Welcome to the fourth National Cipher Challenge. The competition will run from September 29th 2005 to January 5th 2006. Over the next few months you will be assisting Harry Schultz Vandiver as he joins the crew of the Michael 5 submarine chasing mysterious messages from the depths of the Arctic ocean. it will be your job to help Harry decipher these intercepts. Challenges will be set on this website in the cipher room, and will come in two parts. Part A will consist of notes between Harry and the captain of the Michael 5, and these will be lightly encrypted, though as the mission progresses and security becomes more important security will tighten. Part B will be an intercepted message from the depths. This will typically be harder to decipher but you may find some hints in the notes in the part A messages or elsewhere in the Boat's Log. The Challenges will be published at 4pm on a Thursday, according to the schedule on the right. You can submit your solution any time after the challenge has been published and before the deadline at one minute to midnight the day before the next Challenge is published. Solutions to each Challenge will be published after the deadline, so if you can't crack a particular Challenge don't give up.
If you submit a solution with a mistake in it you will receive feedback from us by email telling you where you started to go wrong and you can then submit again. For each Challenge you will receive a score based on your speed and accuracy, and we will use these scores to compile an Honours Board for each Challenge part A and for each part B. These lists will be published so you can see how you are getting on. The part B Honours Lists will be compiled into an overall Championship Leader Board which will be used to determine the overall winners of the competition.
Entries for each challenge, which may be from individuals or from teams, should be submitted using the competition webform Be careful to follow the instructions on the form. Failure to adhere to all the instructions may result in the entry being deemed invalid. The detailed rules are given below.
There will be a range of prizes throughout the competition. At the conclusion of each challenge we will draw ten teams at random from those submitting a solution, and we will award a small bonus prize to those teams. The overall championship prize will be awarded to the team or individual at the head of the overall championship leader board at the end of the competition. The prize will be an IBM Thinkpad laptop. We will also be awarding a second prize valued at £700, sponsored by Trinity College, Cambridge. Other prizes will be announced on the website.
Schedule
| Cipher | Publication Date | Deadline 23.59 on |
|---|---|---|
| 1 | 29 September | 5 October |
| 2 | 6 October | 12 October |
| 3 | 13 October | 19 October |
| 4 | 20 October | 26 October |
| 5 | 27 October | 9 November |
| 6 | 10 November | 23 November |
| 7 | 24 November | 7 December |
| 8 | 8 December | 5 January |
Rules
1. The competition is only open to persons who are in full time school-level education in the United Kingdom*.2. The competition is only open to persons aged 18 or under on 31 August 2006.
3. Entries may be received from individuals or from teams. The teams may be of any size, but we can only list details of four members of the team whose names may be entered on the registration form. Instead you could list your class name or the name of the school or group to which you belong.
4. Teams must nominate a captain.
5. The schedule of messages to be deciphered is given here, the schedule of prizes will be announced in the boat's log on this website.
6. Each challenge consists of two parts, part A and part B. The part A challenges will be aimed at beginning cryptographers and should be accessible to everyone throughout the competition. The part B challenges will start easily but will become more difficult as the challenge progresses. You may submit solutions to either or both parts of the current challenge on the web entry form.
7. For each of the challenges 1 to 8 there will be a range of prizes awarded to competitors chosen at random from those who submit a correct entry to part A.
8. For each of the challenges 1 to 8 for which you submit an entry for part B you will be awarded a score, based on the accuracy of your best submission for that challenge and the order in which we receive the submissions. Your score will be used to determine the winner of the Championship Prize, who will be chosen from among those achieving the highest total scores.
9. A solution will only be deemed to be correct if, disregarding the punctuation [and spacing], the deciphered plaintext (only involving the Roman characters A to Z [UPPER or lower case is fine]) is letter perfect as compared to our master solution.
10 A submission will only be deemed to be valid if it is submitted on the entry webform and all the instructions on the entry form are adhered to.
11. The Challenge Committee may publish clues on the competition website (in the boat's log) if it considers it appropriate.
12. If a correct solution of a challenge is not received before the deadline given on the schedule the Challenge Committee will have the discretion to not award the prize or award some of all of it to the entrant or entrants which it judges to represent the best solution or solutions.
13. The competition will be judged by the Challenge Committee, whose decision will be final in all matters regarding the competition including the award of prizes.
14. In order to qualify for any of the prizes all entrants, whether solo or part of a team agree to their names being used in publicity associated with the competition including publication on the competition's websites.
15. In submitting an entry solo entrants vouch that it is solely their own work and teams warrant that it is solely their own collective work.
16. Entrants who do not abide by the rules will be disqualified from the competition and will not qualify for any of the prizes.
17. In submitting an entry to the competition, all entrants, be they individuals or members of a team agree to be bound by all the rules of the competition.
18. Winners and their schools will be notified as soon as possible after the solution deadline for each message.
19. The organisers reserve the right to change any aspect of the competition at short notice and to split prizes where it is deemed appropriate. Such changes will be announced on the competition website as soon as practical.
* Homeschoolers also qualify as do those attending schools in the Channel Islands and the Isle of Man.