Viakoo, the leader in automated verification of physical security system performance, announced that the United States Patent and Trademark Office (USPTO) has issued its U.S. Patent No. 9,456,190. The patent covers methods for independently calculating the actual time period of retention for an individual video data stream on a recording system. Viakoo has implemented this patent in its products to automatically detect, track, and validate Video Retention Compliance (VRC) as a key performance metric.