Protocols for detection and removal of wormholes for secure routing and neighborhood creation in wireless ad hoc networks

Wireless ad hoc networks are suitable and sometimes the only solution for several applications. Many applications, particularly those in military and critical civilian domains (such as battlefield surveillance and emergency rescue) require that ad hoc networks be secure and stable. In fact, security is one of the main barriers to the extensive use of ad hoc networks in many operations. The primary objective of this dissertation is to propose protocols which will protect ad hoc networks from wormhole attacks - one of the most devastating security attacks - and to improve network stability. Protocols that depend solely on cryptography techniques such as authentication and encryption can prevent/detect several types of security attacks however, they will not be able to detect or prevent a wormhole attack. This attack on routing in ad hoc networks is also considered to be the main threat against neighborhood discovery protocols. Most of the proposed mechanisms designed to defend against this type of attack are based on location information or time measurements, or require additional hardware or a central entity. Other protocols that relied on connectivity or neighborhood information cannot successfully detect all of the various types and cases of wormhole attacks. In the first part of this dissertation, we present a simple, yet effective protocol to detect wormhole attacks along routes in ad hoc networks. The protocol is evaluated using analysis and simulations. In the second part, we present a secure neighbor creation protocol that can securely discover the neighbors of a node in ad hoc networks, and detect and remove wormhole links, if they exist. The proposed protocols do not require any location information, time synchronization, or special hardware to detect wormhole attacks. To the best of our knowledge, this is the first protocol that makes use of cooperation rules between honest nodes. Use of such rules will reduce the overhead associated with the number of checks to be performed in order to detect wormholes and to create a secure neighborhood. This is also the first protocol, to our knowledge, that addresses the complete removal of bogus links without removing legal links.