Index-Based Selective Audio Encryption for Wireless Multimedia Sensor Networks

Wireless multimedia sensor networks (WMSNs) support many acoustic applications for audio surveillance, animal tracking/vocalization, human health monitoring, etc. However, resource constraints in sensor networks (such as limited battery power, bandwidth/computation capability, etc.) pose challenges for the quality and security of audio data transmission and processing. The security is a critical issue since audio information can be accessed or even manipulated in WMSNs. In order to ensure security, audio quality and energy efficiency, we propose an index-based selective audio encryption scheme for WMSNs. The scheme protects data transmissions by incorporating both resource allocation and selective encryption based on modified discrete cosine transform (MDCT). In this proposed scheme, the audio data importance is leveraged using the MDCT audio index, and wireless audio data transmission proceeds with energy efficient selective encryption. The simulation results show that the proposed approach offers a significant gain in terms of energy efficiency, encryption performance and audio transmission quality.