What is is minimum possible number for an ECDSA private key?

5

Private keys are 256 bit numbers. I know the max. possible number is something around: 115792089237316195423570985008687907852837564279074904382605163141518161494336

What about the min. number possible?

Thanks.

John Smith

Posted 2018-09-21T17:03:45.950

Reputation: 261

Answers

11

The all-zero bitstring doesn't have a corresponding public key per the standard (according to "Are all possible EC private keys valid?" on Crypto.SE), so it's 000…001.

Murch

Posted 2018-09-21T17:03:45.950

Reputation: 41 609

8

One is the minimum number. [This space intentionally left unblank.]

G. Maxwell

Posted 2018-09-21T17:03:45.950

Reputation: 6 039

10"♫ One... is... the minimum number for a private key... ♫" – Nate Eldredge – 2018-09-21T21:12:41.257

If only I'd thought of that to get around the minimum answer length. :) – G. Maxwell – 2018-09-22T02:18:03.553

Asked: 2018-09-21T17:03:45.950

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Active: 2018-09-21T17:14:16.223