An encrypted hash that is generated to verify the validity of a transaction; it verifies that whoever created the transaction actually owns and is able to spend the relevant coins.

learn more… | top users | synonyms (1)

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25 views

Getting the wrong hashes for bitcoin core packages

I've been playing around learning more about Bitcoin and was following this tutorial from 21.co on digital signatures. When I open the SHA256SUMS.asc file and try to verify the packages, I get ...
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1answer
22 views

Is it possible to get the public key from a transaction input that is a 'pay to public key' output?

I am looking to be able to calculate the public key from the transaction input. The input is from a 'pay to public key' output. Can the public key of the input be generated from just the signature ...
1
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1answer
29 views

Why can't a transaction be redirected after it is signed? [duplicate]

Scenario: Step 1: User-1 initiates the TXN-1 to pay to User-2 and the TXN is not yet confirmed with the ongoing block POW. Step 2: What prevents fraudster (anyone a miner or someone ...
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1answer
56 views

Is there a way to sign a transaction with BTC or any Altcoin without a computer using only pen and paper?

Was wondering if this is possible to do. Lets say Satoshi Nakamoto ended up prison in a foreign country and he was only able to communicate with the outside world by writing letters using only a pen ...
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1answer
31 views

How does ripple verify the signature?

As I understand, the client send the following information to server 1.the hash of the message, 2. public key 3. signature made by private key And the server verified the signature with the ...
3
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2answers
88 views

How to sign a transaction with multiple inputs?

I have been able to program an application in python that sends valid transactions that spend 1 input, but I really can't get it to work with 2 or more inputs. So my question is, how exactly is the ...
5
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1answer
312 views

Why can't bitcoin miners modify transaction outputs?

I am learning the Bitcoin protocol by reading the bitcoin developer reference documentation. As far as I know, a raw transaction consists of: Version (which is always 1) Inputs. Each input ...
9
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1answer
228 views

Why was the Oct 2015 Transaction Malleability event possible in spite of BIP62/66?

The recent re-emergence of transaction malleability has been responsible for a large number of Txs which are being double spent (October 2015). /r/Bitcoin has posted some C++ code which @amaclin has ...
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0answers
24 views

(CHECKSIG) Why is the ScriptPubKey from tx-inputs part of the signature?

I was checking OP_CHECKSIG today and see that the signature of a transaction will be computed from the transaction but copying the ScriptPubKey from the transaction referenced as input into the SigKey ...
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1answer
95 views

OP_EQUALVERIFY Problem

I'm making a full-service wallet, I already made the UTXOs selection algorithm and now I want to push the transaction hex bytes. It works when I push only a transaction with only 1 input, but if I try ...
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2answers
51 views

Can Bitcoin Core be used to create a raw transaction for CLAM altcoin?

Clam is an altcoin that issued that altcoin to the owner of the private key of each and every Bitcoin address that had funds (0.0001 or more) on May 12, 2014. I don't want to install the Clam client. ...
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1answer
597 views

OP_CHECKSIG signature hash type 0

On the Bitcoin Wiki's OP_CHECKSIG documentation: Firstly always this (the default) procedure is applied: the public key and the signature are popped from the stack, in that order. If the ...
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1answer
83 views

Can you include a signature in a bitcoin payment?

I know you can use the bitcoin client to sign messages (for which you own the private key) and verify messages from other public addresses. But can you actually embed a signed message into a ...
2
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1answer
109 views

Bitcoin how to get X value from Y

How to get X value from Y? ECDSA x,y coordinate validity verification doesn't seem to work X = 0x79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798 Python code, p = ...
0
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1answer
89 views

Bitcoin Testnet Trouble with bitcoin-ruby

I am having trouble with the bitcoin-ruby gem. I get the following error when trying to send money to another address I have on the test network: ...
0
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1answer
62 views

Why the message is need in verify function

here is the how bitcoin works under the hood article http://www.imponderablethings.com/2013/07/how-bitcoin-works-under-hood.html i did not got this why message is needed when using this verify ...
2
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2answers
77 views

The complement of s (when s < curve order / 2)

Bitcoinlib refers to the requirement that if s > ORDER / 2, then the complement of s should be used instead since it's one byte shorter This sounds like it's referring to the inverse or negative s ...
0
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1answer
51 views

Does RevokeSSL Require Self-Signed Certs to Work?

