# Blockchain Application in Internet of Vehicles: Challenges, Contributions and Current Limitations
## 4 Discussion
### Blockchain Contributions in IoV-Assisted Smart Grid
This is because of the possibility of blockchain synchronization and replication between all involved peer nodes to the network. As a result, even if one or more nodes fail, the IoV services can continue to operate normally. Blockchain technology is based on advanced cryptographic algorithms to ensure common security and privacy features [74]. In particular, blockchain promotes the greater security and privacy within IoV networks through encryption. Specifically, numerous studies have used blockchain as a privacy-preserving mechanism for privacy protection and energy storage [75], trusted data sharing [76], identity management [77], prevention of malicious attacks, secure tariff decision [78], protected V2G payment mechanisms [79; 80], as well as authentication [81] and encrypted vehicular communication [82; 83]. Moreover, the decentralized nature of blockchain storage provides safe recording of transactions that occur within a car, and from a car to its surroundings (e.g., other cars or the infrastructure). Transactions within a car are considered (a) any communications transmitted between the various components of a car and (b) information related to the cars' state. Whenever a state is recorded on the blockchain, every component in the IoV network may analyze prior states and messages to determine if the new state constitutes a valid and secure state change. **Contribution 3--Immutability:** The integration of blockchain allows increased security for the IoV. The applied cryptographic techniques combined with the consensus mechanism provide data immutability. Once an energy transaction has been included in the blockchain network, it would be very hard to alter this transaction for illegitimate purposes or to delete the transaction, resulting in a very secure and robust system for IoV services and applications [84; 85]. Blockchain's immutability characteristic may assist in avoiding data tampering and manipulation, as well as enabling reliable auditing. **Contribution 4--Transparency:** Public blockchain is permission-less and is typically open to all entities. Thus, the use of public blockchain potentially opens the door to full access to the data stored in the blockchain and enhances the transparency of the IoV ecosystem. One of the most significant promises of blockchain technology, which provides a completely auditable and legitimate record of transactions, is the ability to provide information transparency. Blockchain ensures transparency by storing data in such a way that it cannot be modified without recording the alterations [86]. Within the IoV environment, blockchain technology will be used to enhance openness in global EV supply chains for raw materials and parts, allowing for their seamless traceability. Transparency is especially crucial when it comes to the usage of such valuable finite resources, most notably EV batteries. This is where BMW has been trying to improve transparency in raw material extraction [87]. Volvo [88] and Volkswagen [89] have also announced their own initiatives that will allow them to accurately trace the origin of their cobalt using the blockchain. **Contribution 5--P2P trading, sharing, and communication:** Blockchain allows peer-to-peer trading, sharing and communication between two entities. Recipients and providers of IoV services can communicate directly in such a network. This functionality is very beneficial in IoV environments, since it allows cars and RSUs to safely share data and resources [90; 91]. Since the involved actors in an IoV network do not need to interact with any mediator, the final outcome is low-latency applications and services [91]. Moreover, due to the benefits of security, decentralization and trust, blockchain, in which every transaction is recorded in a verifiable and permanent manner, has proven its ability to safeguard energy trading [92]. **Contribution 6--Resource Sharing:** The IoV provides the potential to create a cooperative resource-sharing network for both static and moving vehicles.