IMPLEMENTING SHA-224/256 ALGORITHM FOR SECURE COMMITMENT SCHEME APPLICATIONS USING FPGA

This paper uses the similarity between SHA-224 and SHA-256 algorithms to design the SHA-224/256 IP core oriented Digital Signature. The IP core uses parallel structure and pipeline technology to simplify the hardware design and improve the speed by 26%. Finally this IP core is implemented on the Altera’s FPGA EP2C20F484C6 chip. And its simulation result can run rightly under the 100MHz frequency. This IP core can be widely used in the data integrity and consistency verification, pseudo random number generation and other areas of cryptography

Analysis and Implementation of Policy Inference of Uploaded Images on Networking Sites

Human or user increase in the usage of social networking through various platforms by sharing their images increased a need for developing more secure systems which help user to share information among groups or people that he or she authorizes without causing any security issues in future. People can then share their desired images by applying different settings on the image such as who can view the image, who can download the image etc., and least bother about the privacy. To solve the privacy problem of excessive and careless sharing of images and information by users, this paper analyzes and describes a privacy policy development system that helps users to create new privacy settings for the images they share and helps in reducing the security breach or fraud over internet. It also helps the user by providing individual settings to all the images they share individually. Depending on the user history on the sharing site, the system proposes a policy in which the user can approve or make changes to the privacy prediction. Polices are thus improved afterwards in time with all the user inputs. Along with the description, this paper also presents a part of implementation of the system

Enabling Human-Robot Collaboration via Holistic Human Perception and Partner-Aware Control

As robotic technology advances, the barriers to the coexistence of humans and robots are slowly coming down. Application domains like elderly care, collaborative manufacturing, collaborative manipulation, etc., are considered the need of the hour, and progress in robotics holds the potential to address many societal challenges. The future socio-technical systems constitute of blended workforce with a symbiotic relationship between human and robot partners working collaboratively. This thesis attempts to address some of the research challenges in enabling human-robot collaboration. In particular, the challenge of a holistic perception of a human partner to continuously communicate his intentions and needs in real-time to a robot partner is crucial for the successful realization of a collaborative task. Towards that end, we present a holistic human perception framework for real-time monitoring of whole-body human motion and dynamics. On the other hand, the challenge of leveraging assistance from a human partner will lead to improved human-robot collaboration. In this direction, we attempt at methodically defining what constitutes assistance from a human partner and propose partner-aware robot control strategies to endow robots with the capacity to meaningfully engage in a collaborative task

Vakuumbasierte Abscheidung von funktionellen Nanokompositen und deren Modifikation durch Ionenstrahlbehandlung

Nanocomposite thin film coatings with a wide range of metal volume fractions were prepared by co–sputtering of TiO2/Teflon and Ag/Au from two different magnetron sources simultaneously in a home made deposition chamber under high vacuum conditions. Two different types of host materials a polymeric (PTFE) and a ceramic (TiO2) were studied in this work. Morphology, optical and antibacterial properties of these nanocomposites were examined. The formation of metallic nanoparticles upon vapor phase co–deposition of a metal and a dielectric matrix component can be understood in terms of the high cohesive energy of the metal and the low metal-matrix interaction energy which lead to high metal atom mobility on the growing composite surface and metal aggregation whenever metal atoms encounter each other or a metal cluster. Unlike the case of polymers, in the case of Ag nanoparticles on TiO2, segregation of the clusters on the surface also provides a fast pathway for Ostwald ripening without any restrictions by elastic distortions at least for those clusters which are in direct contact with the surface. 3D electron tomography was employed on the TiO2 based nanocomposite thin films to explain the two step model for the particle size distribution. First step involved the formation of small nanoparticles during vacuum phase deposition or on the growing surface. Second step after the deposition process involved the formation of larger particles through particle coarsening by Ostwald ripening and surface segregation. In bimetallic nanocomposites based on sandwich geometry in polymer system, the changes in the particle plasmon spectra of sandwiched Au nanoclusters as a result of the presence of Ag nanoclusters in their vicinity and vice versa was studied. Also, the optimum dielectric barrier thickness for the observation of equal intensity double plasmon resonance was reported. Also efforts towards tuning of the double plasmon resonances by tailoring the dielectric separation were carried out. Special attention was laid on the swift heavy ion irradiation (SHI) of the nanocomposites. The SHI beamlines from both the Hahn–Meitner–Institute in Berlin, Germany and the Inter University Accelerator Center in New–Delhi, India, were employed in this work. The TiO phase formation on SHI irradiation with increasing fluence was understood by the interaction of two different counteracting mechanisms, where at lower fluences, the tendency towards the formation of TiO existed with the larger unaffected areas and at higher fluences, the destruction of the evolved TiO phase into fragments was evident. This served as an evidence for the counter play between "hit" and "no–hit", "single–hit" and "multiple–hit" processes. A comparative study involving the in–situ heating of the TiO2 based nanocomposites in the TEM confirms the absence of the formation of TiO. Changes of the microstructure of the nanocomposite film upon annealing allowed demonstrating the absence of the formation of TiO but rather only the crystallization of the TiO2. SHI irradiation of Ag nanoparticles embedded in PTFE matrix shows a marginal dissolution of Ag nanoparticles along with a slight agglomeration of nanoparticles. At higher fluences, carbon rich areas were observed, which were as a result of the carbonization along the ion tracks. Functionality of the nanocomposites in terms of the antibacterial properties was studied. Cultures of B.megaterium, S.aureus, S.epidermidis and E.coli were used to study the effect on the Ag–TiO2 nanocomposites. Additionally, silver ion release studies were carried out at dfferent MVFs by using X-ray photoelectron and UV-Vis/NIR spectroscopies. Enhancement of the silver ion release after SHI irradiation at a fluence was observed to the fact that the ion trajectories after irradiation provide better silver ion release

