If you are a Microsoft OneNote user, you must have used password protected section. This section of OneNote allows you to store some important notes in a password protected environment. OneNote web app got updated today with support for accessing password-protected sections.
Accessing password-protected sections was one of the most requested features for the OneNote Web App. Enabling this feature allows you to access your sensitive information from anywhere. After opening a password-protected section, you can edit its contents, change the section color, create new pages, and even edit the section name.
After using a password-protected section, you can manually re-enable password protection by selecting Lock Section in the right click menu. Otherwise the section can automatically lock itself after 10 minutes of idle time. This feature is immediately available on SkyDrive, Office365, and the Office Web Apps Server in the latest update.
Source: Office Blog