Chia-Yi Yeh - Academia.edu (original) (raw)
Papers by Chia-Yi Yeh
IEEE Transactions on Information Forensics and Security
The 25th Annual International Conference on Mobile Computing and Networking
The Wireless of the Students, by the Students, and for the Students (S3) Workshop provides a uniq... more The Wireless of the Students, by the Students, and for the Students (S3) Workshop provides a unique venue for graduate students around the world to present, discuss, and exchange ideas on cross-cutting research on mobile wireless networks. As its name suggests, the workshop is organized by students, and the technical sessions are given by student presenters. The workshop aims at fostering early-career development among students and exposing them to the workings of academic life. It provides a venue for students to learn about each other's' work and discover opportunities for collaboration. The workshop invites students to submit papers, posters, and demos. All submissions are peer-reviewed by the student program committee.
2022 IEEE Conference on Communications and Network Security (CNS)
Security against eavesdropping is one of the key concerns in the design of any communication syst... more Security against eavesdropping is one of the key concerns in the design of any communication system. Many common considerations of the security of a wireless communication channel rely on comparing the signal level measured by Bob (the intended receiver) to that accessible to Eve (an eavesdropper). Frameworks such as Wyner's wiretap model ensure the security of a link, in an average sense, when Bob's signal-to-noise ratio exceeds Eve's. Unfortunately, because these guarantees rely on statistical assumptions about noise, Eve can still occasionally succeed in decoding information. The goal of achieving exactly zero probability of intercept over an engineered region of the broadcast sector, which we term absolute security, remains elusive. Here, we describe the first architecture for a wireless link which provides absolute security. Our approach relies on the inherent properties of broadband and high-gain antennas, and is therefore ideally suited for implementation in millimeter-wave and terahertz wireless systems, where such antennas will generally be employed. We exploit spatial minima of the antenna pattern at different frequencies, the union of which defines a wide region where Eve is guaranteed to fail regardless of her computational capabilities, and regardless of the noise in the channels. Unlike conventional zero-forcing beam forming methods, we show that, for realistic assumptions about the antenna configuration and power budget, this absolute security guarantee can be achieved over most possible eavesdropper locations. Since we use relatively simple frequency-multiplexed coding, together with the underlying physics of a diffracting aperture, this idea is broadly applicable in many contexts.
2022 IEEE Conference on Communications and Network Security (CNS)
Proceedings of the 15th ACM Conference on Security and Privacy in Wireless and Mobile Networks
With the large bandwidths available in the terahertz regime, directional transmissions can exhibi... more With the large bandwidths available in the terahertz regime, directional transmissions can exhibit angular dispersion, i.e., frequencydependent radiation direction. Unfortunately, angular dispersion introduces new security threats as increased bandwidth necessarily yields a larger signal footprint in the spatial domain and potentially benefits an eavesdropper. This paper is the first study of secure transmission strategies on angularly dispersive links. Based on information theoretic foundations, we propose to channelize the wideband transmission in frequency, and perform secure coding across frequency channels. With over-the-air experiments, we show that the proposed method exploits the properties of angular dispersion to realize secure wideband transmissions, despite the increased signal footprint and even for practical irregular beams with side lobes and asymmetry. In contrast, without the proposed cross-channel coding strategy, angularly dispersive links can suffer from significant security degradation when bandwidth increases. CCS CONCEPTS • Security and privacy → Mobile and wireless security.
APL Photonics, 2021
Despite the rapidly growing interest in exploiting millimeter and terahertz waves for wireless da... more Despite the rapidly growing interest in exploiting millimeter and terahertz waves for wireless data transfer, the role of reflected non-lineof-sight (NLOS) paths in wireless networking is one of the least explored questions. In this paper, we investigate the idea of harnessing these specular NLOS paths for communication in directional networks at frequencies above 100 GHz. We explore several illustrative transmitter architectures, namely, a conventional substrate-lens dipole antenna and a leaky-wave antenna. We investigate how these high-gain directional antennas offer both new challenges and new opportunities for exploiting NLOS paths. Our results demonstrate the sensitivity to antenna alignment, power spectrum variations, and the disparity in supported bandwidth of various line-of-sight (LOS) and reflected path configurations. We show that NLOS paths can, under certain circumstances, offer even higher data rates than the conventional LOS path. This result illustrates the unique opportunities that distinguish THz wireless systems from those that operate at lower frequencies.
