# Linked Questions

0 votes
0 answers
96 views

### How do I compute a private key, if I have two messages signed using the same nonce? [duplicate]

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, ...
• 143
17 votes
3 answers
9k views

### How do you derive the private key from two signatures that share the same k value?

I wrote my own ECDSA signature algorithm just for the purpose of creating unit tests. With it I created two signatures which went into transaction 56ec7ca7df..., sending from 1GXFXm3es.... These ...
• 1,047
11 votes
1 answer
3k 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 ...
• 864
6 votes
1 answer
1k views

### Why is it important that nonces when signing not be related?

I understand that if nonces (usually denoted k in the signature algorithm) are related signing with the same public key that this reveals information about the private key. I would like to get a ...
• 7,759
2 votes
1 answer
6k views

### How to find Reused R values

I use software from https://github.com/ca333/rng-scanner , I try to find r that is reused. from the software I found results Bitcoin Address : 1GQdrgqAbkeEPUef1UpiTc4X1mUHMcyuGW In Input NR : 141 ~ ...
• 81
1 vote
0 answers
5k 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 ...
• 319
0 votes
1 answer
2k views

### How are P and ((z1*s2 - z2*s1)/(r*(s1-s2))) calculated?

Given: p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 r = 0xd47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1 s1 = ...
• 1
0 votes
2 answers
2k views

### Why did repeated "R" values occur in Bitcoin transactions before?

Please explain why earlier the repeated values of "R" occurred in Bitcoin transactions. For example, this transaction has a repetition of the value "R": https://www.blockchain.com/btc/tx/...
• 49
0 votes
1 answer
2k 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 = '...
• 319
4 votes
1 answer
551 views

### bitcoin two identical R

Blockchain transaction id 30440220d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1022044e1ff2dfd8102cf7a47c21d5c9fd5701610d04953c6836596b4fe9dd2f53e3e01 ...
• 319