The Chinese cybersecurity companies that have grown fastest and are best positioned for the expected boom in spending are often those with the closest ties to government.

Among them, Beijing-based Venustech is one of the largest, most successful and most trusted by China’s government and its ruling Communist Party.

Its company roster reads like a who’s who of former ministry officials. CEO Yan Wang Jia — who founded the company after returning to China with a PhD from University of Pennsylvania — now serves on the government’s highest political advisory body and sits on a series of Communist Party and state organizations.

The company’s headquarters have been visited by two of China’s past presidents and a parade of top party leaders — public endorsements of their trust. And clients listed on its Web site reach into almost every corner of the government and military.

Roughly 67 percent of Venustech’s revenue comes from government, according to analysts at market research firm IDC.

It was entrusted with information security for the 2008 Olympic Games and the 2010 Shanghai Expo, events that were of utmost importance to the government.

In a 2011 interview with a state-run magazine, Yan insisted China’s Internet security should be entrusted primarily to domestic companies.

Like many major Chinese IT security firms, the company operates a research and development lab, funded in large part by government work. And like most most Chinese security companies with close ties to government, Venustech has almost never spoken to foreign media and declined requests to comment for this story.