An Improved Fully Homomorphic Encryption Scheme for Cloud Computing

Abstract

Business in cloud computing is very popular among Small and Medium Enterprises (SMEs). By leveraging services from the cloud, such companies can migrate all of their in-house operations to cloud at low costs with minimum IT facility requirements such as desktop machines and the Internet. Even though the cloud promises tremendous advantages in terms of computing resources and storage spaces, some of the companies are still reluctant to adopt such a technology because of security concerns. To overcome such problems, a fully homomorphic encryption (FHE) scheme with improved efficiency can be implemented as the scheme allows computation on encrypted data without decryption. In this paper, we propose an improved FHE scheme that uses a symmetric key for encryption together with a protocol to implement the scheme. Furthermore, we also provide an analysis regarding to the noise growth in the processed ciphertext and squashing technique that is required to reduce the noise. This analysis is essential to improve the efficiency of the scheme as the squashing technique is time-consuming.