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)

0
votes
2answers
24 views

Signing data with ECDSA

I was reading about the math behind bitcoins in this article, and one thing I can't seem to wrap my head around is how the said algorithm is used to sign "data". What exactly is this "data"? Is it my ...
2
votes
1answer
86 views

Can't find correct z1 & z2 for transaction

I've been trying to understand the issue and repeat Willem Hengeveld's answer, but I think I'm failing at getting correct script for hash. I'm looking for this transaction, my scripts are: ...
0
votes
0answers
8 views

Relationship between SIGHASH types and sequence numbers

The is a specific test case inside of tx_valid.json inside of bitcoin core that I am having issues with for my library bitcoin-s. ["Same as above, but we change the sequence number of the first ...
0
votes
1answer
31 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 ...
2
votes
2answers
45 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
vote
1answer
50 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 ...
0
votes
1answer
64 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 ...
0
votes
1answer
43 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
votes
2answers
236 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
votes
1answer
366 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
votes
1answer
252 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 ...
1
vote
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 ...
1
vote
1answer
118 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 ...
-1
votes
2answers
58 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. ...
1
vote
1answer
643 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 ...
1
vote
1answer
94 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
votes
1answer
135 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
votes
1answer
103 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
votes
1answer
64 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 ...
3
votes
2answers
96 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
votes
1answer
53 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 ...
0
votes
2answers
278 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 ...
0
votes
0answers
198 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 ...
-1
votes
1answer
227 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 = ...
1
vote
0answers
316 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 ...
0
votes
1answer
261 views

Two identical R value finding z value from two transaction

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

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

txid1 txid2 input script 1 304502206bcc247f1259262b4035bfa84f0397a69f69baa01659daaf94fe1164b650c86a022100a044b38e8264a1c928ddd28b4657aa7109d1ea30e911208c7ce57abcb1451fe601 ...
4
votes
1answer
114 views

bitcoin two identical R

Blockchain transaction id 30440220d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1022044e1ff2dfd8102cf7a47c21d5c9fd5701610d04953c6836596b4fe9dd2f53e3e01 ...
1
vote
2answers
144 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 ...
1
vote
2answers
125 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. $ ...
1
vote
1answer
90 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 ...
1
vote
2answers
153 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
votes
1answer
161 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 ...
1
vote
2answers
207 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 ...
1
vote
0answers
83 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
votes
1answer
98 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?
2
votes
2answers
264 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
votes
1answer
413 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 ...
1
vote
2answers
445 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
votes
1answer
232 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 ...
3
votes
2answers
124 views

If block sizes go up, won't sigop limits have to change too?

Gavin Andresen, one of the core developers, has discussed increasing the block size to 16.7 MB (and doubling that every two years). The maximum number of signature operations per block is currently ...
2
votes
2answers
101 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.
1
vote
1answer
247 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 ...
12
votes
3answers
1k 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 ...
1
vote
1answer
106 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. ...
0
votes
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
votes
2answers
88 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
votes
1answer
177 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 ...
1
vote
1answer
120 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) $ ...
1
vote
1answer
202 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, ...