Proceedings of the 13th ACM Conference on Security and Privacy in Wireless and Mobile Networks, 2020
This paper presents the first security study of THz networks with Leaky Wave Antennas (LWAs). We ... more This paper presents the first security study of THz networks with Leaky Wave Antennas (LWAs). We employ a mix of analytical models and over-the-air experiments to explore the unique security properties of LWA links. We show via both models and experiments that the LWA's angle-frequency coupling leads to non-uniform secrecy capacity across sub-channels yielding advantages to an eavesdropper at edge frequencies. Yet, because different frequencies emit energy at different angles, the eavesdropper is thwarted from easily intercepting an entire wideband transmission. The experiments diverge from the analytical model in that the model underpredicts the eavesdropper's advantage at angles smaller than the target user and subsequent asymmetric performance across angles. Nonetheless, both the model and measurements show that increasingly wide bandwidth and correspondingly wide beams have only a modest marginal security penalty. CCS CONCEPTS • Security and privacy → Mobile and wireless security.
2018 IEEE Conference on Communications and Network Security (CNS), 2018
Massive MIMO has the potential to thwart passive eavesdropping as the signals transmitted by a la... more Massive MIMO has the potential to thwart passive eavesdropping as the signals transmitted by a large antenna array become highly focused. Indeed, the impact of passive eavesdropping has been shown to be negligible when the number of base station (BS) antennas approaches infinity for independent Rayleigh channels. In this paper, we experimentally explore eavesdropping in Massive MIMO incorporating real-world factors including a limited BS antenna array size, potential correlation in over-the-air channels, and adaptation of modulating and coding schemes (MCS) over a discrete and finite set. Using a 96-antenna ArgosV2 BS, we (i) explore scaling the array size; (ii) identify eavesdropper advantages due to channel correlation and the resulting increase in array size required to mitigate this advantage; (iii) identify the "MCS saturation regime" as a vulnerability even with high SNR, (iv) characterize transmit power control counter strategies at the BS, and (v) explore the impact of a nomadic eavesdropper that moves to find the most favorable position.
IEEE Transactions on Wireless Communications, 2021
Massive multiple-input and multiple-output (massive MIMO) has the potential to thwart passive eav... more Massive multiple-input and multiple-output (massive MIMO) has the potential to thwart passive eavesdropping as the signals transmitted by large antenna arrays become highly focused. Indeed, the impact of passive eavesdropping has been shown to be negligible when the base station (BS) antenna size approaches infinity for Rayleigh channels. In this paper, we experimentally explore eavesdropping in massive MIMO incorporating real-world factors including a limited BS antenna array size, potential correlation in over-the-air channels, and adaptation of modulating and coding schemes (MCS) over a discrete and finite set. Using a 96-antenna ArgosV2 BS, we first explore scaling the array size and identify eavesdropper (Eve) advantages due to channel correlation. We next identify the “MCS saturation regime” as a vulnerability even with high SNR due to limited MCS levels, and thereby demonstrating the need for power control as a counter-strategy, especially considering Eve’s advantages in the over-the-air channels. We further demonstrate Eve’s gain in optimizing her position, not only via being nomadic and searching for the most favorable position, but also via exploiting predictable line-of-sight (LoS) positional vulnerabilities. Specifically, we demonstrate Eve’s advantage by simply sharing the elevation angle with Bob in the LoS scenario. Finally, we examine how Eve’s advantage due to channel correlation scales with more eavesdropping antennas.
