In a first aspect of the invention, method for classifying characters
within a character string entered via a keyboard device includes logging
interrupts, checking a time between interrupts, checking an interrupt
duration and classifying the characters within the character string based
upon the time between interrupts and the interrupt duration. In a second
aspect of the invention, a method for protecting against timing attacks
against a trusted path mechanism includes employing a multithreaded
process with a first thread to prevent any timing Trojan horses from
running, running the first thread in a loop at a first priority and
preventing unprivileged processes from obtaining a priority higher than
the first priority.