The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge A disguised code
Solved Level 2 challenge Cipher ID — Part 1
Solved Level 2 challenge Wheatstone Cryptograph — Part 2
Solved Level 1 challenge Playfair Encryption
Solved Level 2 challenge Brute-Force-Attack on Triple-DES with Reduced Key Space
Solved Level 2 challenge Polyhomophonic Substitution — Part 2
Solved Level 2 challenge Keyshanc — Part 2
Solved Level 1 challenge Find the right route — Part 1
Four degrees of difficulty, from pen & paper to complex mathematical problems