We present a new type of fault attacks on elliptic curve scalar multiplications: Sign Change Attacks. These attacks exploit different number representations as they are often employed in modern cryptographic applications. Previously, fault attacks on elliptic curves aimed to force a device to output points which are on a cryptographically weak curve. Such attacks can easily be defended against....

A new algorithm for the automatic computation of the complete root classification of a real parametric polynomial is described. The improvement lies in the fact that previous algorithms required ‘revised sign lists’ derived from the discriminant sequence. This is replaced here by the direct use of ‘sign lists’ derived from the discriminant sequence without the need for revision of the lists. As...

Received (received date) Revised (revised date) Communicated by (Name of Editor) ABSTRACT In this paper we study the solution of stable generalized Lyapunov matrix equations with large-scale, dense coeecient matrices. Our iterative algorithms, based on the matrix sign function, only require scalable matrix algebra kernels which are highly ee-cient on parallel distributed architectures. This app...

Coarse-mesh finite difference (CMFD) method is a widely used numerical acceleration method. However, the stability of CMFD not good for problems with optically thick regions. In this paper, rule named “sign preservation rule” in field heat transfer extended to scheme CMFD. It required that disturbance neutron current positively correlated negative value flux gradient. A necessary condition deri...

Inhomogeneities in wave propagation conditions near and below the solar surface have been detected by means of time-distance helioseismology. Here we calculate the effect of temperature inhomogeneities on the travel times of sound waves. A temperature increase, e.g. in active regions, not only increases the sound speed but also lengthens the path along which the wave travels because the expansi...