Zero Dark Thirty

Well, I did say I wanted to make film reviewing more of a regular thing…

The story of Zero Dark Thirty’s production is a both maddeningly frustrating and ever so slightly hilarious one; the original concept, about an intelligence officer’s incessant, bordering on obsessive, quest to try and find Osama bin Laden was first brought up some time around 2010, and the screenplay was finished in the spring of 2011. The film’s centrepiece was the Battle for Tora Bora, which took place in late 2001; American and allied forces had been on the ground for just a few weeks before the Taliban government and political system was in total disarray. Al-Qaeda were on the run, and some quarters thought the war would be pretty much over within a few months, apart from a few troops left over to smoothen the new government’s coming into power (yeah, that really worked out well). All the intelligence (and it was good too) pointed to bin Laden’s hiding in the mountains of Tora Bora, near the Pakistani border, and after a fierce bombing campaign the net was tightening. However, allied Pakistani and Afghan militia (who some believe were on the Al-Qaeda side) requested for a ceasefire so that some dead & wounded might be evacuated and prisoners taken; a move reluctantly accepted by the Americans, who then had to sit back as countless Al-Qaeda troops, including bin Laden, fled the scene.

Where was I? Oh yes, Zero Dark Thirty.

This was originally planned to be the central event of the film, but just as filming was about to commence the news broke that Bin Laden had, in fact, been killed which, whilst it did at least allow the filmmakers to produce a ‘happy’ ending, required that the whole script be torn up and rewritten. However, despite this, the tone and themes of the film have managed to remain true to this original morally ambiguous, chaotic story, despite  including no footage of any events prior to 2003. We still have the story of the long, confused and tortured quest of the small team of CIA operatives whose sole job it was to find and kill bin Laden, and it honestly doesn’t feel like the story would have felt much different were it to end with bin Laden still alive. And tortured is the word; much has been made of the film’s depiction of torture, some deploring the fact that it is shown to get vital information and arguing that the film ‘glorifies’ it, whilst others point out the way that the key information that finally revealed bin Laden’s location was found after the newly-inaugurated President Obama closed down the ‘detainee’ program. Personally, I think it’s depicted… appropriately. This is a very, very real film, telling a real story about real events and the work of real people, even if specifics aren’t the gospel truth (I mean, there’s only so much the CIA are going to be willing to tell the world), and nobody can deny that prisoners were tortured during the first few years of the war. Or, indeed, that the practice almost certainly did give the CIA information. If anything, that’s the point of the torture debate; it’s awful, but it works, and which side of the debate you fall on really depends on whether the latter is worth the former. In any case, it is certainly revealing that the film chooses to open with a torture scene, revealing the kind of pulls-no-punches intent that comes to define it.

There are the depictions of the chaos of the intelligence process, the web of indistinguishable truths and lies, the hopes pinned on half-leads, all amid plenty of timely reminders of just what is at stake; the attacks, both the big ones that everyone’s heard of and can relate to and the littler ones that hide away in the corners of the media reporting that manage to mean so, so much more to our chosen characters. Of particular note is the final attack on bin Laden’s compound, in one of the least ‘Hollywood’ and most painstakingly accurate portrayals of a military operation ever put onto the big screen. It also manages to come across as totally non-judgemental; torture, terrorism and even the killing of one of western culture’s biggest hate figures of the last decade are presented in exactly the same deadpan fashion. In another film, neutrality over contentious issues can come across as a weak cop-out; here it only adds to the realism.

The most obvious comparison to Zero Dark Thirty is The Hurt Locker, director Kathryn Bigelow’s previous ultra-realistic story about the War on Terror, and it is a pretty fair comparison to say that what The Hurt Locker was to soldiers, Zero Dark Thirty is to intelligence. However, whilst The Hurt Locker was very much about its characters  and their internal struggles, with the events of the film acting more as background than anything else, Zero Dark Thirty is instead dedicated to its events (to say ‘story’ would rather overplay the interconnectedness and coherence of the whole business). Many characters are reduced to devices, people who do stuff that the film is talking about, and many of the acting performances are… unchallenging; nothing against the actors concerned, just to say that this is very much Bigelow’s film rather than her characters. The shining exception is Jessica Chastain as our central character of Maya, who manages to depict her character’s sheer drive and unflinching determination with outstanding aplomb: as well as showing her human side (in its brief appearances) in both touching and elegant fashion.

For all these reasons and more, I can wholeheartedly recommend Zero Dark Thirty as something people should try and see if they can; what I cannot do, however, is to really enjoy it. This isn’t because it isn’t fun, for lots of great films aren’t, but because it doesn’t really stir any great emotions within me, despite asking its fair share of moral questions about war. Maybe its because I tend to be very analytical over such matters, but I’m inclined to feel that the film has actually taken its neutrality and frankness of delivery a little too far. By having no really identifiable, consistent, empathetic characters beyond Maya, our emotional investment in the film is entirely dependent on our emotional investment in the subject matter, and by presenting it in such a neutral matter it fails to really do so in people without a strong existing opinion on it. I have heard this film described as a Rorschach test for people’s opinions on the war and the techniques used in it; maybe my response to this film just reveals that I don’t really have many.

