Bi-Deniable Public-Key Encryption Protocol which is Secure against Active Coercive Adversary

Adam O’Neill, Chris Peikert, Brent R. Waters

Rikke Bendlin, Jesper Buus Nielsen, Peter Sebastian Nordholt +1 more

Junzuo Lai, Rupeng Yang, Zhengan Huang +1 more

Nikolay Andreevich Moldovyan, Березин Андрей Николаевич, А. А. Корниенко +1 more

The paper proposes new deniable encryption protocols providing bi-deniability in the case of both the passive coercive attack and the active one. It is supposed the coercive adversary intercepts all data sent during the protocol. The protocols use no shared secret keys that are pre-agreed by parties of the protocol. Bi-deniability is based on computational indistinguishability between deniable encryption and probabilistic one. Significant merit of the proposed protocols is their using the standard public key infrastructure.

Nam Hai Nguyen, Nikolay Andreevich Moldovyan, A.V. Shcherbacov +2 more

There is proposed a new method for deniable encryption based on commutative transformations. The method has been used to design the deniable encryption protocol resistant to the passive coercive attacks, which uses no pre-shared secret keys and no pre-exchanged public keys. The protocol begins with the stage at which the sender and receiver exchange their single-use public keys and compute the single-use shared secret key. Then, it is performed pseudo-probabilistic three-pass protocol with simultaneous commutative encryption of the fake and secret messages. Resistance of the proposed protocol to coercive attacks is provided by its computational indistinguishability from probabilistic no-key three-pass protocol used to send securely the fake message. To perform commutative encryption, it used exponentiation cipher. To provide security against active coercer, the protocol is to be complemented with procedure for authenticating the sent messages.

Ran Canetti, Shai Halevi, Jonathan I. Katz