A survey on group signature schemes

Group Signature, extension of digital signature, allows members of a group to sign messages on behalf of the group, such that the resulting signature does not reveal the identity of the signer. Any client can verify the authenticity of the document by using the public key parameters of the group. In case of dispute, only a designated group manager, because of his special property, is able to open signatures, and thus reveal the signer’s identity. Its applications are widespread, especially in e-commerce such as e-cash, e-voting and e-auction. This thesis incorporates the detailed study of various group signature schemes, their cryptographic concepts and the main contributions in this field. We implemented a popular group signature scheme based upon elliptic curve cryptosystems. Moreover, the group signature is dynamic i.e. remains valid, if some members leave the group or some new members join the group. Full traceability feature is also included in the implemented scheme. For enhanced security the the scheme implements distributed roles of the group manager. We also analysed various security features, formal models, challenges and cryptanalysis of some significant contributions in this area

Spectacular Role of Electron Correlation in the Hyperfine Interactions in 2D5/2^2D_{5/2} States in Alkaline Earth Ions

The low-lying n(=3,4,5)d $^2D_{5/2}$ states alkaline earth ions are of vital importance in a number of different physical applications. The hyperfine structure constants of these states are characterized by unusually strong electron correlation effects. Relativistic coupled-cluster theory has been employed to carry out {\it ab initio} calculations of these constants. The role of the all order core-polarization effects was found to be decisive in obtaining good agreement of the results of our calculations with accurate measurements. The present work is an apt demonstration of the power of the coupled-cluster method to cope with strongly interacting configurations.Comment: Submitted to Physical Review Letters, 3 figures and 5 table

Nuclei Near and Far From β-Stability Line

Proton to neutron ratio around β-stability line presents an open challenge to the nuclear physicists. The prominent milestone in this regard is the discovery of the super heavy elements, nuclear halos in the lightest neutron-rich nuclei, experimental mapping of the nuclear shell structure near and far from stability. In this present paper, the behavior of the p- and n- halo nuclei near the β-stability line are discussed considering the variation of radius with respect to the mass number and N~Z for different nuclei. Our aim is to study the nuclear properties through neutron and proton skin. The isospin symmetry breaking is for heavy halo nuclei of strong interest

Theoretical determination of lifetimes of metastable states in Sc III and Y III

Lifetimes of the first two metastable states in Sc^{2+} and Y^{2+} are determined using the relativistic coupled-cluster theory. There is a considerable interest in studying the electron correlation effects in these ions as though their electronic configurations are similar to the neutral alkali atoms, their structures are very different from the latter. We have made a comparative study of the correlation trends between the above doubly ionized systems with their corresponding neutral and singly ionized iso-electronic systems. The lifetimes of the excited states of these ions are very important in the field of astrophysics, especially for the study of post-main sequence evolution of the cool giant stars.Comment: 13 pages, 1 figure and 5 table

INFLUENCE OF FERTILIZER AND WEED MANAGEMENT ON YIELD AND NUTRIENT UPTAKE IN ONION (Allium cepa L.)

A field experiment was conducted to find out appropriate nutrient and weed management practices for yield maximization and nutrient uptake of onion during rabi 2018-19 at the experimental plot of Regional Research and Technology Transfer Station, Keonjhar of Odisha. The experiment was laid out in Split plot technique with fifteen treatments viz., Main plot belongs to Nutrient management (N) with treatments i.e. N1- Soil test based fertilizer recommendation (STBFR), N2 - 50% STBFR + FYM (Based on N requirement), N3-STBFR + Sulphur), while Subplots belongs to weed management (W) with treatments viz., W1- Pendimethalin (PE) @ 0.8 Lha-1, W2- Oxyflurofen (PE) @ 0.2 Lha-1, W3- Pendimethalin (PE) @ 0.8 Lha-1+ one hand weeding at 25 days after transplanting(DAT), W4-Oxyflurofen (PE) @ 0.2 Lha-1+ one hand weeding at 25 days after transplanting(DAT), W5- one hand weeding at 25 days after transplanting (DAT). The highest onion bulb yield of 16.72 t ha-1 was obtained under the treatment applied with Pendimethalin (PE) @ 0.8 Lha-1 along with one hand weeding at 25 DAT, followed by Oxyfluorfen 0.2Lha-1pre-emergence + 1 hand weeding at 25 DAT (15. 88 t ha-1). The treatment combination of N2W3 (96.83, 16.80, 57.73 kg ha-1) was recorded the highest N, P, and K uptake by crops respectively while N3W3 (51.39 kg ha-1) was recorded as the highest S uptake by a crop over the rest of the treatments

Deletions in the Y-derived amelogenin gene fragment in the Indian population

BACKGROUND: Rare failures in amelogenin-based gender typing of individuals have been observed globally. In this study, we report the deletion of a large fragment of the amelogenin gene in 10 individuals out of 4,257 male samples analyzed from 104 different endogamous populations of India. METHODS: Samples were analyzed using commercial genetic profiling kits. Those that exhibited failures in amelogenin-based gender identification were further analyzed with published as well as newly designed primers to ascertain the nature and extent of mutation. RESULTS: The failure rate among Indian males was 0.23 %. Though the exact size and nature of the deletion (single point mutations at a number of positions or a single large deletion) could not be determined in the present study, it is inferred that the deletion spans a region downstream of the reverse primer-binding site of commercially available amelogenin primer sets. Deletions were conspicuously absent among the Mongoloid tribes of Northeast India, while both caste and tribal groups harbored these mutations, which was predominantly among the Y-chromosomes belonging to J2 lineage. CONCLUSION: Our study indicates that the different amelogenin primer sets currently included in genetic profiling multiplex kits may result in erroneous interpretations due to mutations undetectable during routine testing. Further there are indications that these mutations could possibly be lineage-specific, inherited deletions