Within the computer security industry and the Obama administration, analysts differ over how to interpret the finding that the intrusions appear to come from schools instead of Chinese military installations or government agencies. Some analysts have privately circulated a document asserting that the vocational school is being used as camouflage for government operations. But other computer industry executives and former government officials said it was possible that the schools were cover for a “false flag” intelligence operation being run by a third country. Some have also speculated that the hacking could be a giant example of criminal industrial espionage, aimed at stealing intellectual property from American technology firms.

Independent researchers who monitor Chinese information warfare caution that the Chinese have adopted a highly distributed approach to online espionage, making it almost impossible to prove where an attack originated.

“We have to understand that they have a different model for computer network exploit operations,” said James C. Mulvenon, a Chinese military specialist and a director at the Center for Intelligence Research and Analysis in Washington. Rather than tightly compartmentalizing online espionage within agencies as the United States does, he said, the Chinese government often involves volunteer “patriotic hackers” to support its policies.