By reason and authority: a system for authorization of proof-carrying code

We present a system, BLF, that combines an authorization logic based on the Binder language with a logical framework, LF, able to express semantic properties of programs. BLF is a general system for specifying and enforcing policies that rely on both reason and trust. In particular, BLF supports extensible software systems that employ both digitally signed code and language-based security, especially proof-carrying code. We describe BLF, establish some of its fundamental properties, and explain its use.