A New Lightweight Homomorphic Encryption Scheme for Mobile Cloud Computing

The emerging technology of mobile devices allows mobile users to access a wide range of applications through the Internet connection. As such applications demand extensive computational power, it poses a challenge to the devices with limited computation power, memory, storage and energy. However, such a challenge could be overcome by cloud computing as the cloud offers virtually unlimited dynamic resources for computation, storage and service provision. Nevertheless, mobile users are still reluctant to adopt this technology as moving private data to the cloud with no physical and limited digital control by themselves raises security concerns to their data. Encryption using the primitive encryption schemes is unsuitable for use in cloud environments, as data need to be decrypted first before they can be processed, resulting in the data being exposed to the cloud. Moreover, although homomorphic encryption is believed to be one of the potential solutions to allowing arbitrary computation on encrypted data, its efficiency is still an obstacle for its implementation. Thus, this paper will deeply look at efficiency issues and propose a new Lightweight Homomorphic Encryption (LHE) scheme which minimizes the use of computation power at encryption and key generation. The key contribution of this work is to have a lightweight scheme with improved efficiency, while enabling homomorphism under both addition and multiplication.