[Important] Notice
To enhance security, multi-factor authentication (MFA) will be mandatory for all students, faculty, and staff at keio.jp starting June 1, 2026. As a result, we are reviewing the routine use of "Phone (SMS/Voice Call)," which may be deprecated or discontinued in the future.
The use of phone-based authentication (SMS/Voice Call) carries risks such as interception of verification codes or unauthorized call forwarding. In recent years, a transition to more secure authentication methods has been highly recommended. Okta, the provider of the keio.jp authentication infrastructure, also deprecates phone factors (SMS/Voice Call) and recommends the use of passkeys and other secure methods. If you are currently using "Phone (SMS/Voice Call)" as your primary MFA method, please register an additional "Passkey (Biometric Authentication)" or "Okta Verify" as soon as possible and migrate your login procedure.
As of May 2026, "Phone (SMS/Voice Call)" remains available as a backup for situations such as device replacement or hardware failure.
What Is SMS Authentication and Is It Secure?
https://www.okta.com/blog/identity-security/sms-authentication/
First-time registration of MFA (Multi-Factor Authentication)
To enhance security, please register your authentication factors for multi-factor authentication.
We strongly recommend registering two or more authentication methods in case of loss or malfunction.
First, register your phone number (recommended)
If you have a smartphone or mobile phone, please register your phone number as your primary authentication factor first.
As long as your phone number remains the same, it can still be used even after changing your device. Registering your phone number is the most reliable way to prevent login issues.
For phone authentication, you can choose between "SMS (Text Message)" or "Voice Call."
Note: Regarding Unavailable Phone Numbers or International Travel
Multiple phone numbers can be registered simultaneously.
International phone numbers are supported; however, depending on the SMS/Voice authentication system used by Okta, verification codes may not be delivered to numbers outside of Japan (+81).
If you do not receive the verification code within approximately 3 minutes, SMS or phone authentication may not be supported for that number.
If you do not have a phone number or cannot use your Japanese number while abroad, please refer to [STEP 2: Additional Setup(for Daily Use）] and register two or more authentication factors.
Alternative authentication factors: Biometric Authentication, Okta Verify App, TOTP, etc.