The big news in the UK today is the mysterious destruction of a wind turbine in Lincolnshire.  The 300ft high turbine lost one of its three blades and suffered damage to a second at about 4am on Sunday morning.  Based on careful analysis of the facts, most of the nation’s media has attributed the incident to a UFO.  The Sun “newspaper” felt that this incident was sufficiently important to dedicate its front page to the story:

Dorothy, of Louth, said: “The lights were moving across the sky towards the wind farm.  Then I saw a low flying object. It was skimming across the sky towards the turbines.”

Hours later there was an almighty smash.

Only “hours later”?  I’m ready to believe already, but there’s more.  The BBC corroborates this evidence with a quote from a spokesman for the prestigious Flying Saucer Bureau:

Russ Kellett, from the Flying Saucer Bureau, said witnesses had told him of activity in the area.

“One saw what they at first thought was a low-flying aircraft on the Saturday evening and another heard a loud banging in the early hours of Sunday,” he said.

A low flying aircraft on Saturday, a bang on Sunday, how can they not be linked?  Dale Vince, a spokesman for the turbine’s owners Ecotricity helpfully suggested to the Today programme on Radio 4 that “something the size and weight of a cow would do it” (which itself suggests an appropriate soundtrack for the incident).

If you’re still sceptical about the involvement of extra-terrestrials, possibly the most compelling evidence comes from witness John Harrison:

John Harrison, another witness, described how he looked out of his landing window and saw a “massive ball of light with tentacles going right down to the ground” over the wind farm. He said: “It was huge. With the tentacles it looked just like an octopus.”

Unfortunately, the journalists at the Guardian don’t exhibit the same imagination as John.  They scandalously suggest that John and other witnesses might actually have been observing the fireworks display just down the road from the wind farm.  It’s an easy mistake to make (at least compared to this).

Now I’m not a wind turbine engineer, but I’m not yet ready to rule out the possibility of mechanical failure.  It wouldn’t be the first time.  This particular turbine had only been operational since April and this week experienced its lowest temperatures so far.  Perhaps there’s a link there?  Or maybe I’m just jumping to ridiculous conclusions?

So what the hell does all this have to do with software development?  Not much really, except it provides an opportunity to mention Occam’s Razor, which is as applicable to debugging as it is to debunking.  The idea is that you should favour the explanation that fits the facts and relies on the fewest assumptions.  Next time you hear yourself uttering the fateful phrase “it must be a compiler bug”, think of the good people of Lincolnshire.  Likewise, if there are 100,000 other developers successfully using a given library and it doesn’t work with your program, you shouldn’t be looking at the library’s source until you’ve proved the correctness of your own.

The alternative to Occam’s Razor is to believe that the Earth is flat, that all the space programmes are fakes (because those photos of a spherical Earth can’t be real) and that the destruction of Tower 7 was an inside job to destroy the evidence of the US government’s involvement in this spherical conspiracy.

Forgive me while I take a brief detour into the murky world of politics, but this post is about a couple of IT-related aspects of the debate, rather than the rights and wrongs of the broader political issues.

The big story in UK in the last couple of days has been the vote in the House of Commons on increasing the maximum period that somebody can be detained on suspicion of terrorism, without charge, to 42 days. When the Labour Party came to power in 1997, you could not be held without charge for more than 7 days. Under Tony Blair this was doubled to 14 days. It was later doubled again, to 28 days, but only after an attempt to extend it to 90 days was narrowly defeated.

Yesterday, the government’s bill to extend detention without charge to 42 days was passed by the House of Commons (though it may yet be rejected by the House of Lords or ruled illegal by the European Court of Human Rights). This prompted prominent opposition MP David Davis to resign from Parliament this morning (more on him later).

Throughout the many debates on this issue over the last few years, the justification in favour of the increase has been that terrorist plots are becoming ever more complex. We are constantly told about cases that require the police to examine hundreds of computers and thousands of CDs in the search for evidence. The extra time is needed, so we’re told, to allow police to access these “encrypted” files. The Prime Minister himself mentioned encryption in his press conference this morning (towards the end of the video clip embedded on that page):.

“…certainly involving encrypted computers and everything else… that they will need more time to deal with that.” – Gordon Brown

I’m sorry, but any terrorist who allows their encryption to be cracked by the police within 42 days was not paying attention at terrorist school. The real world is not like one of those badly written crime dramas where the geeky guy cracks the bad guys’ encryption in less than an hour using a desktop PC and a 3D screensaver. Even a 128-bit AES key would take trillions of years to crack:

16. What is the chance that someone could use the “DES Cracker”-like hardware to crack an AES key?

In the late 1990s, specialized “DES Cracker” machines were built that could recover a DES key after a few hours. In other words, by trying possible key values, the hardware could determine which key was used to encrypt a message.

Assuming that one could build a machine that could recover a DES key in a second (i.e., try 2⁵⁵ keys per second), then it would take that machine approximately 149 thousand-billion (149 trillion) years to crack a 128-bit AES key. To put that into perspective, the universe is believed to be less than 20 billion years old.

So it seems to me that the debate should be about detaining suspects without charge for up to 149 trillion years (and let’s just hope that the terrorists don’t think to use 256-bit keys). Anything less would be an ineffective compromise. David Davis touched on this in his resignation speech:

“…because the generic security arguments relied on will never go away – technology, development and complexity and so on, we’ll next see 56 days, 70 days, 90 days…” – David Davis

David Davis is a Computer Science graduate, so he is probably more aware than other MPs of the absurdity of the idea of detaining suspects while their encryption is cracked.

Davis has chosen to wage war on the Labour government’s approach to civil liberties. In his criticism of the national DNA database and proposed ID cards, he coined the term “The Database State“. I think this is a phrase we will be hearing a lot more of in the coming months. Especially given recent failures to protect sensitive data.