Well not really, but yet again I am amazed by the fortitude and ability of everyone who took part this year. Whether you cracked a Casear shift cipher for the first time, or coded a Trifid cracker in assembly code for Challenge 8 you all learned something new.
The Trifid cipher in 8B this year turned out to be really challenging and full credit to everyone who managed it. You fully deserved your success. We will certainly be celebrating all your acheivements at the Prizegiving at Bletchley on April 12th.
And now for the prizes themselves.
The GCHQ prize of £1,000 is awarded to Samson Danziger, Daniel Hu, Anthony Landau and Charlie Hu (the aptly named Winning_Combination) from City of London School who took a mere 44 hours 20 minutes to crack the final challenge.
The IBM Prize of £800 is awarded to Andrew Carlotti (mad_maths_man) from Sir Roger Manwood's School. He was just beaten to the punch, taking 46 hours 54 minutes.
The Trinity College prize of £700 is awarded to the biggest winning team ever, Eve Pound, Thomas Barnard, Tanya Sciamanna, Rachel Sangar, Oliver Kardoosh, Timothy Lennox, Jasmine Brown, Teodor Tzokov, Alexander Murray, Rosemary Stillman, Alice Butler, Thomas Honeywell, Thomas Wilshaw. Eve Pound (TeamSolitaire) from King Edward VII School, Sheffield.
GCHQ Raspberry Pi computers and Netcraft Rucksacks: The fifty members of the top 17 teams on the overall leaderboard have been awarded Raspberry Pi computers and Netcraft rucksacks.
As usual we have the part A prizes to award as well 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.
To everyone else, there is always next year! Good luck, Hope to see you then
Harry
Winners of the Part 8A Prizes:
Claire, Juliet, Nadhira from King Edward VII
HCD,KEH,RPR from Queen Elizabeth's Grammar School
David Dixon, Jordan Curnow ,William Dash from Richard Lander School
jasmine egeh odette burgin from forge valley community school
roots of unity from Teignmouth Community School
Jazz Brush Dan Brush from Yateley School
David Maskill & Souradip Mookerjee from The Manchester Grammar School
Arno Liang, Brian Shi, Tom Hampshire, Jonah Walker, James Anderson-Besant, Alex Lennox, Julian Ting from Abingdon School
That was fun! Well it was for me, anyway. I got the impression that some of you really suffered with 8B this year. Does make it all the more rewarding to do it though, I hope.
I was amazed at the tenacity you all showed, and the ingenuity, congratulations to everyone, however far you got in the 2012 Challenge.
We are delaying publication of the leaderboards and prizewinners in order to coordinate publicity with schools, I am sorry if this is adding to your pain. I hope to make an announcement late next week. In the meantime the boards are still open, so take this opportunity to challenge, entertain and amuse yourselves on the coolest forum on the entire web.
Happy New Year,
Harry
Dear Charles,
In case you are really stuck the transposition stage just reverses the order of the block so if block 1 reads ABCCB then after the transposition it reads BCCBA. I guess once you know this then it should be possible to crack the cipher using some frequency analysis!
Harry
PS, just noticed a typo in my previous message. It should have read:
the first and second characters are entangled, the second, 3rd, and fourth are entangled, the 4th,5th are entangled, the 6th 7th are entangled, the seventh 8th, 9th are entangled , the ninth and 10th are entangled and so on
Sorry, Harry
Dear Charles,
Just in case you didn't work it out yet this is a symmetric cipher! That means that the transposition stage is a permutation with the property that if you do it twice it is the same as not doing it at all! Devious old Tiberius has used a block length of 5 for that stage so that once it has done its work the first and second characters are entangled, the 3rd,4th,5th are entangled, the 6th 7th are entangled, the 8th, 9th, 10th are entangled and so on. I guess that means that working with blocks of fifteen makes a certain amount of sense!
All the best,
Harry
Dear Charles,
I realise I didn't complete the description of the cipher for you! After the transposition stage the resulting text is read off as triples and recoded back (using the same 3x3x3 block encoding) into characters. Maybe to throw the reader off or perhaps to give us some kind of extra crib, Tiberius reformatted the string so it fitted into the original text shapes. I suppose that does give another way to try to break in!
All the best,
Harry
