# Analysis of Gong et al.'s CCA2-secure homomorphic encryption

Research paper by Hyung Tae Lee, San Ling, Huaxiong Wang

Indexed on: 17 Jun '16Published on: 16 Jun '16Published in: Theoretical Computer Science

#### Abstract

It is a well-known result that homomorphic encryption is not secure against adaptive chosen ciphertext attacks (CCA2) because of its malleable property. Very recently, however, Gong et al. proposed a construction asserted to be a CCA2-secure additively homomorphic encryption (AHE) scheme; in their construction, the adversary is not able to obtain a correct answer when querying the decryption oracle on a ciphertext obtained by modifying the challenge ciphertext (Theoretical Computer Science, 2016). Because their construction is very similar to Paillier's AHE, it appeared to support an additively homomorphic property, though they did not specify an evaluation algorithm for the scheme in their paper.