What are the security implications of not hosting your own Electrum server?

texts: Bitcoin-Qt is getting require large and is taking up over 10% of the space on my little laptop. Looking for an alternative, I saw Electrum. I downloaded the app and I'm able to connect to a server, but I'm wondering: what would the security implications be of not connecting to your own server?


texts: Redeem bitcoins of non-standard transactions made with eligius

texts:
As I understand it, Eligius is the only miner pool accepting non-standard transactions.
The Opcodes for the scripts are here.
Some use cases for non-standard transactions can be found here.
My Question:
If I pay some Bitcoins to a non-standard pubkey script mined and accepted by Eligius, can these BTCs be redeemed by a non-standard redeem script (also mined at Eligius) or are these BTCs just lost forever?


texts: What's the worst-case delay for BTC->USD?

texts:
For big exchanges like mtgox, what is the longest delay time seen between ordering a sell and closing it?

In other words if I do an emergency sell of a large amount of coins because the exchange rate is dropping by the second, how much value might I lose while waiting for the sell order to complete?

Are there any exchanges that basically guarantee that the price in USD of my sell order when I place it will be the amount in USD I receive no matter how long their system takes to complete it?


texts: I have a wallet on Breadwallet which I wish to move to Mycelium. Both apps support recovery phrases, however Breadwallet uses BIP39 phrases, while Mycelium uses BIP44 phrases. Is it possible to convert from one format to the other, and if so, could you point me to any tools that can do this?


texts:
As per my understanding mining process in bitcoin is fully automated. A manual intervention is needed only when:
(i)  A hardware failure occurs
(ii) You might want to cool down the hardware
(iii) You completely shut it off (can be due to various reasons)
Are there any more reasons why a miner might switch off his/her system given that the complete process is automated?


texts: How does the network adjust the rate at which the coins are created?

texts: Who runs the Bitcoin network, and how do they adjust the rate at which the coins are created?


texts: Legacy blockchain after upgrade to SegWit

texts: Let's suppose I run a legacy (non-SegWit) node after SegWit gets activated. My blockchain doesn't store any SegWit data. What happens when I upgrade my node? Will I have to re-download the blockchain to include the missing SegWit data?


texts:
I believe that, for some people, the term Block is a sort of holy notion. However, there exist yet some block-free blockchains such as Libra (Sometimes referred to as Zuck Buck).

  Unlike previous blockchains, which view the blockchain as a collection
  of blocks of transactions, the Libra Blockchain is a single data
  structure that records the history of transactions and states over
  time.

It seems that the Block concept is a sort of tradition, neither more nor less. Would you please clarify the reason behind the invention of Blocks?


texts: How come a company partners with Bitcoin?

texts:
I was checking out the Bitcoin website, and I've noticed something that I can't stomach :

  The Bitcoin network is growing at an impressive rate and Bitcoin.com
  is forming new and lasting partnerships within the industry. Here
  are some companies we are working with who are fostering a healthy
  ecosystem.

I believe that Bitcoin is not a private company and it's owned by its community, right ? How is it possible for a company to partner with Bitcoin ?


texts: I bought a bit of a bit coin some years ago and forgot about it the the other day had a look and converted a small amount into an ether wallet. I came back the next day and found the bitcoin wallet empty and transferred as per screen shot. Can anyone help. If any more info needed please say.


texts: Must mining be profitable for Bitcoin to succeed? If no, what are the mitigations?

texts:
It is clear that mining is responsible for securing the network, and it is incentivised by block payouts and transaction fees.

I've also seen discussions regarding different incentives for miners in the event block payouts and transaction fees are insufficient incentive for 51% of the good guys to mine the network.

Question

What are the current proposals (or theories) that will maintain a secure Bitcoin network in the event mining is not profitable?


texts:
At the moment the price of a bitcoin on the Coinbase dashboard is $8247 EUR, however in the buy section it's $8840 EUR.  I know they have some commissions and spreads, but that's 7%... Is this a bug or a feature?

