Russian media reported that Yandex, the country's largest search engine, has refused to turn over encryption keys that would give the country's law enforcement the ability to decode its entire e-mail traffic.
Yandex would not confirm the report, first made by the newspaper RBK on June 4, instead issuing a statement saying that it could meet law enforcement demands without compromising personal privacy.
The report comes as the Kremlin has tightened control in recent years over the country’s Internet -- a move that opponents of President Vladimir Putin say is aimed at squashing discontent and challenges to his rule.
RBK reported that the Federal Security Service had requested the company's encryption keys a few months ago.
The Moscow-based company, whose shares trade on the U.S. tech stock exchange NASDAQ, fears that handing over the keys will drive users toward Google, its largest competitor, and result in a decline in earnings, the news agency reported.
Yandex did not immediately respond to a request from RFE/RL to confirm the report.
"The aim of the law is to ensure safety and we completely share the importance of these goals. However, fulfilling the law is possible without compromising the privacy of personal data," Yandex said in its June 4 statement to local media.
"The law talks about handing over information that is necessary to decode messages, which does not imply a demand to transfer the keys needed to decipher all traffic," Yandex said in a statement.
While Russia's TV and print media largely remain in the hands of the state or businessmen close to power, the Internet remains relatively uncontrolled.
Russia now requires more than 170 entities it calls "information disseminators" -- such as Yandex and popular dating app Tinder -- to store servers containing its residents' communication data inside the country and give access to law enforcement when they demand it.
Roskomnadzor, the nation's communications regulator, last week added Tinder to the list of entities, sparking concern over law enforcement access to intimate messages.
Jonathan Mayer, a Princeton University computer science professor, said Russia's approach contrasted with that of law enforcement agencies in Western nations: requesting the data they need, not the encryption keys.
“What the Russian government aims to do is take online services out of the loop -- eliminating an important backstop for human rights and the rule of law. The Russian government's demand also poses a cybersecurity risk for all users of these online services, regardless of whether they're the target of surveillance,’’ Mayer told RFE/RL.
Roskomnadzor last year tried to block encrypted messaging service Telegram, which is wildly popular within Russia, for not handing over its keys.
It has blocked Microsoft's professional networking website LinkedIn and also fined Facebook and Twitter for not following the nation's Internet laws.
Russia is unlikely to seek to block Yandex as it did with Telegram, Sarkis Darbinian, a partner at the Center for Digital Rights, told RBK. He predicted the two sides would find a compromise because blocking the services of one of Russia's largest Internet companies would be a ''nightmare" for the government.
A shutdown would lock out tens of millions of Russians from their e-mail and force them to use less popular search engines.