Password hashing

[Leichter, Jerry]

| > ...  What's wrong with starting
| > with input SALT || PASSWORD and iterating N times, ....
| 
| Shouldn't it be USERID || SALT || PASSWORD to guarantee that if
| two users choose the same password they get different hashes?
| It looks to me like this wold make dictionary attacks harder too.
As others have pointed out, with a large enough salt, dictionary attacks
become impossible.  But it's worth mentioning another issue:  People's
userid's do change and it's nice not to have the hashed passwords break
as a result.  (This is pretty counter-intuitive to users who change their 
names, and a disaster if a large organization needs to do a mass renaming
and somehow has to coordinate a mass password update at the same time.)

							-- Jerry

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