How do you hide secret plans in a porn video?
Experts say it’s not that hard. Spies have been hiding documents inside other documents or files for hundreds of years. It’s known as steganography, or the science of security through obscurity.
Think about a poem in which the first letter of each word spells out a secret message, or a tiny microdot containing codes hidden in a typewritten period. Now, steganography has gone digital and some terrorists have embraced it.
The German newspaper Die Zeit and CNN reported this week that a Pakistani Al Qaeda operative was caught by German security officials with a memory disk that contained a pornographic video. Embedded inside the video was a file called “Sexy Tanja” with more than 100 documents outlining plans for terror attacks throughout Europe.
Why a porno?
“The video would be easier to ship and distribute,” said Kenneth James Ryan, professor of criminology at California State University, Fresno, and a counter-terrorism expert. “Whoever has ability to decrypt the code would be the intended audience.”
A video file has plenty of space to hide digital documents, according to David Wagner, professor of electrical engineering and computer science at the University of California, Berkeley and an encryption expert. Until recently, it would take a real steganography pro to hide the data, but now commercially available software will do it for you.
Wagner said that human rights workers have been using steganography to hide testimony by exploited workers or political prisoners from government security forces. The testimony is encrypted onto a file on a cellphone, which can then be scanned at a customs checkpoint without revealing the hidden documents.
Wagner said the Al Qaeda documents could have been layered in between digital components of the video file. This method also would allow someone to hide information inside digital photos, for example. Each pixel in a digital image has a number associated with it. By slightly tweaking the color of a pixel, the author can encrypt a pattern of information.
While the human eye could not detect a difference in the pixels, steganography software uses special pass phrases to lock and unlock the data. CNN reported that it took German cryptologists months to break the code, but the result was a spectacular trove of internal Al Qaeda documents.
Steganography “is very difficult to detect because it is hidden in plain sight; you don’t know it’s there,” said Peter Earnest, executive director of the International Spy Museum in Washington, DC.
And hiding terror plots in a porn video could be a way of doing just that, said Steven Weber, professor of information at UC Berkeley.
“It could be someone said, 'this is the last place they will look,'" Weber said. “Or they thought it would be uncomfortable for a government analyst to look at porn videos on their laptop screen. Maybe it was an effort to keep it out of the limelight.”