Techniques for trusted software engineering

How do we decide if it is safe to run a given piece of software on our machine? Software used to arrive in shrink-wrapped packages from known vendors. But increasingly, software of unknown provenance arrives over the internet as applets or agents. Running such software risks serious harm to the hosting machine. Risks include serious damage to the system and loss of private information. Decisions about hosting such software are preferably made with good knowledge of the software product itself, and of the software process used to build it. We use the term Trusted Software Engineering to describe tools and techniques for constructing safe software artifacts in a manner designed to inspire trust in potential hosts. Existing approaches have considered issues such as schedule, cost and efficiency; we argue that the traditionally software engineering issues of configuration management and intellectual property protection are also of vital concern. Existing approaches (e.g., Java) to this problem have used static type checking, run-time environments, formal proofs and/or cryptographic signatures; we propose the use of trusted hardware in combination with a key management infrastructure as an additional, complementary technique for trusted software engineering, which offers some attractive features