The Internet of Things (IoT) comprises many devices distributed across administrative domains. The lack of trust among these cross-domain entities poses significant risks to data security and privacy during information exchange. To address these challenges, a solution that combines certificateless public key cryptography with blockchain technology has been proposed. This approach enhances data security and privacy protection through advanced technical methods. During cross-domain information interactions, the risk of data breaches and privacy leaks increases significantly because of the large volume of sensitive information being generated and stored. Authentication, a critical component in securing IoT communication, plays a vital role in ensuring system security. However, traditional authentication mechanisms often impose high computational and communication overheads, which can be particularly burdensome for resource-constrained IoT devices. To overcome this issue, edge computing has been integrated into IoT systems. By leveraging the powerful computing and storage capabilities of edge nodes and incorporating technologies such as blockchain, elliptic curve-based certificate-less encryption, and the ECDSA digital signature algorithm, the proposed scheme helps mitigate resource limitations. As a result, IoT devices can perform security operations, including authentication, more efficiently and effectively.