Package de.tilman_neumann.jml.factor.siqs.tdiv

Class TDiv_QS_nLarge

java.lang.Object

de.tilman_neumann.jml.factor.siqs.tdiv.TDiv_QS_nLarge

All Implemented Interfaces:

TDiv_QS

public class TDiv_QS_nLarge
extends Object
implements TDiv_QS

A trial division engine where partials can have several large factors. Division is carried out in two stages: Stage 1 identifies prime factors of Q, applying long-valued Barrett reduction Stage 2 does the actual division using BigInteger

Author:

Tilman Neumann

Constructor Summary

Constructors

Constructor	Description
TDiv_QS_nLarge(boolean permitUnsafeUsage)	Full constructor.

Method Summary

Modifier and Type	Method	Description
void	cleanUp()	Release memory after a factorization.
String	getName()
TDivReport	getReport()
void	initializeForAParameter(BigInteger da, int d, BigInteger b, SolutionArrays solutionArrays, int filteredBaseSize, int[] unsievedBaseElements)	Set prime/power base, polynomial parameters and smallest x-solutions for a new a-parameter.
void	initializeForN(double N_dbl, BigInteger kN, double maxQRest)	Initialize this trial division engine for a new N.
void	setBParameter(BigInteger b)	Set a new b-parameter.
List<AQPair>	testList(List<Integer> xList)	Test if Q(x) is smooth (factors completely over the prime base) or "sufficiently smooth" (factors almost over the prime base) for all x in the given list.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TDiv_QS_nLarge

public TDiv_QS_nLarge(boolean permitUnsafeUsage)

Full constructor.

Parameters:

permitUnsafeUsage - if true then SIQS_Small (which is used for N > 310 bit to factor Q-rests) uses a sieve exploiting sun.misc.Unsafe features.

Method Detail

getName

public String getName()

Specified by:

getName in interface TDiv_QS

Returns:

the name of this algorithm

initializeForN

public void initializeForN(double N_dbl,
                           BigInteger kN,
                           double maxQRest)

Description copied from interface: TDiv_QS

Initialize this trial division engine for a new N.

Specified by:

initializeForN in interface TDiv_QS

kN - multiplier k (typically Knuth-Schroeppel) * factor argument N

maxQRest - the biggest QRest admitted for a smooth relation

initializeForAParameter

public void initializeForAParameter(BigInteger da,
                                    int d,
                                    BigInteger b,
                                    SolutionArrays solutionArrays,
                                    int filteredBaseSize,
                                    int[] unsievedBaseElements)

Description copied from interface: TDiv_QS

Set prime/power base, polynomial parameters and smallest x-solutions for a new a-parameter.

Specified by:

initializeForAParameter in interface TDiv_QS

Parameters:

da - d*a, with d = 1 or 2 depending on kN % 8

d - the d-value

b - the (first) b-parameter

filteredBaseSize - number of primes and powers use for sieving

unsievedBaseElements - Prime base elements that were excluded from sieving, like the q's that give the a-parameter in SIQS

setBParameter

public void setBParameter(BigInteger b)

Description copied from interface: TDiv_QS

Set a new b-parameter.

Specified by:

setBParameter in interface TDiv_QS

testList

public List<AQPair> testList(List<Integer> xList)

Description copied from interface: TDiv_QS

Test if Q(x) is smooth (factors completely over the prime base) or "sufficiently smooth" (factors almost over the prime base) for all x in the given list.

Specified by:

testList in interface TDiv_QS

Returns:

the AQ-pairs where Q is at least "sufficiently smooth"

getReport

public TDivReport getReport()

Specified by:

getReport in interface TDiv_QS

Returns:

a description of the performed tests.

cleanUp

public void cleanUp()

Description copied from interface: TDiv_QS

Release memory after a factorization.

Specified by:

cleanUp in interface TDiv_QS