CSI-MURDER takes the move from one of the most flourishing research topics in wireless networks: the ability to exploit communication signals to sense the surrounding environment and hence to localize people and possibly objects. Instead of proposing yet another localization system, this project explores the possibility of preventing unauthorized localization without hampering the communication performance. Sensing techniques use the Channel State Information (CSI) embedded in each Wi-Fi frame for understanding how wireless signals propagate in the environment: for instance, by measuring how CSI amplitude changes over time it is possible to detect human presence or motion, recognize different types of activity, even detect specific gestures or measure human breathing, albeit these fine-grained detection has proven hard to replicate. This project tackles the problem of neutralizing un-authorized surveillance while preserving the communication performance. To this end, we implemented a number of functions for modifying Wi-Fi frames before they are transmitted over the channel in such a way that their content can still be decoded, while the CSI appears as being randomly generated so that eavesdroppers cannot use CSI for sensing the environment.
Imagine someone wants to illegally track the position (and implicitely the time spent) by someone into a laboratory, for instance to track how much time is spent into different activities to be performace ad different desks/instruments, as depicted in the upper picture. How much effective can this attack be?
Actual experiments, reported in the lower picture on the left, tells us the CSI-base localization can be extremely accurate, as all the stimated poings(the marks) basically falls within the circle representing the position where the person in the lab was sitting working. With CSI-MURDER instead the localization becomes impossible, giving random results, thus preserving the person privacy without destroying Wi-Fi communications.
CSI-MURDER continues in Brescia beyond the financial support of the ORCA Project, which has been fundamental to bootstrap our activities, but it’s over.
Interested readers can find all the documents including README files, the scripts we used and the tools for evaluating hte performance of the system on github. The repo is private for the time being, but feel free to ask access if you want to collaborate.
Marco Cominelli, Felix Kosterhon, Francesco Gringoli, Renato Lo Cigno, and Arash Asadi. 2020. An Experimental Study of CSI Management to Preserve Location Privacy. In 14th International Workshop on Wireless Network Testbeds, Experimental evaluation & Characterization (WiNTECH’20), September 21, 2020, London, United Kingdom. ACM, New York, NY, USA, 8 pages. https://doi.org/10.1145/3411276.3412187 local PDF preprint
Final review meeting documents
During this project we develop, with the help from our Patron IMEC, a modified version of the Openwifi stack that embeds the randomization mechanism. Interested readers can find more information here.
We thank our Patron IMEC for their support in the development of the privacy preserving feature inside the openwifi 802.11 stack.
CSI-MURDER has been funded by the European Commission under the Horizon 2020 Orchestration and Reconfiguration Control Architecture – ORCA project (grant no. 732174) Open Call 3 “Experimental analysis of CSI based anti-sensing techniques - CSI-MURDER” experiment.