Exploring Electric Network Frequency for Joint Audio-Visual Synchronization and Multimedia Authentication

Electric network frequency (ENF), a signature in multimedia application, is being utilized as a significant tool to check the authenticity of media recordings. The Normalized Correlation coefficient (NCC) is employed to check the synchronization between the ENF signal extracted from video frames and audio signal incorporated in a multimedia recording. For synchronized media recordings the authentication system compare the ENF signals extracted from the tampered audio recording with the reference ENF database. The authentication system incorporates the tampering detection of the media recordings along with the timestamp verification. The system utilizes the Absolute Error Map between the ENF signals obtained from the reference database and the testing video recordings. Line Detection algorithm, which deals with an exhaustive point search and measurement, is used to jointly deal with timestamp verification and tampering detection. The authentication scheme first checks whether the tampering has occurred or not. If testing data is tampered with, it outputs the tampered type and region along with the timestamp verification.