<p>If you sign two messages using the same nonce, then it is possible for someone to derive your private key. See <a href="https://bitcoin.stackexchange.com/questions/73622/how-do-you-derive-the-private-key-from-two-signatures-that-share-the-same-k-valu">How do you derive the private key from two signatures that share the same k value?</a></p>

CC BY-SA 4.0
2018-08-31T08:31:58.990Z
2018-08-31T08:31:58.990Z
Mike D
<p>To sign a message , we choose nonce k but what happens if we use same k twice to sign a message using DSA algorithm?</p>

<bitcoin-core><signature><algorithms>
What happens if I use same k twice in DSA algorithm?
Maulik Chaudhary
# What happens if I use same k twice in DSA algorithm?

(Asked by: username_0 on 2018-08-31)

To sign a message , we choose nonce k but what happens if we use same k twice to sign a message using DSA algorithm?

**Tags:** bitcoin-core, signature, algorithms


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## 1 answers

### Answer by username_1 on 2018-08-31. Score: 3

If you sign two messages using the same nonce, then it is possible for someone to derive your private key. See [How do you derive the private key from two signatures that share the same k value?](https://bitcoin.stackexchange.com/questions/73622/how-do-you-derive-the-private-key-from-two-signatures-that-share-the-same-k-valu)


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