I agree. There are whole classes of problems that are not at all obvious until one has spent time learning how to break bad crypto. Matasano&#x27;s challenges[0] (which I think tptacek helped create) are a good start.<p>0. <a href="http:&#x2F;&#x2F;cryptopals.com&#x2F;" rel="nofollow">http:&#x2F;&#x2F;cryptopals.com&#x2F;</a>