Proceedings of the 26th Annual International Conference on Mobile Computing and Networking, 2020
THz communication has the potential to realize an order of magnitude increase in data rates due t... more THz communication has the potential to realize an order of magnitude increase in data rates due to the availability of wide THz-scale spectral bands. Unfortunately, establishing and managing highly directional beams in THz networks is challenging as links lack the "pseudo-omni" reception capability of lower bands and the product of AP-client beam resolution is high due to narrow beams of only a few degrees. In this paper, we present One-shot Path discovEry with a THz RAinbow (OPERA), a novel system that identifies dominant paths between the AP and all clients in order to efficiently steer directional beams. The key idea is to embed path direction into the inherent characteristics of signals traveling along each path. To do so, we exploit a single leaky wave antenna and create a THz Rainbow. A THz Rainbow transmission consists of distinct signals with unique spectral characteristics across the angular domain. Leveraging the spatial-spectral signatures in the THz Rainbow, all receivers can correlate the measured signal with the known transmission signatures to discover the sender's path directions in one-shot. Our experiments demonstrate that OPERA achieves average direction estimates within 2 • of ground truth for LOS and reflected paths. CCS CONCEPTS • Networks → Network protocol design; Wireless local area networks; Mobile networks.
Proceedings of the 18th Conference on Embedded Networked Sensor Systems, 2020
IEEE Transactions on Wireless Communications, 2016
When it comes to Machine-to-Machine (M2M) communications in advanced cellular networks, the resou... more When it comes to Machine-to-Machine (M2M) communications in advanced cellular networks, the resource allocation scheme should be reexamined to satisfy both low-cost M2M and mission-critical M2M. Because most M2M applications are uplink-dominated, we propose a mixed waiting-time auction and price-based dedicated uplink resource allocation framework for the low-cost and mission-critical M2M. The prioritized framework guarantees resources for traditional Humanto-Human (H2H) communications while meeting the needs of low-cost and mission-critical M2M devices on the basis of either time bids or direct price. In addition, the scheme ensures the existence and uniqueness of the Bayesian Nash equilibrium and the interregional and waiting-time-based truth-telling properties. This indirect mechanism holds with Bayesian-Nash incentive compatibility, interim efficiency, interim individual rationality and weakly budget balance. The results show that low-cost M2M devices with lower energy awareness are more willing to participate in the waiting-time auction, while mission-critical M2M with higher energy awareness turn to directly pay for guaranteed access. The delay in connected mode and the optimal price vary according to the M2M/H2H traffic loads and resource pool partitions. This work contributes insights that with proper mechanism design, low-cost M2M and mission-critical M2M can be served together, while the operator is financially compensated.
2015 IEEE International Conference on Communications (ICC), 2015
Since Machine-to-Machine (M2M) communications is going to be realized in advanced cellular networ... more Since Machine-to-Machine (M2M) communications is going to be realized in advanced cellular networks, the resource allocation scheme should be re-examined to satisfy both traditional Human-to-Human (H2H) communications (e.g., voice calls) and M2M communications. Because most M2M applications are delay-tolerant and uplink-dominated, we propose a waiting-line based uplink resource allocation framework in the M2M/H2H co-existence scenario. The proposed scheme guarantees resources for H2H communications while meeting the needs of M2M communications on a first-come first-served basis. In addition, the scheme ensures the existence and uniqueness of the Bayesian Nash equilibrium and the truth-telling property. Results show that M2M devices with lower energy opportunity cost are more willing to participate in the waiting-line based scheme, and the delay in the connected mode varies according to the H2H traffic load and the total number of competitors. However, M2M devices with higher energy opportunity cost may not join this time bid resource allocation scheme. This work contributes insights into the types of resource allocation schemes, bidding with time or bidding with money, for M2M devices with different levels of energy awareness.
2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies (UCMMT)
We present the first security study of THz networks which employ leaky wave antennas (LWAs). We s... more We present the first security study of THz networks which employ leaky wave antennas (LWAs). We show that the LWA's angle-frequency coupling leads to non-uniform secrecy capacity across sub-channels, very different from conventional eavesdropping threat models. This offers both challenges and opportunities for designing systems with enhanced security.
