I’ve always been fascinated by the balance between 𝑺𝒊𝒎𝒑𝒍𝒊𝒄𝒊𝒕𝒚 𝒂𝒏𝒅 𝑷𝒐𝒘𝒆𝒓 𝒊𝒏 𝑻𝒆𝒄𝒉𝒏𝒐𝒍𝒐𝒈𝒚. Some tools, like JSON Web Tokens, manage to do so much with so little: compact, elegant and quietly essential 🖤

𓎆

Let’s unravel what makes JWTs so indispensable.

𓎆

→ What is JWT?

JWT is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object.

Structure: Composed of three parts separated by dots (.) - Header, Payload, and Signature.

𓎆

→ Components of JWT

Header: Contains metadata about the token, typically the type of token and the signing algorithm.json

{ "alg": "HS256", "typ": "JWT" }

Payload (Claims): Contains the actual data. This includes registered claims (like iss, exp, sub), public claims, or private claims.json

{ "sub": "1234567890", "name": "John Doe", "iat": 1516239022 }

Signature: Ensures the token hasn't been tampered with. It's created by encoding the header and payload, then signing with a secret or private key.

𓎆

→ How JWT Works

Token Creation: The server generates a JWT when the user logs in.

Token Transmission: This token is sent to the client (e.g., browser).

Token Usage: For subsequent requests, the client sends the JWT, which the server verifies before granting access.

𓎆

→ Advantages

Stateless: Servers don't need to store session information.

Scalability: Ideal for distributed systems and microservices.

Flexibility: Can be used across different domains.

𓎆

→ Security Considerations

Encryption vs Signing: JWTs are signed, not encrypted by default. Use JWE (JSON Web Encryption) for end-to-end encryption.

Token Expiry: Always set an expiration time to limit token lifetime.

Secure Transmission: Use HTTPS to prevent token interception.

𓎆

→ Implementing JWT

Backend: Use libraries like jsonwebtoken in Node.js or PyJWT in Python.

Frontend: Store tokens in HTTP-only cookies or local storage with caution.

𓎆

Hey! I'm Nina, a software tech lead sharing fresh visuals engineers love through my newsletter Sketech. Follow to Decode Complexity ❤️ sketechnews.substack.com