Moreover, the sell price is $8755 EUR! Much higher than the market price! I even bought some for 10 dollars to make sure. In GDAX, which is Coinbase's exchange the price is $8244.  Why does Coinbase sell/buy for so high?


texts: Bitcoint Core Gui will not display once index is loaded

texts:
I have the most recent Bitcoin Core "QT" for 64 bit Windows running on my system, It is working from what I can tell via the debug log. The splash screen loads and displays the loading and rewinding of the index. And when, I gather, it reaches 100%, the window minimizes and will  not restore. It remains on the taskbar as a program running. The little app by the clock is there and a right click brings up a menu. But I cannot see the actual account details.

I am able to quit the program safely. I did so and reinstalled a fresh version but there is no change. The program worked properly, previously. Because of some hardware power problem recently in my region I have not always run the code.

Like I say, the code is working but the Gui screen simply does not display. I gather I can run bitcoind instead and use a CLI, but does anyone know of a way to get the GUI back?


texts: Why is it necessary for Multi-Path Payments in Lightning to be Atomic?

texts:
One way of achieving multi-path payments in lightning is by having the sender use the hash sent by the receiver to send multiple payments along different paths.
The mailing list entry proposing atomic multi-path payments describes a downside where

  the sender fails to
  actually satisfy all the payment flows, then the receiver can still just
  pull the monies (and possibly not disperse a service, or w/e).

But if I understand correctly, if the receiver pulls any flow before all paths are complete, the sender will still end up with the invoice and pre-image which they can use to prove the payment went through, and if the receiver refuses to provide some service, the sender has the same recourse as in the case where the payment was a single-path payment paid in full. Why then, is it necessary to have this atomic multi-path scheme, which makes use of unused bits in the lightning protocol that could potentially be used for something else?


texts:
I'm currently doing a research project about Bitcoin and I've particularily been investigating the seed nodes and I have two questions about them :

How are they chosen ? Well, they have to be nodes with high disponibility (bandwith maybe?) but is there any other criterion ?
Why are some of the nodes located in the network of big companies ? Isn't it a bit contradictory to Bitcoin's spirit to have the ip address of some major financial companies hardcoded in its client ?

Thanks for your answers :)

Ayla


texts: Which opcodes where disabled by Satoshi Nakamoto for cve 2010 5137

texts:
Lot of opcodes where disabled over the years.
But which opcodes where disabled Satoshi himself and specifically for the any one can spend any coin bug?


texts: Error in creating bitcoin raw transaction

texts:
I am creating a raw transaction to send amount from from_address to to_address. While sending a transaction I got an error. I posted the detailed process of creating a raw transaction. Could anyone tell me where it was going wrong?

from_address = '2NAvmqmZmodXKDHyWQaRufsFptZ6cDPVaPQ'
to_address = '2MyTfwJFbWYueyFpDjdN8cJ4ZwsSA7UfN8s'

Unspent of from_address

[{'txid': '421ac74f3fb137ea0f65d20e71825abefd463322b4e4a9033057e78e2a27bb69', 'vout': 1, 'address': '2NAvmqmZmodXKDHyWQaRufsFptZ6cDPVaPQ', 'account': '', 'redeemScript': '00140363a5b9ce91754185b3d39d292f262ac3f417c5', 'scriptPubKey': 'a914c1f4f356a6c6d28742dd1e80270edd55e6a5b0c687', 'amount': 0.5455, 'confirmations': 108, 'spendable': True, 'solvable': True, 'safe': True}]

creating rawtransaction

bitcoin-cli createrawtransaction [{'txid': '421ac74f3fb137ea0f65d20e71825abefd463322b4e4a9033057e78e2a27bb69', 'vout': 1}] {'2MyTfwJFbWYueyFpDjdN8cJ4ZwsSA7UfN8s' : 0.0495 ,'2NAvmqmZmodXKDHyWQaRufsFptZ6cDPVaPQ' : 0.4955}

signing the transaction

bitcoin-cli signrawtransaction '020000000169bb272a8ee7573003a9e4b4223346fdbe5a82710ed2650fea37b13f4fc71a420100000000ffffffff02f0874b000000000017a9149ca7d200ee0b4e751d1de0c56fd3cf8defde173d87b012f4020000000017a914c1f4f356a6c6d28742dd1e80270edd55e6a5b0c68700000000' [{'txid': '421ac74f3fb137ea0f65d20e71825abefd463322b4e4a9033057e78e2a27bb69', 'vout': 1, 'redeemScript': '00140363a5b9ce91754185b3d39d292f262ac3f417c5', 'scriptPubKey': 'a914c1f4f356a6c6d28742dd1e80270edd55e6a5b0c687', 'amount': 545500}] ['cR5YAMiTGaAwFgrEHeXK2MpEm8SEBFXm7pf2R2m6SNBx3sRqvPYw']

