The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Enigma Messages
Solved Level 1 challenge Pigpen with a twist — Part 1
Solved Level 2 challenge Broadcasting and low exponent — RSA Attack
Solved Level 2 challenge Unusual encryption using a diophantine equation
Solved Level 2 challenge Partial Key Exposure with RSA — Part 1
Solved Level 2 challenge RSA: Two different keys — same ciphertext
Solved Level 2 challenge PX-1000 Encryption – Part 1
Solved Level 2 challenge Holographic Encryption — Part 2
Four degrees of difficulty, from pen & paper to complex mathematical problems