How do I verify export as evidence video?
Posted by Dave Boyce on 25 May 2011 02:24 PM
ipConfigure provides the ability to Export as Evidence video content by creating a downloadable zip file which includes all the video content and a hash file for each video file. The hash file can be used to verify the video has not be tampered. To verify that video has not be changed you can generate a new hash file and compare the hash file against the original hash file provided in the downloadable zip from the Export as Evidence. ipConfigure hash file is generated using SHA-512 hashing technology.
Resources for SHA-512 Hashing Programs
Difference between Digital Watermark and Cryptic Hashing
Differences: Watermarking an IP cameras video file is an invasive process since the digital watermark has to be added after the video file is created thus altering the file from its original form. Hashing is the preferred method for maintaining the forensic integrity of IP cameras since it's a passive process that calculates the fingerprint of the video file, which does not change/modify the original file. The reason this is important with IP cameras is because video is encoded on the camera where analog cameras are encoded to a digital file on the DVR and can be simultaneously watermarked. In summary, if you are utilizing IP cameras and the file has been watermarked it can't be authenticated as an original at a later date.
*Please note that this applies to MPEG 4 and H.264 recordings only as there is no hash tag associated with MJPEG recording streams*
The following documentation is available for download below: