An algebraic time-advantage-based key establishment protocol

In this thesis we have built a key-establishment protocol which takes advantage of a resource : time. When two devices spends a pre-determined, mostly uninterrupted time interval with each other they would be able to establish a key. However it is not just the quantity of time but also the quality which matters. The information gained about the key with time by the legitimate party can is flexible and can be chosen by the user. We have analyzed our protocol thoroughly and discussed the circumstances an adversary can gain access to information about the key

Method to secure data in the cloud while preserving summary statistics

In this paper we propose a method which will preserve sum- mary statistics of data organized in a two way table. We have shown that fully homomorphic encryption is a powerful solution. However it has a number of disadvantages which makes it impractical. We have proposed a Restricted homomorphic encryption method which uses Pailier encryp- tion and order preserving encryption. This new method can be used for practical purposes owing to it’s efficiency in terms of both speed and storage

An algebraic time-advantage-based key establishment protocol

In this thesis we have built a key-establishment protocol which takes advantage of a resource : time. When two devices spends a pre-determined, mostly uninterrupted time interval with each other they would be able to establish a key. However it is not just the quantity of time but also the quality which matters. The information gained about the key with time by the legitimate party can is flexible and can be chosen by the user. We have analyzed our protocol thoroughly and discussed the circumstances an adversary can gain access to information about the key.</p

Scholars Journal of Medical Case Reports ISSN 2347-9507 (Print) Intraoperative scrape cytology: A rare case of primary ovarian Burkitt&apos;s lymphoma

Abstract: Here we have presented a case of ovarian Burkitt lymphoma. A 7 year old girl presented with ascites and fever for last two weeks. On Abdominal computer tomography (CT) a solid right ovarian mass was detected measuring 6 cm in greatest dimension. Omental deposits were also found. This patient underwent oopherectomy. We prepared the scrape smears from the ovarian mass and stained by Leishman-Giemsa, Hematoxylin and Eosin (H&amp;E) and papanicolaou (Pap) stain. Smears showed high cellularity, mostly composed of monomorphic, small, non-cleaved cells. Few of them showed cytoplasmic vacuolation. Occasional macrophages were also noted. A provisional diagnosis of Non-Hodgkin&apos;s lymphoma probably Burkitt&apos;s lymphoma was suggested based on the cytomorphological features. Later histopathological correlation was performed which confirmed the cytological diagnosis of Burkitt&apos;s lymphoma. We concluded that intraoperative scrape cytology can be a cheap yet rapid alternative of costly frozen section method for the diagnosis of ovarian lymphoma

Secret Image Sharing Schemes: A Comprehensive Survey

The safeguarding of digitized data against unwanted access and modification has become an issue of utmost importance as a direct result of the rapid development of network technology and internet applications. In response to this challenge, numerous secret image sharing (SIS) schemes have been developed. SIS is a method for protecting sensitive digital images from unauthorized access and alteration. The secret image is fragmented into a large number of arbitrary shares, each of which is designed to prevent the disclosure of any information to the trespassers. In this paper, we present a comprehensive survey of SIS schemes along with their pros and cons. We review various existing verifiable secret image sharing (VSIS) schemes that are immune to different types of cheating. We have identified various aspects of developing secure and efficient SIS schemes. In addition to that, a comparison and contrast of several SIS methodologies based on various properties is included in this survey work. We also highlight some of the applications based on SIS. Finally, we present open challenges and future directions in the field of SIS

Confining charge-transfer complex in a metal-organic framework for photocatalytic CO2 reduction in water

Abstract In the quest for renewable fuel production, the selective conversion of CO2 to CH4 under visible light in water is a leading-edge challenge considering the involvement of kinetically sluggish multiple elementary steps. Herein, 1-pyrenebutyric acid is post-synthetically grafted in a defect-engineered Zr-based metal organic framework by replacing exchangeable formate. Then, methyl viologen is incorporated in the confined space of post-modified MOF to achieve donor-acceptor complex, which acts as an antenna to harvest visible light, and regulates electron transfer to the catalytic center (Zr-oxo cluster) to enable visible-light-driven CO2 reduction reaction. The proximal presence of the charge transfer complex enhances charge transfer kinetics as realized from transient absorption spectroscopy, and the facile electron transfer helps to produce CH4 from CO2. The reported material produces 7.3 mmol g−1 of CH4 under light irradiation in aqueous medium using sacrificial agents. Mechanistic information gleans from electron paramagnetic resonance, in situ diffuse reflectance FT-IR and density functional theory calculation

Developing post-modified Ce-MOF as a photocatalyst: a detail mechanistic insight into CO2_2 reduction toward selective C2 product formation

Visible light-driven C–C bond formation to produce C2-based liquid fuel selectively from CO$_2$ is of great interest and remains a challenging task due to uphill electron transfer kinetics. Herein, we have developed [Ru(bpy)$_2$]$^{2+}$-grafted UiO-66-bpydc Ce-MOFvia post-synthetic modification to harvest visible light based on MLCT $(RU_{d\pi}^{II} \to \pi_{bpy}^*)$ transition. The employment of Ru-grafted Ce-MOF facilitates fast electron transfer due to the vacant low-lying 4f orbital of Ce$^{IV}$, which was realized from ultrafast transient absorption (TA) spectroscopy, XANES, and in situ UV-vis spectroscopy. The synergistic effect of facile electron transfer and concomitant accommodation of two CO$_2$ molecules in the proximal defect-site in Ce$^{IV}$ leads to facile C–C bond formation via COOH* coupling to yield acetic acid. The catalytic assembly produces 1133 μmol g$^{−1}$ of acetic acid with an impressive rate of 128 μmol g$^{−1}$ h$^{−1}$, suppressing the formation of other C1-based carbonaceous products in water (with selectivity 99.5%, apparent quantum yield (AQY) = 0.93%). A detailed DFT calculation has been performed to understand the mechanistic pathway of C–C bond formation, and the generation of different surface-adsorbed intermediates was further supported by in situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy