The company did not immediately respond to a request for comment.
Since the announcement, China has been engaged in an all-out campaign to shore up its homegrown chip industry. Beijing has spent billions of dollars on the efforts at self-reliance and Chinese companies up and down the supply chain have moved to replace Western chips and parts.
The Chinese authorities offered few clues about what they had discovered that posed serious risks. They have also provided little information about what is required of companies during a cybersecurity review. But Graham Webster, the editor in chief of the DigiChina Project at the Stanford University Cyber Policy Center, said that among the risks was the potential for further sanctions by Washington that could cut off important Chinese companies from Micron’s memory chips.
“Supply-chain security includes the risk of a foreign government cutting off supply, which the U.S. government has done in multiple ways for other semiconductors,” Mr. Webster said. He added that China’s decision may have been partly a “derisking measure to avoid further reliance on supplies the U.S. might cut off.”
Washington has urged South Korean officials to prevent its chip makers from filling the market void if Micron was unable to sell its chips to China, The Financial Times reported in April.
China approved a cybersecurity law in 2016 that outlined rules to safeguard what it called “critical information infrastructure,” which refers to technology systems in sectors including telecommunications, transportation and defense that Chinese regulators believe would be vulnerable if they malfunctioned or leaked data.