*[https://blog.cryptographyengineering.com/2014/11/27/zero-knowledge-proofs-illustrated-primer/ Zero Knowledge Proofs: An illustrated primer]
*[https://blog.cryptographyengineering.com/2017/01/21/zero-knowledge-proofs-an-illustrated-primer-part-2/ Zero Knowledge Proofs: An illustrated primer, Part 2]
*[http://cryptnet.net/fdp/crypto/keysigning_party/en/keysigning_party.html The Keysigning Party HOWTO]
==Web==
*[https://paragonie.com/blog/2015/04/secure-authentication-php-with-long-term-persistence Implementing Secure User Authentication in PHP Applications with Long-Term Persistence (Login with "Remember Me" Cookies)]
*[http://crackstation.net/hashing-security.htm Secure Salted Password Hashing - How to do it Properly]