Is “double hashing” a password less secure than just hashing it once?

Is hashing a password twice before storage any more or less secure than just hashing it once? What I’m talking about is doing this: $hashed_password = hash(hash($plaintext_password)); instead of just this: $hashed_password = hash($plaintext_password); If it is less secure, can you provide a good explanation (or a link to one)? Also, does the hash function … Read more