IEEE Transactions on Information Forensics and Security
The 25th Annual International Conference on Mobile Computing and Networking
The Wireless of the Students, by the Students, and for the Students (S3) Workshop provides a uniq... more The Wireless of the Students, by the Students, and for the Students (S3) Workshop provides a unique venue for graduate students around the world to present, discuss, and exchange ideas on cross-cutting research on mobile wireless networks. As its name suggests, the workshop is organized by students, and the technical sessions are given by student presenters. The workshop aims at fostering early-career development among students and exposing them to the workings of academic life. It provides a venue for students to learn about each other's' work and discover opportunities for collaboration. The workshop invites students to submit papers, posters, and demos. All submissions are peer-reviewed by the student program committee.
2022 IEEE Conference on Communications and Network Security (CNS)
Security against eavesdropping is one of the key concerns in the design of any communication syst... more Security against eavesdropping is one of the key concerns in the design of any communication system. Many common considerations of the security of a wireless communication channel rely on comparing the signal level measured by Bob (the intended receiver) to that accessible to Eve (an eavesdropper). Frameworks such as Wyner's wiretap model ensure the security of a link, in an average sense, when Bob's signal-to-noise ratio exceeds Eve's. Unfortunately, because these guarantees rely on statistical assumptions about noise, Eve can still occasionally succeed in decoding information. The goal of achieving exactly zero probability of intercept over an engineered region of the broadcast sector, which we term absolute security, remains elusive. Here, we describe the first architecture for a wireless link which provides absolute security. Our approach relies on the inherent properties of broadband and high-gain antennas, and is therefore ideally suited for implementation in millimeter-wave and terahertz wireless systems, where such antennas will generally be employed. We exploit spatial minima of the antenna pattern at different frequencies, the union of which defines a wide region where Eve is guaranteed to fail regardless of her computational capabilities, and regardless of the noise in the channels. Unlike conventional zero-forcing beam forming methods, we show that, for realistic assumptions about the antenna configuration and power budget, this absolute security guarantee can be achieved over most possible eavesdropper locations. Since we use relatively simple frequency-multiplexed coding, together with the underlying physics of a diffracting aperture, this idea is broadly applicable in many contexts.
2022 IEEE Conference on Communications and Network Security (CNS)
Proceedings of the 15th ACM Conference on Security and Privacy in Wireless and Mobile Networks
With the large bandwidths available in the terahertz regime, directional transmissions can exhibi... more With the large bandwidths available in the terahertz regime, directional transmissions can exhibit angular dispersion, i.e., frequencydependent radiation direction. Unfortunately, angular dispersion introduces new security threats as increased bandwidth necessarily yields a larger signal footprint in the spatial domain and potentially benefits an eavesdropper. This paper is the first study of secure transmission strategies on angularly dispersive links. Based on information theoretic foundations, we propose to channelize the wideband transmission in frequency, and perform secure coding across frequency channels. With over-the-air experiments, we show that the proposed method exploits the properties of angular dispersion to realize secure wideband transmissions, despite the increased signal footprint and even for practical irregular beams with side lobes and asymmetry. In contrast, without the proposed cross-channel coding strategy, angularly dispersive links can suffer from significant security degradation when bandwidth increases. CCS CONCEPTS • Security and privacy → Mobile and wireless security.
APL Photonics, 2021
Despite the rapidly growing interest in exploiting millimeter and terahertz waves for wireless da... more Despite the rapidly growing interest in exploiting millimeter and terahertz waves for wireless data transfer, the role of reflected non-lineof-sight (NLOS) paths in wireless networking is one of the least explored questions. In this paper, we investigate the idea of harnessing these specular NLOS paths for communication in directional networks at frequencies above 100 GHz. We explore several illustrative transmitter architectures, namely, a conventional substrate-lens dipole antenna and a leaky-wave antenna. We investigate how these high-gain directional antennas offer both new challenges and new opportunities for exploiting NLOS paths. Our results demonstrate the sensitivity to antenna alignment, power spectrum variations, and the disparity in supported bandwidth of various line-of-sight (LOS) and reflected path configurations. We show that NLOS paths can, under certain circumstances, offer even higher data rates than the conventional LOS path. This result illustrates the unique opportunities that distinguish THz wireless systems from those that operate at lower frequencies.
