The American Cryptogram Association

Cipher Types

Codes, Ciphers, & Codebreaking

Basic Cryptanalysis

Military Cryptanalysis

Code Penguin's Cryptography Archive

Handbook of Applied Cryptography

List of Free Online Cryptography Books

Self-Study Course in Block Cipher Cryptanalysis

The Cryptanalysis Blues

Identifying Unknown Ciphers

CrypTool List of Ciphers

Online puzzles

Puzzle Baron Cryptograms


Most Common Letters, Digrams, and Trigrams in the English Language

2 Letter Words

3 Letter Words


Practical Cryptography

Hacking Secret Ciphers With Python

An Intro To Crypto Programming Using Python

pycipher - Common classical ciphers implemented in Python


Tools for Cryptography

The CrypTool Portal

EverCrack (GPL) Open Source Cryptanalysis Engine

List of Cryptanalysis Tools

Vigenère Ciphers

The Vigenere Cipher

Vigenère Cipher Code

PyGenere - Automatic Decoder/Solver

Vigenere Online Analysis and Cracking

Vigenère Cipher Codebreaker

Sharky's Vigenere Cipher