New Practical Public-Key Deniable Encryption.

The primitive of deniable encryption aims to protect the privacy of communicated data in the scenario of coercion by allowing the sender (or receiver or both of them) to open the ciphertext transmitted into a different message. There are two types of deniability, namely, multi-distributional deniability and full deniability, and the later provides better security guarantees than the former one. However, all existing schemes under the framework of full deniability are less efficient. In this paper, we first propose a new public key encryption scheme in which the ciphertexts could be decrypted by the receiver depending on the decision of the sender. Additionally, building on this encryption, we construct a new public-key sender-deniable encryption scheme under the framework of full deniability. Compared with Canetti et al.’s party scheme, the proposed scheme is superior in both efficiency andeniability.