The Cipher Challenge Contest
Four degrees of difficulty, from pen & paper to complex mathematical problems
Solved Level 2 challenge Twisting the Rubik's Cube
Solved Level 1 challenge Assembly Point – Part 1
Solved Level 2 challenge ORYX Stream Cipher Part II
Solved Level 2 challenge ORYX Stream Cipher Part I
Solved Level 2 challenge AES key — encoded in the machine readable zone of a European ePassport
Solved Level 2 challenge Cipher ID — Part 1
Solved Level 2 challenge Double Column Transposition — Part 5
Solved Level 2 challenge Advent Challenge — Part 4
Four degrees of difficulty, from pen & paper to complex mathematical problems