Proceedings of the 13th ACM Conference on Security and Privacy in Wireless and Mobile Networks, 2020
This paper presents the first security study of THz networks with Leaky Wave Antennas (LWAs). We ... more This paper presents the first security study of THz networks with Leaky Wave Antennas (LWAs). We employ a mix of analytical models and over-the-air experiments to explore the unique security properties of LWA links. We show via both models and experiments that the LWA's angle-frequency coupling leads to non-uniform secrecy capacity across sub-channels yielding advantages to an eavesdropper at edge frequencies. Yet, because different frequencies emit energy at different angles, the eavesdropper is thwarted from easily intercepting an entire wideband transmission. The experiments diverge from the analytical model in that the model underpredicts the eavesdropper's advantage at angles smaller than the target user and subsequent asymmetric performance across angles. Nonetheless, both the model and measurements show that increasingly wide bandwidth and correspondingly wide beams have only a modest marginal security penalty. CCS CONCEPTS • Security and privacy → Mobile and wireless security.
2018 IEEE Conference on Communications and Network Security (CNS), 2018
Massive MIMO has the potential to thwart passive eavesdropping as the signals transmitted by a la... more Massive MIMO has the potential to thwart passive eavesdropping as the signals transmitted by a large antenna array become highly focused. Indeed, the impact of passive eavesdropping has been shown to be negligible when the number of base station (BS) antennas approaches infinity for independent Rayleigh channels. In this paper, we experimentally explore eavesdropping in Massive MIMO incorporating real-world factors including a limited BS antenna array size, potential correlation in over-the-air channels, and adaptation of modulating and coding schemes (MCS) over a discrete and finite set. Using a 96-antenna ArgosV2 BS, we (i) explore scaling the array size; (ii) identify eavesdropper advantages due to channel correlation and the resulting increase in array size required to mitigate this advantage; (iii) identify the "MCS saturation regime" as a vulnerability even with high SNR, (iv) characterize transmit power control counter strategies at the BS, and (v) explore the impact of a nomadic eavesdropper that moves to find the most favorable position.
IEEE Transactions on Wireless Communications, 2021
Massive multiple-input and multiple-output (massive MIMO) has the potential to thwart passive eav... more Massive multiple-input and multiple-output (massive MIMO) has the potential to thwart passive eavesdropping as the signals transmitted by large antenna arrays become highly focused. Indeed, the impact of passive eavesdropping has been shown to be negligible when the base station (BS) antenna size approaches infinity for Rayleigh channels. In this paper, we experimentally explore eavesdropping in massive MIMO incorporating real-world factors including a limited BS antenna array size, potential correlation in over-the-air channels, and adaptation of modulating and coding schemes (MCS) over a discrete and finite set. Using a 96-antenna ArgosV2 BS, we first explore scaling the array size and identify eavesdropper (Eve) advantages due to channel correlation. We next identify the “MCS saturation regime” as a vulnerability even with high SNR due to limited MCS levels, and thereby demonstrating the need for power control as a counter-strategy, especially considering Eve’s advantages in the over-the-air channels. We further demonstrate Eve’s gain in optimizing her position, not only via being nomadic and searching for the most favorable position, but also via exploiting predictable line-of-sight (LoS) positional vulnerabilities. Specifically, we demonstrate Eve’s advantage by simply sharing the elevation angle with Bob in the LoS scenario. Finally, we examine how Eve’s advantage due to channel correlation scales with more eavesdropping antennas.
