4 ms·

The reason that people move away from a hash function when it looses collision resistance is that collision resistance serves as a measure of the security margi

The reason that people move away from a hash function when it looses collision resistance is that collision resistance serves as a measure of the security margin for preimage resistance. Cryptographic primitives are intended to be rotated out of use about 10-15 years before they become actually broken for their intended purpose. Unless you are willing to extend you bounty to the year 2030 it is means nothing. In addition, you are completely wrong about the harm caused by simplifying the rules of thumb for security. There is not good reason to ever use MD5 for this purpose, and saying "MD5 is ok in some cases" has the potentially to do far more harm than "never use MD5". > note, this is actually a prize for a weaker claim than an preimage attack; all I want is a second preimage (!) Don't act like you are doing GP a favor, second preimage is the attack that would cause a vulnerability in this usage of MD5. You are the one who is"opin[ing] on security threads while not quite understanding anything", so I think before the next time you condescendingly correct someone you should make sure you have a basic understanding of what you are talking about.

megadollar 9y ago
You're clearly somebody who wants to rely on "rules of thumb" for security. I'm arguing against the entire concept of rules of thumb and you've since argued against a strawman. Did I ever say "MD5 is ok in some cases"? Aside: a preimage attack implies a second preimage attack.
- benchaney 9y ago
  >You're clearly somebody who wants to rely on "rules of thumb" for security. I'm arguing against the entire concept of rules of thumb Not all devs are security experts, or can even afford to focus on security. To deny the value of rules of thumb is to deny that they need to consider security. > Did I ever say "MD5 is ok in some cases"? Oh, really? Were you not arguing that MD5 is ok if you only need preimage resistance? > MD5 is not broken for the usage that you think it's broken for. Please don't snipe on things like this again. People like you who say things like "md5 is always bad" or "you should bcrypt, duh" are literally cargo culting the idea of computer security. Hmm. Seems like you were...

megadollar 9y ago

You're clearly somebody who wants to rely on "rules of thumb" for security. I'm arguing against the entire concept of rules of thumb and you've since argued against a strawman. Did I ever say "MD5 is ok in some cases"? Aside: a preimage attack implies a second preimage attack.

benchaney 9y ago
>You're clearly somebody who wants to rely on "rules of thumb" for security. I'm arguing against the entire concept of rules of thumb Not all devs are security experts, or can even afford to focus on security. To deny the value of rules of thumb is to deny that they need to consider security. > Did I ever say "MD5 is ok in some cases"? Oh, really? Were you not arguing that MD5 is ok if you only need preimage resistance? > MD5 is not broken for the usage that you think it's broken for. Please don't snipe on things like this again. People like you who say things like "md5 is always bad" or "you should bcrypt, duh" are literally cargo culting the idea of computer security. Hmm. Seems like you were...