I run Linux on my netbook with an encrypted home directory (decrypted when I log in). One idea I had (partly from Cory Doctorow's Little Brother) was to have a password that I could enter which would login to a fake user account while performing a command (e.g trashing the contents of the disk drive or changing the encryption passwords to something random and very long).
Any ideas how to do this? (Answers involving obscure kernel modules etc are welcomed, though as always a nice command line utility might be a bit nicer! I especially like to have the same username but not the same password: user bob signs in with password ABC and gets logged in, but user bob signs in with password 123 and gets his stuff deleted.)
Best Answer
There is now a GPLv2-licensed PAM-module, that does exactly, what you wish. It allows the same account to login to the same Unix box with different passwords depending on what the user wishes done upon login. Interestingly enough, the author mentions the same book in his description of the module.
You write your own scripts, which will be associated with the different passwords -- from automatically attaching an encrypted filesystem upon entering a "safe" one to automatically wiping the same upon entering the "panic" one. And anything in between.
I wish, something similar were available from e-mail providers and various social media services -- to hide certain mailboxes, images, etc. when the user logs in with a special password. Maybe, we'll come to that too some day...