Extended Selective Encryption of H.264/AVC (CABAC)- and HEVC-Encoded Video Streams

Abstract

This paper proposes an extended Selective Encryption (SE) method for both H.264/AVC (CABAC) and HEVC streams. Namely, this work addresses the main security issue that SE is facing : the content protection, related to the amount of information leakage through a protected video. Our contribution is the improvement of the visual distortion induced by SE approaches. If previous works on both H.264/AVC (CABAC) and HEVC limit encryption to bins treated by one specific mode of CABAC: its by-pass mode - which has the advantage of preserving the overall bitrate -, we propose here to also rely on the encryption of the more widely used mode of CABAC: its regular mode. This allows to encrypt a major codeword for video reconstruction : the prediction modes for Intra blocks/units. Disturbing their statistics may cause bitrate overhead, which is the trade-off for improving the content security level of the SE approach. A comprehensive study of this compromise between the improvement of the scrambling efficiency and the undesirable aftereffects is proposed in this paper, and a specific security analysis of the proposed CABAC regular mode encryption is conducted.

Existing System

Proposed System

Architecture