Chances are you have used a satellite today. Have you watched a foreign channel on TV, used a navigation app in your car, or looked at satellite imagery on an online map? If so, you have been, directly or indirectly, using the services of one or more of the thousands of satellites currently in Earth's orbit. In fact, modern life is so deeply intertwined with satellite technology that most people rely on it several times a day without ever realising it.
Satellites perform diverse tasks. They are used for communication, imaging, positioning, weather reports, and scientific experiments. The weather forecast you checked this morning, for instance, was compiled using data from meteorological satellites, while the GPS that guided you to work depends on a dedicated constellation of navigation satellites orbiting at much higher altitudes.
Concerns of safety and privacy
With increasing traffic and debris in Low Earth Orbit, there are growing concerns over the security of satellites. New satellites are being designed with self-destructing features that allow them to burn up in the atmosphere at the end of their operational life, rather than cluttering the orbit with debris.
Collision avoidance is another critical challenge.
Within the US Defense Advanced Research Projects Agency PROCEED program, Sharemind was used to design and implement a secure solution that estimates satellite collision probabilities on encrypted trajectories. The solution is based on secure floating point arithmetic and uses several numerical analysis methods to predict collisions over a given period of time, such as a week.
Sharemind helps achieve trust among nation states
This application is a strong example of improving international collaboration in low-trust settings. The benefits of collaboration are clear, but satellite operators have no guarantee that shared trajectory information will not be used against them.
With Sharemind, operators do not need to disclose their satellite's location in order to participate in the analysis. This could encourage broader participation in collision prediction and improve orbital safety for everyone sharing the space around our planet.
The application and its security properties are described in full in Secure floating point arithmetic and private satellite collision analysis, published in the International Journal of Information Security. Subsequent work has improved both performance and precision.
Additional reading:
- A safer space: 10 years of innovation by Cybernetica and Estonia