Cecylia Bokovich

Cecylia Bocovich (MMath ’14)
PhD Student, Faculty of Mathematics
> David R. Cheriton School of Computer Science
> Centre for Applied Cryptographic Research

The information age is making the world much smaller for most of us.

We wake up in the morning and check our Facebook or Twitter to find messages or posts from people who might live on the other side of the world. We can check news websites and find out what is happening elsewhere, almost instantly.

But while many of us take access to popular websites for granted, and even expect this flow of information to accelerate, there are places where governments try to restrict information. A survey done by Freedom House showed two thirds of Internet users faced some sort of restriction or blockage when browsing the Internet in 2016.

“Recently, internet censorship has been on the rise,” says Cecylia Bocovich, a PhD candidate in the Faculty of Mathematics at the University of Waterloo. She’s on a mission to help people who want to shine some light into those information-darkened regions of the world

Free, open source, anti-censorship system

Bocovich and her team have developed a free, open source, anti-censorship decoy routing system called Slitheen, named after a family of Doctor Who aliens who disguise themselves by taking human form.

Users of the system make connections to innocuous web pages and request uncensored content, such as cat videos. Slitheen replaces these videos with content from censored sites.

This decoy routing traffic is indistinguishable from regular web traffic, so even if the censors know about the system, they can't distinguish between the Slitheen connection and a normal connection to the uncensored site.

“The decoy routing system not only provides a way to bypass censorship, but will hide the fact that the user is bypassing censorship. The goal is to provide information, but also protect the user from being discovered,” Bocovich says. “The client will ideally see a browser that they can use to browse for censored content, and the actual decoy requests are happening in the background. The software handles this automatically.”

Anti-censorship tech should be deployed this year

The team is hoping to see some small-scale deployments in the coming year. It will depend on getting friendly Internet service providers (ISPs) in the uncensored part of the world to implement the system.

“We have been talking to people who are interested in setting up the system,” she says. “We are also working on improving the code quality and the user experience in terms of how quickly the censored content will load, and on ensuring that our traffic is indistinguishable from regular web traffic.”

Slitheen is one of several proposed anti-censorship systems that use the decoy routing technique, “but ours does have stronger security guarantees” she says.

Censorship-resistant publishing system called Lavinia

The team members have also done work on a model for a censorship-resistant publishing system they call Lavinia. It deals with situations where an adversary is trying to find out what documents are being stored on a server. “We don’t have an implementation of that yet, but we have published a paper and we plan to revisit this problem in the future.”

Bocovich and her team acknowledge that there is still a lot of work to be done, as much of the world is facing oppressive forms of censorship. “Right now we are shooting for baseline internet freedom for everyone,” she says.

Feature image photo: selimaksan/iStock/ThinkStock