AusCert 2010: China set for net blackout on Tiananmen Square anniversary

Hidden bridges keep Chinese online

Tor founder Roger Dingledine

Tor founder Roger Dingledine

The Chinese Government is set to terminate circumvention methods of its mandatory Internet filter ahead of the anniversary of the Tiananmen Square Massacre next month, according to the Tor Project founder.

Tor is an anonymiser network used to bypass Internet filters, help cops catch criminals, and criminals elude cops.

Its creator, Roger Dingledine, said the network needs volunteers around the world to offer their computers as traffic relays which will help obfuscate user identities and protect Tor against attack and censorship.

"The more relays we have, the better chance we have against attackers or governments that want to block access," Dingledine said at AusCERT 2010.

"China doesn't block [Tor] every day, they block it in the lead-up to sensitive events. I want Tor to be big enough to give everyone in the world the privacy they seek."

Dingledine said he is "optimistic" about the content filtering system in China, claiming it is "toning down".

The network anonymises traffic by bouncing it between relays in a way that means no one can know where a web site request comes from and where it is going. Some 30,000 Chinese users switched to hidden bridge relays on the Tor network, which can't be blocked by content filters, when the Chinese government blocked access to the public relays during the contaminated milk scandal in September 2008.

"It's an arms race," Dingledine told Compterworld Australia.

"We really need people to volunteer as relays, particularly exit relays, if we are to stay ahead of those that stand against us."

Tor opponents include hackers who setup rogue relays to capture traffic, and governments and agencies that block access to it.

Dingledine said users can be reluctant to become exit relays, because they are identified as the receiver of millions of routed requests over the Tor network. However, he said it is "easy" to prove that the requests originated elsewhere.


Dingledine attacked the Federal Government's Internet content filter as an ineffective tool to combat cybercrime, and offered to educate Australian politicans on how anonymiser networks such Tor can bypass content filters.

"When other countries tell China they're a bad country for censoring the Internet, they point to Australia, England and Denmark. They say 'we are just keeping our citizens safe, just like you do'," Dingledine said.

"It's telling that your politicians have chosen not to roll out the filter until after the election. The filter sounds great, but when they actually do it, it will make people unhappy - they know that, so they are waiting.

"The government will be faced with a situation where a particular problem will go away at the tick of a box."

He refuted the notion that the government would avoid function-creep, or the censorship of material outside the current scope of restricted content, because it may raise the ire of the public and press.

"People are actually inclined to say, 'I'm happy my government keeps me safe'. That's the UK public's view of their filter."

Join the newsletter!


Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags internet content filteringTor

More about AusCertCERT AustraliaetworkFederal Government

Show Comments