Articles written in Sadhana

    • Dynamic model of fractional thermoelasticity due to ramp-type heating with two relaxation times


      More Details Abstract Fulltext PDF

      This is an attempt to design a fractional heat conduction model in a bounded cylindrical region exposed to axisymmetric ramp-type heat flux and discuss its thermal behaviour. This model is drafted using the classical theory of fractional thermoelasticity due to the involvement of two relaxation times to the heatconduction equation and the equations of motion. In order to achieve finite thermal wave speed, the heat conduction equation is derived from the viewpoint of Maxwell–Cattaneo law in the context of fractional derivative. Analytical results for the distribution of temperature, displacement and thermal stresses are obtainedusing integral transforms in the Laplace domain. The Gaver–Stehfest method has been used to invert the results of Laplace domain. The convergence of infinite series solutions has been discussed. As a specific case this model has been applied to a thick circular plate subjected to the axisymmetric ramp-type heat flux. The results obtained for the thermal variations are validated by comparing to coupled and generalized theory of thermoelasticity. These comparisons are shown graphically.

    • A quantum secure ID-based cryptographic encryption based on group rings


      More Details Abstract Fulltext PDF

      Identity-based (ID-based) encryption is a very important cryptographic primitive. It is advantageous over the conventional public key cryptosystems due to direct and easy verification of the public keys. The security of most of the ID-based encryption schemes is based directly or indirectly on solving integer factorizationproblem, Elliptic curve discrete logarithm problem or discrete logarithm problem. It is known that these well-studied problems are not safe against attacks on a sufficiently large quantum computer. Therefore, in this paper we propose a secure ID-based encryption scheme whose security depends on the newly discovered hard problems in the algebraic structure of group rings. We show that the proposed scheme is IND-ID-CPA secure and safe against the chosen ciphertext attack. Moreover, we also comment on the IND-ID-CCA security of theproposed scheme.

  • Sadhana | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.