A processor, a system, a machine readable medium, and a method. The processor comprises first circuitry to: encrypt a first code image using a first code key; load the encrypted first code image into a memory area allocated in memory for the first code image by an operating system miming on the processor; and send to the operating system a substitute key that corresponds to the first code key, wherein the first code key is concealed from the operating system; and an instruction cache including control circuitry; and second circuitry coupled to the instruction cache, the second circuitry to: receive the substitute key from the operating system; in response to a first request from the operating system to execute the first code image to instantiate a first process, perform a first cryptographic function using a hardware key to generate the first code key from the substitute key; and program the control circuitry of the instruction cache with the first code key to enable the first code image to be decrypted using the first code key.