The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 2 challenge Molehunt (Part 3/3)
Solved Level 2 challenge ORYX Stream Cipher Part I
Solved Level 1 challenge Number Sequence — Part 8
Solved Level 1 challenge Number Sequence — Part 4
Solved Level 2 challenge AES key — encoded in the machine readable zone of a European ePassport
Solved Level 1 challenge Reserve Hand Procedure — Part 1
Solved Level 1 challenge M-138 — Part 1
Solved Level 1 challenge Number Sequence — Part 3
Four degrees of difficulty, from pen & paper to complex mathematical problems