There is no one-size-fits-all secure design for an IoT (or any other) system. Some IT systems operate in a threat environment that requires them to operate offline and air-gapped from any other network. Even these systems face novel attack methods, such as social engineering and insider threats.

No system is ever 100% secure; however, we can define goals for a secure, available, and resilient system that reliably mitigates attacks from all but the most determined adversaries.

Here we define some of these goals, and describe ways to achieve them within your IoT systems. Tailor each of these as necessary to fit your unique system requirements and threat profile.