The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge How do you become a big cryptographer?
Solved Level 1 challenge Advent-Challenge — Part 1
Solved Level 1 challenge Affine Codes / Modulo Arithmetic with N / Extended Euclid
Solved Level 2 challenge Alice's Birthday Party (Part 2)
Solved Level 2 challenge Alice's Birthday Party (Part 1)
Solved Level 1 challenge Letter to the Templars — Part 2
Solved Level 1 challenge The Syllabary Cipher – Part 1
Solved Level 2 challenge The Syllabary Cipher – Part 2
Four degrees of difficulty, from pen & paper to complex mathematical problems