How can you implement refresh tokens to improve the security and usability of your JWT-based authentication system?
.NET interview question for Advanced practice.
Answer
Implement a refresh token mechanism where a short-lived access JWT is paired with a long-lived refresh token.
Explanation
Refresh tokens provide a way to maintain user sessions without using long-lived access tokens. A long-lived refresh token is used to obtain new, short-lived access tokens. This improves security by minimizing the exposure of the access token, while improving usability by not requiring frequent re-logins. Extending the JWT expiration (A) is insecure. Storing tokens in local storage (C) is vulnerable to XSS. A complex algorithm (D) doesn't solve the problem of token lifetime.