The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Letter to the Templars — Part 2
Solved Level 1 challenge Letter to the Templars — Part 1
Solved Level 1 challenge Recycled One-Time Pad
Solved Level 1 challenge A hidden word
Solved Level 1 challenge Enigma Messages
Solved Level 1 challenge Playfair with hints about the grid
Solved Level 1 challenge Reserve Hand Procedure — Part 1
Solved Level 1 challenge Multilingual Monoalphabetic Substitution
Four degrees of difficulty, from pen & paper to complex mathematical problems