Selective video encryption of a distributed coded bitstream using LDPC codes

Abstract

Selective encryption is a technique that is used to minimize computational complexity or enable system functionality by only encrypting a portion of a compressed bitstream while still achieving reasonable security. For selective encryption to work, we need to rely not only on the beneficial effects of redundancy reduction, but also on the characteristics of the compression algorithm to concentrate important data representing the source in a relatively small fraction of the compressed bitstream. These important elements of the compressed data become candidates for selective encryption. In this paper, we combine encryption and distributed video source coding to consider the choices of which types of bits are most effective for selective encryption of a video sequence that has been compressed using a distributed source coding method based on LDPC codes. Instead of encrypting the entire video stream bit by bit, we encrypt only the highly sensitive bits. By combining the compression and encryption tasks and thus reducing the number of bits encrypted, we can achieve a reduction in system complexity.

Securing multi-media transmission over mobile communication channels

“…Figures 13(e) and 13(f) show the decoded frame and its histogram after decoding it with OMHT technique and the same encoding tables but without knowing the secret order by which the tables are used (secret key). Figure 14 shows the effect of several encryption techniques on perceptual quality of the decoded first frame of Akiyo sequence Figure 14(a) shows the original frame, Figure 14(b) shows the reconstructed frame encrypted by selective encryption that encrypts only one MSB and parity bits (Um and Delp, 2006) the PSNR of this technique equals 18.8 dB, Figure 14(c) shows the reconstructed frame encrypted by selective encryption that encrypts the eight MSB and parity bits are encrypted it gives PSNR = 9.9 dB, Figure 14(d) shows the reconstructed frame encrypted by Model I it gives PSNR = 7.4 dB, and Figure 14(e) reconstructed frame encrypted by Model II gives PSNR = 5 dB. By comparing the PSNR obtained above, we can conclude that using OMHT technique can degrade the perceptual quality of cipher frames compared to the other techniques, and hence it increases the security degree.…”

A secure hybrid Intra/Wyner-Ziv video coding for surveillance

“…These operations achieve a reasonable security level by encrypting only a part of the transmitted data. In this case, the first task is to determine easily the important parts to protect [3]. By encrypting only a part of the video, partial encryption enables privacy or multilevel protection by making some Region of Interest (ROI) of the scene unrecognized for low level users [5] [6].…”

“…In classical video encoding, this operation is performed by encrypting with secret keys. To reduce the complexity, partial or selective encryption are generally used [3] [4]. These operations achieve a reasonable security level by encrypting only a part of the transmitted data.…”