The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Monoalphabetic substitution with camouflage — Part 4
Solved Level 1 challenge Letter from the Alleged Countess Julie von Ortenburg
Solved Level 1 challenge Music Code — Part 1
Solved Level 2 challenge Music Code — Part 2
Solved Level 2 challenge Handycipher — Part 1
Solved Level 2 challenge Handycipher — Part 2
Solved Level 2 challenge Double Column Transposition — Part 3
Solved Level 2 challenge ASAC — A Strong(er) ADFGVX Cipher — Part 2
Four degrees of difficulty, from pen & paper to complex mathematical problems