> ## 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.

# ID トークンの署名鍵の変更

> ID トークンの署名鍵の変更手順を説明します。

<Info>
  For **Authlete 2.x** documentation, see [2.x version](/ja/v2/configuration-reference/tokens-and-claims/changing-signing-key-for-id-tokens).
</Info>

## 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

In the Authlete console, go to your service settings, under `Key Management > JWK Set`. You will then need to register a JWK set document in the `JWK Set Content` field.

You can refer to the following article for instructions on how to generate a JWK :

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

After the registration, select the value of "kid" of this keypair set ("1" in this example) for the `ID Token Signature Key ID` field.

![so-jwkset](https://storage.googleapis.com/authlete-website/resources/kb/changing-signing-keys-for-id-token/service-settings.png)

*ID Token Signature Key ID*

##  Client settings

In the Authlete console, go to your client settings, under `Tokens and Claims > ID Token`. You will then need to select the `ES256` parameter in the `ID Token Signature Algorithm` field, in order for the Authlete service to issue an ID token signed with the new key.

![cd-idTokenSigAlg](https://storage.googleapis.com/authlete-website/resources/kb/changing-signing-keys-for-id-token/client-settings.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.