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Comment by zaroth | Hacker News Reader

Please read the RFC, it's right here: http://www.ietf.org/rfc/rfc2945.txt

Password entries are generated as follows:

        <salt> = random()
        x = SHA(<salt> | SHA(<username> | ":" | <raw password>))
        <password verifier> = v = g^x % N

   G = 47
   N = 112624315653284427036559548610503669920632123929604336254260115573677366691719

What was stolen was no better than LinkedIn hashes -- for the purposes of dictionary attacking the database

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Define slow tedunangst - Big O notation please.

Maybe you can look here: http://en.wikipedia.org/wiki/Modular_exponentiation.

Ok, I'll save you the trouble -- the modular exponentiation is O(log exponent). That's log as in... FAST.

What's the Big-O of PBKDF2 ?

Constants matter.

(Also, computational complexity of crypto algorithms is usually specified in terms of nbits, not numeric magnitude)

(Although this argument has given me an idea for everyone that thinks using the same password on different sites is reasonable - a browser extension that runs a client-side KDF :P)

slow == 172.959 times slower than sha1("password")

Actually, I forgot one minor thing. LinkedIn hashes were unsalted. Even assuming SRP is no better than sha1, cracking all of the battle.net passwords is going to be $number_of_users times harder than LinkedIn.

g^x is slow, therefore better than linkedin hashes for the purpose of dictionary attacking the database.

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