The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 2 challenge Not-so-Secret Message from Malawi — Part II (ECC)
Solved Level 1 challenge Playfair Encryption
Solved Level 1 challenge Original Caesar Cipher
Solved Level 1 challenge Molehunt (Part 2/3)
Solved Level 1 challenge Number Sequence — Part 10
Solved Level 1 challenge Number Sequence — Part 9
Solved Level 1 challenge The Book Code: A Challenge for Bookworms
Solved Level 1 challenge Pigpen with a twist — Part 1
Four degrees of difficulty, from pen & paper to complex mathematical problems