The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Cryptanalysis Hacking Puzzles — Part 1
Solved Level 1 challenge Lightweight Introduction to Lattices — Part 1
Solved Level 1 challenge Autokey Cipher
Solved Level 1 challenge Cryptanalysis Hacking Puzzles — Part 2
Solved Level 1 challenge Polyhomophonic Substitution — Part 1
Solved Level 3 challenge The SIGABA Challenge — Part 5
Solved Level 1 challenge Wheatstone Cryptograph — Part 1
Solved Level 1 challenge Alberti Challenge — Part 1
Four degrees of difficulty, from pen & paper to complex mathematical problems