Algorithms pp 191-200 | Cite as

Distributed algorithms for deciphering

  • Michel Cosnard
  • Jean-Laurent Philippe
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 450)


Many authors have already presented parallel implementations of the Multiple Polynomial Quadratic Sieve algorithm used to break RSA keys. They only parallelize the sieve step. We present in this paper a theoretical study of the parallelization of all the steps of the MPQS factoring algorithm for a distributed memory multiprocessor. We propose a first solution ensuring no communications during the sieve phase but with a bad load balancing. Then, a new distribution strategy of the polynomials permits us to get a better load balancing. We derive an implementation on the FPS T40 hypercube. We compare various distribution strategies and show how to achieve superlinear speedups.


Distributed algorithm factorization decipher quadratic sieve superlinear speedup 


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Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • Michel Cosnard
    • 1
  • Jean-Laurent Philippe
    • 1
  1. 1.LIP/IMAG — Ecole Normale Supérieure de LyonLyon Cedex 07France

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