Constructing secure‐channel free identity‐based encryption with equality test for vehicle‐data sharing in cloud computing

Abstract

AbstractWith the rapid rise of connected vehicles on the road, there is an exponential growth in vehicle‐related data (vehicle‐data) generated and accumulated by connected vehicles. Taking advantage of cloud computing, enabling a vehicle‐data sharing system can make various services based on vehicle‐data available. However, the untrusted nature of the cloud server raises a challenge on how to balance privacy and functionality over the vehicle‐data outsourced to the vehicle‐data sharing system. Identity‐based encryption with equality test (IBEET) is a viable solution to this challenge as it not only ensures data privacy but also enables searchable functionality over the encrypted data while dealing with the certificate management issue that exists in public key encryption with equality test (PKEET). However, the existing IBEET schemes are unable to be applicable into the vehicle‐data sharing in cloud computing due to the fact that they did not consider the consequences of unexpected exposure of trapdoors given to cloud server and different levels of computing capabilities of the system entities. Therefore, this article introduces the notion of secure‐channel‐free IBEET (SCF‐IBEET) scheme and presents a generic construction of the SCF‐IBEET scheme by addressing the above‐mentioned issues simultaneously. The proposed SCF‐IBEET construction achieves one‐wayness under chosen‐identity and chosen‐ciphertext attacks, indistinguishability under chosen‐identity and chosen‐ciphertext attacks, and trapdoor anonymity securities with respect to five different types of adversaries. Furthermore, the security comparison and efficiency analysis indicate that the proposed construction is reasonable with regard to security and viable in terms of efficiency to be applied to practical scenarios as vehicle‐data sharing in cloud computing.