5,406 research outputs found
Sen-Lab-LMS/Senescence_nuclear_features: Publication_version_2.0
No full text<p>Author checklist.</p>
The Contributions of Professor Amartya Sen in the Field of Human Rights
No full textThis paper analyses the work of the Nobel Prize winning economist Professor Amartya Sen from the perspective of human rights. It assesses the ways in which Sen's research agenda has deepened and expanded human rights discourse in the disciplines of ethics and economics, and examines how his work has promoted cross-fertilisation and integration on this subject across traditional disciplinary divides. The paper suggests that Sen's development of a 'scholarly bridge' between human rights and economics is an important and innovative contribution that has methodological as well as substantive importance and that provides a prototype and stimuli for future research. It also establishes that the idea of fundamental freedoms and human rights is itself an important gateway into understanding the nature, scope and significance of Sen's research. The paper concludes with a brief assessment of the challenges to be addressed in taking Sen's contributions in the field of human rights forward.Amartya Sen, human rights, poverty, freedom, obligation, capability approach, meta-rights, entitlements, opportunity freedom, liberty-rights
Inequalities, Agency, and Well-being: Conceptual Linkages and Measurement Challenges in Development
No full textdevelopment, inequality, gender, well-being, agency, capability, distribution, Sen
Advanced Low-Cost Electro-magnetic and Machine Learning Side-Channel Attacks
No full textSide-channel analysis (SCA) is a prominent tool to break mathematically secure cryptographic engines, especially on resource-constrained devices. SCA attacks utilize physical leakage vectors like the power consumption, electromagnetic (EM) radiation, timing, cache hits/misses, that reduce the complexity of determining a secret key drastically, going from 2128 for brute force attacks to 212 for SCA in the case of AES-128. Additionally, EM SCA attacks can be performed non-invasively without any modifications to the target under attack, unlike power SCA. To develop defenses against EM SCA, designers must evaluate the cryptographic implementations against the most powerful side-channel attacks. In this work, systems and techniques that improve EM side-channel analysis have been explored, making it lower-cost and more accessible to the research community to develop better countermeasures against such attacks. The first chapter of this thesis presents SCNIFFER, a platform to perform efficient end-to-end EM SCA attacks. SCNIFFER introduces leakage localization – an often-overlooked step in EM attacks – into the loop of an attack. Following SCNIFFER, the second chapter presents a practical machine learning (ML) based EM SCA attack on AES-128. This attack addresses issues dealing with low signal-to-noise ratio (SNR) EM measurements, proposing training and pre-processing techniques to perform an efficient profiling attack. In the final chapter, methods for mapping from power to EM measurements, are analyzed, which can enable training a ML model with much lower number of encryption traces. Additionally, SCA evaluation of high-level synthesis (HLS) based cryptographic algorithms is performed, along with the study of futuristic neural encryption techniques
Leakage Conversion for Training Machine Learning Side Channel Attack Models Faster
No full textRecent improvements in the area of Internet of Things (IoT) has led to extensive utilization of embedded devices and sensors. Hence, along with utilization the need for safety and security of these devices also increases proportionately. In the last two decades, the side-channel attack (SCA) has become a massive threat to the interrelated embedded devices. Moreover, extensive research has led to the development of many different forms of SCA for extracting the secret key by utilizing the various leakage information. Lately, machine learning (ML) based models have been more effective in breaking complex encryption systems than the other types of SCA models. However, these ML or DL models require a lot of data for training that cannot be collected while attacking a device in a real-world situation. Thus, in this thesis, we try to solve this issue by proposing the new technique of leakage conversion. In this technique, we try to convert the high signal to noise ratio (SNR) power traces to low SNR averaged electromagnetic traces. In addition to that, we also show how artificial neural networks (ANN) can learn various non-linear dependencies of features in leakage information, which cannot be done by adaptive digital signal processing (DSP) algorithms. Initially, we successfully convert traces in the time interval of 80 to 200 as the cryptographic operations occur in that time frame. Next, we show the successful conversion of traces lying in any time frame as well as having a random key and plain text values. Finally, to validate our leakage conversion technique and the generated traces we successfully implement correlation electromagnetic analysis (CEMA) with an approximate minimum traces to disclosure (MTD) of 480
Design of Intelligent Internet of Things and Internet of Bodies Sensor Nodes
