International Association for Cryptologic Research
The idea of homomorphic encryption can be traced back to 1978 by the researcher, it means that an entity can carry out computations on encrypted data without decryption. This trait of encryption scheme sounds appealing in network services. People need to conduct various kinds of operations, such as search, sum up or computing the average value, on data stored in a remote server. Suppose every operation requires a series of works including downloading the ciphertext, decryption, compute the target value, encryption and upload the new ciphertext, the communication and computation cost may grow very large and become unbearable.