Pretty much every crypto library you use was badly broken, multiple times, during its long history. New attacks are still being found, and browsers and librarie

Pretty much every crypto library you use was badly broken, multiple times, during its long history. New attacks are still being found, and browsers and libraries are updated as we learn more. For a small sample, read the wikipedia page for http://en.wikipedia.org/wiki/Secure_Sockets_Layer http://en.wikipedia.org/wiki/Secure_Sockets_Layer and take a look at how many times we all got that wrong. The first rule of crypto is not to write crypto code. Reuse a high level library that already made all the mistakes you're about to. If you absolutely have to break the first rule, you need to budget between 5 and 6 digits for experts to review it against known attacks and best practices.