Somewhat homomorphic encryption scheme for arithmetic operations on large integers

Homomorphic encryption allows for processing encrypted data without the need to decrypt them. This technique aggregates privacy and security for data processing in unreliable environments. In this paper, we propose a new encryption scheme oriented for calculating arithmetic functions of large integer numbers. Our proposal is an extension of the encryption scheme proposed in [1]. We also provide an implementation of both the original and the proposed scheme. Even though the total number of allowed homomorphic operations is limited in our scheme, our results show that the new extension is more efficient in terms of processing and that the ratio between the ciphertext and plaintext sizes is similar to that of the original scheme.