They are different things. I think the proper term for scrypt, bcrypt, etc. is a key derivation function. They take a password, add a salt, and produce a key

They are different things. I think the proper term for scrypt, bcrypt, etc. is a key derivation function. They take a password, add a salt, and produce a key that can be used for authentication. http://en.wikipedia.org/wiki/Key_derivation_function http://en.wikipedia.org/wiki/Key_derivation_function The hash functions in the OP are cryptographic hash functions. http://en.wikipedia.org/wiki/Cryptographic_hash_function http://en.wikipedia.org/wiki/Cryptographic_hash_function The 'cryptographic' part of the name means that it is hard to find two files that produce a collision (hash to the same value). I believe that key derivation functions will include cryptographic hash functions.