The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Original Caesar Cipher
Solved Level 1 challenge Number Sequence
Solved Level 1 challenge A disguised code
Solved Level 1 challenge Alberti Challenge — Part 1
Solved Level 2 challenge ASAC — A Strong(er) ADFGVX Cipher — Part 1
Solved Level 1 challenge The Syllabary Cipher – Part 1
Solved Level 1 challenge A hidden word
Solved Level 2 challenge New Year's Greetings — Part 5
Four degrees of difficulty, from pen & paper to complex mathematical problems