METHOD FOR ENCRYPTING A PROGRAM FOR SUBSEQUENT EXECUTION BY A MICROPROCESSOR CONFIGURED TO DECRYPT AND EXECUTE THE ENCRYPTED PROGRAM

摘要

A method for encrypting a program for subsequent execution by a microprocessor configured to decrypt and execute the encrypted program includes receiving an object file specifying an unencrypted program that includes conventional branch instructions whose target address may be determined pre-run time. The method also includes analyzing the program to obtain chunk information that divides the program into a sequence of chunks each comprising a sequence of instructions and that includes encryption key data associated with each of the chunks. The encryption key data associated with each of the chunks is distinct. The method also includes replacing each of the conventional branch instructions that specifies a target address that is within a different chunk than the chunk in which the conventional branch instruction resides with a branch and switch key instruction. The method also includes encrypting the program based on the chunk information.

主权项

1. A method for encrypting a program for subsequent execution by a microprocessor configured to decrypt and execute the encrypted program, the method comprising:
receiving an object file specifying an unencrypted program that includes conventional branch instructions whose target address may be determined prior to the time in which the microprocessor runs the program; analyzing the program to obtain chunk information, wherein the chunk information divides the program into a sequence of chunks, wherein each of the chunks comprises a sequence of instructions, wherein the chunk information further comprises encryption key data associated with each of the chunks, wherein the encryption key data associated with each of the chunks is distinct; replacing each of the conventional branch instructions that specifies a target address that is within a different chunk than the chunk in which the conventional branch instruction resides with a branch and switch key instruction; and encrypting the program based on the chunk information.