Encrypted computing: Speed, security and provable obfuscation against insiders

Abstract

Over the past few years we have articulated theory that describes ‘encrypted computing’, in which data remains in encrypted form while being worked on inside a processor, by virtue of a modified arithmetic. The last two years have seen research and development on a standards-compliant processor that shows that near-conventional speeds are attainable via this approach. Benchmark performance with the US AES-128 flagship encryption and a 1GHz clock is now equivalent to a 433MHz classic Pentium, and most block encryptions fit in AES's place. This summary article details how user data is protected by a system based on the processor from being read or interfered with by the computer operator, for those computing paradigms that entail trust in data-oriented computation in remote locations where it may be accessible to powerful and dishonest insiders. We combine: (i) the processor that runs encrypted; (ii) a slightly modified conventional machine code instruction set architecture with which security is achievable; (iii) an ‘obfuscating’ compiler that takes advantage of its possibilities, forming a three-point system that provably provides cryptographic ‘semantic security’ for user data against the operator and system insiders.