The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 2 challenge Cracking SHA1-Hashed Passwords
Solved Level 2 challenge Not-so-Secret Message from Malawi — Part II (ECC)
Solved Level 2 challenge ORYX Stream Cipher — Part 4a
Solved Level 2 challenge The Hutton Cipher – Part 2
Solved Level 2 challenge The Hutton Cipher – Part 1
Solved Level 2 challenge Alice's Birthday Party (Part 2)
Solved Level 2 challenge Alice's Birthday Party (Part 1)
Solved Level 2 challenge Factorization Cipher — Part 3
Four degrees of difficulty, from pen & paper to complex mathematical problems