Security Evaluation for Block Scrambling-Based Image Encryption Including JPEG Distortion against Jigsaw Puzzle Solver Attacks
This addresses privacy protection for social media users by highlighting vulnerabilities in a specific encryption method, though it is incremental as it focuses on evaluating an existing scheme rather than proposing a new one.
The paper evaluates the security of block scrambling-based image encryption schemes used in Encryption-then-Compression systems against jigsaw puzzle solver attacks, finding that encrypted images remain vulnerable despite large key spaces due to preserved block correlations.
Encryption-then-Compression (EtC) systems have been considered for the user-controllable privacy protection of social media like Twitter. The aim of this paper is to evaluate the security of block scrambling-based encryption schemes, which have been proposed to construct EtC systems. Even though this scheme has enough key spaces against brute-force attacks, each block in encrypted images has almost the same correlation as that of original images. Therefore, it is required to consider the security from different viewpoints from number theory-based encryption methods with provable security such as RSA and AES. In this paper, we evaluate the security of encrypted images including JPEG distortion by using automatic jigsaw puzzle solvers.