51–56 of 56 posts
Earlier quoted context omitted.
So migrate? Hash the hashes with Bcrypt or PBKDF2. Bcrypt(MD5(password)) is just as effective as Bcrypt(password) at knocking brute force attempts on the head.
Unless the Bad Guys already have the MD5 hashes
Earlier quoted context omitted.
These aren't cryptographic hash functions exactly , though, at least not in the sense that a cryptographer would think. I mean, they will fit just about any definition of a cryptographic hash function you can think of, but really it's not that useful to label them as such. Instead, they're usually called key derivation functions. On top of that, even if we were to include these in a hash function list, they're decide…
Cryptographic hash functions must be efficient to compute. Those examples (scrypt, bcrypt, etc) were designed to be difficult to compute. Those are password hash functions, not cryptogrpahic hash functions. Two totally different things with different purposes.
I mean, wouldn't you say that scrypt is efficient to compute? For instance, is 5 seconds not a relatively quick function evaluation? Compare that to super-polynomial-time attacks, some of which wouldn't succeed before our Sun burned out and Earth died. And if you ramp up the security parameters to an insane degree, the user can no longer compute the function themselves. That's the reason for the "efficient to compute" clause in most definitions.
So, while you're right that the fact that KDFs are designed to be much slower than hashes is what really separates them, that doesn't disqualify KDFs from (technically) being cryptographic hash functions. At least, not if you view the definition in a theoretical sense, which is the appropriate way to do so. Still, I agree with your premise; in a practical sense, KDFs shouldn't feel like they are cryptographic hashes, since their purpose is markedly different.
Why is SHA-2 orange? As far as I know, besides length-extension, there's no known weakness on the full hash function.
https://en.wikipedia.org/wiki/Comparison_of_cryptographic_ha... or more specifically: http://dx.doi.org/10.1007/978-3-642-38348-9_16 and http://eprint.iacr.org/2010/016.pdf
I think labeling SHA-256 as orange is highly misleading. The SHA-2 family of hashes is going nowhere unless the partial-round attacks get a lot closer to the full-round versions. They're still about 20+ rounds away.
Earlier quoted context omitted.
So migrate? Hash the hashes with Bcrypt or PBKDF2. Bcrypt(MD5(password)) is just as effective as Bcrypt(password) at knocking brute force attempts on the head.
Unless the Bad Guys already have the MD5 hashes