Based on a novel proof model we prove security for simple discrete log cryptosystems for which security has been an open problem. We consider a combination of the random oracle (RO) model and the generic model. This corresponds to assuming an ideal hash function H given by an oracle and an ideal group of prime order q, where the binary encoding of the group elements is useless for cryptographic...

The concept of residual intersection, introduced by Artin and Nagata [l] in 1972, is a fruitful generalization of linkage as the following two examples attest. Let I be a strongly Cohen-Macaulay ideal in a CohenMacaulay local ring R. If Z satisfies the condition (G,), then Huneke [6, Proposition 4.31 has proved that the extended Rees algebra R[It, t‘1 is defined by an ideal which is obtained fr...

Abstract A relationship between a parametric ideal and its generic Gröbner basis is discussed, new stability condition of given. It shown that the quotient by generated using provides condition. Further, utilized to compute comprehensive system, hence as an application, we obtain algorithm for computing systems. The proposed has been implemented in computer algebra system Risa/Asir experimented...

Monomial ideals which are generic with respect to either their generators or irreducible components have minimal free resolutions derived from simplicial complexes. For a generic monomial ideal, the associated primes satisfy a saturated chain condition, and the Cohen-Macaulay property implies shellability for both the Scarf complex and the Stanley-Reisner complex. Reverse lexicographic initial ...

Abstract Abstract Background: Availability and affordability of medicines are crucial to achieving success in prevention programs, particularly in developing countries. Objective: The aim of this study was to determine the availability and affordability of cardiovascular medicines for secondary prevention in Tehran province of Iran. Methods: A cross-sectional survey was conducted in Tehran pro...