The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge A hidden word — Part 2
Solved Level 2 challenge Cracking SHA1-Hashed Passwords
Solved Level 1 challenge ADFGVX — Part 1
Solved Level 1 challenge A disguised code
Solved Level 1 challenge Assembly Point – Part 1
Solved Level 1 challenge Merkle-Hellman Knapsack Challenge - Part 1
Solved Level 1 challenge Bigram Substitution – Part 1 (Tutorial)
Solved Level 1 challenge MACs in Orbit
Four degrees of difficulty, from pen & paper to complex mathematical problems