ROI Encryption for the CABAC in VVC Codec

In coded video sequences, the Versatile Video Coding (VVC) standard allows the frame to be divided into non-square coding blocks that are executed independently. This work introduction the solution for encrypting coding blocks containing Regions Of Interest (ROI), which can be used to protect the privacy of video content in VVC frames. The proposed method encrypts all CABAC syntax elements in ROI blocks at the bitstream level, and encrypts ROI blocks while maintaining the same bitrate and format requirements. To prevent the encryption from leaking outside the ROI boundaries due to mutual prediction, motion vectors in non-ROI regions are restricted to the unencrypted blocks in the reference frame. Simulation results show that the ROI containing faces can be well performed by proposed encryption algorithm, while the background regions remain clear. Thus, the proposed solution provides secure and adaptive encryption for ROIs in VVC videos.