Generates a salt string with default options. The purpose of salt is to make dictionary attacks against a whole password database much harder, by causing the crypted password to be different even if two users have the same uncrypted password.

Generates a salt string. Options are used to modify the salt generation. The purpose of salt is to make dictionary attacks against a whole password database much harder, by causing the crypted password to be different even if two users have the same uncrypted password. Randomness in a crypted password comes from its salt string, as do all recorded options. The same salt string, when combined with the same password, will generate the same crypted password. If the salt string differs, the same password will generate a different crypted password (crypted passwords have the form algorithm+salt+hash, so the salt is always carried along with the crypted password).