3 ms·
Wait, is AC bad or good? I can't tell whether the gp means it'll cause problems because the protocols are hard to implement or wrong.
by yters 19y ago
Wait, is AC bad or good?
I can't tell whether the gp means it'll cause problems because the protocols are hard to implement or wrong.
- tptacek 19y agoAC is bad. If you implement cryptography and you're not depending on it in some way, you're wasting time. If you do depend on it, you have to get it exactly right. Even people who do that for a living don't know exactly what that means. http://www.matasano.com/log/487/rsa-signature-forgery-explained-with-nate-lawson-part-ii/ http://www.matasano.com/log/487/rsa-signature-forgery-explai...
- icey 19y agoI would say AC is good from a theory point of view, but bad as an implementation guide. Kind of in the same way that a Chilton guide will tell you all sorts of things about your car, but you shouldn't try to build a car from scratch based on it.
- tptacek 19y agoFerguson and Schneier wrote a followup book, "Practical Cryptography", which addresses the shortcomings of "Applied Cryptography" --- it selects the "best" algorithms and protocols to use, and tries to document the pitfalls of actually implementing them in real software. I recommend it with reservations. It's an extremely valuable book, especially if you're a security evaluator looking for crypto vulnerabilities. As an implementation guide, it misses glaring faults that real software constantly introduces. There simply is no by-the-numbers guide to implementing crypto in an application, and doing it wrong is worse than not doing it at all.