Bi-Deniable Public-Key Encryption

In CRYPTO 1997, Canetti et al.put forward the intruiging notion of deniable encryption, which (informally) allows a sender and/or receiver, having already performed some encrypted communication, to produce ‘fake’ (but legitimate-looking) random coins that open the ciphertext to another message. Deniability is a powerful notion for both practice and theory: apart from its inherent utility for resisting coercion, a deniable scheme is also noncommitting (a useful property in constructing adaptively secure protocols) and secure under selective-opening attacks on whichever parties can equivocate. To date, however, known constructions have achieved only limited forms of deniability, requiring at least one party to withhold its randomness, and in some cases using an interactive protocol or external parties. In this work we construct bi-deniable public-key cryptosystems, in which both the sender and receiver can simultaneously equivocate; we stress that the schemes are noninteractive and ...

• Type: Journal
• Year: 2011
• Where: CRYPTO
• Authors: Adam O'Neill, Chris Peikert, Brent Waters
• Keywords: CRYPTO 2011, Cryptology, Cryptosystems, External Parties, Independent Interest