Explain OAuth and JWT. How would you use them to secure APIs in microservices?

• OAuth: OAuth is an open standard for access delegation, commonly used to grant

limited access to third-party applications without exposing user credentials. OAuth

provides a token-based approach to secure APIs.

• Authorization Flow: OAuth typically involves three parties—Resource

Owner (user), Client (application), and Authorization Server (auth

provider)—that work together to issue access tokens.

• JWT: JSON Web Tokens (JWT) are compact, URL-safe tokens used to securely

transmit information between parties. JWT tokens are signed and optionally

encrypted to protect the integrity and confidentiality of the data.

• Structure: JWT consists of three parts—Header, Payload, and Signature.

How to use them in microservices: