A Secure Data Sharing Based on Key Aggregate Searchable Encryption in Fog-Enabled IoT Environment

Cloud server and fog computing have been utilized to manage enormous volumes of data with low service transmission time in Internet of Things (IoT) environment. However, untrustworthy relationships between network entities and cloud server cause a lot of security concerns. Many researches have been studied based on traditional cryptosystems for data sharing systems. But they lead to key management difficulty and do not ensure the data owner's authority by depending on Trusted Third Party (TTP). Therefore, we use key aggregate searchable encryption (KASE), which enables owners to exercise their rights in data management and sharing without the help of TTP and resolves the key management problem. In this paper, we propose a secure data sharing system based on KASE in fog-enabled IoT environment using blockchain. We prove the resistance of the proposed scheme against various attacks through informal analysis and Automated Validation of Internet Security Protocols and Applications (AVISPA) simulation tool. We prove the guarantee of secure mutual authentcation using Burrows-Abadi-Needham (BAN) logic. Furthermore, we compare security features and performance of the proposed scheme with existing schemes through Multiprecision Integer and Rational Arithmetic Cryptographic Library (MIRACL).