BEIJING: A Chinese man has been sentenced to death for selling 150,000 classified documents that revealed key secrets about military and government data encryption to an unidentified foreign spy agency, state broadcaster CCTV said Tuesday.

Huang Yu, a former computer technician at a Chinese research firm specializing in encryption, received $700,000 for providing the documents between 2002 and 2011, CCTV said.

It did not say when Huang, 41, was tried on the espionage charge. The case was publicized as part of a national campaign to raise public awareness about state security following China’s first national security education day last Friday.

CCTV said Huang leaked highly classified national secrets and caused “immeasurable” damage to the security of encrypted communications used by multiple departments within the ruling Communist Party, the government, the military and the financial sector.