Image Encryption Based on Compressive Sensing and Scrambled Index for Secure Multimedia Transmission.

With the rapid growth of multimedia message exchange and digital communication, multimedia big data has become a research hotspot in various fields. The storage and transmission of multimedia big data have high requirements for security. Images, covering the highest proportion of multimedia data, should be processed and transmitted with high security. Compressive sensing (CS) has a beneficial property for the encryption that the image can be recovered with fewer samples than conventional approaches use. In recent years, CS has been studied not only to reduce the resource requirements for signal acquisition but also to ensure the security of data. It is still an open challenge to improve security and enhance the quality of the decrypted image simultaneously using the key with small size. In this article, a CS-based encryption method is presented that associates the quantization with random measurement permutation. An enormous number of experiments have been conducted on both standard test images and face images chosen from the big database LFW. Experimental results show that our proposal has dramatic improvements on ensuring the security, enhancing the quality of the decrypted image, and raising the efficiency. Additionally, this proposal remarkably reduces storage and transmission resources. Accordingly, this encryption scheme can be applied to ensure the security of multimedia transmission.