Security by obscurity fails again
The secret codes used by Europe's Galileo navigation satellite have been broken by researchers at Cornell University.
A team from Cornell's Global Positioning System Laboratory succeeded in cracking so-called pseudo random number (PRN) codes of Europe's first global navigation satellite, despite attempts to keep the data under wraps.
The development means "free access" for consumers who use navigation devices that would need PRNs to access satellite data from Galileo, according to the team from Cornell.
The $4bn Galileo project is Europe's answer to the United States' GPS system. Unlike the US system, where the signal is provided at no cost, Galileo must make money for its investors, presumably by charging a fee for PRN codes. The discovery from Cornell would undermine such a model, at least in theory. Galileo is still in the process of development.
The cryptographic attack developed by the Cornell team targeted GIOVE-A (Galileo In-Orbit Validation Element-A), a prototype for the 30 satellites that will make up the Galileo system by 2010. Galileo and GPS share frequency bandwidths. Because of this, some of Galileo's PRN codes must be "open source". Thus far, however, none of GIOVE-A's codes have been made public since it went live in early January. Researchers from Cornell and in Germany were politely refused access to these codes, so the Cornell team decide to extract them independently.
"It dawned on me: maybe we can pull these things off the air, just with an antenna and lots of signal processing,"
explained Mark Psiaki, professor of mechanical and aerospace engineering at Cornell and co-leader of Cornell's GPS Laboratory.
Psiaki's group consulted with Cornell's university counsel to allay concerns that cracking the code might be considered a copyright infringement.
"We were told that cracking the encryption of creative content, like music or a movie, is illegal, but the encryption used by a navigation signal is fair game," said Psiaki, who compared the work of his team on Galileo to working out the frequency of light flashes and co-ordinates of a lighthouse. "The Europeans cannot copyright basic data about the physical world, even if the data is coming from a satellite that they built," he added.
Under pressure, Galileo published PRN codes in mid-April but these labeled some open source codes as intellectual property, incorrectly claiming a license was required for any commercial receiver. Furthermore, the codes published were not those currently used by the GIOVE-A satellite.
The Cornell team published these codes - along with the methods used to extract them - in the June issue of
GPS World. Cryptography experts point to the case as illustrating the futility of relying on secret data as opposed to more robust encryption schemes as an approach to system security.
"Security by obscurity: it doesn't work, and it's a royal pain to recover when it fails," said crypto guru Bruce Schneier in a blog
posting.
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