Is it legal in the US for a professor to publicly reveal a student's performance in PhD comprehensive exams?
Edit, again: The question seems to have changed, yet again. :)


A student can reveal their own performance in an exam. That information is their property.
Faculty cannot publicly reveal students' performances, as that would, indeed, violate the "FERPA" laws. (As parent of over-18 college student, whose tuition I'm paying, I do not have access to her grades without her permission!)


Edit: Hm... the sense of the question is radically changed. [Initially, it was about faculty publicly disclosing students' performance results. When this answer was written, it had become about whether one could disclose one's own results.] Sure, one is at liberty to reveal one's own quality-of-performance on an exam in the U.S. The "FERPA" laws would only prevent your examiners from revealing your performance publicly or to anyone who did not have a legitimate operational professional reason to have access.

It might be that the content of the exam might be partly confidential, but that is a different issue.