Disc Wobble

Disc wobble, otherwise known as "wobble groove," was a technology developed by Royal Philips Electronics.

The point of the technology, when used with a digital watermark, was to make sure only authorized discs could be played on next-gen players, DVD and Blu-ray.

Disc Wobble encodes hidden protection data onto the lead-in groove along the inner edge of a disc in a way that can be very difficult to replicate.

The tech reshapes the groove in a subtle pattern that is usually not visible except for experts. The wobble is then too fast for the laser head to follow, allowing for the copyright protection data to be read separately from the main content.

Most discs will have authentication keys in the wobble, making replicas unplayable.

Piracy would be relegated to analog, since copying would be almost impossible unless you had a press capable of creating the wobble.