Proceedings of the 26th Annual International Conference on Mobile Computing and Networking, 2020
THz communication has the potential to realize an order of magnitude increase in data rates due t... more THz communication has the potential to realize an order of magnitude increase in data rates due to the availability of wide THz-scale spectral bands. Unfortunately, establishing and managing highly directional beams in THz networks is challenging as links lack the "pseudo-omni" reception capability of lower bands and the product of AP-client beam resolution is high due to narrow beams of only a few degrees. In this paper, we present One-shot Path discovEry with a THz RAinbow (OPERA), a novel system that identifies dominant paths between the AP and all clients in order to efficiently steer directional beams. The key idea is to embed path direction into the inherent characteristics of signals traveling along each path. To do so, we exploit a single leaky wave antenna and create a THz Rainbow. A THz Rainbow transmission consists of distinct signals with unique spectral characteristics across the angular domain. Leveraging the spatial-spectral signatures in the THz Rainbow, all receivers can correlate the measured signal with the known transmission signatures to discover the sender's path directions in one-shot. Our experiments demonstrate that OPERA achieves average direction estimates within 2 • of ground truth for LOS and reflected paths. CCS CONCEPTS • Networks → Network protocol design; Wireless local area networks; Mobile networks.
Proceedings of the 18th Conference on Embedded Networked Sensor Systems, 2020
IEEE Transactions on Wireless Communications, 2016
When it comes to Machine-to-Machine (M2M) communications in advanced cellular networks, the resou... more When it comes to Machine-to-Machine (M2M) communications in advanced cellular networks, the resource allocation scheme should be reexamined to satisfy both low-cost M2M and mission-critical M2M. Because most M2M applications are uplink-dominated, we propose a mixed waiting-time auction and price-based dedicated uplink resource allocation framework for the low-cost and mission-critical M2M. The prioritized framework guarantees resources for traditional Humanto-Human (H2H) communications while meeting the needs of low-cost and mission-critical M2M devices on the basis of either time bids or direct price. In addition, the scheme ensures the existence and uniqueness of the Bayesian Nash equilibrium and the interregional and waiting-time-based truth-telling properties. This indirect mechanism holds with Bayesian-Nash incentive compatibility, interim efficiency, interim individual rationality and weakly budget balance. The results show that low-cost M2M devices with lower energy awareness are more willing to participate in the waiting-time auction, while mission-critical M2M with higher energy awareness turn to directly pay for guaranteed access. The delay in connected mode and the optimal price vary according to the M2M/H2H traffic loads and resource pool partitions. This work contributes insights that with proper mechanism design, low-cost M2M and mission-critical M2M can be served together, while the operator is financially compensated.
2015 IEEE International Conference on Communications (ICC), 2015
Since Machine-to-Machine (M2M) communications is going to be realized in advanced cellular networ... more Since Machine-to-Machine (M2M) communications is going to be realized in advanced cellular networks, the resource allocation scheme should be re-examined to satisfy both traditional Human-to-Human (H2H) communications (e.g., voice calls) and M2M communications. Because most M2M applications are delay-tolerant and uplink-dominated, we propose a waiting-line based uplink resource allocation framework in the M2M/H2H co-existence scenario. The proposed scheme guarantees resources for H2H communications while meeting the needs of M2M communications on a first-come first-served basis. In addition, the scheme ensures the existence and uniqueness of the Bayesian Nash equilibrium and the truth-telling property. Results show that M2M devices with lower energy opportunity cost are more willing to participate in the waiting-line based scheme, and the delay in the connected mode varies according to the H2H traffic load and the total number of competitors. However, M2M devices with higher energy opportunity cost may not join this time bid resource allocation scheme. This work contributes insights into the types of resource allocation schemes, bidding with time or bidding with money, for M2M devices with different levels of energy awareness.
2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies (UCMMT)
We present the first security study of THz networks which employ leaky wave antennas (LWAs). We s... more We present the first security study of THz networks which employ leaky wave antennas (LWAs). We show that the LWA's angle-frequency coupling leads to non-uniform secrecy capacity across sub-channels, very different from conventional eavesdropping threat models. This offers both challenges and opportunities for designing systems with enhanced security.