Title
Lockpicking physical layer key exchange: weak adversary models invite the thief
Abstract
Physical layer security schemes for wireless communications are currently crossing the chasm from theory to practice. They promise information-theoretical security, for instance by guaranteeing the confidentiality of wireless transmissions. Examples include schemes utilizing artificial interference---that is 'jamming for good'---to enable secure physical layer key exchange or other security mechanisms. However, only little attention has been payed to adjusting the employed adversary models during this transition from theory to practice. Typical assumptions give the adversary antenna configurations and transceiver capabilities similar to all other nodes: single antenna eavesdroppers are the norm. We argue that these assumptions are perilous and 'invite the thief'. In this work, we evaluate the security of a representative practical physical layer security scheme, which employs artificial interference to secure physical layer key exchange. Departing from the standard single-antenna eavesdropper, we utilize a more realistic multi-antenna eavesdropper and propose a novel approach that detects artificial interferences. This facilitates a practical attack, effectively 'lockpicking' the key exchange by exploiting the diversity of the jammed signals. Using simulation and real-world software-defined radio (SDR) experimentation, we quantify the impact of increasingly strong adversaries. We show that our approach reduces the secrecy capacity of the scheme by up to 97% compared to single-antenna eavesdroppers. Our results demonstrate the risk unrealistic adversary models pose in current practical physical layer security schemes.
Year
DOI
Venue
2015
10.1145/2766498.2766514
ACM Conference on Security and Privacy in Wireless and Mobile Networks
Field
DocType
Citations 
Wireless,Transceiver,Key exchange,Adversary model,Computer security,Computer science,Secrecy,Computer network,Physical layer,Adversary,Jamming
Conference
6
PageRank 
References 
Authors
0.46
21
3
Name
Order
Citations
PageRank
Daniel Steinmetzer1698.50
Matthias Schulz211112.74
Matthias Hollick375097.29