keio.jp Multi-Factor Authentication Setup Manual

Phone number

[Important] Notice

Phone authentication (SMS/Voice) carries risks such as interception of verification codes and unauthorized call forwarding. 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/Voice) factors and recommends using alternatives like Passkey (Biometrics/PIN).

If you currently use Phone (SMS/Voice) as your primary Multi-Factor Authentication (MFA) method, please register and switch to "Passkey (Biometrics/PIN)" or "Okta Verify App" as soon as possible.

Although Phone (SMS/Voice) authentication is expected to remain available after June 1, 2026, as a backup option for situations such as device replacement or malfunction, its regular use will be deprecated to enhance security. (Please note that this method may be discontinued in the future.)

What Is SMS Authentication and Is It Secure?

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

Content

Initial Setup Guide (Phone)

Phone number　Setup Video Guide

❓FAQ

Initial Setup Guide (Phone)

IInitial Setup Guide (Phone)

　Setup: Smartphone

Setup Guide

　Setup: PC & Smartphone

Setup Guide

Features :

You will receive a 5 or 6-digit one-time code via SMS or voice call, valid for a limited time only. Enter this code to complete authentication. （Reference:：How to Log In）
The phone number registered here will also be used for "Additional Setup."

Notes :

Please ensure that spam filters or "Silence Unknown Callers" features are disabled.

For users without a phone number :

Please refer to "Additional Setup" and register at least two authentication factors as a backup.

Planning to go abroad :

Please refer to "Additional Setup" and register two or more authentication factors. We highly recommend using "Biometric Authentication" as your primary method. For smartphone users, we recommend setting up "Biometric Authentication" and installing the "Okta Verify App" as well.

If you have completed phone registration :