Blockchain-Based Secured IPFS-Enable Event Storage Technique With Authentication Protocol in VANET Sanjeev Kumar Dwivedi, Ruhul Amin, and Satyanarayana Vollala Abstract—In recent decades, intelligent transportation systems (ITS) have improved drivers’ safety and have shared information (such as traffic congestion and accidents) in a very efficient way. However, the privacy of vehicles and the security of event information is a major concern. The problem of secure sharing of event information without compromising the trusted third party (TTP) and data storage is the main issue in ITS. Blockchain technologies can resolve this problem. A work has been published on blockchain-based protocol for secure sharing of events and authentication of vehicles. This protocol addresses the issue of the safe storing of event information. However, authentication of vehicles solely depends on the cloud server. As a result, their scheme utilizes the notion of partially decentralized architecture. This paper proposes a novel decentralized architecture for the vehicular ad-hoc network (VANET) without the cloud server. This work also presents a protocol for securing event information and vehicle authentication using the blockchain mechanism. In this protocol, the registered user accesses the event information securely from the interplanetary file system (IPFS). We incorporate the IPFS, along with blockchain, to store the information in a fully distributed manner. The proposed protocol is compared with the state-of-the-art. The comparison provides desirable security at a reasonable cost. The evaluation of the proposed smart contract in terms of cost (GAS) is also discussed. Index Terms—Authentication, blockchain, interplanetary file system (IPFS), secure information sharing, security.    I. Introduction T HE vision of Industry 4.0 is the digital transformation of industries based on innovative technologies such as cloud and cognitive computing, internet-of-things (IoT), blockchain, machine learning, etc. Industry 4.0 can provide more automation than the previous industrial revolution, and it bridges the gap between the physical and digital world. It helps to develop smart products and create a good ecosystem for them. Presently, various researchers and developers have put their efforts into developing intelligent systems. More smart devices evolve with the introduction of IoT devices, and RS U these smart devices provide a foundation for the smart transportation system (STS). The security and safety of the drivers and efficiency of the transportation system are the main goals behind the STS. An intelligent vehicle equips with devices such as an on-board unit (OBU) and sensors that collect information and sends it to the nearby roadside units ( s) and cloud servers in this system. Traditionally, a transportation system employs a centralized architecture where a trusted third party such as a cloud server stores the required information. The single-point-of-failure (SPoF) and the trust issue are the two significant problems associated with this architecture. Moreover, the number of intelligent vehicles and users is increasing. As a result, the present system and the communication protocols cannot provide sufficient response to the system’s requirement [1]. Researchers utilize the distributed network architecture instead of a centralized architecture to provide trust and fairness in the system. Blockchain is a new distributed system, and Satoshi Nakamoto first implemented the underlying concept of blockchain in the famous bitcoin cryptocurrency [2]. Blockchain technology combines the ledger and consensus concept with peer-to-peer networking and security properties. Its architecture generally consists of six layers starting from the data layer (block structure), the network layer (block and transaction propagation), the consensus layer (block agreement), the incentive layer (reward), the smart contracts layer (business logic), and the application layer (programmable applications) [3]. In this respect, various researchers have attempted to utilize blockchain technology in multiple applications to address current issues. Blockchain technology is combined with the existing vehicular ad-hoc network (VANET) protocols to solve the problems related to data sharing and vehicle authentication. In the present system, data is shared among the intelligent vehicles and RSUs over non-secure channels. As a result, there is a high probability that data may manipulate while sharing it with others. In its continuation, authors [4] presented a protocol for the secure sharing of event details among the RSU and vehicle authentication. They use the blockchain mechanism for secure storage of the event details. We found that their protocol uses a centralized mechanism (i.e., cloud server) for vehicle authentication. In this paper, we improve their protocol without involving a trusted cloud server. The proposed solution uses the interplanetary file system (IPFS) and blockchain to store the event details and vehicle authentication.    Manuscript received November 20, 2020; revised January 25, 2021; accepted March 14, 2021. Recommended by Associate Editor Mohammad Mehedi Hassan. (Corresponding author: Ruhul Amin.) Citation: S. K. Dwivedi, R. Amin, and S. Vollala, “Blockchain-based secured IPFS-enable event storage technique with authentication protocol in VANET,” IEEE/CAA J. Autom. Sinica, vol. 8, no. 12, pp. 1913–1922, Dec. 2021. The authors are with the Department of CSE, Dr. Shyama Prasad Mukherjee International Institute of Information Technology Naya Raipur, Chhattisgarh 492002, India (e-mail: sanjeevdwivedi131988@gmail.com; amin_ruhul@live.com; satya4nitt@gmail.com). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/JAS.2021.1004225 IEEE/CAA JOURNAL OF AUTOMATICA SINICA, VOL. 8, NO. 12, DECEMBER 2021 1913