No full textEnergy-efficient communication has remained the primary bottleneck in achieving fully energy-autonomous IoT nodes. Several scenarios including In-Sensor-Analytics (ISA), Collaborative Intelligence (CI) and Context-Aware-Switching (CAS) of the cluster-head during CI have been explored to trade-off the energies required for communication and computation in a wireless sensor network deployed in a mesh for multi-sensor measurement. A real-time co-optimization algorithm was developed for minimizing the energy consumption in the network for maximizing the overall battery lifetime of individual nodes.The difficulty of achieving the design goals of lifetime, information accuracy, transmission distance, and cost, using traditional battery powered devices has driven significant research in energy-harvested wireless sensor nodes. This challenge is further amplified by the inherent power intensive nature of long-range communication when sensor networks are required to span vast areas such as agricultural fields and remote terrain. Solar power is a common energy source is wireless sensor nodes, however, it is not reliable due to fluctuations in power stemming from the changing seasons and weather conditions. This paper tackles these issues by presenting a perpetually-powered, energy-harvesting sensor node which utilizes a minimally sized solar cell and is capable of long range communication by dynamically co-optimizing energy consumption and information transfer, termed as Energy-Information Dynamic Co-Optimization (EICO). This energy-information intelligence is achieved by adaptive duty cycling of information transfer based on the total amount of energy available from the harvester and charge storage element to optimize the energy consumption of the sensor node, while employing event driven communication to minimize loss of information. We show results of continuous monitoring across 1Km without replacing the battery and maintaining an information accuracy of at least 95%.Decades of continuous scaling in semiconductor technology has resulted in a drastic reduction in the cost and size of unit computing. This has enabled the design and development of small form factor wearable devices which communicate with each other to form a network around the body, commonly known as the Wireless Body Area Network (WBAN). These devices have found significant application for medical purposes such as reading surface bio-potential signals for monitoring, diagnosis, and therapy. One such device for the management of oropharyngeal swallowing disorders is described in this thesis. Radio wave transmission over air is the commonly used method of communication among these devices, but in recent years Human Body Communication has shown great promise to replace wireless communication for information exchange in a WBAN. However, there are very few studies in literature, that systematically study the channel loss of capacitive HBC for wearable devices over a wide frequency range with different terminations at the receiver, partly due to the need for miniaturized wearable devices for an accurate study. This thesis also measures and explores the channel loss of capacitive HBC from 100KHz to 1GHz for both high-impedance and 50Ω terminations using wearable, battery powered devices; which is mandatory for accurate measurement of the HBC channel-loss, due to ground coupling effects. The measured results provide a consistent wearable, wide-frequency HBC channel loss data and could serve as a backbone for the emerging field of HBC by aiding in the selection of an appropriate operation frequency and termination.Lastly, the power and security benefits of human body communication is demonstrated by extending it to animals (animal body communication)
Energy-Efficient Sensing and Communication for Secure Internet of Bodies (IOB)
No full textThe last few decades have witnessed unprecedented growth in multiple areas of electronics spanning low-power sensing, intelligent computing and high-speed wireless connectivity. In the foreseeable future, there would be hundreds of billions of computing devices, sensors, things and people, wherein the technology will become intertwined with our lives through continuous interaction and collaboration between humans and machines. Such human-centric ideas give rise to the concept of internet of bodies (IoB), which calls for novel and energy-efficient techniques for sensing, processing and secure communication for resource-constrained IoB nodes.As we have painfully learnt during the pandemic, pointof-care diagnostics along with continuous sensing and long-term connectivity has become one of the major requirements in the healthcare industry, further emphasizing the need for energy-efficiency and security in the resource-constrained devices around us.With this vision in mind, I’ll divide this dissertation into the following chapters. The first part (Chapter 2) will cover time-domain sensing techniques which allow inherent energyresolution scalability, and will show the fundamental limits of achievable resolution. Implementations will include 1) a radiation sensing system for occupational dosimetry in healthcare and mining applications, which can achieve 12-18 bit resolution with 0.01-1 µJ energy dissipation, and 2) an ADC-less neural signal acquisition system with direct Analog to Time