The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 2 challenge Polyphonic Substitution Cipher — Part 1
Solved Level 2 challenge Polyphonic Substitution Cipher — Part 2
Solved Level 3 challenge The SIGABA Challenge — Part 5
Solved Level 1 challenge Beaver Code
Solved Level 1 challenge Caesar Encryption
Solved Level 1 challenge Number Sequence — Part 2
Solved Level 1 challenge Original Caesar Cipher
Solved Level 1 challenge Number Sequence
Four degrees of difficulty, from pen & paper to complex mathematical problems