American research universities are facing an increasing spate of cyberattacks, many of which are thought to come from China, testing their ability to ward off the attacks and forcing some to overhaul their security policies, The New York Times reports.

Campus officials who specialize in information technology and data security told the Times that detection is a key concern for institutions in trying to thwart the attacks because many hackers are adept at routing their efforts though computers and countries around the world. William S. Mellon, associate dean for research policy at the University of Wisconsin at Madison, told the newspaper that his institution’s system is besieged by 90,000 to 100,000 hacking attempts per day from China alone, with many others coming from Russia and Vietnam.

The threat has forced many universities to rethink the basic structure of their networks, while others no longer allow professors to take their laptops to certain countries because of security concerns, the Times reported.