The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Autokey Cipher
Solved Level 1 challenge Find the right route — Part 1
Solved Level 1 challenge Letter from the Alleged Countess Julie von Ortenburg
Solved Level 2 challenge Twisting the Rubik's Cube
Solved Level 2 challenge "The Road" — Part 1
Solved Level 1 challenge A modified homophonic cipher with reduced alphabets — Part 2
Solved Level 1 challenge A modified homophonic cipher with reduced alphabets — Part 1
Solved Level 1 challenge Grille Cipher
Four degrees of difficulty, from pen & paper to complex mathematical problems