XSecureLock vs XScreenSaver

• Authentication and screen saving in separate processes so that crash of these processes will not unlock the screen.
  • The main process is kept minimal for easy auditing.
  • The main process regularly refreshes the screen grabs (just in case).
  • The main process regularly brings its window to the front, to avoid leaking notifications.
  • The main process resizes its window to the size of the root window, avoid leaking information by attaching a secondary display.
  • The main processes uses only a single buffer - to hold a single keystroke. Therefore it is impossible to exploit a buffer overrun in the main process by e.g. an overlong password entry.
  • The only exit condition of the program is the Authentication Module returning with exit status zero, on which xsecurelock itself will return with status zero; therefore especially paranoid users might want to run it as sh -c "xsecurelock ... || kill -9 -1" :)

...although it will make your multiscreen return to mirrors screens afterwards.

Runs as a daemon with non-root display modes.... See here.