ALAN TURING CENTENARY CRYPTOGRAPHY COMPETITION

Chapter 1
(Is released!)

Chapter 2
(Is released!)

Chapter 3
(Is released!)

Chapter 4
(Is released!)

Chapter 5
(Is released!)

Chapter 6
(Is released!)

Epilogue
(Is released!)

Solutions
(Is released!)

News

 Wed 11 Apr 4:51 pm Competition closes coming Friday at midnight! Dear all, just a gentle reminder that coming Friday the 13th at midnight the competition will close! This means that only until that time you can submit your solutions to the chapters. Coming Monday the 16th at 4pm the solutions will be released. The forum will stay open for now, we will close it at some point but haven't yet decided when that exactly will be. Good luck with the last bits if you're still trying to solve chapters!
 Wed 4 Apr 4:08 pm 2nd Hint for Chapter 6 It's a Vigenère cipher. To solve it you need to work out what the keyword is. Perhaps you can guess it. If not, then one way to do work out the keyword is to guess some words that might be in the plaintext and work out the keyword that would have been used to encode them - maybe there's a clue in the picture?
 Sun 18 Mar 1:49 am Certificate for teams who solve all 6 chapters As just announced by email as well, since we believe it is an achievement indeed to solve all 6 chapters in this competition we have decided to reward all teams who manage to solve all chapters before the competition closes on 13th April with a nice certificate. Albeit not a very big prize, we do hope you nevertheless consider it as us recognising the effort you put in and success you had in the competition as a result of that!
 Fri 16 Mar 4:26 pm 3rd hint for Chapter 5 This could be hexadecimal (if you ignore some of the letters); perhaps there's a standard method for translating hexadecimal numbers into characters...
 Mon 12 Mar 4:01 pm 2nd Hint for Chapter 5 Sometimes null characters (symbols that should be ignored) are added to a message, just to confuse! Try starting with the common pairs of characters (65 6E 20) and remember that punctuation could also be part of the code...
 Fri 9 Mar 4:07 pm Hint for Chapter 5
 Mon 27 Feb 4:04 pm 2nd Hint - Chapter 4 In her message, Barbara says that this is a book cipher. Now in a book cipher, each letter of the plaintext is enciphered by referring to the location of a word in a given book, perhaps using just the initial letter of that word. There are many of ways of locating words in books: page then word on that page, or chapter then word in that chapter, etc. For a given book, you can rule out some ways of locating words by looking at the numbers in the code. (For example: if the book you are looking at starts on page 6 and the code contains 1.9 then the first number can't refer to the page number - so maybe it refers to the chapter number instead.) Of course, the big problem is to work out which book was used. Barbara said it was a `wizard book code'. Perhaps she was thinking of books about wizards that children like Mike and Ellie would have easy access to: I think I might potter down to the library to get some ideas...
 Fri 24 Feb 1:38 pm The role of the epilogue Just to make things absolutely clear: we've been delighted (and very pleasantly surprised!) at the vast amount of interest in the competition. As you may know, early on in the competition we had to change the original scoring system by introducing a points system so as to make the competition as fair and as open as possible. The original scoring system used an `epilogue' as a tie-breaker in the case of winners tied at the top of the leaderboard; however, the `points-based' leaderboard eliminates the need for this.So, for the record, here's a summary of how the winners will be decided (this is explained in greater detail in the Rules section of the website): the leaderboard displays teams in order of the number of chapters correctly solved teams who have solved the same number of chapters are listed in order of points awarded teams equal on points are ranked in the total time between the release of each chapter (4pm on the appropriate Monday) and submission of the correct answer (when received by our server). The prizes will be awarded to the top three teams on the leaderboard when the competition closes at midnight Friday April 13th.There are points available for Chapters 1 to 6, but not for the epilogue. The epilogue will tie up the story of Mike and Ellie, and also give one final puzzle - which will be just for fun for you to play around with and to discuss on the forum.
 Wed 22 Feb 3:57 pm Hint for Chapter 4
 Wed 22 Feb 2:18 am New feature: team notepad Dear all, following a request on the forum we have implemented a 'team notepad', i.e. a page that can only be accessed by you and your team members (and by us, the organisers) where you can leave notes for each other, inform each other about ideas you have about how to solve a chapter etc. You can find it by clicking 'Notes' next to your team name (or click here). We hope you'll find it useful!
 Mon 13 Feb 4:05 pm Hint for Chapter 3 Dear all, this time it is Alan Turing himself who will provide you with a hint for chapter 3 ;):
Tue 17 Jan 2:32 amIMPORTANT: introduction of a points system

We've been extremely pleased by the popularity of the competition, but unfortunately the original scoring system is no longer suitable for such a large number of teams. Therefore, we are going to introduce a points-based system that will still reward teams that solve codes as quickly as possible, but prevents teams from falling too far behind if they struggle with one chapter. The revised system also means that teams that didn't find out about the competition until after it started still have a chance; and those that were initially unable to view the first code because they had to use older version of Internet Explorer are not disadvantaged.

As well as their rank, teams will be awarded a number of points for each chapter they solve correctly. The first team to solve each code will be awarded fifteen points and then the clock starts ticking for the other teams. The other teams will be awarded points based on how much longer it takes them to solve the code compared to the first team to crack it, according to the following table:

 Points awarded: If the correct solution is received by our server: 15 within one hour of the first team to submit the correct solution 14 within two hours of the first team to submit the correct solution 12 within four hours of the first team to submit the correct solution 11 within one day of the first team to submit the correct solution 10 within two days of the first team to submit the correct solution 9 within three days of the first team to submit the correct solution 8 within four days of the first team to submit the correct solution 7 within five days of the first team to submit the correct solution 6 within six days of the first team to submit the correct solution 5 within one week of the first team to submit the correct solution 3 within ten days of the first team to submit the correct solution 2 within two weeks of the first team to submit the correct solution 1 later than two weeks after the first team to submit the correct solution,but before the end of the competition

Teams who have solved the most number of chapters will appear at the top of the leaderboard. If teams have solved the same number of chapters, the number of points awarded for each chapter will be summed to give a total points score and the team with the highest score wins. If teams tie on the number of points, these teams will be ranked according to the total time taken to solve all the codes. The team with the shortest overall time being ranked highest.

Note that the introduction of points will not change the ranking of the teams that solve each chapter it just bunches up teams with similar times. We believe that this revised scheme will make the competition fairer and much more exciting!

Remember that the codes get harder as the competition progresses, so it's still wide open....

 Tue 17 Jan 12:30 am Read about cryptography and see some examples Following some requests at the forum we have put in the effort of writing a few paragraphs to introduce cryptography and some of the most well known methods of encryption. It should hopefully be an entertaining and interesting read with some opportunities to practise your code breaking skills! The text also includes a few tips for further reading. You can find it by clicking "Intro" in the menu bar, or just click here. Enjoy!
 Mon 16 Jan 5:16 pm Hint for Chapter 1 It's not too late to make a start with the Cryptography Competition and you could still be in with a chance of winning a prize! Here's a clue for the first chapter: sometimes the best way to crack a code is to start at the bottom and read it in the right way...
 Mon 9 Jan 8:05 am Competition starts today! The first chapter of the competition is released today at 4pm. Good luck to all the teams registered! If you haven't registered yet then it's still not too late!
 The cartoon of Alan Turing is (c) 2011 ...is organised ...is sponsored and is organised in honour Charles F Cooper, coopertoons.com. by the University by of the Centenary of Alan Turing's Furthermore this competition... of Manchester www.skyscanner.net birth in London on June 23, 2012