The Sentinel Hardlock Key (often referred to as a Sentinel USB Key, Sentinel Hardware Key, or Sentinel HASP Key) is a type of dongle used for software licensing protection. It allows software developers to secure their products by enforcing licensing rules such as ensuring that the software can only be used when the key is physically connected to the computer. These keys are commonly used in industries where software piracy needs to be controlled, or where software needs to be tied to a particular machine.

The Sentinel Hardlock Key is part of the Sentinel HASP family of hardware-based copy protection devices, which includes both USB keys (dongles) and parallel port-based devices. The key is essentially a form of digital rights management (DRM).