In　the　Industrial　Internet　of　Things　(IIoT)　landscape,　machine-to-machine　(M2M)　communication　is　extensively　employed,　allowing　IoT　devices　to　interact　autonomously　without　human　intervention.　Despite　its　benefits,　M2M　communication　faces　substantial　challenges　related　to　privacy　and　data　security,　particularly　due　to　malicious　attacks　within　the　network　and　data　transmission　over　insecure　channels.　Existing　security　solutions　often　incur　high　computational　costs,　making　them　impractical　for　resource-constrained　IoT　devices.　Furthermore,　many　of　these　solutions　remain　vulnerable　to　replay　attacks,　denial-of-service　(DoS)　attacks,　and　fail　to　provide　sufficient　anonymity,　limiting　their　real-world　applicability.　To　tackle　these　issues,　we　propose　a　secure,　lightweight　authentication　protocol　leveraging　Physical　Unclonable　Functions　(PUFs)　and　cryptographic　hash　functions,　aimed　at　safeguarding　M2M　communications　within　IIoT　environments.　Our　protocol　effectively　verifies　participant　legitimacy　and　secures　data　transmission　without　imposing　significant　computational　burdens.　Informal　analyses　indicate　that　the　proposed　protocol　offers　enhanced　security　and　performance　compared　to　existing　approaches.　©　2024　Copyright　held　by　the　owner/author(s).　Publication　rights　licensed　to　ACM.