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0 pointspx435y ago0 comments

> PBKDF2 is a slow algorithm specifically created for password hashing.

Yeah, over 20 years ago. It's woefully out of date by modern standards.

PBKDF2 doesn't even attempt memory hardness, so there are whole classes of attacks on later generation slow hashing algorithms that don't even apply to PBKDF2 because of how old it is. Argon2 is extremely resistant to Time-Memory-Trade-Off (TMTO) attacks, which older algorithms like bcrypt and scrypt are vulnerable to.

PBKDF2 is essentially a linear slowdown, which is effectively pointless these days.

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user59944615y ago

Math doesn't age. Cheers.

bcrypt and scrypt, the successors to PKDF2, are both more than a decade old.

RSA is half a century old and it's still up to date by modern standards. In fact nobody has came up with anything better.

Edit: Actually, bcrypt might be as far as 1999, possibly older than PBKDF2.

goalieca5y ago

> RSA is half a century old and it's still up to date by modern standards. In fact nobody has came up with anything better.

RSA is currently a minefield of gotchas and few security companies even get it right. Just generating a good key is actually a very difficult task. It is also very computationally slow and has many practical issues for the level of security it provides.

There are many superior replacements in both pqc and elliptic spaces. I would take EdDSA over rsa-pss any day of the week.

user59944615y ago

RSA is extremely simple, it's just multiplications and powers. It can be reasonably explained to high school students. The tooling is mature and keys are trivial to generate safely with a openssl command.

EdDSA is another level entirely. I don't know how you can recommend elliptic curve cryptography with a straight face if you think RSA is hard.

P.S. It's a myth that EdDSA is faster. This depends on operation (signing vs verification) and key size.

goalieca5y ago

Elliptic curves are also quite simple. Computing a public key boils down to point addition with a modulus.

The private key is a byte string and the quality of it only depends on the random generator. It’s trivially fast to generate 32 bytes of decent quality random numbers these days. There are many insecure rsa generation methods with weak criteria. Too many are fossilized in libraries and crypto cores. Rsa also has half a dozen padding schemes and most are now considered weak or vulnerable.

EC is generally considered much stronger for a much smaller key size.

upofadown5y ago

Note that we are talking about a single RSA operation. So attacks that require repeated trials are not relevant here.

dheera5y ago

> essentially a linear slowdown

Why does it have to be linear? Just use 1M irritations today, 2M irritations next year, 4M irritations the year after that, and you'll have an exponential version of it.

You can even take your 1M irritated hashes from this year and execute an additional 1M more irritations on them to update them to 2M irritations when you want to upgrade.

j / k navigate · click thread line to collapse

0 comments

user59944615y ago

Math doesn't age. Cheers.

bcrypt and scrypt, the successors to PKDF2, are both more than a decade old.

RSA is half a century old and it's still up to date by modern standards. In fact nobody has came up with anything better.

Edit: Actually, bcrypt might be as far as 1999, possibly older than PBKDF2.

goalieca5y ago

> RSA is half a century old and it's still up to date by modern standards. In fact nobody has came up with anything better.

There are many superior replacements in both pqc and elliptic spaces. I would take EdDSA over rsa-pss any day of the week.

user59944615y ago

EdDSA is another level entirely. I don't know how you can recommend elliptic curve cryptography with a straight face if you think RSA is hard.

P.S. It's a myth that EdDSA is faster. This depends on operation (signing vs verification) and key size.

goalieca5y ago

Elliptic curves are also quite simple. Computing a public key boils down to point addition with a modulus.

EC is generally considered much stronger for a much smaller key size.

upofadown5y ago

Note that we are talking about a single RSA operation. So attacks that require repeated trials are not relevant here.

dheera5y ago

> essentially a linear slowdown

Why does it have to be linear? Just use 1M irritations today, 2M irritations next year, 4M irritations the year after that, and you'll have an exponential version of it.

You can even take your 1M irritated hashes from this year and execute an additional 1M more irritations on them to update them to 2M irritations when you want to upgrade.

j / k navigate · click thread line to collapse