Advanced Encryption Standard: http://csrc.nist.gov/encryption/aes/
OpenBSD security page: http://www.openbsd.org/security.html
OpenSSH: http://www.openssh.com/
OpenSSL: http://www.openssl.org/
RSA Freedom Clock: http://www.kfu.com/~nsayer/encryption/rsaclock.html
Sequential Innovation, Patents, and Imitation by James Bessen and Eric Maskin: http://www.researchoninnovation.org/patent.pdf