A Multi-Key Based Lightweight Additive Homomorphic Encryption Scheme

Usually, IoT devices have low power. Merging IoT and cloud computing provides the IoT environment with data management flexibility, such as data scalability, enhanced devices capacity, economies of scale, etc. But solutions based on cloud computing can put privacy at risk when operating an unreliable provider. The introduction of the homomorph allows a third party to perform operations on the data without having access to it. In this paper, we propose a partially homomorphic lightweight asymmetric encryption technique, which allows to encrypt decimal digits of the message separately, by multiplying each by a different key. There are many encryption techniques in the literature, most of them suffer from size and slowness in terms of execution time. In our proposed technique, the size of the ciphertext is close to the size of the original one. Moreover, we obtained a time complexity equal to O(n). Thus, the proposed scheme is suitable for devices and networks with limited resources, while offering high security.