A Fully Homomorphic Encryption Scheme With a Smaller Public Key

In order to improve the efficiency of the homomorphic encryption scheme, an improved homomorphic encryption scheme based on integer is proposed. On the basis of the DGHV scheme, the size of the public key is first reduced to (0) over tilde(lambda(4)) by using the public key element quadratic technique and the parameter offset technique. Then, by changing the modulo 2(k) operation to modulo operation, the improved scheme can encrypt the data of k bits at one time, which has smaller public key size and higher efficiency than the original DGHV scheme. Finally, the correctness and security of the scheme are proved by the theory, and the efficiency analysis of the scheme is given.