Passive Blind Forensic Scheme for Copy-Move Temporal Tampering Detection

This paper contributes in detecting temporal tampering in the Moving Picture Experts Group-4 (MPEG-4) digital video using passive blind forensic scheme. In temporal tampering attack, one or more frames are copied from video and pasted at some other location in the same video to hide or highlight particular activity. Sometimes the original frames are modified and then pasted at some other location. This tampering activity is carried out so smartly that it is difficult to identify with naked eyes. The proposed forensic scheme uses two-step algorithm to detect the tampering. First, the suspicious frame is detected and then this frame is compared with others frames in the sequence to find the duplicate frame. Comparison of the frames is carried out with the help of Scale Invariant Feature Transform (SIFT) key-points. Random Sample Consensus (RANSAC) is used to take the final decision on the matching of the frames. The simulation results show that the proposed scheme is able to detect and locate the tampered frame with 100% accuracy regardless of how many number of frames of the video sequence are duplicated.