National Cipher Challenge 2026 — University of Southampton
QUICK SUMMARY
Rated Advanced, A free online UK codebreaking competition built around a serial mystery and ten progressively harder weekly chapters. Anyone may participate individually or in a team, while prizes are reserved for eligible UK and Channel Islands school-level entrants. Success requires sustained cryptanalysis, careful checking, self-written tools and increasingly sophisticated reasoning across the full season.
COMPETITION DATE
8 Oct 2026