What are the common authentication methods in REST APIs?

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Here are the most common authentication methods used in REST APIs, along with brief descriptions: 1. Basic Authentication How it works: Sends username:password encoded in Base64 via the Authorization header.Example: Authorization: Basic dXNlcjpwYXNzPros: Simple, widely supported.Cons: Insecure without HTTPS; credentials are sent with every request. 2. Bearer Token Authentication (OAuth 2.0) How it works: Sends a token (usually a JWT or opaque token) in the Authorization header.Example: Authorization: Bearer eyJhbGciOi...Pros: Secure, stateless, supports token expiration and scopes.Cons: Requires token issuance and management. 3. API Key Authentication How it works: Sends a static API key with each request (usually in a header, query, or body).Example: x-api-key: abc123xyzPros: Easy to implement.Cons: Harder to manage securely, no user context, no expiration by default. 4. JWT (JSON Web Token) How it works: A signed token that contains claims (user info, roles, etc.), sent via Authorization: Bearer.Pros: Self-contained, stateless, fast validation.Cons: Tokens can’t be revoked easily without extra mechanisms (e.g., token blacklists). 5. OAuth 2.0 with Authorization Code Flow How it works: Standard for delegated access (e.g., login with Google/Facebook). Client gets a token after user consents.Use case: Public APIs, third-party app access.Pros: Very secure; supports access and refresh tokens.Cons: More complex to implement. 6. Digest Authentication How it works: Sends a hashed username/password instead of plain text.Pros: More secure than basic auth.Cons: Deprecated in many modern APIs; rarely used today. 7. Mutual TLS (mTLS) How it works: Both client and server authenticate each other using certificates.Pros: Very secure, prevents man-in-the-middle attacks.Cons: Complex setup, less common in public APIs. Summary Table Method Secure w/ HTTPS Stateless Supports User Roles Easy to Implement Basic Auth (without HTTPS) Yes NO Yes Bearer Token (JWT) Yes Yes Yes Yes API Key (without HTTPS) Yes NO Yes OAuth 2.0 Yes Yes Yes NO (complex) mTLS Yes Yes NO NO (complex)

Method	Secure w/ HTTPS	Stateless	Supports User Roles	Easy to Implement
Basic Auth	(without HTTPS)	Yes	NO	Yes
Bearer Token (JWT)	Yes	Yes	Yes	Yes
API Key	(without HTTPS)	Yes	NO	Yes
OAuth 2.0	Yes	Yes	Yes	NO (complex)
mTLS	Yes	Yes	NO	NO (complex)

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What are the common authentication methods in REST APIs?

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1 Answers

1. Basic Authentication

2. Bearer Token Authentication (OAuth 2.0)

3. API Key Authentication

4. JWT (JSON Web Token)

5. OAuth 2.0 with Authorization Code Flow

6. Digest Authentication

7. Mutual TLS (mTLS)

Summary Table