[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?
To enhance security, please ensure you register your authentication factors for multi-factor authentication. We strongly recommend registering two or more authentication methods to prepare for potential device loss or hardware failure.
The following factors can be registered for keio.jp Multi-Factor Authentication
Standard Authentication Factors:
FIDO Security Key (Must be purchased separately by the user)
Authentication Factor for Recovery/Backup:
⚠️ Please note: You cannot log into the keio.jp portal site using phone authentication.
We highly recommend the following methods depending on your device
For Smartphone / Tablet Users: "Passkey (Biometrics/PIN)" or "Okta Verify App"
For PC Users: "Passkey (Biometrics/PIN)"
If you are using a shared/public PC where Passkeys cannot be used, please register the "Okta Verify App" or "TOTP" on your smartphone.
Depending on your destination country and network environment, some authentication methods may become unavailable. To prepare for any unexpected issues, please register multiple authentication methods in advance.
For Smartphone / Tablet Users: We highly recommend combining "Passkey (Biometrics/PIN)" with either "Okta Verify App" or "TOTP".
For PC Users: We recommend using "Passkey (Biometrics/PIN)".
For Those Acquiring a Device Locally (Overseas): You can authenticate by either registering a "Synced Passkey" beforehand, or by registering a "FIDO Security Key" as a keio.jp authentication factor and bringing it with you to your destination.
📌 Notes:
Synced Passkeys include Microsoft Authenticator/Password Manager, iCloud Keychain, and Google Password Manager (using a non-keio.jp Google account).
FIDO Security Keys must be purchased separately by the user.