Yahoo! JAPAN ワンタイムパスワード is a software token application that supports the Yahoo! JAPAN security feature. It generates a one-time password (code) that changes every 30 seconds and is valid only once. By setting up the "One-Time Password," the user adds an extra layer of authentication to their Yahoo! JAPAN ID and password.

This application is easy to use and provides a smooth authentication experience. Users only need to launch the app to check the code, and even if someone else knows the password, they cannot log in without the code. Yahoo! JAPAN ワンタイムパスワード is available for free and uses RFC standard HOTP (HMAC-based One-Time Password Algorithm). However, please note that this application will be discontinued on March 31, 2021. Users can opt for SMS or email as an alternative method to receive one-time passwords after that date.