Cryptography and Other Projects

It’s now exactly 6 months since I started at Southampton – boy does time fly when you’re having fun! I can clearly remember sitting in the car half a year ago, not quite sure what I would find here, but half a year down the line I can honestly say I am having the time of my life. Indeed, it is currently our Easter holidays and it seems really strange being at home and not being able to just wander into Zepler or my flat whenever I please. Admittedly though, after the manic last two weeks of term it is quite nice to be able to have a bit of a rest! We had five coursework deadlines to contend with, as well as the usual maths tests, all of which meant my feet rarely touched the ground. It’s definitely the hardest we’ve all had to work since we got here, but I’m sure it’s only a taste of things to come in the future!

I can’t take a complete rest over the holidays though, as the summer exams are actually really quite soon after we get back, and we have also been set a mammoth C# programming project. We have all been asked to become cryptographers and our challenge is to solve the message of a piece of cipher text. We know it has been encoded using the ‘Playfair Cipher’, but unfortunately we haven’t been given the keyword that is needed to solve it! But then that would be too easy really, wouldn’t it? Instead, we first have to write another program capable of analysing a large piece of English Language text and working out what letter combinations occur most frequently (e.g.: ‘ST’ and ‘TH’ occur very often, but ‘QW’ and ‘ZX’ do not, for example). We can then use this information to see what pairs occur during the code and extrapolate this back to try and crack the message. Believe me, this is much harder than it sounds! I am making good progress though; so far I have finished the first two tasks (Digraph, the program that analyses the English text and Encrypt, that can code some text if you give it a key – this can be used for testing) and am getting there with Decrypt, the decoding task, but it will take a lot more work!

Amongst all the work, things continued apace with SUJO, the university’s big band that I am a member of. We had our main termly concert at The Cube, as well as a small band night at The Bridge. We also had our AGM and I am pleased to announce that I was elected as the new Vice President/Treasurer! The new committee have already had our first meeting and we have lots of exciting plans for next year, so watch this space…

P.S: Out of interest, and excluding this footnote, I decided to run the text of this blog through Digraph, the analysis program. In third place with 35 occurrences is ‘HA’, in second with 38 is ‘HE’, but by far and away the most combination is ‘TH’ with a staggering 59 occurrences! Just thought you might like to know : )