Notezilla uses Microsoft's Azure cloud system, which is highly secure. You can read about it over here: https://azure.microsoft.com/en-us/support/trust-center/security/ . Also we are using SSL to securely transfer notes.
Notezilla lets you to password protect a note so that it cannot be read or edited. Also, the note is encrypted so that it cannot be read from the database too.
Watch this video to learn more:
A single master password is used to lock/unlock any note. If you are locking a note for the first time after installing Notezilla , you will be requested to set the master password. You can change this master password using Preferences.
Locking a Note
Right click on the note title or note toolbar and choose Lock menu item to lock the note. A locked note is always rolled up so that its content cannot be seen or edited.
Unlocking a Note
To unlock a locked note, click on the lock icon in the note toolbar.