Luca Gammaitoni,1 Markus Löcher,4 Adi Bulsara,2 Peter Hänggi,3 Joseph Neff,4 Kurt Wiesenfeld,4 William Ditto,4 and Mario E. Inchiosa2 1Dipartimento di Fisica, Universitá di Perugia and Instituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06100 Perugia, Italy 2Space and Naval Warfare Systems Center San Diego, Code D-364, San Diego, California 92152-5001 3Institut für Physik, Universität...

EEcient numerical schemes for nonlinear diiusion ltering based on additive operator splitting (AOS) were introduced in 15]. AOS schemes are eecient and unconditionally stable, yet their accuracy is limited. Future applications of nonlinear diiusion ltering may require better accuracy at the expense of a relatively modest cost in computations and complexity. In this report we explore second orde...

We investigate the factored ADI iteration for large and sparse Sylvester equations. A novel low-rank expression for the associated Sylvester residual is established which enables cheap computations of the residual norm along the iteration, and which yields a reformulated factored ADI iteration. The application to generalized Sylvester equations is considered as well. We also discuss the efficie...

This paper shows how a well-balanced trade-off between a generic workstation and dumb but fast reconfigurable hardware can lead to a more efficient implementation of a cryptanalysis than a full hardware or a full software implementation. A realistic cryptanalysis of the A5/1 GSM stream cipher is presented as an illustration of such trade-off. We mention that our cryptanalysis requires only a mi...

1. Introduction. This note presents a few of the results which we have obtained by applying a classical and fundamental idea to the analysis of certain partial difference equations. The idea is that certain multidimensional problems can be solved by solving a few one-dimensional problems—it is the basis of the classical method of separation of variables of mathematical physics. In the case of p...

This issue of Wireless Security Perspectives focuses on GSM and the December 1999 article titled Real Time Cryptanalysis of the Alleged A5/1 on a PC (preliminary draft) by Alex Biryukov and Adi Shamir. The authors describe an attack on the GSM A5/1 traffic encryption algorithm and claim that by analyzing the output of the algorithm, one can recover the cryptographic key in less than a second us...

Balanced truncation (BT), as applied to date in model order reduction (MOR), is known for its superior accuracy and computable error bounds. Positive-real balanced truncation (PRBT) is a particular BT procedure that preserves passivity and stability, and imposes no structural constraints on the original state space. However, PRBT requires solving two algebraic Riccati equations (AREs), whose co...