This is an unofficial archive of the British National Cipher Challenge (https://www.cipherchallenge.org/). The purpose is to collect all parts of the challenges in one place and to preserve them before they are lost to bit rot and server decay. The official site only goes back a few years, and archive.org and other sites are also incomplete. Preserving them allows competitors (or anyone else who is interested) to use them as practice.
The official site:
www.cipherchallenge.org [current/most recent season]
2016.cipherchallenge.org
2017.cipherchallenge.org
2018.cipherchallenge.org
2019.cipherchallenge.org
2020se.cipherchallenge.org
Stuff in this archive is copyright University of Southampton (except for the identification of ciphers and keys ("solution.txt" for each challenge) and any scripts or programs in this archive).
For the official challenges, all ciphertexts and plaintexts are present, and all ciphers and keys have been identified. All information that was given when each challenge began is present, so you can do the challenges for yourself.
Some plaintexts and solutions are missing for non-official challenges. The missing ones are
- 2005 forum post from Captain Cool: missing key phrase
- 2013 bonus 9B
- 2013 forum posts
- 2020 forum post #52705 from Awesomeness
- 2020 forum post #52538 from Hazzataytay
Other bits we wish we had:
- 2001 official hints
- 2002 some of the GIFs of the texts: plaintexts 3, 5, 6, 8, 9, 12, 14, 15; ciphertext 13
- 2002 solution15.pdf that isn't broken
- 2003 some of the GIFs of the texts: plaintexts 3, 4, 5, 8; ciphertexts 1, 2, 3, 4, 5, 7
- 2005 GIFs of the ciphertexts (we have 2B, 3B, 4B, and 5B)
- 2006 GIFs of the ciphertexts
- 2006 PDFs of the plaintexts (and solutions) 1 through 6
- 2007 GIFs of the ciphertexts and plaintexts (we only have 0A, 0B, and ciphertexts 1B, 8A, 8B)
- 2008 parts 1A and 1B from the challenges that appeared in the forum
- 2008 GIFs of the ciphertexts and plaintexts (we only have 8A and 8B plaintexts)
- 2010 GIFs of plaintexts 2B, 5A, 5B
- 2010 part 8B "teaser" that was released before the challenge was posted
- 2012 Harry's Game (following the 2011 competition): ciphertexts (and plaintexts) 3A, 4A and onward
- 2015 part 8B: remaining hints (images of the deck with more cards showing)
- 2017 images of ciphertexts for 4A through 8B
- 2018 images of ciphertexts for 2A through 10B
- 2018 bonus Hutton cipher that was promised
- any other years of Harry's Game
- the official keywords for the transposition ciphers. I won't list them here, so no spoilers.
- any official hints that we have not found yet
For those who care about such things, these posters and graphics are missing:
- 2002 poster
- 2006 desktop wallpapers (3 images in various sizes)