A novel symbolic model for analyzing Internet of Things protocols based on event logic

The unique characteristics of the Internet of Things (IoT) make IoT protocols more vulnerable to security risks compared to traditional security protocols. Formal methods are widely used to analyze and verify the security properties of IoT protocols, but existing methods often fail to address the special security mechanisms required in the complex IoT network environment. A novel symbolic model based on event logic is proposed to implement the comprehensive analysis of secure IoT protocols. The model enhances the description of message flow and match, while also extending the inference capabilities of equivalence and injectivity. Aiming at the pre-shared key, cookie, raw public key, and certificate authority in the IoT protocols, a proof system of the model is proposed to prove the security properties of these mechanisms. To improve efficiency, the match buffer reduction method is also presented to eliminate the redundant proof steps. Formal analysis and verification of protocols, including DTLS, SRTP, CoAP, and PUF, uncover several attacks that violate security properties. The results reveal that the proposed symbolic model is an effective method for the formal analysis and proof of IoT protocols.