sendrawtransaction

bitcoin-cli sendrawtransaction '0200000000010169bb272a8ee7573003a9e4b4223346fdbe5a82710ed2650fea37b13f4fc71a4201000000171600140363a5b9ce91754185b3d39d292f262ac3f417c5ffffffff02f0874b000000000017a9149ca7d200ee0b4e751d1de0c56fd3cf8defde173d87b012f4020000000017a914c1f4f356a6c6d28742dd1e80270edd55e6a5b0c68702483045022100ccf694b3439a163ca100743c749ba80e6732d96e2f1dc951ea38c6aba7624cf102203463130bec546cd5cf5d0a18067b51cdd63b879eb34cbecf61b2883ee58021110121034fb6dfc450dd53dcb083cb38ad8ad4d5ad744e3da6c93b579eb19354c3ff2e6600000000'

Error:

raise Exception('Error in RPC call: ' + str(responseJSON['error']))
Exception: Error in RPC call: {'code': -26, 'message': '64: non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation)'}


texts:
I wanted to try out P2Pool mining, so I installed the newest Bitcoin (0.5.2, also tried it with 0.5.1).

Unfortunately when I start run_p2pool.exe it immediately crashes my Bitcoin!

My OS: Win7 x64

Any ideas?


texts: I spilled a little bit of candle wax on my Bitcoin private key and now it won't scan electronically what can I do?

texts: I need help. What can I do to still use my paper key?


texts: Why isn't the price of BTC rapidly growing due to WannaCry?

texts:
This occurred to me today: the ongoing ransomware attack (started on May 12) caused by the WannaCry virus infected over 230 000 computers so far (source: Wikipedia). This probably means that a lot of these people (and/or companies) will pay the demanded price in Bitcoin, which, intuitively, should lead to a rapid growth of BTC value.

However, as it can be seen in the image below (BTC-USD chart taken from Kraken), this isn't happening. This is slightly confusing, so I'm looking for an explanation.


texts: How is Transaction malleability affected by SIGHASH flags?

texts:
SIGHASH flags allow for the flexible alteration of a transaction.

Given that there are legitimate usages of SIGHASH, and changing a Tx (and presumably the TxID as well), what is the correct way of using Sighash w.r.t. a TxID and tracking its progress?

What malleability risks do SIGHASH transactions incur by virtue of their usage?


texts:
I know that the miner who has the hash matching with the bitcoin's root software gets to stamp the block and put it onto the blockchain (correct me if I'm wrong). Accordingly, that miner takes the awarded amount of bitcoins.

On the other hand, isn't there with a possibility of earning partial bitcoins (I see people calculating how much they can earn with their respective computing specs)? How does this happen if I can't find the hash correctly?


texts: What are the minimum security expectations of an online wallet service?

texts:
If you wanted to assess the security of an online wallet service such as a bitcoin bank or ewallet, what would expect to see addressed?

Obviously SSL connections, but what about authentication, authorization, protection of staff from rubber hose attacks and so on?


texts:
What cryptocurrency is the fastest in terms of reaching 100% transaction confirmation?

I've found sites like this that show that Fastcoin is the fastest at 48 seconds.

I think David Schwartz said that Ripple gets 100% confirmation in ~10 seconds.

Is Ripple the fastest, or is there another coin that is left out of calculations because of bias like that attributed to Ripple?

In this world of high frequency trading, is 10 seconds the best that can be done right now?


texts: Is there some way to buy Bitcoin with my "locked up" funds for my pre-paid mobile phone number?

