Blockchain-based Vehicular Ad-hoc Network (VANET) is widely considered as secure communication architecture for a connected transportation system. With the advent of quantum computing, there are concerns regarding the vulnerability of this architecture against cyber-attacks. In this study, a potential threat is investigated in a blockchain-based VANET, and a corresponding quantum cyber-attack is developed. Specifically, a quantum impersonation attack using Quantum-Shor algorithm is developed to break the Rivest-Shamir-Adleman (RSA) encrypted digital signatures of VANET and thus create a threat for the trust-based blockchain scheme of VANET. A blockchain-based VANET, vehicle-to-everything (V2X) communication, and vehicular mobility are simulated using OMNET++, the extended INET library, and vehicles-in-network simulation (VEINS) along with simulation of urban mobility (SUMO), respectively. A small key RSA based message encryption is implemented using IBM Qiskit, which is an open-source quantum software development kit. The findings reveal that the quantum cyber-attack, example, impersonation attack is able to successfully break the trust chain of a blockchain-based VANET. This highlights the need for a quantum secured blockchain.

翻译：基于区块链的车载自组织网络（VANET）被广泛视为互联交通系统的安全通信架构。随着量子计算的出现，该架构易受网络攻击的脆弱性引发了关注。本研究探究了基于区块链的VANET中潜在威胁，并开发了相应的量子网络攻击。具体而言，利用量子Shor算法开发了量子身份冒充攻击，用于破解VANET中基于RSA加密的数字签名，从而对VANET的信任型区块链方案构成威胁。通过OMNET++、扩展INET库、车辆网络仿真（VEINS）以及城市交通仿真（SUMO），分别模拟了基于区块链的VANET、车联万物（V2X）通信和车辆移动性。基于小密钥的RSA消息加密采用IBM Qiskit（开源量子软件开发工具包）实现。研究结果表明，量子网络攻击（例如身份冒充攻击）能够成功破坏基于区块链的VANET的信任链。这凸显了开发抗量子区块链的必要性。