113,761 research outputs found

    Secure and Efficient RNS Approach for Elliptic Curve Cryptography

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    Scalar multiplication, the main operation in elliptic curve cryptographic protocols, is vulnerable to side-channel (SCA) and fault injection (FA) attacks. An efficient countermeasure for scalar multiplication can be provided by using alternative number systems like the Residue Number System (RNS). In RNS, a number is represented as a set of smaller numbers, where each one is the result of the modular reduction with a given moduli basis. Under certain requirements, a number can be uniquely transformed from the integers to the RNS domain (and vice versa) and all arithmetic operations can be performed in RNS. This representation provides an inherent SCA and FA resistance to many attacks and can be further enhanced by RNS arithmetic manipulation or more traditional algorithmic countermeasures. In this paper, extending our previous work, we explore the potentials of RNS as an SCA and FA countermeasure and provide an description of RNS based SCA and FA resistance means. We propose a secure and efficient Montgomery Power Ladder based scalar multiplication algorithm on RNS and discuss its SCAFA resistance. The proposed algorithm is implemented on an ARM Cortex A7 processor and its SCA-FA resistance is evaluated by collecting preliminary leakage trace results that validate our initial assumptions

    Employer-based support for registered nurses undertaking postgraduate study via distance education

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    Previous literature has focused on the need for support of undergraduate nursing students during clinical placements. Little is known about the support provided by employers for registered nurses (RNs) who pursue further education. This study sought to identify and describe the types, levels and perceived need for support in the workplace for RNs as they undertake further postgraduate nursing study by distance education (DE).Using an exploratory descriptive design a self-report questionnaire was distributed to a convenient sample of 270 RNs working in one acute care public hospital in Tasmania, Australia.92 questionnaires (response rate 34%) were returned with 26 (28%) reporting being currently enrolled in further study by DE and a further 50 (54)% of RNs planning future study. Results revealed that 100% of participants with a Masters degree completed this by DE. There were differences between the support sought by RNs to that offered by employers, and 16 (34%) who had done or were currently doing DE study, received no support to undertake DE. There was an overwhelming desire by RNs for support; 87 (94%), with a majority believing some support should be mandatory 76 (83%).This study may encourage employers to introduce structured support systems that will actively assist nurses to pursue further study. © 2010

    Residue Number System Hardware Emulator and Instructions Generator

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    Residue Number System (RNS) is an alternative form of representing integers on which a large value gets represented by a set of smaller and independent integers. Cryptographic and signal filtering algorithms benefit from the use of RNS, due to its capabilities to increase performance and security. Herein, a simulation tool is presented which emulates the hardware implementation of an actual RNS co-processor. An “high-level to assembly” instructions generator is also built into this tool. The programmability and scalable architecture of the considered processor along with the high level description of the algorithm allows researchers and developers to easily evaluate and test their RNS algorithms on an actual architecture, using Java

    Covariant Map Between Ramond-Neveu-Schwarz and Pure Spinor Formalisms for the Superstring

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    A covariant map between the Ramond-Neveu-Schwarz (RNS) and pure spinor formalisms for the superstring is found which transforms the RNS and pure spinor BRST operators into each other. The key ingredient is a dynamical twisting of the ten spin-half RNS fermions into five spin-one and five spin-zero fermions using bosonic pure spinors that parameterize an SO(10)/U(5) coset. The map relates massless vertex operators in the two formalisms, and gives a new description of Ramond states which does not require spin fields. An argument is proposed for relating the amplitude prescriptions in the two formalisms.Comment: Added referenc

    Condensation phase transitions of symmetric conserved-mass aggregation model on complex networks

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    We investigate condensation phase transitions of symmetric conserved-mass aggregation (SCA) model on random networks (RNs) and scale-free networks (SFNs) with degree distribution P(k)kγP(k) \sim k^{-\gamma}. In SCA model, masses diffuse with unite rate, and unit mass chips off from mass with rate ω\omega. The dynamics conserves total mass density ρ\rho. In the steady state, on RNs and SFNs with γ>3\gamma>3 for ω\omega \neq \infty, we numerically show that SCA model undergoes the same type condensation transitions as those on regular lattices. However the critical line ρc(ω)\rho_c (\omega) depends on network structures. On SFNs with γ3\gamma \leq 3, the fluid phase of exponential mass distribution completely disappears and no phase transitions occurs. Instead, the condensation with exponentially decaying background mass distribution always takes place for any non-zero density. For the existence of the condensed phase for γ3\gamma \leq 3 at the zero density limit, we investigate one lamb-lion problem on RNs and SFNs. We numerically show that a lamb survives indefinitely with finite survival probability on RNs and SFNs with γ>3\gamma >3, and dies out exponentially on SFNs with γ3\gamma \leq 3. The finite life time of a lamb on SFNs with γ3\gamma \leq 3 ensures the existence of the condensation at the zero density limit on SFNs with γ3\gamma \leq 3 at which direct numerical simulations are practically impossible. At ω=\omega = \infty, we numerically confirm that complete condensation takes place for any ρ>0\rho > 0 on RNs. Together with the recent study on SFNs, the complete condensation always occurs on both RNs and SFNs in zero range process with constant hopping rate.Comment: 6 pages, 6 figure
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