Essentially, what's the next step up from plaintext password storage? I suspect the answer is going to be MD5, but I'm not familiar with a broad enough variety of examples to be sure.
The reason that I ask is that I'm trying to determine an appropriate strength to shoot for when generating passphrases. I know that a dedicated cracking rig like this one can run MD5 hashes at around 300 billion per second, so I'm thinking a minimum of about 67 bits of entropy (~10 years to crack.)
Is it reasonable to treat MD5 as the lower limit for password hashing?
EDIT: To clarify, I'm not trying to store passwords, and if I were I certainly wouldn't be using MD5. I'm just trying to figure out what's the worst-case scenario I'm likely to run into as a user, so that I can set a reasonable minimum complexity for my passphrases. Obviously the true worst case would be plaintext password storage, but in that case no amount of complexity will save me.
I'm pulling from a dictionary of 15 thousand words, which gives my passphrases an entropy of ~14 bits per word. So a 5-word passphrase should get me up to about 70 bits of entropy, which should be enough to defend against most attacks even if the password is stored via MD5.
My question essentially boils down to "Is there some other commonly-used hashing algorithm, that's even faster than MD5, that I should be aware of?" If there is, then I need to reconsider my passphrase strength.