The Impossibility of Keeping Secrets
Studer, T.
Corresponding Email: [email protected]
Received date: 29 October 2020
Accepted date: 5 July 2021
Abstract:
Controlled query evaluation (CQE) is an approach to guarantee data privacy for database and knowledge base systems. CQE-systems feature a censor function that may distort the answer to a query in order to hide sensitive information. We introduce a high-level formalization of
controlled query evaluation in the language of modal logic. We then use this to define several desirable properties of CQE-systems. Finally we establish two impossibility theorems, which show that certain combinations of these properties cannot be obtained.
Keywords: no-go theorem; data privac; controlled query evaluation; modal logic