Secure computing using cryptographic assurance of execution correctness

Final report and documentation for the security enabled programmable switch for protection of distributed internetworked computers LDRD.

“…At run-time, within the protected volume of the computer system, the processor removes the protection and confirms the instruction and sequence integrity. This method protection over a large portion of the software life cycle from the time it is shrink-wrapped in the trusted facility through the distribution, loading, and storage phases, up to the point where the instructions or data are accessed by the target CPU [2]. More details on the FE concept can be found in earlier works [3], [4], [5].…”

“…This research is producing a method of hardening the corporate computer infrastructure by prototyping a mixed hardware and software architecture that will enforce policies by pushing distributed security functions closer to the end user's computer, but without reconfiguring the end user's computer itself, and without relying on the correct configuration of the end user's computer. Previous research has developed highly secure network components [2][3] [4][5] [6] [7]. Because it is impractical to replace our entire infrastructure with secure, trusted components, this paper investigates how to improve the security of a heterogeneous infrastructure (Distributed Internetworked Computers) composed of both trusted and untrusted components.…”

“…This device, hardened against malicious code by using cryptographically protected processor techniques initially described in a previous paper [2], provides many security functions. Some of the functions required are secure reprogrammability and/or secure administration by authorized parties 1) without the end user giving up control of his/her computer and 2) without relying on the timely installation of patches by the end user.…”

“…We have developed a method of faithfully executing instruction sequences called "Cryptographic Assurance of Execution Correctness" (CAEC). This method protects instruction sequences from subversion during code distribution and storage [2][5]. Our method cryptographically seals the program instructions at a certification facility, then decrypts and authenticates each instruction within the executing Central Processing Unit (CPU), thereby providing a mechanism for detecting and responding to the insertion of malicious code or the unauthorized modification of previously certified code.…”

“…For this project the "Cryptographic Assurance of Execution Correctness" techniques were redesigned for the chosen hardware and embedded software platform that was chosen for the prototyping of the distributed security functions. This method provides a type of software protection that begins when the software leaves the control of the developer and ends within the trusted volume of a target processor [2] [5]. That is, CAEC provides program integrity, even while the program is in execution.…”