Browsing by Author "Kumar, Vireshwar"

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    3D printed graphene-based self-powered strain sensors for smart tires in autonomous vehicles
    Maurya, Deepam; Khaleghian, Seyedmeysam; Sriramdas, Rammohan; Kumar, Prashant; Kishore, Ravi Anant; Kang, Min-Gyu; Kumar, Vireshwar; Song, Hyun-Cheol; Lee, Seul-Yi; Yan, Yongke; Park, Jung-Min (Jerry); Taheri, Saied; Priya, Shashank (2020-10-26)
    The transition of autonomous vehicles into fleets requires an advanced control system design that relies on continuous feedback from the tires. Smart tires enable continuous monitoring of dynamic parameters by combining strain sensing with traditional tire functions. Here, we provide breakthrough in this direction by demonstrating tire-integrated system that combines direct mask-less 3D printed strain gauges, flexible piezoelectric energy harvester for powering the sensors and secure wireless data transfer electronics, and machine learning for predictive data analysis. Ink of graphene based material was designed to directly print strain sensor for measuring tire-road interactions under varying driving speeds, normal load, and tire pressure. A secure wireless data transfer hardware powered by a piezoelectric patch is implemented to demonstrate self-powered sensing and wireless communication capability. Combined, this study significantly advances the design and fabrication of cost-effective smart tires by demonstrating practical self-powered wireless strain sensing capability. Designing efficient sensors for smart tires for autonomous vehicles remains a challenge. Here, the authors present a tire-integrated system that combines direct mask-less 3D printed strain gauges, flexible piezoelectric energy harvester for powering the sensors and secure wireless data transfer electronics, and machine learning for predictive data analysis.
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    Cumulative Message Authentication Codes for Resource-Constrained IoT Networks
    Li, He; Kumar, Vireshwar; Park, Jung-Min (Jerry); Yang, Yaling (IEEE, 2021-08-01)
    In resource-constrained Internet-of-Things networks, the use of conventional message authentication codes (MACs) to provide message authentication and integrity is not possible due to the large size of the MAC output. A straightforward yet naive solution to this problem is to employ a truncated MAC which undesirably sacrifices cryptographic strength in exchange for reduced communication overhead. In this article, we address this problem by proposing a novel approach for message authentication called cumulative MAC (CuMAC), which consists of two distinctive procedures: 1) aggregation and 2) accumulation. In aggregation, a sender generates compact authentication tags from segments of multiple MACs by using a systematic encoding procedure. In accumulation, a receiver accumulates the cryptographic strength of the underlying MAC by collecting and verifying the authentication tags. Embodied with these two procedures, CuMAC enables the receiver to achieve an advantageous tradeoff between the cryptographic strength and the latency in the processing of the authentication tags. Furthermore, for some latency-sensitive messages where this tradeoff may be unacceptable, we propose a variant of CuMAC that we refer to as CuMAC with speculation (CuMAC/S). In addition to the aggregation and accumulation procedures, CuMAC/S enables the sender and receiver to employ a speculation procedure for predicting future message values and precomputing the corresponding MAC segments. For the messages which can be reliably speculated, CuMAC/S significantly reduces the MAC verification latency without compromising the cryptographic strength. We have carried out a comprehensive evaluation of CuMAC and CuMAC/S through simulation and a prototype implementation on a real car.
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    Group signatures with probabilistic revocation
    (United States Patent and Trademark Office, 2019-06-18)
    Aspects of group signatures with probabilistic revocation are described. In one example employing these aspects, at least one computing device can map an alias token to an alias code comprising a plurality of alias code segments. Each of the alias code segments is based at least in part on a set of orthogonal codes. Also, each of the alias code segments corresponds to a segment of the alias token. A revocation code is based at least in part on a plurality of revoked alias codes. One of the alias code segments and a corresponding segment of the revocation code can be utilized to determine a revocation status of the alias token.
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    Transmitter Authentication in Dynamic Spectrum Sharing
    Kumar, Vireshwar (Virginia Tech, 2017-02-02)
    Recent advances in spectrum access technologies, such as software-defined radios, have made dynamic spectrum sharing (DSS) a viable option for addressing the spectrum shortage problem. However, these advances have also contributed to the increased possibility of "rogue" transmitter radios which may cause significant interference to other radios in DSS. One approach for countering such threats is to employ a transmitter authentication scheme at the physical (PHY) layer. In PHY-layer authentication, an authentication signal is generated by the transmitter, and embedded into the message signal. This enables a regulatory enforcement entity to extract the authentication signal from the received signal, uniquely identify a transmitter, and collect verifiable evidence of a rogue transmission that can be used later during an adjudication process. There are two primary technical challenges in devising a transmitter authentication scheme for DSS: (1) how to generate and verify the authentication signal such that the required security and privacy criteria are met; and (2) how to embed and extract the authentication signal without negatively impacting the performance of the transmitters and the receivers in DSS. With regard to dealing with the first challenge, the authentication schemes in the prior art, which provide privacy-preserving authentication, have limited practical value for use in large networks due to the high computational complexity of their revocation check procedures. In this dissertation, the novel approaches which significantly improve scalability of the transmitter authentication with respect to revocation, are proposed. With regard to dealing with the second challenge, in the existing PHY-layer authentication techniques, the authentication signal is embedded into the message signal in such a way that the authentication signal appears as noise to the message signal and vice versa. Hence, existing schemes are constrained by a fundamental tradeoff between the message signal's signal to interference and noise ratio (SINR) and the authentication signal's SINR. In this dissertation, the novel approaches which are not constrained by the aforementioned tradeoff between message and authentication signals, are proposed.