kz.gamma.hardware.crypto.software.ec
Class WNafMultiplier

java.lang.Object
  kz.gamma.hardware.crypto.software.ec.WNafMultiplier

All Implemented Interfaces:

ECMultiplier

 class WNafMultiplier
extends java.lang.Object
implements ECMultiplier

Class implementing the WNAF (Window Non-Adjacent Form) multiplication algorithm.

Constructor Summary

WNafMultiplier()

Method Summary

ECPoint	multiply(ECPoint p, java.math.BigInteger k, PreCompInfo preCompInfo) Multiplies this by an integer k using the Window NAF method.
byte[]	windowNaf(byte width, java.math.BigInteger k) Computes the Window NAF (non-adjacent Form) of an integer.

Methods inherited from class java.lang.Object

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

Constructor Detail

WNafMultiplier

WNafMultiplier()

Method Detail

windowNaf

public byte[] windowNaf(byte width,
                        java.math.BigInteger k)

Computes the Window NAF (non-adjacent Form) of an integer.

Parameters:

width - The width w of the Window NAF. The width is defined as the minimal number w, such that for any w consecutive digits in the resulting representation, at most one is non-zero.

k - The integer of which the Window NAF is computed.

Returns:

The Window NAF of the given width, such that the following holds: k = ∑i=0l-1 ki2i , where the ki denote the elements of the returned byte[].

multiply

public ECPoint multiply(ECPoint p,
                        java.math.BigInteger k,
                        PreCompInfo preCompInfo)

Multiplies this by an integer k using the Window NAF method.

Specified by:

multiply in interface ECMultiplier

Parameters:

k - The integer by which this is multiplied.

p - The ECPoint to be multiplied.

Returns:

A new ECPoint which equals this multiplied by k.