As of Sept. 17, 2013, Twitch now requires that you log into IRC using an OAuth token instead of your plaintext password or hash for additional security.

Use this tool to generate an OAuth token to authenticate with Twitch IRC. The entire presented token (including "oauth:") can be substituted for your old password in your IRC client.

To revoke access, disconnect "Twitch Chat OAuth Token Generator" from your Twitch settings.

(Technical: This application uses the implicit grant flow for the Twitch API to retrieve your token. This means that your token is only ever visible to your browser and not our server.)