Browsing by Author "Jiménez Urroz, Jorge"
Now showing items 113 of 13

A study of the separating property in ReedSolomon codes by bounding the minimum distance
Fernández Muñoz, Marcel; Jiménez Urroz, Jorge (202202)
Article
Open AccessAccording to their strength, the tracing properties of a code can be categorized as frameproof, separating, IPP and TA. It is known that, if the minimum distance of the code is larger than a certain threshold then the TA ... 
ANÀLISI REAL (Examen 2n quadrim)
Jiménez Urroz, Jorge (Universitat Politècnica de Catalunya, 20070525)
Exam
Restricted access to the UPC academic community 
Cropping Euler factors of modular Lfunctions
González Rovira, Josep; Jiménez Urroz, Jorge; Lario Loyo, Joan Carles (201309)
Article
Open AccessAccording to the Birch and SwinnertonDyer conjectures, if A/Q is an abelian variety, then its Lfunction must capture a substantial part of the properties of A. The smallest number field L where A has all its endomorphisms ... 
Every integer can be written as a square plus a squarefree
Jiménez Urroz, Jorge (20211230)
Article
Restricted access  publisher's policyIn the paper we can prove that every integer can be written as the sum of two integers, one perfect square and one squarefree. We also establish the asymptotic formula for the number of representations of an integer in ... 
Factorization and Malleability of RSA Moduli, and Counting Points on Elliptic Curves Modulo N
Dieulefait, Luis Victor; Jiménez Urroz, Jorge (Multidisciplinary Digital Publishing Institute (MDPI), 20201127)
Article
Open AccessIn this paper we address two different problems related with the factorization of an RSA (Rivest–Shamir–Adleman cryptosystem) modulus N. First we show that factoring is equivalent, in deterministic polynomial time, to ... 
Modular forms with large coefficient fields via congruences
Dieulefait, Luis; Jiménez Urroz, Jorge; Ribet, Keneth (Springer, 20150501)
Article
Open AccessWe use the theory of congruences between modular forms to prove the existence of newforms with squarefree level having a fixed number of prime factors such that the degree of their coefficient fields is arbitrarily large. ... 
On fields of definition of torsion points of elliptic curves with complex multiplication
Dieulefait, Luis Victor; Gonzalez Jimenez, Enrique; Jiménez Urroz, Jorge (201106)
Article
Open AccessFor any elliptic curve E defined over the rationals with complex multiplication (CM) and for every prime p, we describe the image of the mod p Galois representation attached to E. We deduce information about the field of ... 
On some classes of irreducible polynomials
Gutiérrez Gutiérrez, Jaime; Jiménez Urroz, Jorge (202007)
Article
Restricted access  publisher's policyOne of the fundamental tasks of Symbolic Computation is the factorization of polynomials into irreducible factors. The aim of the paper is to produce new families of irreducible polynomials, generalizing previous results ... 
Orders of CM elliptic curves modulo p with at most two primes
Iwaniec, Henryk; Jiménez Urroz, Jorge (2006)
Article
Open AccessWe prove the analog of Koblitz conjecture when replacing primes by almost prime numbers and considering elliptic curves with complex multiplication. In other words for infinitely many primes $p$, (given in a quantitative ... 
Orders of CM elliptic curves modulo p with at most two primes
Iwaniec, H.; Jiménez Urroz, Jorge (2010)
Article
Restricted access  publisher's policyNowadays the generation of cryptosystems requires two main aspects. First the security, and then the size of the keys involved in the construction and comunication process. About the former one needs a di±cult ... 
Primes represented by quadratic polynomials via exceptional characters
Chamizo Lorente, Fernando; Jiménez Urroz, Jorge (Springer Nature, 20210801)
Article
Open AccessWe estimate the number of primes represented by a general quadratic polynomial with discriminant ¿, assuming that the corresponding real character is exceptional. 
Small primitive roots and malleability of RSA
Jiménez Urroz, Jorge; Dieulefait, Luis Victor (2012)
Conference report
Open AccessIn their paper [9], P. Paillier and J. Villar make a conjectur e about the malleability of an RSA modulus. In this paper we present an ex plicit algo rithm refuting the conjecture. Concretely we can factorize an RSA ... 
Squarefree discriminants of Frobenius rings
David, Chantal; Jiménez Urroz, Jorge (201009)
Article
Open AccessLet E be an elliptic curve over Q. It is well known that the ring of endomorphisms of $E_p$, the reduction of E modulo a prime p of ordinary reduction, is an order of the quadratic imaginary field $Q(\pi_p)$ generated ...