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Description: TOPIC: Mitigation of GPS Spoofing Attacks on Civilian Surface Transportation
ABSTRACT: Global Positioning System (GPS), operated by the U.S. government, provides positioning, navigation, and timing (PNT) services free of charge to users around the world. GPS consists of three parts working in conjunction to deliver PNT data worldwide. The Space Segment is comprised of a constellation of 24 satellites transmitting data containing position and time information to the receivers on the ground; The Control Segment is made up of monitoring and command stations on the ground which control and maintain the satellites in space; The User Segment includes the users and GPS receivers on earth that utilize the data from the satellites signals and computes 3D position and current time. GPS satellites transmit two main categories of signals: one encrypted signal for military use and one unencrypted for civilian use. GPS has become an essential element of global information infrastructure with endless applications in nearly every sector worldwide. The U.S. no longer monopolizes global navigation satellite systems (GNSS) in orbit. Other nations are racing to bring their own GNSS to widespread use: Europes Galileo, Russias GLONASS, and China Compass or BeiDou-2, just to name a few.

Although GPS is commonly used in safety applications for surface transportation, it is by no means a secure system. Societys reliance on GPS has attracted the attention of malicious parties to tamper with the unprotected civilian signals. Adversaries can launch spoofing attacks, fooling the receiver with false information about location, timing, and other factors. These attacks are relatively simplistic, inexpensive, and can be detrimental to ordinary GPS users as well as to homeland security. Current defense technology for civilian GPS is in its infancy. Traditional wireless security schemes are impractical in GPS applications, and a systematic analysis has become very important.

This thesis work starts with modeling and characterizing GPS spoofing from a system perspective. The attack model explores various scenarios to analyze every vulnerable aspect of civilian GPS. The feasibility of successful GPS spoofing attacks is researched based upon results obtained through experimentation under secure and controlled circumstance on approved equipment to assure no ill-intention or real harm to the society. The aim is to determine the best course of action for a defense scheme.

The defense scheme focuses on the authentication of GPS signals. Design alternatives are explored through simulation. An innovative authentication protocol for civilian GPS on surface transportation is proposed, prototyped and tested. The work resulted in a GPS receiver incorporated with Secure Digital (SD) card and microprocessor. Upon receiving GPS signals, an authenticity check is conducted by cross-checking with the logged data in both temporal and spatial differentiations. The validated GPS signals will be used on visual navigation for the end user, or the user will be warned of possible spoofing attacks. Evaluation of the authentication protocol shows the effect of various parameters. The work demonstrates the feasibility and effectiveness of securing civilian GPS applications by enhancing only the User Segment without the need to modify the Space Segment, enormous economic value.