// , I don't want to go to https://bankofamerica.com and see it self-certified. I don't want to go to https://amazon.com and see it self-certified. I don't mind going to ...
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2answers
207 views

Download of Multibit Windows 64 Bit has corrupt signature

I'm trying to download Multibit from https://multibit.org/community.html the Win 64 version. it consistently gives a 'The signature of multibit-0.5.18-windows-setup.exe is corrupt of invalid.' is ...
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0answers
138 views

Any bitcoin transaction to get S1 and Z1 and R value script need

bitcoin transaction to get S1 and Z1 and R value script need Need script that gives bitcoin translation to S1 and Z1 and R value like below link ...
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1answer
186 views

converting RUBY script into PYTHON ( Recovering private key when someone uses the same k twice )

require 'ecdsa' public_key_hex = '02a50eb66887d03fe186b608f477d99bc7631c56e64bb3af7dc97e71b917c5b364' msghash1_hex = '01b125d18422cdfa7b153f5bcf5b01927cf59791d1d9810009c70cd37b14f4e6' msghash2_hex = ...
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0answers
222 views

Same identical R value of all transaction not provide corresponding privatekey

ECDSA Signature and the “z” value from above link learn calculation of z value and to get private key https://blockchain.info/tx/9ec4bc49e828d924af1d1029cacf709431abbde46d59554b62bc270e3b29c4b1 ...
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1answer
184 views

Two identical R value finding z value from two transaction

tx1 from the trans1 i got Input Scripts 30450220262e481b6d8905b5adba67aff05eb8261501b0a9434c0b7f043d00cf8d23c91b022100bf82c0d212f30d3a0599e9b879516d762eaf5688ab83787cf470e99af5a6917101 ...
0
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1answer
177 views

same R value is used for two different addresses? finding z1 and z2 value and privatekey

txid1 txid2 input script 1 304502206bcc247f1259262b4035bfa84f0397a69f69baa01659daaf94fe1164b650c86a022100a044b38e8264a1c928ddd28b4657aa7109d1ea30e911208c7ce57abcb1451fe601 ...
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1answer
103 views

bitcoin two identical R

Blockchain transaction id 30440220d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1022044e1ff2dfd8102cf7a47c21d5c9fd5701610d04953c6836596b4fe9dd2f53e3e01 ...
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2answers
120 views

blockchain checksig fail

i'm attempting to verify a checksig from a transaction in the live blockchain. it is failing on my debian jessie pc with openssl 1.0.1k, failing on my ubuntu 12.04 virtual machine with openssl 1.0.1 ...
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2answers
104 views

How to check if raw transaction is signed?

I have a raw transaction and would like to check if signed or not. How can I do this. I tried using bitcoind and verifying a transaction from be blockchain but it says its not complete. $ ...
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1answer
80 views

Signature: encoding a message - transaction to a point of curve y^2=x^3+7 and Bitcoin Core

Where should I look at in Bitcoin Core source code to figure out how the signature process trasform a message in a curve point? To sign a transaction (message) in Bitcoin system, you need to encode ...
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2answers
122 views

How are SIGHASH flags encoded into a signature?

This page describes SIGHASH flags: OP_CHECKSIG extracts a non-stack argument from each signature it evaluates, allowing the signer to decide which parts of the transaction to sign. Since the ...
2
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1answer
147 views

Do new SIGHASH types need a hard fork or a soft fork?

There have been a few new sighash types proposed. SIGHASH_NORMALIZED : Use a 'normalized' TXID in the inputs when serializing for signing. This normalized transaction id is calculated by removing ...
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2answers
159 views

How to create the <sig> <PubK> part in “scriptSig”?

I've decoderawtransaction and see in the vin part a "scriptSig" ,which I believe to be the "unlocking script" . Assuming I have the private key in a paper wallet and someone send me transaction to ...
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0answers
66 views

How do I get hash to verify transaction?

If I have the public key and signature for a transaction how do I get the hash value that is used in verify(hash, sig, pubkey). I want to know how to work backwards from a raw transaction to get it, ...
0
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1answer
88 views

How to extract the signature of a transaction using bitcoinj

I am trying to extract the signatures from a transaction. What is the best way to do this given a com.google.bitcoin.core.Transaction object I just received from the network?
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2answers
220 views

How can someone verify the signature of a Bitcoin ECDSA signature without knowing the signer's public key?

