| A Cryptographic Compendium | | Outline of the various types of cipher systems that have been used historically and the relationships between them. |
| Coderpunks | | Little sister of the cypherpunk mailing list. Discussion of implementations of strong, robust cryptosystems. |
| Crypto Machines | | Features machines and systems used in secure communications. Includes brief history on cryptography. |
| Crypto-Gram | | Free monthly email newsletter covering developments in cryptography and other computer security issues. |
| Cryptography FAQ | | Ten part FAQ list that is essential reading for any newcomer to cryptography. |
| Cryptography World | | Introduction to cryptography, including concepts, key management and application. |
| CryptoMX Tools | | Set of cryptography tools written entirely in JavaScript, designed to work on any computer with a JavaScript capable browser. |
| Cryptonomicon | | Cryptography related articles, downloads, news, links and discussions. |
| Cyphernomicon | | Tim May's CryptoNotes, and an introduction to the Cypherpunks. |
| Cypherpunks | | Group, with mailing list, that is interested in privacy and cryptography. |
| Deschall | | Articles describing the first crack of a DES-encrypted message, with some source code and mailing list archives. |
| Home of HB9CUF | | Free cryptographic tools: CryptoUP to secure and transport any kind of file; FindSR helps to analyze ciphertext. |
| MD5 Reverse Lookup | | Project to record and search for mappings of MD5 hashes to their original messages. | |
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