Skip to comments.Cracking the Secret Codes of Europe's Galileo Satellite [means consumers could use it for free]
Posted on 07/09/2006 6:49:32 AM PDT by John Jorsett
Members of Cornell's Global Positioning System (GPS) Laboratory have cracked the so-called pseudo random number (PRN) codes of Europe's first global navigation satellite, despite efforts to keep the codes secret. That means free access for consumers who use navigation devices -- including handheld receivers and systems installed in vehicles -- that need PRNs to listen to satellites.
The codes and the methods used to extract them were published in the June issue of GPS World.
The navigational satellite, GIOVE-A (Galileo In-Orbit Validation Element-A), is a prototype for 30 satellites that by 2010 will compose Galileo, a $4 billion joint venture of the European Union, European Space Agency and private investors. Galileo is Europe's answer to the United States' GPS.
Because GPS satellites, which were put into orbit by the Department of Defense, are funded by U.S. taxpayers, the signal is free -- consumers need only purchase a receiver. Galileo, on the other hand, must make money to reimburse its investors -- presumably by charging a fee for PRN codes. Because Galileo and GPS will share frequency bandwidths, Europe and the United States signed an agreement whereby some of Galileo's PRN codes must be "open source." Nevertheless, after broadcasting its first signals on Jan. 12, 2006, none of GIOVE-A's codes had been made public.
In late January, Mark Psiaki, associate professor of mechanical and aerospace engineering at Cornell and co-leader of Cornell's GPS Laboratory, requested the codes from Martin Unwin at Surrey Space Technologies Ltd., one of three privileged groups in the world with the PRN codes.
"In a very polite way, he said, 'Sorry, goodbye,'" recalled Psiaki. Next Psiaki contacted Oliver Montenbruck, a friend and colleague in Germany, and discovered that he also wanted the codes. "Even Europeans were being frustrated," said Psiaki. "Then it dawned on me: Maybe we can pull these things off the air, just with an antenna and lots of signal processing."
Within one week Psiaki's team developed a basic algorithm to extract the codes. Two weeks later they had their first signal from the satellite, but were thrown off track because the signal's repeat rate was twice that expected. By mid-March they derived their first estimates of the code, and -- with clever detective work and an important tip from Montenbruck -- published final versions on their Web site () on April 1. The next day, NovAtel Inc., a Canadian-based major manufacturer of GPS receivers, downloaded the codes from the Web site and within 20 minutes began tracking GIOVE-A for the first time.
Galileo eventually published PRN codes in mid-April, but they weren't the codes currently used by the GIOVE-A satellite. Furthermore, the same publication labeled the open source codes as intellectual property, claiming a license is required for any commercial receiver. "That caught my eye right away," said Psiaki. "Apparently they were trying to make money on the open source code."
Afraid that cracking the code might have been copyright infringement, Psiaki's group consulted with Cornell's university counsel. "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. The upshot: The Europeans cannot copyright basic data about the physical world, even if the data are coming from a satellite that they built.
"Imagine someone builds a lighthouse," argued Psiaki. "And I've gone by and see how often the light flashes and measured where the coordinates are. Can the owner charge me a licensing fee for looking at the light? No. How is looking at the Galileo satellite any different?"
Other authors of the GPS World article are Paul Kintner, Cornell professor of electrical and computer engineering, graduate students Todd Humphreys, Shan Mohiuddin and Alessandro Cerruti, and engineer Steven Powell.
This story was written by graduate student Thomas Oberst, a writer intern at Cornell News Service.
NEW YORK TIMES: "Women and minorities hurt worst."
HOWARD DEAN: "It's Bush's fault. He didn't have a plan for this."
MSN: "Bush poll on satellite reaches all time low."
You would have thought that the European companies that intended to make a profit off this service would have realized this little tidbit of legal information...
...but I'm sure if they make a few healthy donations to congress, the law will quickly be changed to protect their signals.
All your GPS are belong to us.
Since when has legality bothered the Euro Socialists?
Our Geeks spank Euroweeny Geeks! Hee!Hee!
The terrestrial reference was local and had to be licensed, installed, and maintained by a local entity (business or government) willing to foot the bills for all that stuff. The terrestrial station received decryption data from a second source, via landline I think (another recurring cost). Finally, the GPS receiver had to be able to receive the terrestrial signal as well as the satellite signal. If the terrestrial transmitter was in a poor location, you might not be able to use the GPS system throughout a given area.
With all the complications, I suppose the DoD decided that the benefits to local governments and others outweighed security risks and the requirement for "decryption" was dropped. The satellites now send true data that needs no correction for accuracy.
It may be that the article got its facts wrong (imagine that!) and what the Europeans want to do is for security purposes. Europe is a far more dangerous place vis-a-vis Islamism.
I am VERY surprised they didn't encode the signal better.
I am NOT surprised they are trying to pull a fast one.
So how does that impact security issues in Europe? Can't the euro-terrorists just use a standard American GPS device to determine position?
The classified GPS keys are changed annually. Still, I'm surprised the folks at Cornell had so little problem breaking Galileo's PRN code. They seem to expended only a fairly trivial amount of effort. If they did it this easily, I'll wager that NSA and NKVD had it within hours, if not minutes of its coming on the air. I suspect they'll beef it up next time around.
You're, wrong, you need four satellites to determine three position coordinates and one time coordinate.
You are correct, GPS works just fine in most of Europe. (Not so good at extreme northern latitudes.)
I suppose it helps when you know exactly what the message says when you're trying to crack a code.
You'd think so. Good point.
I didn't even think about using "our" GPS in Europe. If that's true, why would anyone in their right minds go to the expense and trouble of building a European GPS, unless it provides some features not available from the existing one?
Anyone here know more about it?
Europe wants to get back on top. The egos over there are just too massive to do otherwise. They are envisioning a world in which the major world powers are the US, China, and Europe...
and the American liberals (euro-trash-wannabees) would like to help them pull the US out of that circle...
That lawyer's statement overturns perfectly the whole of the Founder's intent regarding the Constitution patent and copyright clause. What is allowed to be protected by grant of the sovereign is works of "science and the useful arts". The "Useful Arts" means technology, and NOT the artistic arts such as music, plays, paintings etc.
The Founder's especially wanted to protect MAPS, navigational aids, and so on -- so vital were they to our nations growth, economy and welfare at the time.
The Euros aren't comfortable with the US controlling the only source of accurate position data (the Russions created Glonass, but it's suffering from deferred maintenance and it'd be risky to count on it being there in the future). If I recall correctly, Galileo also has a stronger signal, so it can be used inside some buildings. The new US GPS satellites will supposedly allow this as well.
The Indians are helping to fund GLONASS and a new constellation is going up.
>>Anyone here know more about it?
My understanding is that they were concerned that we could change things during a war (Like turn all the satellites off, encrypt, send incorrect data that kind of stuff) so their military and civilian devices that depend on it would become useless. (Imagine shooting a missile at us and we just tweak the GPS for 10 min and your missiles fly into the water thinking its at the target, how embarrassing) They dont want the USA to own GPS any more than they want us to own the Internet, but here we are.
Hadn't heard that. Interesting.
Possibly the Europeans were "encouraged" to code the signals in some compromise over accuracy, availability, etc. with the US.
But they purposefully made it easy to crack.
Actually, these are just spread spectrum pseudo random noise codes, and have nothing to do with security.