This is an introductory course on cryptography, freely available for programmers of all ages and skill levels. It comes with everything you need to understand complete systems such as SSL/TLS, block ciphers, stream ciphers, hash functions, message authentication codes, public key encryption, key agreement protocols, and signature algorithms.
Crypto 101 is intended as an introduction to cryptography for programmers of any skill level. It starts with very simple primitives, and gradually introduces new ones, demonstrating why they are necessary. And eventually, all of this is put together into complete, practical cryptosystems, such as TLS, GPG and OTR.
If you are an everyday programmer who is also interested in how cryptosystems work, what are you waiting for?