texts:
I have a cellphone, which is disassembled > 99% of the time. Once a year, one day before it "expires", I assemble it (sticking in the SIM card and battery), power it on and pay 100 SEK (the minimal possible amount) om Comviq's website to "top it up". Not that it needs to be "topped up", but if you don't do it at least once a year, they delete your number. In other words, they force me to waste at least 100 SEK per year simply to keep the phone in working order for the possible future need to send an odd SMS or perhaps make an emergency call to somebody.
This means that I now have over 500 SEK "wasted" which I cannot get back in any obvious way, and which I will never use up through sending SMSes or making phone calls.
I'm now wondering if there's any way to spend that money somehow, preferably to buy some Bitcoin.
I would ask them directly, if it weren't for the fact that they have engineered their website to make it impossible in practice to contact them.
I've of course tried to search for things such as "buy Bitcoin through pay SMS" and "paying for things with pay SMS", but all it finds are services to charge people via SMS, or irrelevant websites.
Ideally, there is some kind of website where they make me enter a Bitcoin receive address, and then show me a telephone number where I send one or more SMSes to with some code and then they send the corresponding number of satoshis to that address. With no KYC/AML. To make it clear, this is in Sweden.


texts:
Is there a comprehensive list of Bitcoin's core consensus rules anywhere?

In the Bitcoinwiki "Full Node" article  it says:

  Here are examples of consensus rules, though there are many more:

  Blocks may only create a certain number of bitcoins. (Currently 12.5    BTC per block.)
  Transactions must have correct signatures for the bitcoins being spent.
  Transactions/blocks must be in the correct data format.
  Within a single block chain, a transaction output cannot be double-spent.

I've looked around for a list of the "many more" but haven't located one yet.


texts: Is there a legal way and free way to open a Bitcoin exchange in the United States?

texts:
I've been doing some reading on the state of starting a Bitcoin exchange in the United States, and I have a couple of unanswered questions.

1) What are the legal fees and process for starting a regular exchange?

2) When are the legalities surrounding exchanges like coinffeine, where two anonymous users exchange and coinffeine acts as the intermediary?

3) How can I connect with a partner in a developing country like Panama, where it is much easy to start an exchange?


texts: couple years ago I set up a coinabase wallet or blockchain wallet to make a couple of purchases. How do Iretrive any bitcoin left in that wallet?

texts:
A couple of years ago I set up a bitcoin wallet on blockchain. How do I retrieve any bitcoin left in if I don't remember all my passcode info.  I'm VERY tech ignorant! HELP!! I'm on disability and need every penny I can find. Anyone kind enough to offer ideas or suggestions?
There may be a reward if I can access my wallet and what's in it! Please and thank you in advance
Denise


texts: Self assembling of hardware for bitcoin mining

texts: Are there any guides or material available for helping us build dedicated ASIC hardware for bitcoin mining .


texts: For someone in the USA what is the easiest way to convert bitcoins to usd while incurring minimal fees. I've heard of using mtgox with dwolla, or mtgox with internation wire transfer. But it strikes me as tedious to use dwolla. Why isn't there something like direct deposit, simple and fast?


texts: How is subscript computed for OP_CHECKMULTISIG?

texts:
I'm trying to learn the Bitcoin protocol by implementing it, and I've got OP_CHECKSIG working (following instructions in https://en.bitcoin.it/wiki/OP_CHECKSIG), but I can't get an transaction input using OP_CHECKMULTISIG to pass signature verification.

Specifically, I'm stuck with the second tx_input of transaction eb3b82c0884e3efa6d8b0be55b4915eb20be124c9766245bcc7f34fdac32bccb, and I suspect that the culprit is subscript (the one to replace signature script in current transaction).

Here's how subscript is computed in my implementation.

First, generate the script by concatenating [sigScript][OP_CODESEPARATOR][pubkeyScript] (I understand that script execution has evolved from this).

So a (parsed) script for the input would be like this:

Frame 00: 0(00)
Frame 01:
0000 - 30 44 02 20 27 6d 6d ad 3d ef a3 7b 5f 81 ad d3
0010 - 99 2d 51 0d 2f 44 a3 17 fd 85 e0 4f 93 a1 e2 da
0020 - ea 64 66 02 02 20 0f 86 2a 0d a6 84 24 93 22 ce
0030 - b8 ed 84 2f b8 c8 59 c0 cb 94 c8 1e 1c 53 08 b4
0040 - 86 81 57 a4 28 ee 01 END
Frame 02: OP_CODESEPARATOR(0xab)
Frame 03: 1(0x51)
Frame 04:
0000 - 02 32 ab dc 89 3e 7f 06 31 36 4d 7f d0 1c b3 3d
0010 - 24 da 45 32 9a 00 35 7b 3a 78 86 21 1a b4 14 d5
0020 - 5a END
Frame 05: 1(0x51)
Frame 06: OP_CHECKMULTISIG(0xae)
Frame 07: OP_CODESEPARATOR(0xab)
Frame 08:
0000 - 2a 9b c5 44 7d 66 4c 1d 01 41 39 2a 84 2d 23 db
0010 - a4 5c 4f 13 END
Frame 09: OP_NOP2/OP_CHECKLOCKTIMEVERIFY(0xb1)
Frame 10: OP_DROP(0x75)

