[Will Scott] and [Gabe Edwards] shed some light on the current state of consumer computing technology at 34C3 in their talk DPRK Consumer Technology. The pair has also created a website to act as a clearinghouse for this information — including smartphone OS images up at koreaComputerCenter.org.
Not a whole lot is known about what technology North Korean citizens have available to them. We have seen Red Star OS, the Mac-like Linux based operating system used on PC based desktops. But what about other systems like smartphones?
[Will] and [Gabe] found that cell phones in North Korea are typically manufactured by Chinese companies, running a custom version of the Android Operating system. The phone hardware is common — the phone sold as the Pyongyang 2407 in North Korea is also sold in India as the Genie v5. If you can get your hands on the Genie, you can run the Korean version of the Android OS on that hardware.
App stores are also different. North Korean Android has no software app store. To buy an app, a user goes to a physical store and picks from a catalog. The store owner then downloads the app to the customer’s phone via a cable.
North Korea places a lot of emphasis on education. Phones and tablets include a number of PDFs for textbooks. You can learn Java, Linux, and other topics. The PDF files are encrypted and locked to a specific device though. [Will] and [Gabe] found that a common library used by the ezPDF Android had been changed. Someone in North Korea had actually gone in and modified the binary to hook a decryption algorithm in the library’s file handling code. The encryption system itself is not too difficult to defeat — a 512 byte XOR pad is hardcoded at the end of the library. The device’s MAC address is used to calculate an offset into that XOR pad and decrypt the file.