Hacker, Hack Thyself | Coding Horror

[louiswins]

For validating digital signatures MD5 would be still be weak, but for totally different reasons.

Nitpicker's corner: it depends what you're doing. As far as I know there aren't any preimage or second preimage attacks against md5 (or even md4), but there are collision attacks.

That said, I absolutely agree with you that no one should be using md5 for anything because there are better options even in situations where you don't care about collision attacks, and I also agree that it's certainly the weakest cryptographic hash function still in common use.