The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge An 'unhearable' message
Solved Level 1 challenge A Secret Message from Castle Mansfeld
Solved Level 1 challenge Letter from the Alleged Countess Julie von Ortenburg
Solved Level 1 challenge Classical Ciphers^3
Solved Level 1 challenge Zodiac Cipher
Solved Level 1 challenge Monoalphabetic Substitution
Solved Level 1 challenge Caesar Encryption
Solved Level 1 challenge Molehunt (Part 1/3)
Four degrees of difficulty, from pen & paper to complex mathematical problems