Abstract: There is provided a method of providing secure access to data stored in a system memory of a computer system, the computer system comprising a memory controller for writing data to and reading data from the system memory. The method comprises generating a random encryption key each time the computer system is booted and storing the random encryption key in a volatile memory region of the memory controller. The method additionally comprises encrypting data using the random encryption key to create encrypted data, and storing the encrypted data in the system memory. Also provided are a memory subsystem and a computer system for performing the method.