Analysis of tradeoffs between security strength and energy savings in security protocols for WLANs

Energy sayings are extremely important in wireless networks where devices operate using battery power. Security in wireless networks is also becoming crucial with the deployment of wireless local area networks in hot spot areas, organizations, hospitals and so on. Security protocols depend on energy consuming operations that occur in the cryptographic primitives used in the protocols. It has been observed that different cryptographic algorithms consume different amounts of energy. Also, the amount of energy consumed can depend on the key size, the number of cryptographic operational rounds, and packet or frame size. At the same time, the strength of a security protocol also depends on the key sizes and ciphers used to build it. We apply these results to protocols in wireless local area networks and study the tradeoffs between the security strengths of these protocols and the amount of energy consumed. For the analysis, we use distributions of packet sizes based on packets collected in home and campus wireless local area networks and measurements of the number of CPU cycles taken for cryptographic computation.