Package de.tilman_neumann.jml.factor.siqs.poly

Interface AParamGenerator

All Known Implementing Classes:
AParamGenerator01, AParamGenerator02
public interface AParamGenerator
Interface for generators that produce the leading coefficient a of the quadratic polynomial Q(x) = (d*a*x+b)^2 - kN used by SIQS. d is typically 1 or 2.

The a-parameter in SIQS is chosen as a product of primes from the prime base: a = q1 * ... * q_s. Its value should be roughly a ~ sqrt(2*k*N)/(d*M), where M is the sieve array size, such that |Q(x)| is about the same at x=+M and x=-M, and |Q(x)| <= kN for all x. The quality of the a-generator is crucial for both stability and performance of SIQS.

  • Method Summary

    Modifier and Type Method Description
    void cleanUp()
    Release memory after a factorization.
    java.math.BigInteger computeNextAParameter()  
    double getBestQ()  
    java.lang.String getName()  
    int[] getQArray()  
    int getQCount()  
    int[] getQTArray()  
    void initialize​(int k, java.math.BigInteger N, java.math.BigInteger kN, int d, int primeBaseSize, int[] primesArray, int[] tArray, int sieveArraySize)
    Initialize this a-parameter generator for a new N.

  • Method Details

    • getName

      java.lang.String getName()

    • initialize

      void initialize​(int k, java.math.BigInteger N, java.math.BigInteger kN, int d, int primeBaseSize, int[] primesArray, int[] tArray, int sieveArraySize)
      Initialize this a-parameter generator for a new N. One result has to be a qCount value fixed throughout the rest of the factorization of N.
      Parameters:
      k -
      N -
      kN -
      d - the d-value in Q(x) = (d*a*x + b)^2 - kN; typically 1 or 2
      primeBaseSize -
      primesArray -
      tArray - the modular square roots t with t^2 == kN (mod p)
      sieveArraySize -

    • computeNextAParameter

      java.math.BigInteger computeNextAParameter()

    • getBestQ

      double getBestQ()
      Returns:
      approximate optimal size of q-parameters

    • getQCount

      int getQCount()
      Returns:
      number of primes s with a-parameter = q_1 * ... * q_s

    • getQArray

      int[] getQArray()
      Returns:
      the q-values that give the a-parameter = q_1 * ... * q_s

    • getQTArray

      int[] getQTArray()
      Returns:
      the modular sqrt values for the chosen q's.

    • cleanUp

      void cleanUp()
      Release memory after a factorization.