1. At least one non-transitory computer-readable medium comprising computer-readable code embodied therein, the computer-readable code to provide a computing device with a first binary translator, which in response to execution of the code in a first execution environment of the computing device having a first security level, cooperates with a second binary translator within a second execution environment of the computing device with a second security level that is more secure than the first security level to securely execute a computer program in the second execution environment; wherein instructions of the computer program are encrypted and loaded into the first execution environment; and wherein cooperation includes provision by the first binary translator to the second binary translator of a first execution context of the computer program for use by the secondary binary translator to decrypt and execute a first portion of the computer program in the second execution environment, and provision by the second binary translator to the first binary translator of a second execution context of the computer program for emulation, by the first binary translator, of execution of a second portion of the computer program in the first execution environment.