Re: Salt -- Something I've Never Understood

You've got it right. It makes the encryption key* more random. As far as I know, there is no real random number generation on computers, so you need something that goes beyond whatever the algorithm/processor combination can create. The salt is that something. GPG, like PGP, uses "entropy" during key creation---moving the mouse, hitting keys, anything that increases makes the state of the computer unique.

Update: Added "key" above, which is what I meant. Thanks to Abigail-II for pointing out my wording mistake. saintmike's post is very much to the point.

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Allolex

Comment on Re: Salt -- Something I've Never Understood

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Re: Salt -- Something I've Never Understood by Abigail-II (Bishop) on Feb 05, 2004 at 10:28 UTC
It doesn't make the encryption more random. That doesn't make any sense. You don't want any randomness in your encryption - if there were any randomness, how would you ever be able to determine your password was correct? The salt serves two points, both already explained higher up in the thread: it increases the size of a pre-computed dictionary with a factor of 4096, and it reduces the chance that two users using the same password have identical encrypted passwords. Points that were important a couple of decades ago, but less so nowadays. Pre-computed dictionaries are now much more feasible (although the factor 4096 still hinders), and most modern Unix systems use a non-user readable `/etc/shadow` to store the encrypted passwords. Of course, if you use NIS, anyone being able to snoop the network can see the encrypted passwords. Abigail	[reply]
Re: Re: Salt -- Something I've Never Understood by jonadab (Parson) on Feb 05, 2004 at 20:14 UTC
It doesn't make the encryption more random. That doesn't make any sense. I suspect he meant the encryption key, not the encryption process. Indeed, making the process random wouldn't make any sense. `$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}} split//,".rekcah lreP rehtona tsuJ";$\=$ ;->();print$/` [download]	[reply] [d/l]