Video Authentication Using File Structure Analysis

The video recordings captured from DVR (Digital Video Recorder) machines or from mobile phones are presented in front of the court as the main source of evidence in the crimes such as sexual assaults, child exploitation, kidnapping, armed robberies, murders etc. Admissibility of the CCTV footages or videos procured from DVRs or from mobile phone depends on its proven authenticity. The recent technologies provide easy access of editing in to the digital media and therefore the acceptance of such evidences becomes questionable in the court of law. In this study we presented how the file structure analysis of the video recording file captured from mobile, helped in identifying the tampering. Rather than the frame by frame analysis or content analysis, the file structure analysis is the purely technical approach of video authentication. The original video recording in .mp4 format was deliberately edited using freely available video editors, the file also travelled through social media. The file structures of original file and the edited files were compared and on the basis of the differences in the structures and metadata, results were obtained on authentication.