Thanks Pierce and hernanmd I decided to adopt the solution of the prepended salt as Erik said in the previous post. Here is my code, I hope it can be useful for the community First I hash the password with an empty salt PBKDF2 derivedKeyHashFunction: SHA256 password: 'aSimplePassword' salt: '' iterations: 3000 length: 16 . I would have liked to avoid the empty salt but the message deriveKey needs it. Then I used UUID new as real salt and the string '$$' as separator between the salt and the hashed password. So here is the byte array I'm going to store in my db saltPlusHashedPassword := UUID new , '$$' asByteArray , (PBKDF2 derivedKeyHashFunction: SHA256 password: 'aSimplePassword' salt: '' iterations: 3000 length: 16 ). To validate the password, I retrieve the saltPlusHashedPassword from the db and splitting it hashedPassword := (saltPlusHashedPassword splitOn:('$$' asByteArray)) second. Finally the validation (PBKDF2 derivedKeyHashFunction: SHA256 password: 'aSimplePassword' salt: '' iterations: 3000 length: 16 ) = (ByteArray new, hashedPassword). Note, I have to concatenate ByteArray new with hashedPassword because hashedPassword is not a ByteAttay but a UUID, if you have a smarter way to do it you are welcome. HTH Francis Erik Stel wrote

Francis,

The hashpw function returns a hash with the salt prepended. So it contains both elements. (See for example explanation at: https://stackoverflow.com/questions/27413248/why-can-bcrypt-hashpw-be-used-b...).

You can do the same thing here. Assuming you have a fixed size salt, just prepend it before the hash value. Since the salt is (should be) random, returning it's value does not weaken the security. Using a salt prevents against rainbow table attacks: pre-generated hash values for many possible passwords. (See https://en.wikipedia.org/wiki/Rainbow_table).

Cheers, Erik

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