SafeNet Sentinel Hardware Key (often referred to as a Sentinel USB dongle) is a hardware-based software protection solution provided by Thales (previously SafeNet). It is commonly used to enforce licensing and copy protection for software applications, ensuring that only authorized users with the physical dongle (a USB device) can access the software. This hardware key contains unique cryptographic information and interacts with software to validate the user's license.

When you plug the SafeNet Sentinel hardware key into your system, you need a driver that allows Windows to communicate with the dongle. The driver ensures that your operating system recognizes the dongle and allows your software to interact with it properly.