> The only solution is to require face-to-face proctored exams and not allow students to use technology of any kind while taking the test. But any teacher doing this will end up with no students signing up for their class.

When I was in college, this was every math class. You could cheat all you want on the 20% of your grade that came from homework, but the remaining 80% was from 3-4 in-class, proctored exams.