Trust in a small package: minimized MRTM software implementation for mobile secure environments

In this paper we present a software-based implementation of a Mobile Remote Owner Trusted Module, using security extensions of contemporary System-On-Chip architectures. An explicit challenge are the constrained resources of such on-chip mechanisms. We expose a software architecture that minimizes the code and data size of the MRTM, applying some novel approaches proposed in recent research. Additionally, we explore alternatives within the specification to further optimize the size of MTMs. We present an analysis of specific new security issues induced by the architecture. Performance figures for an on-the-market mobile handset are provided. The results clearly indicate that a software-based MRTM is feasible on modern embedded hardware with legacy security environments.