US Patent 10102151 Protecting a memory from unauthorized access

A method includes generating a set of virtual-machine-specific (VMS) encryption keys for a dedicated virtual machine, storing the set of VMS encryption keys in a protected memory, storing a first look-up table in the protected memory, and replacing an encryption key stored in a crypto unit with at least one VMS encryption key of the set of VMS encryption keys in an operation mode where the dedicated virtual machine is executed by a processor. The protected memory is selectively excluded from access by operating systems executable on a computer system. The look-up table being accessible only by firmware of the computer system.