Digital image encryption techniques for wireless sensor networks using image transformation methods: DCT and DWT

Confidentiality in storing and transmitting images is needed for different fields such as medical, military, online personal albums, confidential communications and video conferencing, etc. Many image encryption techniques are proposed to ensure confidentiality of data. Digital images are different from text data as they have more data, higher data redundancy and correlation between image pixels. In wireless sensor networks (WSN), many encryption techniques are proposed. Sensor nodes have limited resources in memory, energy and processing capabilities; therefore, the proposed techniques must consider these limitations. However, most of the proposed techniques are not applicable for digital images due to image structure and size; therefore, the traditional cryptosystems can not be applied on WSN. In this paper, the following two digital images transformation techniques: (1) discrete cosine transform and (2) discrete wavelet transform are used to propose digital images encryption techniques for WSN.