Quote from: LesLie_0300dbdd1b on January 12, 2024, 10:27:46 AM

Quote from: ABCbits on January 12, 2024, 10:15:18 AM

Few thoughts,
1. Long time ago i read Bitcoin Core doesn't implement BIP39 due to security issue[1], which isn't solved by your proposal.
2. If i understood your proposal correctly, does that mean 12 word mnemonic have less than 128-bit entropy due to version field addition?

[1] https://bitcoin.stackexchange.com/a/88244

[1] If the security issue you are referring to involves the use of PBKDF2, this could be addressed by implementing versioning, although it would break compatibility with non-versioned BIP39 software.

[2] Correct, a 128-bit entropy results in a 15-word mnemonic when considering the 24-bit general-purpose field is used.
For a 12-word mnemonic phrase under the versioned BIP39, you can attain a maximum of 120 bits of entropy, whereas the non-versioned BIP39 allows for 128 bits of entropy with a 12-word mnemonic.

1. I see. It looks there's major trade-off between preserving backward compatibility (not many things could be added) or breaking backward compatibility (less adaption/usage).

2. 120-bit should be fine since IIRC 112-bit security is still acceptable today.