Cyberlogic is a semantic foundation for implementing evidential transactions using the public key infrastructure (PKI). Evidential transactions form the basis of frameworks for authorization and authentication, electronic commerce, business workflow, and digital government. Such transactions involve the exchange of physical evidence in the form of identity cards, driver's licenses, money, checks, visas, airline tickets, traffic tickets, birth certificates, and stock certificates, as well as electronic evidence including PIN numbers, passwords, keys, certificates, and nonces. Cyberlogic is an enabling foundation for building and analyzing protocols that involve the exchange of electronic forms of evidence.
Cyberlogic builds on evidence, public keys, and protocols. First, evidence is encoded by means of numbers using digital certificates and nonces. Second, public keys are predicates so that any information $i$ signed by a private key corresponding to the public key $P$ entails that $P$ holds of $i$. Indeed, the signed certificate is a proof for the assertion contained in the certificate. Third, protocols are distributed logic programs that gather evidence by using both ordinary predicates and digital certificates. These simple building blocks can be used to construct a rich variety of services in a variety of domains ranging from digital government to access control in computer systems.
The public key infrastructure (PKI) provides basic services for encryption, authentication, trust, authorization, and digital certificates. Cyberlogic is a protocol layer over the PKI that serves as a reliable foundation for evidential transactions. It provides a standardized semantic and computational infrastructure for exchanging evidence in electronic form. With such a foundation, it is possible to design secure electronic versions of transactions that currently require physical forms of evidence.