DuckCorp Dico

Found one definition

1.                 From The Jargon File (version 4.4.7, 29 Dec 2003):
                   
   
   
                   
                     
   salt
    n.
       A tiny bit of near-random data inserted where too much regularity would be
       undesirable; a data frob (sense 1). For example, the Unix crypt(3) man
       page mentions that “the salt string is used to perturb the DES algorithm in
       one of 4096 different ways.”