GAN you train your network

2022 Summer.Includes bibliographical references.Zero-shot classifiers identify unseen classes — classes not seen during training. Specifically, zero-shot models classify attribute information associated with classes (e.g., a zebra has stripes but a lion does not). Lately, the usage of generative adversarial networks (GAN) for zero-shot learning has significantly improved the recognition accuracy of unseen classes by producing visual features on any class. Here, I investigate how similar visual features obtained from images of a class are to the visual features generated by a GAN. I find that, regardless of metric, both sets of visual features are disjointed. I also fine-tune a ResNet so that it produces visual features that are similar to the visual features generated by a GAN — this is novel because all standard approaches do the opposite: they train the GAN to match the output of the model. I conclude that these experiments emphasize the need to establish a standard input pipeline in zero-shot learning because of the mismatch of generated and real features, as well as the variation in features (and subsequent GAN performance) from different implementations of models such as ResNet-101

Reinventing Integrated Photonic Devices and Circuits for High Performance Communication and Computing Applications

The long-standing technological pillars for computing systems evolution, namely Moore\u27s law and Von Neumann architecture, are breaking down under the pressure of meeting the capacity and energy efficiency demands of computing and communication architectures that are designed to process modern data-centric applications related to Artificial Intelligence (AI), Big Data, and Internet-of-Things (IoT). In response, both industry and academia have turned to \u27more-than-Moore\u27 technologies for realizing hardware architectures for communication and computing. Fortunately, Silicon Photonics (SiPh) has emerged as one highly promising ‘more-than-Moore’ technology. Recent progress has enabled SiPh-based interconnects to outperform traditional electrical interconnects, offering advantages like high bandwidth density, near-light speed data transfer, distance-independent bitrate, and low energy consumption. Furthermore, SiPh-based electro-optic (E-O) computing circuits have exhibited up to two orders of magnitude improvements in performance and energy efficiency compared to their electronic counterparts. Thus, SiPh stands out as a compelling solution for creating high-performance and energy-efficient hardware for communication and computing applications. Despite their advantages, SiPh-based interconnects face various design challenges that hamper their reliability, scalability, performance, and energy efficiency. These include limited optical power budget (OPB), high static power dissipation, crosstalk noise, fabrication and on-chip temperature variations, and limited spectral bandwidth for multiplexing. Similarly, SiPh-based E-O computing circuits also face several challenges. Firstly, the E-O circuits for simple logic functions lack the all-electrical input handling, raising hardware area and complexity. Secondly, the E-O arithmetic circuits occupy vast areas (at least 100x) while hardly achieving more than 60% hardware utilization, versus CMOS implementations, leading to high idle times, and non-amortizable area and static power overheads. Thirdly, the high area overhead of E-O circuits hinders them from achieving high spatial parallelism on-chip. This is because the high area overhead limits the count of E-O circuits that can be implemented on a reticle-size limited chip. My research offers significant contributions to address the aforementioned challenges. For SiPh-based interconnects, my contributions focus on enhancing OPB by mitigating crosstalk noise, addressing the optical non-linearity-related issues through the development of Silicon-on-Sapphire-based photonic interconnects, exploring multi-level signaling, and evaluating various device-level design pathways. This enables the design of high throughput (\u3e1Tbps) and energy-efficient (\u3c1pJ/bit) SiPh interconnects. In the context of SiPh-based E-O circuits, my contributions include the design of a microring-based polymorphic E-O logic gate, a hybrid time-amplitude analog optical modulator, and an indium tin oxide-based silicon nitride microring modulator and a weight bank for neural network computations. These designs significantly reduce the area overhead of current E-O computing circuits while enhancing the energy-efficiency, and hardware utilization