Due to the advancement of wireless technology, the Internet of Things (IoT) Device to Device communication for exchanging messages is feasible without human involvement. Authentication and identification of device location are highly essential tasks to verify the originality of IoT Devices (IoTDs) during communication via open channel. In recent days, IoTD registration is processed through the Registration Center Authority (RAC) and this may face single point of failure and insider attack. To solve these problems, we propose a Blockchain based Internet of Things (IoT) Device to Device Authentication Protocol for Smart City Applications using 5G Technology (BIDAPSCA5G). In the proposed protocol, the IoT Devices registration process is performed through private blockchain. The Blockchain has the Distributed Ledger (DL) for storing IoTD credential details, which is accessed only by authenticated entities. In the proposed protocol, mutual authentication was performed without involvement of RAC/Gate-Way-Node (GWN) to reduce the computation cost. The proposed protocol has the additional features such as location based authentication, blockchain based revocation phase and registration of IoTDs, IoTD anonymity property at device level. The security analysis of the proposed protocol was performed through formal security verification using Proverif tool, formal security analysis using Random Oracle Model (RoM) and informal security analysis. The security analysis proved that the proposed protocol is secured against well-known attacks and also it provides better performance as well as additional features when compared to existing protocols.

由于无线技术的发展，无需人工干预，用于交换消息的物联网（IoT）设备到设备通信是可行的。设备位置的身份验证和标识是非常重要的任务，用于在通过开放渠道进行通信期间验证IoT设备（IoTD）的原始性。近年来，IoTD注册通过注册中心机构（RAC）进行处理，这可能会遇到单点故障和内部攻击。为了解决这些问题，我们为使用5G技术（BIDAPSCA5G）的智能城市应用提出了一种基于区块链的物联网（IoT）设备到设备身份验证协议。在提出的协议中，IoT设备注册过程是通过私有区块链执行的。区块链具有用于存储IoTD凭据详细信息的分布式账本（DL），只有经过身份验证的实体才能访问。在提出的协议中，在不涉及RAC /网关-节点（GWN）的情况下执行相互身份验证以减少计算成本。提议的协议具有其他功能，例如基于位置的身份验证，基于区块链的吊销阶段和IoTD的注册，设备级别的IoTD匿名性。通过使用Proverif工具进行正式的安全验证，使用随机Oracle模型（RoM）进行的正式安全分析和非正式的安全分析，对提议的协议进行了安全分析。