Conversion at 13pJ/Sample. The second part (Chapters 3 and 4) of this dissertation will involve the fundamentals of developing secure energy-efficient electro-quasistatic (EQS) communication techniques for IoB wearables as well as implants, and will demonstrate 2 examples: 1) Adiabatic Switching for breaking the αCV2f limit of power consumption in capacitive voltage mode human-body communication (HBC), and 2) Bi-Phasic Quasistatic Brain Communication (BP-QBC) for fully wireless data transfer from a sub-6mm3 , 2 µW brain implant. A custom modulation scheme, along with adiabatic communication enables wireline-like energy efficiencies (\u3c5pJ/b) in HBC-based wireless systems, while the BP-QBC node, being fully electrical in nature, demonstrates sub-50pJ/b efficiencies by eliminating DC power consumption, and by avoiding the transduction losses observed in competing technologies, involving optical, ultrasound and magneto-electric modalities. Next in Chapter 5, we will show an implementation of a reconfigurable system that would include 1) a humanbody communication transceiver and 2) a traditional wireless (MedRadio) transceiver on the same integrated circuit (IC), and would demonstrate methods to switch between the two modes by detecting the placement of the transmitter and receiver devices (on-body/away from the body). Finally, in Chapter 6, we shall show a technique of augmenting security in resource-constrained devices through authentication using the Analog/RF properties of the transmitter, which are usually discarded as non-idealities in a digital transceiver chain. This method does not require any additional hardware in the transmitter, making it an extremely promising technique to augment security in highly resource-constrained scenarios. Such energy-efficient intelligent sensing and secure communication techniques, when combined with intelligent in-sensor-analytics at the resource-constrained nodes, can potentially pave the way for perpetual, and even batteryless systems for next-generation IoT, IoB and healthcare applications
Electro-Quasistatic Human Body Communication: From Bio-Physical Modeling to Broadband Circuits and HCI Applications
No full textDecades of scaling in semiconductor technology has resulted in a drastic reduction in the cost and size of unit computing. This has enabled computing capabilities in small form factor wearable and implantable devices. These devices communicate with each other to form a network around the body, commonly known as the Wireless Body Area Network (WBAN). Radio wave transmission over air is the commonly used method of communication among these devices. However, the human body can be used as the communication medium by utilizing its electrical conductivity property. This has given rise to Human Body Communication (HBC), which provides higher energy efficiency and enhanced security compared to over the air radio wave communication enabling applications like remote health monitoring, secure authentication. In this thesis we characterize the human body channel characteristics at low frequencies, utilize the insight obtained from the channel characterization to build high energyefficiency, interference-robust circuits and demonstrate the security and selectivity aspect of HBC through a Common Off the Shelf (COTS) component-based system. First, we characterize the response of the human body channel in the 10KHz1MHz frequency range with wearable transmitter/ receiver to study the feasibility of using it as a broadband communication channel. Voltage mode measurements with capacitive termination show almost flat-band response in this frequency range, establishing the body as a broadband channel. The body channel response is also measured across different interaction scenario between two wearable devices and a wearable and a computer. A bio- physical model of the HBC channel is developed to explain the measurement results and the wide discrepancies found in previous studies.We analyze the safety aspect of different type of HBC by carrying out theoretical circuit and FEM based simulations. A study is carried out among multiple subjects to assess the effect of HBC on the vital parameters of a subject. A statistical analysis of the results shows no significant change in the vital parameters before and during HBC transmission, validating the theoretical simulations showing ¿1000x safety margin compared to the established ICNIRP guidelines. Next, an HBC transceiver is built utilizing the wire-like, broadband human body channel to enable high energy efficiency. The transceiver also provides robustness to ambient interference picked up by the human body through integration followed by periodic sampling. The transceiver achieves 6.3pJ/bit energy efficiency while operating at a maximum data rate of 30 Mbps, while providing -30dB interference tolerant operation. Finally, a COTS based HBC prototype is developed, which utilizes low frequency operation to enable selective and physically secure communication strictly during touch for Human Computer Interaction (HCI) between two wearable devices for the first time. A thorough study of the effect of different parameters such as environment, posture, subject variation, on the channel loss has also been characterized to build a robust HBC system working across different use cases. Applications such as secure authentication (e.g. opening a door, pairing a smart device) and information exchange (e.g. payment, image, medical data, personal profile transfer) through touch is demonstrated to show the impact of HBC in enabling new human-machine interaction modalities
