The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 2 challenge Fastest in the West
Solved Level 2 challenge Monoalphabetic Substitution with Nostradamus Flavor
Solved Level 2 challenge M-138 — Part 3
Solved Level 1 challenge Number Sequence — Part 8
Solved Level 1 challenge The Syllabary Cipher – Part 1
Solved Level 1 challenge A disguised code
Solved Level 1 challenge Bigram Substitution – Part 1 (Tutorial)
Solved Level 1 challenge Find the right route — Part 1
Four degrees of difficulty, from pen & paper to complex mathematical problems