<p>The Industrial Internet of Things (IIoT) is increasingly being adopted by factories, making the security of communication ever more significant. In order to realize secure communication between users and smart devices in IIoT, researchers have proposed numerous schemes, but these schemes are difficult to meet the needs of IIoT for security, efficiency, and low latency. In this paper, we design an efficient fog-assisted smart factory anonymous authentication protocol that is resistant to physical device capture attacks and that can fulfill these requirements. Our proposed protocol considers the special case of IIoT devices with limited resources and the requirement for low latency. It introduces fog computing, employs lightweight cryptography, and designs an authentication process with less information exchange. And noting the security of physical devices, which is ignored by many protocols, we use Physical Unclonable Functions (PUF) to protect physical devices from physical device capture attacks. We have analyzed the protocol’s security and proved that the protocol is secure under the ROR model and can achieve the proposed security requirements. Finally, by comparing the protocol with other protocols, it is also proved that the protocol has better security features along with commendable performance.</p>