1. Introduction

2. Surveys articles for the IoT

3. Threat models

4. Countermeasures and formal security verification techniques
4.1. Countermeasures
4.2. Formal security verification techniques

5. Taxonomy and comparison of authentication protocols for the IoT
5.3. Authentication protocols for IoE
5.4. Authentication protocols for IoS

6. Open Issues
6.1. M2M Open Issues
6.2. IoV Open Issues
6.3. IoE Open Issues
6.4. IoS Open Issues
6.5. Pattern recognition and biometrics for the IoT

7. Conclusion