The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Caesar Encryption
Solved Level 3 challenge Sigaba Part 2
Solved Level 1 challenge Strange Message from Thessaloniki
Solved Level 1 challenge How do you become a big cryptographer?
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
Four degrees of difficulty, from pen & paper to complex mathematical problems