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org.bouncycastle.asn1.ua

public abstract Class DSTU4145PointEncoder

extends Object
Class Inheritance
Imports
java.math.BigInteger, java.util.Random, org.bouncycastle.math.ec.ECConstants, .ECCurve, .ECFieldElement, .ECPoint
DSTU4145 encodes points somewhat differently than X9.62 It compresses the point to the size of the field element

Constructor Summary

AccessConstructor and Description
public
DSTU4145PointEncoder()

Method Summary

Modifier and TypeMethod and Description
public static ECPoint
decodePoint(ECCurve curve, byte[] bytes)

public static byte[]
encodePoint(ECPoint Q)

private static ECFieldElement

Returns:

the solution for z2 + z = beta or null if no solution exists.
solveQuadraticEquation(ECCurve curve, ECFieldElement
The value to solve the quadratic equation for.
beta)

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

private static ECFieldElement
trace(ECFieldElement fe)

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Constructor Detail

DSTU4145PointEncoderback to summary
public DSTU4145PointEncoder()

Method Detail

decodePointback to summary
public static ECPoint decodePoint(ECCurve curve, byte[] bytes)
encodePointback to summary
public static byte[] encodePoint(ECPoint Q)
solveQuadraticEquationback to summary
private static ECFieldElement solveQuadraticEquation(ECCurve curve, ECFieldElement beta)

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

Parameters
beta:ECFieldElement

The value to solve the quadratic equation for.

Returns:ECFieldElement

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

traceback to summary
private static ECFieldElement trace(ECFieldElement fe)