This site aims to provide a practical approach to cryptography. We attempt to provide javascript examples and detailed diagrams where possible, in order to make the learning process much smoother.

In our effort to provide a practical approach to these, we have developed a javascript implementation for each cipher that allows encryption and decryption of abitrary text (of your choosing) using the cipher. …

Cryptanalysis This section documents the ways in which many cryptographic ciphers can be cryptanalysed and broken. The easiest ciphers to break are the ones which have existed for a long …

This is not very practical because the vowels and other diacritics are used inconsistently, for example just on one or two letters to disambiguate the word.

Simon Singh's 'The Code Book' is an excellent introduction to ciphers and codes, and includes a section on ADFGVX ciphers. Singh, Simon (2000). The Code Book: The Science of Secrecy from Ancient …

Cryptanalysis of the Simple Substitution Cipher For a recap of how substitution ciphers work, see here. The Simple substitution cipher is one of the simplest ciphers, simple enough that it can usually be …

[1] Wikipedia has a good description of the encryption/decryption process, history and cryptanalysis of this algorithm [2] A decent overview of the affine cipher: …

Letter Frequencies for Various Languages Provides ngram models for several languages. Techniques Danish Letter Frequencies This page provides letter frequencies for Danish. This includes …

ADFGVX Cipher Introduction § In cryptography, the ADFGVX cipher was a field cipher used by the German Army during World War I. ADFGVX was in fact an extension of an earlier cipher called the …

"Cryptography: Theory and Practice" If you're looking for something online that you can access immediately, try: "Introduction to Modern Cryptography" subject at University of California, San Diego …