Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cornell sleuths crack secret codes of Europe's Galileo satellite

11.07.2006
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 mid-January, Mark Psiaki, professor of mechanical and aerospace engineering at Cornell and co-leader of Cornell's GPS Laboratory, requested the codes from Martin Unwin at Surrey Satellite Technology 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 period 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 (http://gps.ece.cornell.edu/galileo) on April 1. Two days later, NovAtel Inc., a Canadian-based major manufacturer of GPS receivers, downloaded the codes from the Web site in a few minutes and soon afterward 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.

Graduate student Thomas Oberst is a writer intern at Cornell News Service.

Blaine Friedlander | EurekAlert!
Further information:
http://www.cornell.edu

More articles from Information Technology:

nachricht Cutting edge research for the industries of tomorrow – DFKI and NICT expand cooperation
21.03.2017 | Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, DFKI

nachricht Molecular motor-powered biocomputers
20.03.2017 | Technische Universität Dresden

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>