Linux users may face yet another hurdle related to Secure Boot when the Microsoft-signed key used by many distributions to support the firmware-based security feature expires on September 11, leaving users at the mercy of distribution from OEMs, and systems possibly not receiving a necessary firmware update.
Let's start with a quick overview of what Secure Boot is. It's part of the Unified Extensible Firmware Interface (UEFI) that has replaced the Basic Input/Output System (BIOS) on modern systems. (Although it's still often referred to as the BIOS by enthusiasts and manufacturers.) Microsoft's knowledge base article about the feature explains that it "is a security standard developed by members of the PC industry to help make sure that a device boots using only software that is trusted by the [manufacturer]."