Then, I create the subscript from the closest OP_CODESEPARATOR before the OP_CHECKMULTISIG that I am executing till the end of the script. So, I include Frame 03 to Frame 10.

Then, I remove other OP_CODESEPARATORs in the script, which is Frame 07.

That means these frames should compose the subscript:

Frame 03: 1(0x51)
Frame 04:
0000 - 02 32 ab dc 89 3e 7f 06 31 36 4d 7f d0 1c b3 3d
0010 - 24 da 45 32 9a 00 35 7b 3a 78 86 21 1a b4 14 d5
0020 - 5a END
Frame 05: 1(0x51)
Frame 06: OP_CHECKMULTISIG(0xae)
Frame 08:
0000 - 2a 9b c5 44 7d 66 4c 1d 01 41 39 2a 84 2d 23 db
0010 - a4 5c 4f 13 END
Frame 09: OP_NOP2/OP_CHECKLOCKTIMEVERIFY(0xb1)
Frame 10: OP_DROP(0x75)

Serialized, the final subscript looks like this:

0000 - 51 21 02 32 ab dc 89 3e 7f 06 31 36 4d 7f d0 1c
0010 - b3 3d 24 da 45 32 9a 00 35 7b 3a 78 86 21 1a b4
0020 - 14 d5 5a 51 ae 14 2a 9b c5 44 7d 66 4c 1d 01 41
0030 - 39 2a 84 2d 23 db a4 5c 4f 13 b1 75

However, when this subscript is used to replace signature script, and eventually generate hash, the ecdsa_verify function reports that signature verification fails (but the inputs are legal).

Since the same procedure works for OP_CHECKSIG, I probably missed something obvious, but I couldn't figure this out reading the original Satoshi code, the current implementation, or Bitcoin Wiki.

If it helps, my code for OP_CHECKMULTISIG is here:
https://github.com/blaesus/tinybtc/blob/checkmultisig/src/script.c#L687

A more simplistic version (using prevTx.pubkeyScript as subscript) doesn't yield valid results either: https://github.com/blaesus/tinybtc/blob/validate/src/script.c#L344


texts: My transaction has been on pending for 27hrs

texts: I need to know how to confirm my transaction it's been on pending for a while and I really need the transaction


texts:
I once created a bitcoin account and obtained an address. When i needed to transfer some bitcoin, i didn't check the address hoping it was active. After the transfer, I tried opening it but it did not. I thereafter created another account. What happens to my transfer?
Secondly, how do I use the address to locate the bitcoin wallet so my money wont be lost?
Thanks.


texts: Why isn't 'classic' Multi-Paxos Byzantine Consensus used for public Blockchains?

texts:
Any solution to the Byzantine General's Problem can be used as a consensus method to base a distributed ledger on.

Why then, did Satoshi Nakamoto choose for the super-expensive (in electricity and CPU cycles) Proof-Of-Work?

I can think of these reasons:

Proof of Work takes time, which means that blocks take time. (But nowadays this is actually a drawback?)
Miners are paid out by the PoW. (But couldn't this work in a Multi-Paxos environment as well, where basically all miners would like to become leader for the next round?)
A Proof-of-Work chain will still work if the network netsplits into two pieces. This will create separate blocks in each half of the network, actually being a problem when the two halves are joined again (because then one of the two chains is discarded, which, if the netsplit took multiple minutes before healing, means that people and external systems might have acted based on their now-invalid balances.)

Clearly these reasons are not good enough. So what real reasons are there to use Proof-of-Work over e.g. Multi-Paxos or another 'classical' solution to the Byzantine Generals Problem?


texts: I need to find a pool that supports cpuminer

texts: I've been to mine with cpuminer with lots of different pools but nothing works!!! I only made it to mine litecoin on litecoinpool.org, but I need bitcoin! Which pool would you recommend?