org.bouncycastle.math.ec

Class ECCurve.AbstractF2m

java.lang.Object

org.bouncycastle.math.ec.ECCurve

org.bouncycastle.math.ec.ECCurve.AbstractF2m

Direct Known Subclasses:

ECCurve.F2m, SecT113R1Curve, SecT113R2Curve, SecT131R1Curve, SecT131R2Curve, SecT163K1Curve, SecT163R1Curve, SecT163R2Curve, SecT193R1Curve, SecT193R2Curve, SecT233K1Curve, SecT233R1Curve, SecT239K1Curve, SecT283K1Curve, SecT283R1Curve, SecT409K1Curve, SecT409R1Curve, SecT571K1Curve, SecT571R1Curve

Enclosing class:

ECCurve

public abstract static class ECCurve.AbstractF2m
extends ECCurve

Nested Class Summary

Nested classes/interfaces inherited from class org.bouncycastle.math.ec.ECCurve

ECCurve.AbstractF2m, ECCurve.AbstractFp, ECCurve.Config, ECCurve.F2m, ECCurve.Fp

Field Summary

Fields inherited from class org.bouncycastle.math.ec.ECCurve

a, b, cofactor, coord, COORD_AFFINE, COORD_HOMOGENEOUS, COORD_JACOBIAN, COORD_JACOBIAN_CHUDNOVSKY, COORD_JACOBIAN_MODIFIED, COORD_LAMBDA_AFFINE, COORD_LAMBDA_PROJECTIVE, COORD_SKEWED, endomorphism, field, multiplier, order

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractF2m(int m, int k1, int k2, int k3)

Method Summary

Modifier and Type	Method and Description
ECPoint	createPoint(java.math.BigInteger x, java.math.BigInteger y)
protected ECPoint	decompressPoint(int yTilde, java.math.BigInteger X1) Decompresses a compressed point P = (xp, yp) (X9.62 s 4.2.2).
static java.math.BigInteger	inverse(int m, int[] ks, java.math.BigInteger x)
boolean	isKoblitz() Returns true if this is a Koblitz curve (ABC curve).
boolean	isValidFieldElement(java.math.BigInteger x)
ECFieldElement	randomFieldElement(java.security.SecureRandom r)
ECFieldElement	randomFieldElementMult(java.security.SecureRandom r)
protected ECFieldElement	solveQuadraticEquation(ECFieldElement beta) Solves a quadratic equation z2 + z = beta(X9.62 D.1.6) The other solution is z + 1.

Methods inherited from class org.bouncycastle.math.ec.ECCurve

checkPoint, checkPoints, checkPoints, cloneCurve, configure, createCacheSafeLookupTable, createDefaultMultiplier, createRawPoint, createRawPoint, decodePoint, equals, equals, fromBigInteger, getA, getAffinePointEncodingLength, getAllCoordinateSystems, getB, getCofactor, getCoordinateSystem, getEndomorphism, getField, getFieldElementEncodingLength, getFieldSize, getInfinity, getMultiplier, getOrder, getPreCompInfo, hashCode, importPoint, normalizeAll, normalizeAll, precompute, supportsCoordinateSystem, validatePoint

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractF2m

protected AbstractF2m(int m,
                      int k1,
                      int k2,
                      int k3)

Method Detail

inverse

public static java.math.BigInteger inverse(int m,
                                           int[] ks,
                                           java.math.BigInteger x)

createPoint

public ECPoint createPoint(java.math.BigInteger x,
                           java.math.BigInteger y)

Overrides:

createPoint in class ECCurve

isValidFieldElement

public boolean isValidFieldElement(java.math.BigInteger x)

Specified by:

isValidFieldElement in class ECCurve

randomFieldElement

public ECFieldElement randomFieldElement(java.security.SecureRandom r)

Specified by:

randomFieldElement in class ECCurve

randomFieldElementMult

public ECFieldElement randomFieldElementMult(java.security.SecureRandom r)

Specified by:

randomFieldElementMult in class ECCurve

decompressPoint

protected ECPoint decompressPoint(int yTilde,
                                  java.math.BigInteger X1)

Decompresses a compressed point P = (xp, yp) (X9.62 s 4.2.2).

Specified by:

decompressPoint in class ECCurve

Parameters:

yTilde - ~yp, an indication bit for the decompression of yp.

X1 - The field element xp.

Returns:

the decompressed point.

solveQuadraticEquation

protected ECFieldElement solveQuadraticEquation(ECFieldElement beta)

Solves a quadratic equation z2 + z = beta(X9.62 D.1.6) The other solution is z + 1.

Parameters:

beta - The value to solve the quadratic equation for.

Returns:

the solution for z2 + z = beta or null if no solution exists.

isKoblitz

public boolean isKoblitz()

Returns true if this is a Koblitz curve (ABC curve).

Returns:

true if this is a Koblitz curve (ABC curve), false otherwise