General Secure Function Evaluation using standard trusted computing hardware

In this paper, we show how Trusted Platform Modules (TPMs), standard security hardware devices, can be used with minor modification to efficiently support Secure Function Evaluation (SFE), a fundamental and extremely powerful cryptographic operation. Prior research by others has shown how SFE can benefit from using security hardware, but prior work has used either custom hardware tokens or powerful secure co-processors which require significant changes to current computing systems. In this paper we show that similar techniques can be supported by TPMs with enhancements that are at the level of a firmware upgrade (albeit a secure firmware upgrade endorsed by the TPM manufacturer) - specifically, no new physical devices would need to be purchased or added to most modern business-class systems. This paper describes the specific changes that need to be made, and evaluates efficiency for a simple example in location-based privacy. Our evaluation shows that performance is reasonable for supporting simple privacy-enhanced applications.