APIs play a crucial role in cybersecurity but can also pose security risks if not designed properly.Cloud Native Data Security with OAuth emphasizes the importance of architectural solutions for data security in APIs.The book explains scalable zero-trust architecture principles and implementation without vendor dependence.OAuth 2.0, specified by RFC 6079, is essential for API-first security scalability and extensibility.Access tokens, integral to OAuth, validate API calls, making cloud-native security platform-agnostic.OAuth architecture involves Resource Owner, Resource Server, Client, and Authorization Server roles in securing APIs.Zero-trust architecture, as discussed, is crucial for addressing internal and external threats in modern API security.Components of a zero-trust system include an authorization server and a policy engine for comprehensive security governance.Access tokens like JWTs are the backbone of zero-trust authorization, providing verified security context for API transactions.Implementation of zero-trust authorization in OAuth involves validation of digital signatures and key management strategies for secure API operations.