Secure storage and execution of processor control programs by encryption and a program loader/decryption mechanism

Abstract

A method and a mechanism for securely storing and executing a program in a computer system processing unit, including a storage unit for storing an encrypted version of the program and a loader/decryption mechanism responsive to a request and a decryption key for decrypting the encrypted version of the program, writing the un-encrypted version into a memory for execution, and deleting the un-encrypted version from the memory when execution is completed. The encrypted version is constructed as encrypted code blocks that are decrypted and loaded into the memory only as required, and the encrypted version of the program includes a clear text header identifying the encrypted version as an encrypted program. The processor unit includes a context store for storing the context of a process in which the program is being executed, and a context switching mechanism for performing context switching operations wherein the context switching mechanism is responsive to a context switch of the process in which the program is being executed for storing the clear text header in the context store when the process is suspended in a context switch and returning the clear text header to the memory when the process is resumed.