Florian Grunow and Niklaus Schiess downloaded the sourcecode for Red Star OS, North Korea's homegrown, paranoid fork of Red Hat's Fedora, a flavor of GNU/Linux. The researchers analyzed the OS and presented their findings to the thirty second Chaos Communications Congress in Hamburg yesterday.
The OS is a marvel of paranoid terribleness, with lots of marvellously bad features. The one I was most interested in is its covert insertion of watermarks into every file that it touches, either on the OS's launch disk or removable USB sticks. This is used to track down North Koreans who share illicit media files with their friends and mark them out for punishment in the country's notorious gulags.
Illegal media is usually passed person-to-person in North Korea using USB sticks and microSD cards, making it hard for the government to track where they come from.
Red Star tackles this by tagging, or watermarking, every document or media file on a computer or on any USB stick connected to it. That means that all files can be traced.
"It's definitely privacy invading. It's not transparent to the user," Grunow said. "It's done stealthily and touches files you haven't even opened."
Nat Kretchun, an authority on the spread of foreign media in North Korea, said such efforts reflected Pyongyang's realisation that it needs "new ways to update their surveillance and security procedures to respond to new types of technology and new sources of information".