API security focuses on protecting the interfaces that allow different software systems to communicate with each other. As APIs expose application logic and sensitive data, they are attractive targets for attackers who exploit vulnerabilities such as broken authentication, excessive data exposure and injection attacks.
Robust API security requires a multi-layered approach including strong authentication (OAuth 2.0, API keys), encryption in transit (TLS), input validation, rate limiting and comprehensive logging. With the rise of microservices and cloud-native architectures, API security has become a critical component of both ISO 27001 technological controls and SOC 2 trust service criteria.