CYBERSECURITYKeeping Web-Browsing Data Safe from Hackers

By Adam Zewe

Published 9 June 2022

Studying a powerful type of cyberattack, researchers identified a flaw in how it’s been analyzed before, then developed new techniques that stop it in its tracks.

Malicious agents can use machine learning to launch powerful attacks that steal information in ways that are tough to prevent and often even more difficult to study.

Attackers can capture data that “leaks” between software programs running on the same computer. They then use machine-learning algorithms to decode those signals, which enables them to obtain passwords or other private information. These are called “side-channel attacks” because information is acquired through a channel not meant for communication.

Researchers at MIT have shown that machine-learning-assisted side-channel attacks are both extremely robust and poorly understood. The use of machine-learning algorithms, which are often impossible to fully comprehend due to their complexity, is a particular challenge. In a new paper, the team studied a documented attack that was thought to work by capturing signals leaked when a computer accesses memory. They found that the mechanisms behind this attack were misidentified, which would prevent researchers from crafting effective defenses.

To study the attack, they removed all memory accesses and noticed the attack became even more powerful. Then they searched for sources of information leakage and found that the attack actually monitors events that interrupt a computer’s other processes. They show that an adversary can use this machine-learning-assisted attack to exploit a security flaw and determine the website a user is browsing with almost perfect accuracy.

With this knowledge in hand, they developed two strategies that can thwart this attack.

“The focus of this work is really on the analysis to find the root cause of the problem. As researchers, we should really try to delve deeper and do more analysis work, rather than just blindly using black-box machine-learning tactics to demonstrate one attack after another. The lesson we learned is that these machine-learning-assisted attacks can be extremely misleading,” says senior author Mengjia Yan, the Homer A. Burnell Career Development Assistant Professor of Electrical Engineering and Computer Science (EECS) and a member of the Computer Science and Artificial Intelligence Laboratory (CSAIL).

The lead author of the paper is Jack Cook ’22, a recent graduate in computer science. Co-authors include CSAIL graduate student Jules Drean and Jonathan Behrens PhD ’22. The research will be presented at the International Symposium on Computer Architecture.