4 ms·
If they're hashing the password, then the actual password should be already hashed in the DB, and even if the hash comparison is not constant-time, the avalanch
by ReactiveJelly 6y ago
If they're hashing the password, then the actual password should be already hashed in the DB, and even if the hash comparison is not constant-time, the avalanche effect should make it difficult to "safe-crack" the password one character at a time, because each change in the password will change half the hashed bits.
- ArchOversight 6y agoPasswords are a bad example, but think of a simple signed cookie for example. It's signed with a key that is only known to the server, and the cookie is sent as signature + content. The server has to hash the content using the key, and then validate the signature matches the signature the server just created. If you don't use constant time comparison for this you leak information about the valid signature.