Use Tor? Riffle promises to protect your privacy even better

The network combines three cryptographic techniques and boasts much faster performance

Privacy-minded people have long relied on Tor for anonymity online, but a new system from MIT promises better protection and faster performance.

Dubbed Riffle, the new system taps the same onion encryption technique after which Tor is named, but it adds two others as well. First is what's called a mixnet, a series of servers that each permute the order in which messages are received before passing them on to the next server.

If messages arrive at the first server in the order A, B, C, for example, that server would send them to the second server in a different order, such as C, B, A. The second server would them reshuffle things again when sending the messages on. The advantage there is that a would-be attacker who had tracked the messages’ points of origin would have no idea which was which by the time they exited the last server.

A mixnet used with onion encryption is protected against passive adversaries, which can only observe network traffic. But active adversaries, which can infiltrate servers with their own code, are another matter. If one has commandeered a mixnet router and wants to determine the destination of a particular message, for instance, it could simply replace all the other messages it receives with its own, bound for a single destination. Then it could passively track the one message that doesn’t follow its own prespecified route.

That's where Riffle's third protective measure comes in. Essentially, it takes a two-pronged approach to validating the authenticity of messages using techniques called verifiable shuffle and authentication encryption. Verifiable shuffle keeps things secure while each user and each mixnet server agree upon a cryptographic key; authentication encryption, which is much more efficient, then takes over for the remainder of the communication session.

The overall result is that Riffle remains cryptographically secure as long as one server in the mixnet remains uncompromised, according to MIT. Meanwhile, Riffle also uses bandwidth much more efficiently than competing systems, its creators say. In experiments, it required only one-tenth as much time as similarly secure experimental systems to transfer a large file between anonymous users.

Riffle was developed by researchers at MIT’s Computer Science and Artificial Intelligence Laboratory and the École Polytechnique Fédérale de Lausanne. The system isn't yet available for public use, but the researchers will present a paper describing their work at the Privacy Enhancing Technologies Symposium in Germany next week.

“The idea of mixnets has been around for a long time, but unfortunately, it’s always relied on public-key cryptography and on public-key techniques, and that’s been expensive,” says Jonathan Katz, director of the Maryland Cybersecurity Center and a professor of computer science at the University of Maryland. “One of the contributions of this paper is that they showed how to use more efficient symmetric-key techniques to accomplish the same thing. They do one expensive shuffle using known protocols, but then they bootstrap off of that to enable many subsequent shufflings.”

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Katherine Noyes

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?