minnebeskyttelsesnøkler

Minnebeskyttelsesnøkler, also known as memory protection keys, are a hardware-based security feature found in some modern CPUs, notably Intel's processors starting with the Tiger Lake generation. Their primary function is to enhance the security of memory regions by allowing software to control which processes or threads have access to specific pages of memory.

This mechanism works by associating a "key" with each page of physical memory. Processes can then be assigned specific keys. When a process attempts to access a memory page, the CPU checks if the process's assigned key matches the key associated with the memory page. If the keys do not match, the access is denied, preventing unauthorized reading or writing to that memory.

Minnebeskyttelsesnøkler are particularly useful for protecting sensitive data, such as cryptographic keys or user credentials, from being accessed by other, potentially malicious, processes running on the same system. They can also be employed to isolate different components of an operating system or applications, reducing the attack surface.

The implementation typically involves a set of registers within the CPU that manage the keys and their associations with memory pages. Software, often operating system components, is responsible for configuring and managing these keys, granting and revoking access as needed. This hardware enforcement provides a strong layer of protection that is difficult to circumvent through software vulnerabilities alone.