In multi-user MIMO (MU-MIMO) systems using zero-forcing beamforming (ZFBF), an Access Point (AP) utilizes downlink channel state information (CSI) to transmit data streams to multiple clients simultaneously. Since private information of clients can be extracted from CSI, leaking CSI to attackers is considered as harmful so that some research efforts suggest to encrypt CSI feedback. However, a recent study shows that an attacker can infer CSI by eavesdropping data streams with known symbols, not the feedback. To this end, we propose CSIstray that intentionally increases the proportion of inter-client interference to suppress CSI leakage while maintaining bit error rates (BERs) at the clients. Simulation results with a 2×2 MU-MIMO scenario show that CSIstray effectively degrades the attack performance with little impact on downlink transmission. We further implement CSIstray on our testbed to validate the proposed mechanism works properly in a room-scale environment as well as in simulation results.
|Title of host publication||IEEE INFOCOM 2020 - IEEE Conference on Computer Communications Workshops, INFOCOM WKSHPS 2020|
|Publisher||Institute of Electrical and Electronics Engineers Inc.|
|Number of pages||2|
|Publication status||Published - 2020 Jul|
|Event||2020 IEEE INFOCOM Conference on Computer Communications Workshops, INFOCOM WKSHPS 2020 - Toronto, Canada|
Duration: 2020 Jul 6 → 2020 Jul 9
|Name||IEEE INFOCOM 2020 - IEEE Conference on Computer Communications Workshops, INFOCOM WKSHPS 2020|
|Conference||2020 IEEE INFOCOM Conference on Computer Communications Workshops, INFOCOM WKSHPS 2020|
|Period||20/7/6 → 20/7/9|
Bibliographical noteFunding Information:
ACKNOWLEDGEMENT This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2019R1A2C2088812). Wonjun Lee is the corresponding author.
© 2020 IEEE.
- Channel state information leakage
- Multi-user MIMO
- Zero-forcing beamforming
ASJC Scopus subject areas
- Computer Networks and Communications
- Computer Science Applications
- Hardware and Architecture
- Information Systems and Management
- Safety, Risk, Reliability and Quality