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package org.bouncycastle.math.ec;
import java.math.BigInteger;
public class ZSignedDigitR2LMultiplier extends AbstractECMultiplier
{
/**
* 'Zeroless' Signed Digit Right-to-Left.
*/
protected ECPoint multiplyPositive(ECPoint p, BigInteger k)
{
ECPoint R0 = p.getCurve().getInfinity(), R1 = p;
int n = k.bitLength();
int s = k.getLowestSetBit();
R1 = R1.timesPow2(s);
int i = s;
while (++i < n)
{
R0 = R0.add(k.testBit(i) ? R1 : R1.negate());
R1 = R1.twice();
}
R0 = R0.add(R1);
return R0;
}
}
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