This isn't new tech - RFID is an extremely common and well vetted implementation for physical security. This only replaces the fobs you have to carry with you (usually key fob or credit card sized fob) with a microscopic one under your skin. Every single office I've ever worked at (5) use RFID keys for facility access.

Some RFID implementations are vulnerable to cloning and other attacks (brute force, IIRC). There isn't any information about the implementation given here other than "RFID" and some implementations are much more secure than others.

There's attack demonstrations on some RFID access implementations on YouTube - some more viable than others.