> ## Documentation Index
> Fetch the complete documentation index at: https://developers.authlete.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Changing signing key for ID tokens

> Guide on changing a signing key for ID tokens by configuring both a service of Authlete and a client registered to the service.

<Note>
  This page is for **Authlete 2.x**. For current (3.0) documentation, see [this page](/configuration-reference/tokens-and-claims/changing-signing-key-for-id-tokens).
</Note>

## Overview

This article explains an example on changing a signing key for ID tokens. In order to have Authlete to sign an ID token with the new key, you may have to configure both a service of Authlete and a client registered to the service.

## Service settings

Register a JWK set document to "JWK Set Content" section in Service Settings. See the following article for instructions.

* [JWK set settings for an Authlete service](/configuration-reference/key-management/jwk-set-settings-for-an-authlete-service)

After the registration, add the value of "kid" of this keypair set ("1" in this example) to "ID Token Signature Key ID" section in the same "JWK Set" tab.

<img src="https://mintcdn.com/authlete/VMCNat22v2IOj3-M/img/kb/en/oauth-and-openid-connect/id-tokens/so-jwkset.png?fit=max&auto=format&n=VMCNat22v2IOj3-M&q=85&s=2495f30771a63641b13f89e0ed4a4e60" alt="so-jwkset" width="996" height="1076" data-path="img/kb/en/oauth-and-openid-connect/id-tokens/so-jwkset.png" />

*ID Token Signature Key ID*

##  Client settings

In order for the Authlete service to issue an ID token signed with the new key (signature algorithm: ES256), choose "ES256" on "ID Token Signature Algorithm" section in Client Settings.

<img src="https://mintcdn.com/authlete/VMCNat22v2IOj3-M/img/kb/en/oauth-and-openid-connect/id-tokens/cd-idTokenSigAlg.png?fit=max&auto=format&n=VMCNat22v2IOj3-M&q=85&s=9e71d3daca3d719ba45a063e44445145" alt="cd-idTokenSigAlg" width="996" height="807" data-path="img/kb/en/oauth-and-openid-connect/id-tokens/cd-idTokenSigAlg.png" />

*ID Token Signature Algorithm*

With the settings above, Authlete will be using the ES256 key (identified by "kid=1") to sign ID tokens for the client.