The situation is that: For the encrypted home directory, any passphrase less than 10 characters is useless at all. If someone physically get the harddisk, the data and the other sensitive password stored in keyring can be leaked as a cracking machine can attempt trillion passwords per second. So I prefer a long passphrase, which typed only once a day.
For the use of a laptop, however, the screensaver can be triggered very often and it sleeps sometimes in which entering long password just waste time. In this situation, fast password attempts is not possible. I just dont want random guy touch it, so I prefer a short password. Also, a laptop is more likely to loss, so a stronger encrypted passphrase is even deserved.
On the other hand, forgetting passphrase for login will loss all data so it changes rarely. In contrast, forgetting screensaver password makes no harm as it should be able to reset by relogin, so it encourages to change often.
This is a typical usage pattern, so I want to set a different password for screensaver? Is there any programs to do that? Any script? Thanks
Edit
I have tested the xscreensaver, and in the manual, it says:
If you change your password after xscreensaver has been launched, it will continue using your old password to unlock the screen until xscreensaver is restarted. On some systems, it may accept both your old and new passwords.
So I would think there is a way to use a different password.