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 Advent Challenge — Part 4
Solved Level 2 challenge Advent Challenge — Part 3
Solved Level 2 challenge Advent-Challenge — Part 2
Solved Level 2 challenge Double Column Transposition — Part 5
Solved Level 2 challenge A Cloaked Substitution Cipher — Part 2
Solved Level 1 challenge ADFGVX — Part 1
Solved Level 1 challenge ADFGVX — Part 1
Four degrees of difficulty, from pen & paper to complex mathematical problems