# Evolution of V2X Communication and Integration of Blockchain for Security Enhancements
## 6 Blockchain Potential in V2X Networks
### Blockchain as a Security Mechanism in V2X
#### 6.2.1 Motivation for Using Blockchain in V2X  
Blockchain can fulfill the above requirements by building trust among the peer vehicular nodes in a trustless environment without the presence of a central authority. One of the main features of blockchain is decentralization that maintains and stores the event information in a transparent and immutable manner, and transmits the event information in a timely, secure, and distributed way. The decentralized validation feature is used for rapid validation of exchange messages based on the consensus protocol that helps in timely management of immutable history of accidents or traffic events in vehicular networks. The co-participation of all the vehicles in creating the block based on consensus mechanism makes it more resilient. The inherent features of the blockchain help to obtain the information traceability and transparency in vehicular networks. In case of accident events, the traffic police, law and enforcement department, and the insurance companies can utilize the information stored in the blockchain to resolve the particular events. The participating vehicles can use the event information stored in the blockchain and act accordingly, because the information stored in the blockchain can be considered as the ground truth.  
Hence, blockchain provides a series of features, such as protecting the security and privacy of vehicular nodes against different types of advanced cyberattacks. This guarantees resilience and provides immutability of information despite unknown attacks on the vehicular networks. As a number of vehicular nodes join the blockchain networks, they guarantee the resilience of the blockchain system. Even though certain vehicles go offline or become unavailable due to malicious code, malfunctions in vehicles, or cyber threats, the original blockchain would still be available to other member vehicular nodes. All events or transactions in the blockchains are time stamped and authenticated with private keys. The vehicle owners can securely trace the history of transactions and trace events or transactions at any particular time. This tracing capability prevents possible threats or malicious messages in V2X communications, thus securing the network against deceptive attack. An attacker may attempt to de-anonymize the vehicle identity or track the vehicle's private data, which might jeopardize the privacy of the user. The blockchain can secure the anonymity of the user by using the hash function and encrypting sensitive information using asymmetric cryptography. This function also helps each vehicular node to track the provenance or the source of the data. Moreover, the vehicles cannot collude with other neighbor vehicles while generating the hash functions, which prevents the blockchain network from being compromised by a large-scale attack, and provides more security. A lot of research has been done on integrating blockchain into intelligent vehicles for security purposes [66; 67; 68; 69]. Because of these capabilities, the use of blockchain as a security mechanism is increasing in V2X networks.