In　this　paper,　a　cyber-physical　digital　signature　creation　method　and　a　resilient　load　frequency　control　approach　are　proposed　to　improve　the　security　of　the　existing　SCADA　protocols　used　in　the　load　frequency　control　of　interconnected　power　systems.　In　specific,　the　dynamic　model　of　the　power　system　is　used　to　predict　the　future　states　of　the　system　and　the　statistics　of　a　number　of　future　states　are　calculated　and　used　as　the　dynamic　hash　to　determine　the　integrity　of　the　data　communicated　between　remote　telemetry　units　and　the　power　system　SCADA　control　center.　The　proposed　algorithm　has　inherently　the　cyber-physical　characteristics　and　enhanced　robustness　to　collisions　without　adding　a　larger　overhead　to　the　message　frame　of　the　packets　in　current　SCADA　protocols.　To　compensate　for　the　possible　performance　degradation　and　instability　of　the　power　system　caused　by　corrupted　data,　a　model-based　resilient　load　frequency　controller　is　designed　for　the　smart　grid.　The　maximum　interval　between　two　consecutive　feedback　updates　in　the　model-based　control　scheme　is　obtained　for　securing　the　stability　of　the　power　system.　The　investigation　of　three　types　of　integrity　attacks　on　a　two-area　power　system　shows　that　the　proposed　model-based　digital　signature　attack　detection　scheme　is　able　to　detect　even　a　little　inconsistency　of　the　communicated　data.　By　using　the　designed　resilient　load　frequency　controller,　the　stability　and　dynamic　performance　of　the　smart　grid　are　guaranteed.