Enhancing Security in the Memory Management Unit.

We propose an hardware solution to several security problems that are difficult to solve on classical processor architectures, like licensing, electronic commerce, or software privacy. The memory management unit which provides multitasking and virtual memory support is extended and given a third purpose: to supply strong hardware security support for the software layer. The principle of this enhanced device, that we call a Security Management Unit (or SMU), is based on ciphered program execution and access control. It is composed of a pipelined block ciphering/deciphering unit, an infernal permanent memory and logic control, whose interaction is explained in this pape