Secure Localisation with Location Assurance Provider

Benoît Jager is junior security IT consultant at itrust consulting s.à r.l. since one year, working almost full time on the ESA project " Developing a proof of location for Galileo ". He has a Master in Brian Gent (NSN) joined Nokia Siemens Networks SA (then named Siemens SA) in July 2006 and assumed the role of CSI (consulting & systems integration) solution consultant in February 2008. He has been involved in the FP6 project U2010 and in several studies on Space applications. He studied Physics at Portsmouth University where he received his M.Sc. in Microwave and Solid State Physics. ABSTRACT This paper describes deliberate threats to the Galileo localisation system and then suggests security features which can provide localisation assurance i.e. that can prove that a given device was at a given location at a given time. Security objectives are then derived, which can be used to identify and assess appropriate countermeasures such as a tamper resistant chipset or a reliable clock for the user device or a Location Assurance service provided by a central Trusted Third Party (TTP) with plausibility checks (based on tracking), use of Public Key Infrastructure (PKI), correction services and verification of input data for the localisation. A service architecture scheme is described which can be used over traditional communication channels like General Packet Radio Service (GPRS) or Universal Mobile Telecommunications System (UMTS) to provide a Location Assurance Certificate (LAC) for a registered user device. This certificate can be used by a Location-Based Service Provider (LBSP) to verify the correctness of the device location. Concerning authentication of Galileo Navigation Message Content (NMC), since there are too few spare bits to add a fast message authentication, we suggest an alternative approach which compares NMC received by Galileo receivers with those collected by reference Galileo receivers distributed over earth's surface. Note that the proposed solution does not require any changes to the Galileo space or ground segment. 1 CONTEXT Over last 10 years, thanks to the decreasing price of Global Navigation Satellite System (GNSS) receiver and the freely available US Global Positioning System (GPS), GNSS has become a widely used technology which has subsequently led to the appearance of numerous Location-Based Service (LBS). LBS is taken to mean the provision of a service by a Location-Based Service Provider