If their slides are correct, then disabling boot from USB is enough. But then they state > Using a simple tool, Olle and Pasi learned how to rewrite the non-vo

If their slides are correct, then disabling boot from USB is enough. But then they state > Using a simple tool, Olle and Pasi learned how to rewrite the non-volatile memory chip that contains these settings, disable memory overwriting, and enable booting from external devices The phrasing is confusing in that had they find a way to switch 'boot from USB' BIOS setting 'using a simple tool'.