From sending SWAT teams into exam centers to arresting rule-breakers, China's public security authorities have been cracking down hard on college entrance examination cheaters who could face jail if caught.

This week's university entrance exam, the origins of which date back to imperial China, determines which students will attend and what major they're able to select — and as a result, much of their future.

This year, 9.4 million high school students have been taking the exam, known in China as the "gaokao," competing for the few open places in universities, state media reported.