On the left, users first access mailboxes. Then, the server disconnects users from the mailboxes and adds cover traffic. An adversary cannot tell who is talking to whom by looking at mailbox access patterns.
Courtesy of the researchers
New untraceable text-messaging system comes with statistical guarantees.
Anonymity networks, which sit on top of the public Internet, are designed to conceal people’s Web-browsing habits from prying eyes. The most popular of these, Tor, has been around for more than a decade and is used by millions of people every day.
Recent research, however, has shown that adversaries can infer a great deal about the sources of supposedly anonymous communications by monitoring data traffic through just a few well-chosen nodes in an anonymity network. At the Association for Computing Machinery Symposium on Operating Systems Principles in October, a team of MIT researchers presented a new, untraceable text-messaging system designed to thwart even the most powerful of adversaries.
The system provides a strong mathematical guarantee of user anonymity, while, according to experimental results, permitting the exchange of text messages once a minute or so.
“Tor operates under the assumption that there’s not a global adversary that’s paying attention to every single link in the world,” says Nickolai Zeldovich, an associate professor of computer science and engineering, whose group developed the new system. “Maybe these days this is not as good of an assumption. Tor also assumes that no single bad guy controls a large number of nodes in their system. We’re also now thinking, maybe there are people who can compromise half of your servers.”
Because the system confuses adversaries by drowning telltale traffic patterns in spurious information, or “noise,” its creators have dubbed it “Vuvuzela,” after the noisemakers favored by soccer fans at the 2010 World Cup in South Africa.
Joining Zeldovich on the paper are joint first authors David Lazar, a PhD student in electrical engineering and computer science, and Jelle van den Hoof, who received his MIT master’s in the spring, and Matei Zaharia, an assistant professor of computer science and engineering and, like Zeldovich, one of the co-leaders of the Parallel and Distributed Operating Systems group at MIT’s Computer Science and Artificial Intelligence Laboratory.
Covering your tracks
Vuvuzela is a dead-drop system, in which one user leaves a message for another at a predefined location — in this case, a memory address on an Internet-connected server — and the other user retrieves it. But it adds several layers of obfuscation to cover the users’ trails.
To illustrate how the system works, Lazar describes a simplified scenario in which it has only three users, named, by cryptographic convention, Alice, Bob, and Charlie. Alice and Bob wish to exchange text messages, but they don’t want anyone to be able to infer that they’ve been in touch.
If Alice and Bob send messages to the dead-drop server, and Charlie doesn’t, then an observer would conclude that Alice and Bob are communicating. So the system’s first requirement is that all users send regular messages to the server, whether they contain any information or not.
If an adversary has infiltrated the server, however, he or she can see which users are accessing which memory addresses. If Charlie’s message is routed to one address, but both Alice’s and Bob’s messages are routed to another, the adversary, again, knows who’s been talking.
So instead of using a single server, Vuvuzela uses three. Corresponding to the three servers, every message sent through the system is wrapped in three layers of encryption. The first server peels off the first layer of encryption before passing messages on to the second server. But it also randomly permutes their order. So if, for example, Alice’s message arrived at the first server before Bob’s, and Bob’s arrived before Charlie’s, the first server will pass them to the second in the order Bob, Alice, Charlie, or Charlie, Bob, Alice, or the like.
The second server peels off the second layer of encryption and permutes the message order yet again. Only the third server sees which messages are bound for which memory addresses. But even if it’s been infiltrated, and even if the adversary observed the order in which the messages arrived at the first server, he or she can’t tell whose message ended up where.
The adversary does, however, know that two users whose messages reached the first server within some window of time have been talking. And even that is more information than Vuvuzela’s designers want to give away.
Here’s where the noise comes in: When the first server passes on the messages it’s received, it also manufactures a slew of dummy messages, with their own encrypted destinations. The second server does the same. So statistically, it’s almost impossible for the adversary to determine even whether any of the messages arriving within the same time window ended up at the same destination.
Those statistical guarantees hold even if two of the three servers are infiltrated. As long as one of them remains uncompromised, the system works.
Read more: Untraceable communication — guaranteed
The Latest on: Untraceable communication
via Google News
The Latest on: Untraceable communication
- What are ghost guns?: Biden executive action targets 'dangerous' and 'untraceable' firearmson April 8, 2021 at 7:46 am
Among the actions Biden will announce is directing the Department of Justice to propose a rule within 30 days to stop the proliferation of "ghost guns," a sort of untraceable weapon often made ...
- Biden plans first executive actions against gunson April 8, 2021 at 1:02 am
Those are guns that are untraceable and self-assembled. In the next 60 days, the DOJ also be asked to propose limits on “stabilizing braces,” which effectively turn pistols into rifles. The official ...
- Silencing vibrations in the ground and sounds underwateron April 6, 2021 at 10:11 am
It is gaining attention as it can be used to escape from threatening earthquakes or build submarines untraceable to SONAR. Professor Junsuk Rho of POSTECH's departments of mechanical engineering ...
- Biden White House tries to craft gun executive orders that can't be undoneon April 2, 2021 at 5:12 am
Among the measures being considered - and strongly encouraged by activists - is one directing the Department of Justice (DOJ) to reinterpret existing law on untraceable "ghost guns." So-called "ghost ...
- Washington needs to address the rising tide of 'ghost guns'on April 1, 2021 at 11:59 pm
These firearms, manufactured without a serial number, are virtually untraceable — and for that reason, increasingly prevalent. The meeting is an encouraging sign that the Biden administration ...
- Pro-Trump group accused of illegally concealing donorson March 25, 2021 at 9:25 am
Why it matters: The groups, politically active nonprofits, funneled more than $1 billion in untraceable cash into the 2020 elections ... more than $250 on independent expenditures — or paid ...
- BBB warns Hoosiers about gift card scamon March 22, 2021 at 1:15 pm
“Gift card scams are hugely prevalent and are becoming even more common because they are untraceable,” said Nichole Thomas, the communications director for the Better Business Bureau serving N ...
- Chambersburg man arrested for selling ‘ghost guns:’ AGon March 20, 2021 at 1:34 pm
“Once these DIY homemade gun kits are in the wrong hands, in mere hours they become untraceable ... four counts of criminal use of a communication facility, two counts of sale or transfer ...
- ‘Ghost gun’ trafficker arrested for selling on the streets of Harrisburgon March 20, 2021 at 9:22 am
Once these DIY homemade gun kits are in the wrong hands, in mere hours they become untraceable ... 4 counts of Criminal Use of a Communication Facility, 2 counts of Sale or Transfer of a Firearm ...
- Pennsylvania gun show promoter becomes first to ban sales of 'ghost gun' kitson March 15, 2021 at 10:19 am
A Pennsylvania gun show promoter became the first in the U.S. to ban the sale of kits used to build untraceable “ghost guns,” the state's attorney general announced Monday. Pennsylvania ...
via Bing News