A Physical Layer Secured Key Distribution Technique for IEEE 802.11g Wireless Networks

Key distribution and renewing in wireless local area networks is a crucial issue to guarantee that unauthorized users are prevented from accessing the network. In this paper, we propose a technique for allowing an automatic bootstrap and periodic renewing of the network key by exploiting physical layer security principles, that is, the inherent differences among transmission channels. The proposed technique is based on scrambling of groups of consecutive packets and does not need the use of an initial authentication nor automatic repeat request protocols. We present a modification of the scrambling circuits included in the IEEE 802.11g standard which allows for a suitable error propagation at the unauthorized receiver, thus achieving physical layer security.Comment: 9 pages, 7 figures. Accepted for publication in IEEE Wireless Communications Letters. Copyright transferred to IEE

Improving the efficiency of the LDPC code-based McEliece cryptosystem through irregular codes

We consider the framework of the McEliece cryptosystem based on LDPC codes, which is a promising post-quantum alternative to classical public key cryptosystems. The use of LDPC codes in this context allows to achieve good security levels with very compact keys, which is an important advantage over the classical McEliece cryptosystem based on Goppa codes. However, only regular LDPC codes have been considered up to now, while some further improvement can be achieved by using irregular LDPC codes, which are known to achieve better error correction performance than regular LDPC codes. This is shown in this paper, for the first time at our knowledge. The possible use of irregular transformation matrices is also investigated, which further increases the efficiency of the system, especially in regard to the public key size.Comment: 6 pages, 3 figures, presented at ISCC 201

Summary Report of the Spin Physics Working Group

The contributions to the Spin Physics WG are summarized. Several new experimental results and plans for new measurements have been reported. An improved theoretical understanding of the most recent hot topics in spin physics has been discussed by many authors especially in the new fields of the transversity and generalized parton distributions.Comment: 20 pages, 14 Postscript figures, summary talk presented at the 9th International Workshop on Deep Inelastic Scattering (DIS 2001), Bologna, April 200

Low-power Secret-key Agreement over OFDM

Information-theoretic secret-key agreement is perhaps the most practically feasible mechanism that provides unconditional security at the physical layer to date. In this paper, we consider the problem of secret-key agreement by sharing randomness at low power over an orthogonal frequency division multiplexing (OFDM) link, in the presence of an eavesdropper. The low power assumption greatly simplifies the design of the randomness sharing scheme, even in a fading channel scenario. We assess the performance of the proposed system in terms of secrecy key rate and show that a practical approach to key sharing is obtained by using low-density parity check (LDPC) codes for information reconciliation. Numerical results confirm the merits of the proposed approach as a feasible and practical solution. Moreover, the outage formulation allows to implement secret-key agreement even when only statistical knowledge of the eavesdropper channel is available.Comment: 9 pages, 4 figures; this is the authors prepared version of the paper with the same name accepted for HotWiSec 2013, the Second ACM Workshop on Hot Topics on Wireless Network Security and Privacy, Budapest, Hungary 17-19 April 201

Selection criteria and robust optimization of a traction PM-Assisted Synchronous Reluctance motor

In the coming years, the electrification and the deployment of the electric motors in the urban transports will become a more and more widespread reality. The optimization stage of the electric motors usually does not consider in detail the real driving conditions of the car in which the motor is installed. It follows that the actual motor performance in operating points, particularly as regards the torque ripple and the efficiency, might be worse than expected. A robust solution is a required target. This paper deals with the design and optimization of a high-speed permanent-magnet-assisted synchronous reluctance motor for traction applications, taking into account both city and highway driving cycles. A procedure is employed in order to evaluate the most representative operating points, which have to be considered when a global optimization is required. An analysis of the solution robustness has been performed. Both results and advantages of the adopted methodology are highlighted

Synchronous reluctance motor iron losses: considering machine non-linearity at MTPA, FW, and MTPV operating conditions

Synchronous reluctance machine has high flux density fluctuations in the iron due to the high harmonics results from the rotor anisotropy. Thus, an accurate computation of the iron losses is of paramount importance, especially during the design stage. In this paper, a non-linear analytical model considering the magnetic iron saturation and the slotting effect is proposed. The model estimates accurately the iron losses at a wide range of operating speed. In addition, the accuracy of the non-linear model when the machine is highly saturated, i.e. when it works along the MTPA trajectory, is presented and verified. The model presented is general and can be applied to other configurations. A 36-slot four-pole machine, with three flux-barriers per pole is considered as a case study. Finite element analysis is used to validate the results achieved by means of the non-linear analytical model. Furthermore, an experimental setup is built to validate the simulation results

Patient safety competencies in undergraduate nursing students: a rapid evidence assessment

Aims To identify patient safety competencies, and determine the clinical learning environments that facilitate the development of patient safety competencies in nursing students. Background Patient safety in nursing education is of key importance for health professional environments, settings, and care systems. To be effective, safe nursing practice requires a good integration between increasing knowledge and the different clinical practice settings. Nurse educators have the responsibility to develop effective learning processes and ensure patient safety. Design Rapid Evidence Assessment. Data Sources MEDLINE, CINAHL, SCOPUS, and ERIC were searched, yielding 500 citations published between 1 January 2004 - 30 September 2014. Review Methods Following the Rapid Evidence Assessment process, 17 studies were included in this review. Hawker's (2002) quality assessment tool was used to assess the quality of the selected studies. Results Undergraduate nursing students need to develop competencies to ensure patient safety. The quality of the pedagogical atmosphere in the clinical setting has an important impact on the students’ overall level of competence. Active student engagement in clinical processes stimulates their critical reasoning, improves interpersonal communication, and facilitates adequate supervision and feedback. Conclusion Few studies describe the nursing students’ patient safety competencies and exactly what they need to learn. In addition, studies describe only briefly which clinical learning environments facilitate the development of patient safety competencies in nursing students. Further research is needed to identify additional pedagogical strategies and the specific characteristics of the clinical learning environments that encourage the development of nursing students’ patient safety competencies