The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge The Syllabary Cipher – Part 1
Solved Level 1 challenge Wheatstone Cryptograph — Part 1
Solved Level 2 challenge The Josse Challenge – Part 2
Solved Level 2 challenge The Josse Challenge – Part 1
Solved Level 2 challenge RSA: Two different keys — same ciphertext
Solved Level 1 challenge Pigpen with a twist — Part 1
Solved Level 2 challenge Hybrid Encryption I
Solved Level 1 challenge Reserve Hand Procedure — Part 1
Four degrees of difficulty, from pen & paper to complex mathematical problems