The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 1 challenge Original Caesar Cipher
Solved Level 2 challenge Factorization Cipher — Part 2
Solved Level 1 challenge Factorization Cipher — Part 1
Solved Level 2 challenge Letter to the Templars — Part 3
Solved Level 1 challenge Playfair Encryption
Solved Level 2 challenge AES key — encoded in the machine readable zone of a European ePassport
Solved Level 2 challenge M-138 — Part 4
Solved Level 2 challenge The T52 Sturgeon Challenge — Part 11
Four degrees of difficulty, from pen & paper to complex mathematical problems