A Lightweight Hybrid Encryption Scheme for Secure IoT Data Storage in the Cloud

Abstract

Internet-of-Things devices increasingly store their data in the cloud, raisingconcerns about the confidentiality of sensitive information held by third-party providers. Strong asymmetric encryption protects data effectively but is computationally heavy for resource-constrained devices, while symmetricencryption is fast but complicates secure key sharing. This paper proposes alightweight hybrid encryption scheme for secure IoT data storage in the cloud that combines fast symmetric encryption of the data with efficient elliptic-curve cryptography for key protection. Each data item is encrypted with a symmetric key, which is itself protected using elliptic-curve cryptography, giving the security of asymmetric key management at a fraction of the cost of traditional asymmetric encryption of the data. The scheme was implemented and compared against pure symmetric and pure asymmetric baselines across a range of data sizes. The hybrid scheme delivered processing times close to the fast symmetric baseline while providing the strong key security of the asymmetric approach, far outperforming pure asymmetric encryption on large data. The results show that lightweight hybrid encryption is a practical means of securing IoT data in the cloud without overburdening constrained devices. KEYWORDS: cloud security, Internet of Things, encryption, elliptic-curve cryptography, data confidentiality, lightweight cryptography