Reflections on the riots: part one

Standard
AddRoundKey operation for AES

Image via Wikipedia

This is a blog about computing (along with some maths and science) – and not about politics, and having disciplined myself to stick to that for the last nine months, I intend to keep it that way, even as I write about the biggest political event of the year.

But I will allow myself two short political observations: firstly, that disrespect for the law and contempt for order are not new things in London. If you read Albion’s Fatal Tree you will see that there have long been many in the capital who have made their at least part of their livelihoods from criminality and who celebrated their fellows. Pretending that recent events represent some terrible breakdown in ancient respect for authority is ahistorical.

And, before people start to say it is the fault of rap music or other “alien” influences, do they remember this? Perhaps the Fast Show is the real cause of the disorder?

So, that over, what is the science point? Well, it was consistently reported during last week’s disturbances that the looters were sharing their intelligence through BlackBerry smart phones, specifically through “BlackBerry Messenger” (BBM). Given that the UK has one of the most sophisticated signals intelligence set-ups in the world at GCHQ, the fact that the police were clearly left in the halfpenny seats by the looters suggests to me that nobody there has yet proved that P=NP or developed an algorithm to crack the one way functions used to  encrypt the BBMs.

According to Wikipedia Blackberry encrypt everything with “Advanced Encryption Standard” (AES). A brute force attack on this would, on average, require 2^{255} attempts (for the 256 bit encryption), so that is not a practical option (eg the universe is very roughly 4^{17} seconds old).

Now, it could be that the US government has cracked this thing and just refuses to tell even its closest ally (I dare say the name Kim Philby is still spat out in various places), but my guess is that AES is safe, for now.

As I have said before that is probably a pity: while a world where P=NP would be one where internet commerce was broken, it would also be one with many compensatory benefits.