The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 3 challenge Handycipher — Part 4
Solved Level 3 challenge Extended Handycipher — Part 6
Solved Level 2 challenge The Hutton Cipher – Part 2
Solved Level 2 challenge Cracking SHA1-Hashed Passwords
Solved Level 3 challenge Handycipher — Part 6
Solved Level 1 challenge The Syllabary Cipher – Part 1
Solved Level 3 challenge Extended Handycipher — Part 4
Solved Level 1 challenge Bigram Substitution – Part 1 (Tutorial)
Four degrees of difficulty, from pen & paper to complex mathematical problems