The Truth Machine
James L. Halperin
"The Truth Machine (1996) is a science fiction novel by James L. Halperin about a genius who invents an infallible lie detector. Soon, every citizen must pass a thorough test under a Truth Machine to get a job or receive any sort of license. Eventually, people begin wearing them all the time, thus eliminating dishonesty in all parts of human interaction, and eliminating crime, terrorism and a great deal of general social problems."