[Important] Notice

End of Regular Use for Phone/SMS Authentication

Global security standards warn of the risks of "unauthorized third-party use" via phone/SMS authentication due to the potential for verification code interception or communication eavesdropping. Consequently, transitioning to more secure authentication methods has been highly recommended in recent years.

Okta, the provider of the keio.jp authentication platform, also deprecates Phone/SMS authentication and strongly recommends alternatives like "Passkey (Biometrics/PIN)."

To enhance security and improve user convenience, the regular use of Phone/SMS authentication will be phased out starting August 2026.

For the detailed timeline, please check the "Discontinuation Schedule for Regular Use of Phone/SMS Authentication" section below on this page.

⚠️ Please Note:

Even after the end of its regular use, you can still register and use Phone/SMS authentication exclusively as a recovery method. However, please be aware that you will no longer be able to log into the keio.jp portal site using Phone/SMS authentication.

Please ensure you register an alternative authentication factor other than Phone/SMS authentication before your respective discontinuation date.

To configure your multi-factor authentication, please refer to the "keio.jp MFA Setup Manual."

What Is SMS Authentication and Is It Secure?

• https://www.okta.com/blog/identity-security/sms-authentication/