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