Advanced Em/Power Side-Channel Attacks and Low-Overhead Circuit-Level Countermeasures
No full textThe huge gamut of today’s internet-connected embedded devices has led to increasing concerns regarding the security and confidentiality of data. To address these requirements, most embedded devices employ cryptographic algorithms, which are computationally secure. Despite such mathematical guarantees, as these algorithms are implemented on a physical platform, they leak critical information in the form of power consumption, electromagnetic (EM) radiation, timing, cache hits and misses, and so on, leading to side-channel analysis (SCA) attacks. Non-profiled SCA attacks like differential/correlational power/EM analysis (DPA/CPA/DEMA/CEMA) are direct attacks on a single device to extract the secret key of an encryption algorithm. On the other hand, profiled attacks comprise of building an offline template (model) using an identical device and the attack is performed on a similar device with much fewer traces.This thesis focusses on developing efficient side-channel attacks and circuit-level lowoverhead generic countermeasures. A cross-device deep learning-based profiling power sidechannel attack (X-DeepSCA) is proposed which can break the secret key of an AES-128 encryption engine running on an Atmel microcontroller using just a single power trace, thereby increasing the threat surface of embedded devices significantly. Despite all these advancements, most works till date, both attacks as well as countermeasures, treat the crypto engine as a black box, and hence most protection techniques incur high power/area overheads.This work presents the first white-box modeling of the EM leakage from a crypto hardware, leading to the understanding that the critical correlated current signature should not be passed through the higher metal layers. To achieve this goal, a signature attenuation hardware (SAH) is utilized, embedding the crypto core locally within the lower metal layers so that the critical correlated current signature is not passed through the higher metals, which behave as efficient antennas and its radiation can be picked up by a nearby attacker. Combination of the 2 techniques – current-domain signature suppression and local lower metal routing shows \u3e 350× signature attenuation in measurements on our fabricated 65nm test chip, leading to SCA resiliency beyond 1B encryptions, which is a 100× improvement in both EM and power SCA protection over the prior works with comparable overheads. Moreover, this is a generic countermeasure and can be utilized for any crypto core without any performance degradation.Next, backed by our physics-level understanding of EM radiation, a digital library cell layout technique is proposed which shows \u3e 5× reduction in EM SCA leakage compared to the traditional digital logic gate layout design. Further, exploiting the magneto-quasistatic (MQS) regime of operation for the present-day CMOS circuits, a HFSS-based framework is proposed to develop a pre-silicon EM SCA evaluation technique to test the vulnerability of cryptographic implementations against such attacks during the design phase itself.Finally, considering the continuous growth of wearable and implantable devices around a human body, this thesis also analyzes the security of the internet-of-body (IoB) and proposes electro-quasistatic human body communication (EQS-HBC) to form a covert body area network. While the traditional wireless body area network (WBAN) signals can be intercepted even at a distance of 5m, the EQS-HBC signals can be detected only up to 0.15m, which is practically in physical contact with the person
OVERCOMING POSITIVISM IN ECONOMICS: AMARTYA SEN'S PROJECT OF INFUSING ETHICS INTO ECONOMICS
No full textLogical Positivism, which arose in philosophy early in the twentieth century, proclaimed the sharp distinction between facts and values. Despite objections at the time, positivism was imported into economics in the 1930s. Over time, objections lessened; economics was transformed and ethical considerations were driven out of its core. In the 1950s, debates about positivism arose within the discipline which had exported it. According to the American philosopher Hilary Putnam, the fact/value distinction is now discredited in philosophy. If that is so, the methodological foundations of contemporary economics are also discredited. In this article I examine Amartya Sen’s moral science of economics. First, I will present his historical account of the connections between economics and ethics. Sen claims that there was a close connection between the two until positivism was imported. Second, I will sketch some of Sen’s ethical objections to modern economics, which is still suffering from positivism. Finally, I will lay out some of his ideas on how economics can be returned to an ethical path. Once the ground has been cleared of positivism, ethics can re-emerge in economics in various ways. One path has been marked out by Sen.Teaching/Communication/Extension/Profession,
- …
