3 research outputs found
Demo: iJam with Channel Randomization
Physical-layer key generation methods utilize the variations of the
communication channel to achieve a secure key agreement between two parties
with no prior security association. Their secrecy rate (bit generation rate)
depends heavily on the randomness of the channel, which may reduce
significantly in a stable environment. Existing methods seek to improve the
secrecy rate by injecting artificial noise into the channel. Unfortunately,
noise injection cannot alter the underlying channel state, which depends on the
multipath environment between the transmitter and receiver. Consequently, these
methods are known to leak key bits toward multi-antenna eavesdroppers, which is
capable of filtering the noise through the differential of multiple signal
receptions. This work demonstrates an improved approach to reinforce
physical-layer key generation schemes, e.g., channel randomization. The channel
randomization approach leverages a reconfigurable antenna to rapidly change the
channel state during transmission, and an angle-of-departure (AoD) based
channel estimation algorithm to cancel the changing effects for the intended
receiver. The combined result is a communication channel stable in the eyes of
the intended receiver but randomly changing from the viewpoint of the
eavesdropper. We augmented an existing physical-layer key generation protocol,
iJam, with the proposed approach and developed a full-fledged remote
instrumentation platform to demonstrate its performance. Our evaluations show
that augmentation does not affect the bit error rate (BER) of the intended
receiver during key establishment but reduces the eavesdropper's BER to the
level of random guessing, regardless of the number of antennas it equips
A Survey on Wireless Security: Technical Challenges, Recent Advances and Future Trends
This paper examines the security vulnerabilities and threats imposed by the
inherent open nature of wireless communications and to devise efficient defense
mechanisms for improving the wireless network security. We first summarize the
security requirements of wireless networks, including their authenticity,
confidentiality, integrity and availability issues. Next, a comprehensive
overview of security attacks encountered in wireless networks is presented in
view of the network protocol architecture, where the potential security threats
are discussed at each protocol layer. We also provide a survey of the existing
security protocols and algorithms that are adopted in the existing wireless
network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term
evolution (LTE) systems. Then, we discuss the state-of-the-art in
physical-layer security, which is an emerging technique of securing the open
communications environment against eavesdropping attacks at the physical layer.
We also introduce the family of various jamming attacks and their
counter-measures, including the constant jammer, intermittent jammer, reactive
jammer, adaptive jammer and intelligent jammer. Additionally, we discuss the
integration of physical-layer security into existing authentication and
cryptography mechanisms for further securing wireless networks. Finally, some
technical challenges which remain unresolved at the time of writing are
summarized and the future trends in wireless security are discussed.Comment: 36 pages. Accepted to Appear in Proceedings of the IEEE, 201