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Mathematics of Computation

Published by the American Mathematical Society since 1960 (published as Mathematical Tables and other Aids to Computation 1943-1959), Mathematics of Computation is devoted to research articles of the highest quality in computational mathematics.

ISSN 1088-6842 (online) ISSN 0025-5718 (print)

The 2020 MCQ for Mathematics of Computation is 1.78.

What is MCQ? The Mathematical Citation Quotient (MCQ) measures journal impact by looking at citations over a five-year period. Subscribers to MathSciNet may click through for more detailed information.


Speeding the Pollard and elliptic curve methods of factorization
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by Peter L. Montgomery PDF
Math. Comp. 48 (1987), 243-264 Request permission


Since 1974, several algorithms have been developed that attempt to factor a large number N by doing extensive computations modulo N and occasionally taking GCDs with N. These began with Pollard’s $p - 1$ and Monte Carlo methods. More recently, Williams published a $p + 1$ method, and Lenstra discovered an elliptic curve method (ECM). We present ways to speed all of these. One improvement uses two tables during the second phases of $p \pm 1$ and ECM, looking for a match. Polynomial preconditioning lets us search a fixed table of size n with $n/2 + o(n)$ multiplications. A parametrization of elliptic curves lets Step 1 of ECM compute the x-coordinate of nP from that of P in about 9.3 ${\log _2}$ n multiplications for arbitrary P.
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Additional Information
  • © Copyright 1987 American Mathematical Society
  • Journal: Math. Comp. 48 (1987), 243-264
  • MSC: Primary 11Y05; Secondary 11A51, 68Q40
  • DOI:
  • MathSciNet review: 866113