JWT
also: JSON Web Token
JWT (JSON Web Token) is a compact, self-contained token format used to securely transmit information between parties, commonly used for authentication and authorization in web applications and APIs.
JWT is a stateless authentication mechanism that encodes claims (user information) into a digitally signed token. It consists of three base64-encoded parts separated by dots: a header (token type and algorithm), a payload (claims/data), and a signature (cryptographic hash).
Example JWT: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIn0.dozjgNryP4J3jVmNHl0w5N_XgL0n3I9PlFUP0THsR8U
In Linux environments, JWTs are often used by web servers (nginx, Apache with modules), containerized applications, microservices, and API gateways to validate requests without maintaining server-side session storage. The signature ensures the token hasn't been tampered with, making it useful for stateless, distributed architectures.
JWTs are commonly implemented in Go, Node.js, Python, and Java applications running on Linux servers, and tools like jq can be used to inspect token contents from the command line.