The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 3 challenge CMEA 2
Solved Level 2 challenge Factorization Cipher — Part 2
Solved Level 2 challenge Unconcealed RSA messages
Solved Level 1 challenge An Invisible Message
Solved Level 1 challenge Turing Bombe Enigma I
Solved Level 1 challenge Factorization Cipher — Part 1
Solved Level 1 challenge Grille Cipher
Solved Level 2 challenge Pigpen with a twist — Part 3
Four degrees of difficulty, from pen & paper to complex mathematical problems