Yet Another Case for Cryptographic Cameras

In December 2007 I started writing this horribly incomplete proto-draft of an essay on "cryptographic cameras", a concept inspired entirely by Bruce Schneier's paper "An Authenticated Camera". In April 2008 I was inspired to finally getting around to finishing this paper when a move by the NSW police raised again for me the potential social importance of the widespread adoption of cameras with cryptographic authentication possibilities.

That essay of mine sits still horribly incomplete today, shortly after the blogosphere, and later the mainstream media, became abuzz over the fact that a photo recently released by the Iranian government purporting to show successful test missile launches had been, rather obviously, Photoshopped to show one more missile than was actually launched. Here is the photo the Iranians release. The "Little Green Footballs" blog (which I was pointed to by Reddit) has an article with a static picture showing the cloned exhaust plumes, and "Suitably Flip" has an animated version, which I personally find less enlightening. Mainstream coverage is available at the BBC and the Daily Telegraph, amongst other places.

This revelation is an even better example than the NSW police situation of why some sort of cryptographic photograph authentication technology is important, and probably just as good an example of this as Adnan Hajj's doctored photos from Beirut in 2006, which are the (only) example currently present in my proto-draft. Perhaps a lesser example is the controversy surrounding photographs of the toppling of Saddam Hussein's statue in Firdus Square, Baghdad. I say "lesser" because it is not immediately apparent that cryptography can guard against careful selection of camera angles and positions, although as products like Nintendo's Wii console bring down the cost of accelerometer-based motion sensing devices (like the Wii Remote) I suspect that a good authenticated camera system could in fact detect this sort of manipulation. Perhaps a solution based on some sort of miniature, internal magnetic compass could suffice here as well. I've not given the details tremendous consideration, but I am digressing enough as it is.

The above examples (and perhaps more that I'm unaware of - comments welcome!) make it abundantly clear that, in this age of Photoshop, to assume photographs shown in the mainstream media are undoctored or accurately indicative of true events requires an entirely unjustified level of trust in that media. For every poorly executed and blatantly obvious manipulation like Iran's missiles or Hajj's Beirut, there is an unknown number of better executed and yet to be uncovered manipulations that currently enjoy status as fact. This knowledge must necessarily damage the credibility of photography in mainstream media for any critically thinking person. More worryingly, this trend can only reasonably be expected to continue.

Embedding cryptographic processors into digital cameras can reverse this trend, and further more it is probably the only technological solution which can reverse it. Once there exist cameras which can provide digitally signed copies of a photo (to establish a lack of subsequent doctoring) and digitally signed meta-data (to establish the time, location - via GPS - and orientation - via accelerometers or compasses - of the photo), and these cameras are available en-masse for even as much as a few thousand dollars, then it can and should be considered extremely suspicious for any professional media outlet to not make this supporting evidence available to the public. I honestly believe that such a cost is eminently achievable: Nokia's N95 mobile phone already contains an integrated GPS receiver, a camera and an accelerometer and, according to this Cnet review, cost just $1379 Australian a little over a year ago. Obviously professional media photography would require a better quality camera component, but the rapid progress of the mobile phone industry will continue to drive the price of this technology down, to the point where it seems realistic to expect these capacities to be available in a good professional camera for a few grand in just a matter of years. A proof of concept implementation for $10,000 today is unquestionably possible and would help to get us there faster.

Not only would an investment in this sort of technology help to salvage the credibility of professional journalism and help us to spot falsified governmental saber-rattling, but it would open the doors to trustworthy citizen journalism, increase the trustworthiness of crime scene photography used in criminal trials and quite likely a whole host of other things I can even think of.

I really need to finish that essay.

Random and unrelated link drop: Donald Knuth's infrequently asked questions.