A processor includes a first model specific register (MSR); and memory encryption circuitry to receive a request to access a memory, determine if a key identifier (ID) of the request is zero, and if the key ID is zero, to bypass data encryption when the request is to write data to the memory and to bypass memory decryption when the request is to read data from the memory and when a selected bit of the first MSR is set, and if the selected bit of the first MSR is not set, to encrypt write data when the request is to write data or decrypt data in a read response when the request is to read data, with a key associated with the key ID equal to zero.