4 ms·

I find it weird that hash signatures are not commonly used since most asymmetric hash signature schemes (if not all) are provably safe as long as the hash funct

I find it weird that hash signatures are not commonly used since most asymmetric hash signature schemes (if not all) are provably safe as long as the hash function used is safe and they are also quantum-safe and very trivial to implement. It is also extremely annoying that programs like gpg do not support the generation of large RSA keysizes such as 15360 bits which would require many more qbits in order to break (and since RSA 4096 and 2048 are much more commonly used, they might not even build a quantum computer capable of breaking them or they might create a much smaller amount of them).

jacquesm 10y ago
A signature is a trap-door, encryption is reversible. So they are two entirely different things, you can't use a signature hash for encryption.
- snakeanus 10y ago
  I am not claiming that you can though.
  - jacquesm 10y ago
    Then you probably meant to start a new thread. The one you are replying to is about encryption exclusively.
    - snakeanus 10y ago
      Nope, the poster I replied to talked about asymmetric crypto in general, which includes signatures.
      - jacquesm 10y ago
        I think that was in reference to public key cryptography, not in reference to hashing, but I'll leave it to the OP to clarify, that's at least how I interpreted it.
- wyager 10y ago
  You are correct, but we're talking about asymmetric key crypto in general, not just encryption. Presumably the GP is referring to quantum-resistant hash-based signature schemes such as https://en.wikipedia.org/wiki/Merkle_signature_scheme https://en.wikipedia.org/wiki/Merkle_signature_scheme