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_Nobody_ is hashing thousands of passwords per second as part of a typical webapp load. Even if somebody was, they would need only ~50 cores for hashing. I'm sure anybody with that much traffic could easily shell out a few thousand bucks for the extra processors without blinking.

Also, an 8 character password hashed with scrypt with a very low (64ms) cost takes on average $4.8 million to brute force[1].

1: http://www.tarsnap.com/scrypt/scrypt.pdf

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Thanks for citing your source! You rock.

They are claiming 6.57 * 8 = 52.5 bits of entropy would cost $4.8m to crack a single password in a year.

They also state 4.7 * 8 = 37.6 bits of entropy would cost $150 to crack a single password in a year.

Their own citation of 'A large scale study of web password habbits' http://research.microsoft.com/pubs/74164/www2007.pdf found that the average password has only 40.5 bits of entropy. I'm afraid even scrypt will not save you from 40 bit entropy passwords.

The point is that nothing will "save" a single user for whom there is a dedicated attacker. But you can make it uneconomical to attack the whole database. That's what bcrypt, scrypt et al do.

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