Crypto

Cryptography is a funny business; shady from the beginning, the whole business of codes and ciphers has been specifically designed to hide your intentions and move in the shadows, unnoticed. However, the art of cryptography has been changed almost beyond recognition in the last hundred years thanks to the invention of the computer, and what was once an art limited by the imagination of the nerd responsible has now turned into a question of sheer computing might. But, as always, the best way to start with this story is at the beginning…

There are two different methods of applying cryptography to a message; with a code or with a cipher. A code is a system involving replacing words with other words (‘Unleash a fox’ might mean ‘Send more ammunition’, for example), whilst a cipher involves changing individual letters and their ordering. Use of codes can generally only be limited to a few words that can be easily memorised, and/or requires endless cross-referencing with a book of known ‘translations’, as well as being relatively insecure when it comes to highly secretive information. Therefore, most modern encoding (yes, that word is still used; ‘enciphering’ sounds stupid) takes the form of employing ciphers, and has done for hundreds of years; they rely solely on the application of a simple rule, require far smaller reference manuals, and are more secure.

Early attempts at ciphers were charmingly simple; the ‘Caesar cipher’ is a classic example, famously invented and used by Julius Caesar, where each letter is replaced by the one three along from it in the alphabet (so A becomes D, B becomes E and so on). Augustus Caesar, who succeeded Julius, didn’t set much store by cryptography and used a similar system, although with only a one-place transposition (so A to B and such)- despite the fact that knowledge of the Caesar cipher was widespread, and his messages were hopelessly insecure. These ‘substitution ciphers’ suffered from a common problem; the relative frequency with which certain letters appear in the English language (E being the most common, followed by T) is well-known, so by analysing the frequency of occurring letters in a substitution-enciphered message one can work out fairly accurately what letter corresponds to which, and work out the rest from there. This problem can be partly overcome by careful phrasing of messages and using only short ones, but it’s nonetheless a problem.

Another classic method is to use a transposition cipher, which changes the order of letters- the trick lies in having a suitable ‘key’ with which to do the reordering. A classic example is to write the message in a rectangle of a size known to both encoder and recipient, writing in columns but ‘reading it off’ in rows. The recipient can then reverse the process to read the original message. This is a nice method, and it’s very hard to decipher a single message encoded this way, but if the ‘key’ (e.g. the size of the rectangle) is not changed regularly then one’s adversaries can figure it out after a while. The army of ancient Sparta used a kind of transposition cipher based on a tapered wooden rod called a skytale (pronounced skih-tah-ly), around which a strip of paper was wrapped and the message written down it, one on each turn of paper. The recipient then wrapped the paper around a skytale of identical girth and taper (the tapering prevented letters being evenly spaced, making it harder to decipher), and read the message off- again, a nice idea, but the need to make a new set of skytale’s for everyone every time the key needed changing rendered it impractical. Nonetheless, transposition ciphers are a nice idea, and the Union used them to great effect during the American Civil War.

In the last century, cryptography has developed into even more of an advanced science, and most modern ciphers are based on the concept of transposition ciphers- however, to avoid the problem of using letter frequencies to work out the key, modern ciphers use intricate and elaborate systems to change by how much the ‘value’ of the letter changes each time. The German Lorenz cipher machine used during the Second World War (and whose solving I have discussed in a previous post) involved putting the message through three wheels and electronic pickups to produce another letter; but the wheels moved on one click after each letter was typed, totally changing the internal mechanical arrangement. The only way the British cryptographers working against it could find to solve it was through brute force, designing a computer specifically to test every single possible starting position for the wheels against likely messages. This generally took them several hours to work out- but if they had had a computer as powerful as the one I am typing on, then provided it was set up in the correct manner it would have the raw power to ‘solve’ the day’s starting positions within a few minutes. Such is the power of modern computers, and against such opponents must modern cryptographers pit themselves.

One technique used nowadays presents a computer with a number that is simply too big for it to deal with; they are called ‘trapdoor ciphers’. The principle is relatively simple; it is far easier to find that 17 x 19 = 323 than it is to find the prime factors of 323, even with a computer, so if we upscale this business to start dealing with huge numbers a computer will whimper and hide in the corner just looking at them. If we take two prime numbers, each more than 100 digits long (this is, by the way, the source of the oft-quoted story that the CIA will pay $10,000 to anyone who finds a prime number of over 100 digits due to its intelligence value) and multiply them together, we get a vast number with only two prime factors which we shall, for now, call M. Then, we convert our message into number form (so A=01, B=02, I LIKE TRAINS=0912091105201801091419) and the resulting number is then raised to the power of a third (smaller, three digits will do) prime number. This will yield a number somewhat bigger than M, and successive lots of M are then subtracted from it until it reaches a number less than M (this is known as modulo arithmetic, and can be best visualised by example: so 19+16=35, but 19+16 (mod 24)=11, since 35-24=11). This number is then passed to the intended recipient, who can decode it relatively easily (well, so long as they have a correctly programmed computer) if they know the two prime factors of M (this business is actually known as the RSA problem, and for reasons I cannot hope to understand current mathematical thinking suggests that finding the prime factors of M is the easiest way of solving this; however, this has not yet been proven, and the matter is still open for debate). However, even if someone trying to decode the message knows M and has the most powerful computer on earth, it would take him thousands of years to find out what its prime factors are. To many, trapdoor ciphers have made cryptoanalysis (the art of breaking someone else’s codes), a dead art.

Man, there’s a ton of cool crypto stuff I haven’t even mentioned yet… screw it, this is going to be a two-parter. See you with it on Wednesday…