An efficient heterogeneous online/offline anonymous certificateless signcryption with proxy re-encryption for Internet of Vehicles

In the Internet of Vehicles (IoV) domain, the collection of traffic data is executed by intelligent devices and stored within a cloud-assisted IoV system. However, ensuring confidentiality and authorized access to data are the main problems of data storage. To address these problems, this paper proposes an efficient heterogeneous online/offline certificateless signcryption with a proxy re-encryption scheme (HOOCLS-PRE). This scheme enables IoV nodes in a certificateless cryptosystem (CLC) environment to store encrypted IoV-related data in the cloud. When an authorized user from an identity-based cryptosystem (IBC) wishes to access the data, the IoV node delegates the task of re-encrypting the data to the cloud, and only an authorized user can decrypt the data and verify its integrity and authenticity. The cloud cannot obtain any plaintext details about the data. In the proposed scheme, the signcryption process is split into offline and online phases. Most heavy computations are conducted without knowledge of the message during the offline phase. Only light computations are performed in the online phase when a message is available. The scheme protects the privacy and anonymity of vehicles by preventing adversaries from linking vehicle identities and locations. Moreover, a formal security proof is provided in the random oracle model. Finally, the performance analysis reveals that HOOCLS-PRE outperforms existing relevant schemes. Hence, HOOCLS-PRE is ideal for cloud-assisted IoV environments.