Five simple strategies are proposed for securing APIs: 1. Validate all parameters from consumers to prevent injection attacks. 2. Apply explicit threat detection such as blacklisting dangerous tags and virus scanning. 3. Enable SSL encryption everywhere to protect against man-in-the-middle attacks. 4. Apply rigorous authentication and authorization using multiple identity factors and OAuth. 5. Use proven security solutions like an API gateway to separate the API implementation from security concerns and provide access control, monitoring, and auditing.