2022-08-12
1634
Fernando Doglio
72
Aug 12, 2022 ⋅ 5 min read

How to secure a REST API using JWT authentication

Fernando Doglio Technical Manager at Globant. Author of books and maker of software things. Find me online at fdoglio.com.

Recent posts:

Exploring the new Chakra UI MCP Server

Discover how the Chakra UI MCP server integrates AI into your editor, reducing context switching and accelerating development by fetching real-time documentation, component data, and code insights directly in-app.

Emmanuel John
Oct 9, 2025 ⋅ 6 min read
Build AI Agent Without Langchain JS

LangChain.js is overrated; Build your AI agent with a simple fetch call

Skip the LangChain.js overhead: How to build a Retrieval-Augmented Generation (RAG) AI agent from scratch using just the native `fetch()` API.

Ikeh Akinyemi
Oct 9, 2025 ⋅ 3 min read
the replay october 8

The Replay (10/8/25): Data enrichment, CSS is back, TypeScript 5.9

Discover what’s new in The Replay, LogRocket’s newsletter for dev and engineering leaders, in the October 8th issue.

Matt MacCormack
Oct 8, 2025 ⋅ 30 sec read
Goodbye, messy data: An engineer’s guide to scalable data enrichment

Goodbye, messy data: An engineer’s guide to scalable data enrichment

Walk through building a data enrichment workflow that moves beyond simple lead gen to become a powerful internal tool for enterprises.

Alexandra Spalato
Oct 8, 2025 ⋅ 6 min read
View all posts

7 Replies to "How to secure a REST API using JWT authentication"

  1. You swapped the meaning of the issuer and the subject. The issuer is the authentication server which issued the token (usually a URI). The subject is the user being authenticated.

  2. this is best article, I have read every with context of explaining. you have explaines evrythig nicely and to the point. Thank you very much.

  3. That is a nice explanation! What about the need of changing the shared key, in case of symmetric encryption and signing? What option is there?
    I think the asymmetric encryptions would not be feasible for many client apps and even those keys have to be changed after some time!

  4. What problem does this solve that isn’t solved by, for example, Basic Authentication with a simple shared secret? How do you revoke access for a live JWT?

  5. Overall good explanation with the exception of having the JWT-secret known to the client.
    The only validation of the JWT that the client should do is to check the expiration-date of the JWT before using it.
    If it’s expired, then the client can go the route of re-authenticating the user.

    The back-end (API) is the only place that should know the JWT-secret so that it can verify if any JWT it receives was actually created by the back-end and was not tampered with.

  6. Great article. Note that JSON Web Tokens come in two flavors (or structures) – JSON Web Signature (JWS) and JSON Web Encryption (JWE). From the RFC: “JWT – A string representing a set of claims as a JSON object that is encoded in a JWS or JWE, enabling the claims to be digitally signed or MACed and/or encrypted.”

    The JWE compact serialization results in 5 parts, JWS is 3 parts.

Leave a Reply