= S =
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
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.