Selective Encryption of the Versatile Video Coding Standard
Abstract
Versatile Video Coding (VVC) is the next generation video coding standard developed by the Joint Video Experts Team (JVET) jointly established by Moving Picture Experts Group (MPEG) and ITU-T. VVC standard was released in July 2020. It introduces several new coding tools providing a significant coding gain over the High Efficiency Video Coding (HEVC) standard. It is well known that increasing the coding efficiency adds more dependencies in the video bitstream making format-compliant encryption with the standard more challenging. In this paper we tackle the problem of selective encryption of the VVC standard in format-compliant and constant bitrate. These two constraints ensure that the encrypted bitstream can be decoded by any VVC decoder while the bitrate remains unchanged by the encryption. The selective encryption of all possible VVC syntax elements is investigated. A new algorithm is proposed to encrypt in format-compliant and constant bitrate the Transform Coefficients (TCs) together with other syntax elements at the level of the entropy encoder. The proposed solution is implemented and assessed under the VVC reference software model version 6.0. Experimental results showed that the encryption drastically decreases the video quality and remains robust against several types of attacks. The encryption space is estimated in the range of 15% to 26% of the bitstream size resulting in a lightweight encryption/decryption process.