I understand how ECDSA exactly works and for verification of a signature, the public key of the signer is required. But in Bitcoin, public key is double hashed and the only information the receiver ...
5
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1answer
345 views

Problems with deterministic ECDSA based on RFC6979 in Bitcoin

Generating random number k in elliptic curve is crucial and in any transactions signature in Bitcoin, random number k is required to compute a point k*G. If this k is chosen not randomly, it instantly ...
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2answers
384 views

Multisig vs Multi input transaction signing

Let's say we have a 2 of 2 multisig address that we want to spend from, so the transaction should be signed by both of the private keys. Now let's say we have a transaction with two inputs, so once ...
0
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1answer
213 views

How to find Z value of multisig transaction?

for example this transaction: http://2coin.org/txinfo.aspx?txid=6c3dc603da32bba3f56f2b33053aaf0f0f17322386c0c6846786bffe49f6ef22&cur=BTC Script not of right size to be a scriptSig, expecting 2 ...
2
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2answers
92 views

For what purposes do we need “Sign message”?

I got a simple but straight question: Why do we need "Sign message". Also give explanations and examples.
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1answer
224 views

How do we verify the signature on a raw transaction using Bitcoinj?

I managed to create a raw tx using Bitcoinj but not able to figure out how to verify its signatures. Assuming I know the addresses corresponding to the (supposedly) unspent outputs used as inputs to ...
11
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3answers
974 views

What are the implications of Schnorr signatures?

Adam Back (adam3us) explained in March, 2014, but it is all math. There's another short post with advantages, though. This answer on crypto.SE claims that Bitcoin considered using Ed25519 which is ...
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1answer
86 views

Double Counting SigOps to Prevent CPU Exhaustion Attacks

In the bitcoin v0.9.3 source: https://github.com/bitcoin/bitcoin/blob/v0.9.3/src/main.cpp ConnectBlock() calls CheckBlock() as one of the first things it does. ...
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1answer
23 views

Is the a library for generating signatures and transactions for scrypt coins?

I'm looking for a library similar to this bitcoin one but that works with scrypt based coins.
2
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2answers
76 views

Why does txID generation consider signatures?

I've been reading a lot about transaction malleability, and noticed that the only way to achieve it is by altering the transaction signature/s. Why does the protocol even consider the signature in ...
2
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1answer
154 views

How to specify ECDSA nonce used in bitcoin signing code?

Below is the CECKey::Sign() code (v0.9.3). bool Sign(const uint256 &hash, std::vector<unsigned char>& vchSig) { vchSig.clear(); ECDSA_SIG *sig = ECDSA_do_sign((unsigned ...
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1answer
101 views

Why would sending a raw transaction from a different node fail?

When I make a transaction spending an output on one machine (sending it to another locally owned address), and then broadcast it on the same machine, it all works fine, as below. (NODE A) $ ...
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1answer
177 views

If I am spending multiple inputs from the same address, must I provide a signature for each input?

Suppose I have two inputs belonging to the same address. Do I need to provide a signature script for each input that proves that I own it? Wouldn't that waste space? Also, in the standard client, ...
5
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2answers
608 views

How does the ECDSA verification algorithm work during transaction?

I understand the basic concept ECDSA where if Bob wants to sign a message it generates a random number n, multiply it with the secp256k1, r = the x value , s = (H(x)dr)*n^-1 mod q. Also the ...
2
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1answer
60 views

What is the algorithm used to sign data within Nxt?

I understand that Nxt uses Curve25519 to generate pubkeys for user accounts, however, I can't find a reference that states what which signing algorithm/process is used for transactions and blocks. ...
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1answer
85 views

How many Secp256k1 signatures exist for a piece of data?

ECDSA signatures are not deterministic. That is, random information is used in calculating the signature for a piece of data. Approximately how many unique signatures exist for a piece of data? ...
2
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1answer
1k views

How to sign bitcoin transaction with 'bitcoind' and non-bitcoind-wallet private key?

My Target I want to create and sign bitcoin transactio using 'bitcoind' and 'bitcoin-cli' only. But the private key is unrelated to 'bitcoind' built-in wallet. That is, private / public key pair was ...