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）被广泛认为是互联交通系统中一种安全的通信架构。随着量子计算的出现，人们开始担忧该架构面对网络攻击时的脆弱性。本研究调查了基于区块链的VANET中一个潜在威胁，并开发了相应的量子网络攻击方法。具体而言，我们利用量子Shor算法设计了一种量子伪装攻击，旨在破解VANET中采用Rivest-Shamir-Adleman（RSA）加密的数字签名，从而对VANET基于信任的区块链方案构成威胁。我们分别使用OMNET++、扩展的INET库、车辆网络仿真（VEINS）以及城市交通仿真（SUMO）对基于区块链的VANET、车联网（V2X）通信及车辆移动性进行了模拟。同时，采用开源量子软件开发工具包IBM Qiskit实现了基于小密钥RSA的消息加密。研究结果表明，量子网络攻击（例如伪装攻击）能够成功破坏基于区块链的VANET信任链。这凸显了构建量子安全区块链的必要性。