Digitally-signed video

Last modified: Wednesday August 31, 2022.

When you export video from your Alta video security systems, Alta Video creates a zip archive containing your selected MP4 video clips, together with a metadata file for each clip. The metadata file contains information such as:

• Make, model, and firmware version of the camera used to capture the video.
• Information relating to the camera from Alta Video (camera name, location information, MAC address, and camera serial number).
• Timestamps for the start and end of the video clip.

To prove that the video and metadata has not been tampered with in any way, the archive includes the digitally signed hash information for each video and metadata file.

Archive folder structure

The signature files are created using SHA-256 hashing and asymmetric cryptography with a key and certificate that is unique to the Alta Video deployment used to capture and export the video. The archive also contains the public certificate used to verify the identity of the signer, allowing verification of the signatures.

File signing process

The video and metadata files use a two-stage signing process:

• Each file has a SHA-256 hash created.
• Each SHA-256 hash is then asymmetrically encrypted using the unique private key from the Alta Video deployment that is creating the archive.

Hashing and signing process

Verifying the video and metadata is untouched

By creating a hash of the video and metadata files in your possession, and comparing those hashes with the signed hashes from the Avigilon AltaAlta Video deployment, you can confirm the files have not been tampered with.

Compare hashes to verify the file