What is refresh token?

A refresh token is a type of token that is used to obtain a new access token. Access tokens have a limited lifetime, after which they expire and are no longer valid. When an access token expires, the user would have to go through the authentication process again to get a new one. This can be inconvenient, especially in cases where the user has been actively using the application.

To solve this problem, refresh tokens were introduced. A refresh token is a long-lived token that can be used to obtain a new access token without going through the authentication process again. Refresh tokens are typically issued along with access tokens, and are stored securely on the client. When the access token expires, the user can use the refresh token to request a new access token from the authorization server.

Refresh tokens have several benefits:

• They provide a convenient way for users to keep using the application without having to re-authenticate.
• They allow the application to obtain new access tokens without having to store the user’s credentials.
• They provide a way to revoke access to the application, by revoking the refresh token on the authorization server.

It’s important to store refresh tokens securely, as they provide a way to obtain new access tokens. If a refresh token is compromised, an attacker could use it to get access to the user’s data. To mitigate this risk, refresh tokens are typically stored securely on the client and are encrypted. Additionally, refresh tokens should be rotated regularly, to reduce the risk of unauthorized access if a token is compromised.