An Efficient Public-Key Dual-Receiver Encryption Scheme

Public-key dual-receiver encryption (PK-DRE) is a kind of particular public-key encryption for enabling two independent recipients to obtain the same plaintext from the same ciphertext. Due to its dual-receiver property, PK-DRE is quite helpful in many scenarios, such as deniable authentication, global key escrow, security puzzle, and even blockchain. In this paper, we revisit the PK-DRE scheme CFZ14 proposed at CT-RSA 2014 and propose a variant. This variant is original from a new security proof which allows us to remove some steps in CFZ14. To the best of our knowledge, the obtained variant is more efficient than the existing PK-DRE schemes in terms of public verifiability and key size.