Numerous efforts are under way in the West to help Chinese web users get around China's censorship of the internet, reports technology correspondent Clark Boyd.
Bill Xia left China for the US in the late 1990s. He keeps up with events in his homeland, mostly online.
He has been amazed by the rapidly growing number of people in China who can join him in cyberspace.
But he has also watched as Beijing tries to keep tighter and tighter control over those Chinese web users.
"I started realising the media controls in China. And then I realised the internet presented a great opportunity to get around those media controls," he said.
In 2001, Mr Xia and some other US-based volunteers started Dynamic Internet Technology.
The company helps Chinese web users get around China's firewall.
Net bypass
The way the company does it is not new. It allows a user inside China to access the internet, not through a system controlled by the government, but through a proxy server.
"The basic method of these technologies is to find a helpful computer in the United States or Canada or Europe that is willing to act as an intermediary for requests," said Ben Edelman, a fellow at Harvard Law School's Berkman Center for Internet and Society.
Mr Edelman cites the example of a website that China often censors, the BBC. The country will block the BBC's domain name - bbc.co.uk.
But, a friendly intermediary in, say, Canada, could help to bypass the controls.
"You might find a computer at the University of Toronto that is willing to get you the BBC, and provide it to you with a domain that says toronto.ca, it doesn't say BBC," he explained.
"China would never think Toronto would have the BBC, what an odd combination, and so you'd be able to get the BBC site that way."
It means the BBC site is accessible through a different web address. But how do you tell users in China how to find it?
Agile technology
One idea is to e-mail Chinese users directly. However there is a catch. The Chinese government has 30,000 people who routinely scan e-mails for this kind of information.
Officials keep a close eye on net activity
Agents can could also pose as cyber-dissidents, and sign up for these e-mail lists.
Nart Villeneuve from the Citizen Lab at the University of Toronto says the trick is making sure that only people you know and trust get that e-mail with the proxy web address.
The Citizen Lab is working on a project called Psiphon. Mr Villieneuve says it relies on a human peer-to-peer network made up of say, the Chinese diaspora community.
"The idea is to get them to install this on their computer, and then deliver the location of that circumventor, to people in filtered countries by the means they know to be the most secure," said Mr Villeneuve.
"What we're trying to build is a network of trust among people who know each other, rather than a large tech network that people can just tap into."
Another idea is to present the Chinese authorities with so many proxy addresses, that they would never be able to block them all.
The US-based peacefire.org group has adopted this approach, saying its system is designed to be technologically agile.
"The idea behind the circumventor was to make it so easy to install and run while it's on your machine, that if one is blocked, you can always send an e-mail to your friend, and say hey, can you set one up here," said Bennett Haselton, Peacefire's webmaster.
"Instead of having a small number of sites that people have to go through, where those can all be blocked, rather it's a distributed network of so many of them that they can't find them and block them all."
Secret codes
Others are taking more hi-tech approaches. They are developing harder to crack encryption that would keep e-mails and proxy servers secret.
But some wonder whether most Chinese internet users really want this kind of help.
Bobson Wong, an independent internet researcher based in New York, says the majority of Chinese web users are not looking to be cyber-dissidents.
"They spend most of their time chatting with their friends, playing games online, and sending e-mails to each other," he says.
"These are not the people itching to read CNN. There have been surveys done of internet users in China, and the surveys reveal that most internet users in China trust the government."
But California Congressman Christopher Cox does not buy that. He has sponsored legislation that would create a Global Internet Freedom Office.
He says the office would fund private and public organisations that help web users get through the Chinese government's firewall.
"People everywhere want to be able to use the internet for political communication, for getting news and information," says Mr Cox.
"Yet it is precisely that act that too often is gonna land them in prison for an indefinite period.
"Sometimes they're subjected to worse, to torture. We simply need to make sure the pipelines of the internet aren't cut off by repressive governments."
Internet activists in the US say they would welcome an influx of American government money in their battle against Chinese censorship. Right now, most of them work as volunteers.
For its part, China is reportedly pouring billions into its internet infrastructure.
No one expects the cat and mouse game between cyber-dissidents and Chinese authorities to end anytime soon.
http://news.bbc.co.uk/1/hi/technology/3548035.stm
Topic: Bypassing China's net firewall (Read 876 times)