An Experimental Study on Energy Consumption of Video Encryption for Mobile Handheld Devices

Secure video communication on mobile handheld devices is challenging mainly due to (a) the significant computational needs of both video coding and encryption algorithms and (b) the limited battery capacity of handheld devices. In this paper, we evaluate several video encryption schemes from the perspective of energy consumption both analytically and experimentally. Specifically, we implement video encryption schemes on mobile handhelds to support a H.263 based secure video application, and extensively measure the energy consumption due to encoding and encryption for several classes of video clips. Contrary to popular belief, our experiments show that energy overhead of full video encryption is insignificant compared to the energy consumed for video encoding (between 2% and 4% of total energy cost) in most cases

1. Motivation

Interactive multimedia applications on mobile handhelds are gaining popularity in a variety of domains. Video applications executing on battery-operated handheld devices consume significant amounts of energy due to the high complexity of video processing (encoding and decoding). Recent work in power-aware mobile multimedia focuses on addressing the communication computation tradeoffs involved in preserving video QoS while increasing device lifetimes. Ubiquitous wireless networks supporting video communication are vulnerable to a host of security attacks that can compromise both the quality and integrity of the communication. Indeed, for many critical applications — military services, financial transactions, and crisis communications to name a few — specific bitstreams must be encoded and protected using cryptographic techniques.