11.7. Future Directions
In this section we provide some future directions that need to be taken to make secure cognitive radio networks against both accidental and intentional attacks. Most of our proposed solutions are easy to implement (for example, using existing security protocols). However, we also propose solutions (for example, developing analog crypto primitives) that require more work.
11.7.1. Using Existing Security Protocols
Security services provided in cellular, WLAN and wireless ad-hoc networks can be applied to cognitive networks as well. In a centralized wireless network architecture, the backbone network is usually a wired medium. Hence, strong security mechanisms exist that protect this network. It is the last hop between the wireless base stations and the wireless terminals that needs to be protected over the air. As cellular networks are centralized, security solutions in existing cellular networks (3G in particular) could be used as a model to provide security in cognitive networks. In cellular networks, user identity is obtained by using a temporary identity called international mobile user identity. Authentication is achieved by a challenge/response mechanism using a secret key. A challenge/response mechanism is where one entity in the network proves to another entity that it knows a particular secret without revealing it. The UMTS authentication and key agreement (UMTS AKA) is used to achieve authentication. Confidentiality is provided by using the confidentiality ...