A Tutorial Example of the Semantic Approach to Foundational Proof-Carrying Code: Abstract

Abstract

Proof-carrying code provides a mechanism for insuring that a host, or code consumer, can safely run code delivered by a code producer. The host specifies a safety policy as a set of axioms and inference rules. In addition to a compiled program, the code producer delivers a formal proof of safety expressed in terms of those rules that can be easily checked. Foundational proof-carrying code (FPCC) provides increased security and greater flexibility in the construction of proofs of safety. Proofs of safety are constructed from the smallest possible set of axioms and inference rules. For example, typing rules are not included. In our semantic approach to FPCC, we encode a semantics of types from first principles and the typing rules are proved as lemmas. In addition, we start from a semantic definition of machine instructions and safety is defined directly from this semantics.