Re:Ask HN: How do you handle server security/intrusion monit...
by JoachimSchipper on Sunday November 22, 2009 @06:39PM
(#956423)
There are no currently known cryptographic weaknesses in this application of MD5, and using salts is adequate protection against rainbow tables. But a weakish password can still be guessed far too quickly.
Using a proper key derivation function like OpenBSD's pessimised Blowfish (with a suitable numbers of rounds), John the Ripper tries about 60 passwords per second on my hardware. Against salted MD5, 3000. (Also see PBKDF2, which is also a good solution.)
SHA1 isn't really that much better here, sadly - the problem is not cryptographic weaknesses, it's weak passwords and a function that can be evaluated too quickly.
Using a proper key derivation function like OpenBSD's pessimised Blowfish (with a suitable numbers of rounds), John the Ripper tries about 60 passwords per second on my hardware. Against salted MD5, 3000. (Also see PBKDF2, which is also a good solution.)
SHA1 isn't really that much better here, sadly - the problem is not cryptographic weaknesses, it's weak passwords and a function that can be evaluated too quickly.