Comment by lemmikins on 14/12/2006 at 20:58 UTC

3 upvotes, 1 direct replies (showing 1)

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I don't really see what encryption gains you over hashing. [...] Encryption, though it does have all sorts of obvious benefits over cleartext,

As far as passwords go, you can brute-force hashing as well -- you just compare the hashes. In fact, as it's not 1-to-1, you don't always have to guess the correct plaintext in order to get the same hash. Plus you still need some method for forgotten passwords.

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Comment by duketime at 14/12/2006 at 21:32 UTC

4 upvotes, 1 direct replies

You're right on both accounts: hashing can be brute forced or you can find a collision (and MD5 has been cracked). But the key difference is that if you use a good algorithm / hash length it's practically infeasible: there really isn't a reasonable short cut to crack it.

With 1-to-1 encryption (with a decryption algorithm) there is a method to get the cleartext in constant time (i.e. there is a short cut) and this is the key.

It's more desirable (in general) to live with the certainty that it will take a very very long time to crack / collide your hash than it is to live with the (off) chance that a leaked algorithm / key will **instantly** allow access (plus risk of the exact same brute force).