Deceptive Secret Sharing

摘要

Confidentiality is a fundamental goal in many security contexts. Deception is another goal in which the intention is to mislead adversaries, for example by planting false information in a system. In this paper, we consider an approach that combines confidentiality and deception using secret sharing, which has traditionally been used strictly for confidentiality purposes. The motivation for this is to protect confidentiality as far as possible while acknowledging that no confidentiality scheme provides perfect protection. If confidentiality is breached and information is accessed by unauthorized individuals, our techniques will reveal, with high probability, only false information. This provides deception on top of the confidentiality provided by ordinary secret sharing. We refer to our approach as "deceptive secret sharing" and we present techniques that work with both XOR secret sharing and Shamir's polynomial-based threshold secret sharing. We provide extensive evaluations of both overhead and security of our techniques and we also show how they provide tunable security that can trade off security and overhead by varying a single parameter of the schemes.