The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Number Sequence
Solved Level 2 challenge ASAC — A Strong(er) ADFGVX Cipher — Part 1
Solved Level 1 challenge Bigram Substitution – Part 1 (Tutorial)
Solved Level 1 challenge Advent-Challenge — Part 1
Solved Level 1 challenge Beaver Code
Solved Level 1 challenge Original Caesar Cipher
Solved Level 1 challenge Affine Codes / Modulo Arithmetic with N / Extended Euclid
Solved Level 1 challenge Letter to the Templars — Part 1
Four degrees of difficulty, from pen & paper to complex mathematical problems