Well that was another fantastic year! The whole team here would like to congratulate you all on your amazing efforts, the future of the country's cyber security is clearly safe in your hands. I would like to give particular thanks to the elves here at Southampton who run the site and the forum, and to all the teachers and parents who encouraged you and didn't make you go to bed too early to finish the challenge. Big thanks too, of course, to all of you who took part.You should be very proud of your achievments.
For the last time this year we can announce the winners of the weekly challenge prizes, and the winners for Challenge 8A are
Jonathan from Beechen Cliff School
Mohamed Hamza from Ealing Independent College
Eric Hoang, Oscar from Bryanston School
Ella Margetts from Roding Valley High School
Nathan Kurien, Muntaha Naeem, Chisom from Westcliff High School for Boys Academy
Yasmin England from King Edward VI Grammar School
ReginaldJeeves team from Bournemouth School
and CrypticCipher from Ermysted's Grammar School
Now to the winners of the four main prizes this year:
The GCHQ prize for best individual entry of £1000 is awarded to Jolyon Shah of St Edwards School, Cheltenham
The Trinity College prize of £800 is awarded to James Hogge of the Abingdon School
The University of Southampton prize for the best team entry of £1,000 is awarded to Ilya Shemmer's team Thunder+c, of King Edward VII School, Sheffield
The IBM prize of £800 for runner-up team is awarded to to Alex Barter's team The Grizzly Armadillos of the Cotswold Academy
There will be a prizegiving at Bletchley Park on Friday, 4 March, and if you would like tickets you can apply for them online at www.cipher.maths.soton.ac.uk/tickets.
We hope to see you there.
Congratulations once more to all of you I hope that those who are not too old will try again next year. The National Cipher Challenge the challenge will return in October 2016.
Best wishes and good luck with all your exams,
Harry
Well, technically yes. The elves are pouring over your entries and we will be contacting the winners early next week to let them know, watch this space for info. In the meantime however, as the points scheme shows, you still have another week to try to finish your decrypts for Challenge 8, and we will post the leader board on Thursday 14th January.
The Prizegiving at Bletchley PArk will be held on Friday 4th March and you can apply for tickets online at https://www.cipher.maths.soton.ac.uk/tickets. Just log in using your usual account details and let us know how many ou would like. We will reserve a number of tickets for prize winners, sponsors and guests, but there should be some left over, and it makes a great school trip. There will be talks and tour of the home of British code breaking, and our hosts there always treat us as friends. It is a fabulous way to feel part of history and of the community of cryptographers.
Challenge 7B was a beast! The AMSCO cipher is a classic pencil and paper column transposition, with a twist. As we said in the hint the other day, you can read about it at https://cryptogram.org/cdb/aca.info/aca.and.you/chapter_09.pdf#AMSCO. It was tough, but still 281 of you cracked it which really impressed us. The solution to 7A contains a lot of intel about Challenge 8 so whether or not you tackled that last week, take a good look at the solution.
If you have enjoyed the Cipher Challenge you should definitely try the Christmas puzzles set by Robert Hannigan, the Director of GCHQ. The first one is not too tough and you should all be able to crack it, after that things get really interesting. You can find the first stage at https://www.gchq.gov.uk/press_and_media/news_and_features/Pages/Directors-Christmas-puzzle-2015.aspx
If you have any other good puzzles or wondered how to send us a Christmas Card then tweet us with your messages. We love to get them!
As usual we are providing random prizes to competitors who took part in part A this time, and each of the following 8 teams will win a cheque for £25. We will be in touch by email to the address you gave us when registering, so do please check it and get back to us promptly so we can process your award.
And for the last time this year "To everyone else, there is always next week".
Good luck,
Harry
Winners of the Part 7A Prizes:
Robin Lyster, Elizabeth Perry from Matthew Arnold School
Adil Moosa from Ealing Independent College
Kush Christie-Verma, Flynn Whittaker, Tom Patterson, David Hamer, egor kaygorodov from Danes Hill Preparatory School
Jessica Richards from South Wilts Grammar School for Girls
Esther from William Farr CofE Comprehensive School
Alan King, Michael Stevens from St Nicholas Catholic High School
Rebecca Smy, Daniel Whiteley from Plume School
Siddhant Nayak, Sankarsh Makam, Alfie Cross, Jacob Spence from Bishop Wordsworth's Grammar School
I can't believe we have reached the end of yet another Cipher Challenge! We had 4277 of you taking part in 1765 teams from 610 schools, and there were still 566 teams submitting to Challenge 7. It ws an amazing response from an amazing crowd and you should all be very proud of your achievements. Whether this was your first attempt at the competition and you cracked just Challenge 1, or you are a devoted competitor who spent hours polishing your skills this year, you have all done very well.
Winners will of course be decided after the last Challenge closes in January. It goes live today at 3.15, and I wish you all luck with it.
First prize for the best individual entry this year will be the GCHQ prize of £1,000. The prize for the best team entry, Harry's prize, will be supported by THe University of Southampton Mathematics Department, again for £1,000. Runners up prizes for the best indovidual are sponsored by Trinity College Cambridge and for the best team by IBM who have both agreed again to support the competition with prizes of £800.
The winners will be invited to a prizewgiving at Bletchley Park organised by our partners at BCS on Friday 4th March. There will be some tickets available for the event whcih will involve a fun lecture and an opportunity to tour the park and museums. You can apply for tickets online from 9am on Friday 18th December and the ticket system will be open unitl January 31st. We will do our best to accommodate all requests, but this is a very popular event so do apply early.
Good luck and best wishes,
Harry
If you have cracked Challenge 7A you will have discovered that Challenge 7B is an AMSCO cipher. This is a column transposition cipher with a twist. You can find out how it works at https://cryptogram.org/cdb/aca.info/aca.and.you/chapter_09.pdf#AMSCO
The real security in the cipher lies in the fact that you dont know the length of the keyword, though cribs can help you to reconstruct that if you have some. If you really like a challenge you could try that first. Otherwise you could use the exceptionally useful advice from 7A where we tell you the length of the keyword. Once you have that it is possible to lay out the text in columns and use cribs and smarts to reassemble the plain text. Or it would be if you knew which of two possible conventions we have used. Pairs then singles or singles then pairs. But no hint about that I am afraid. You will have to try it for yourself.
Good luck!
Harry