Bouncy Castle Cryptography Library 1.80 · org.bouncycastle.math.ec.WNafUtil

Modifier and Type	Field and Description
private static final int[]	DEFAULT_WINDOW_SIZE_CUTOFFS
private static final byte[]	EMPTY_BYTES
private static final int[]	EMPTY_INTS
private static final ECPoint[]	EMPTY_POINTS
private static final int	MAX_WIDTH
public static final String	PRECOMP_NAME

Access	Constructor and Description
public	WNafUtil()

Method Summary

Modifier and Type	Method and Description
public static void	configureBasepoint(ECPoint p)
public static int[]	generateCompactNaf(BigInteger k)
public static int[]	generateCompactWindowNaf(int width, BigInteger k)
public static byte[]	generateJSF(BigInteger g, BigInteger h)
public static byte[]	generateNaf(BigInteger k)
public static byte[]	Returns: The Window NAF of the given width, such that the following holds: `k = ∑_i=0^l-1 k_i2ⁱ`, where the `k_i` denote the elements of the returned `byte[]`. generateWindowNaf(int 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. width, BigInteger The integer of which the Window NAF is computed. k) Computes the Window NAF (non-adjacent Form) of an integer.
public static int	getNafWeight(BigInteger k)
public static int	Returns: the window size to use getWindowSize(int the bit-length of the scalar to multiply by bits) Determine window width to use for a scalar multiplication of the given size.
public static int	Returns: the window size to use getWindowSize(int the bit-length of the scalar to multiply by bits, int the maximum window width to return maxWidth) Determine window width to use for a scalar multiplication of the given size.
public static int	Returns: the window size to use getWindowSize(int the bit-length of the scalar to multiply by bits, int[] a monotonically increasing list of bit sizes at which to increment the window width windowSizeCutoffs) Determine window width to use for a scalar multiplication of the given size.
public static int	Returns: the window size to use getWindowSize(int the bit-length of the scalar to multiply by bits, int[] a monotonically increasing list of bit sizes at which to increment the window width windowSizeCutoffs, int the maximum window width to return maxWidth) Determine window width to use for a scalar multiplication of the given size.
public static WNafPreCompInfo	getWNafPreCompInfo(ECPoint p)
public static WNafPreCompInfo	getWNafPreCompInfo(PreCompInfo preCompInfo)
public static WNafPreCompInfo	precompute(final ECPoint p, final int minWidth, final boolean includeNegated)
public static WNafPreCompInfo	precomputeWithPointMap(final ECPoint p, final ECPointMap pointMap, final WNafPreCompInfo fromWNaf, final boolean includeNegated)
private static ECPoint[]	resizeTable(ECPoint[] a, int length)
private static byte[]	trim(byte[] a, int length)
private static int[]	trim(int[] a, int length)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

DEFAULT_WINDOW_SIZE_CUTOFFS	back to summary
private static final int[] DEFAULT_WINDOW_SIZE_CUTOFFS

EMPTY_BYTES	back to summary
private static final byte[] EMPTY_BYTES

EMPTY_INTS	back to summary
private static final int[] EMPTY_INTS

EMPTY_POINTS	back to summary
private static final ECPoint[] EMPTY_POINTS

MAX_WIDTH	back to summary
private static final int MAX_WIDTH

PRECOMP_NAME	back to summary
public static final String PRECOMP_NAME

WNafUtil	back to summary
public WNafUtil()

Method Detail

configureBasepoint	back to summary
public static void configureBasepoint(ECPoint p)

generateCompactNaf	back to summary
public static int[] generateCompactNaf(BigInteger k)

generateCompactWindowNaf	back to summary
public static int[] generateCompactWindowNaf(int width, BigInteger k)

generateJSF	back to summary
public static byte[] generateJSF(BigInteger g, BigInteger h)

generateNaf	back to summary
public static byte[] generateNaf(BigInteger k)

generateWindowNaf back to summary

generateWindowNaf	back to summary
public static byte[] generateWindowNaf(int width, BigInteger k) Computes the Window NAF (non-adjacent Form) of an integer. Parameters width:int 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:BigInteger The integer of which the Window NAF is computed. Returns:byte[] The Window NAF of the given width, such that the following holds: `k = ∑_i=0^l-1 k_i2ⁱ`, where the `k_i` denote the elements of the returned `byte[]`.

public static byte[] generateWindowNaf(int width, BigInteger k)

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

Parameters

width:int: 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:BigInteger: The integer of which the Window NAF is computed.

Returns:byte[]

The Window NAF of the given width, such that the following holds: k = ∑_i=0^l-1 k_i2ⁱ, where the k_i denote the elements of the returned byte[].

getNafWeight	back to summary
public static int getNafWeight(BigInteger k)

getWindowSize	back to summary
public static int getWindowSize(int bits) Determine window width to use for a scalar multiplication of the given size. Parameters bits:int the bit-length of the scalar to multiply by Returns:int the window size to use

getWindowSize

back to summary

public static int getWindowSize(int bits)

Determine window width to use for a scalar multiplication of the given size.

Parameters

bits:int: the bit-length of the scalar to multiply by

Returns:int

the window size to use

getWindowSize	back to summary
public static int getWindowSize(int bits, int maxWidth) Determine window width to use for a scalar multiplication of the given size. Parameters bits:int the bit-length of the scalar to multiply by maxWidth:int the maximum window width to return Returns:int the window size to use

getWindowSize

back to summary

public static int getWindowSize(int bits, int maxWidth)

Determine window width to use for a scalar multiplication of the given size.

Parameters

bits:int: the bit-length of the scalar to multiply by
maxWidth:int: the maximum window width to return

Returns:int

the window size to use

getWindowSize	back to summary
public static int getWindowSize(int bits, int[] windowSizeCutoffs) Determine window width to use for a scalar multiplication of the given size. Parameters bits:int the bit-length of the scalar to multiply by windowSizeCutoffs:int[] a monotonically increasing list of bit sizes at which to increment the window width Returns:int the window size to use

getWindowSize

back to summary

public static int getWindowSize(int bits, int[] windowSizeCutoffs)

Determine window width to use for a scalar multiplication of the given size.

Parameters

bits:int: the bit-length of the scalar to multiply by
windowSizeCutoffs:int[]: a monotonically increasing list of bit sizes at which to increment the window width

Returns:int

the window size to use

getWindowSize	back to summary
public static int getWindowSize(int bits, int[] windowSizeCutoffs, int maxWidth) Determine window width to use for a scalar multiplication of the given size. Parameters bits:int the bit-length of the scalar to multiply by windowSizeCutoffs:int[] a monotonically increasing list of bit sizes at which to increment the window width maxWidth:int the maximum window width to return Returns:int the window size to use

getWindowSize

back to summary

public static int getWindowSize(int bits, int[] windowSizeCutoffs, int maxWidth)

Determine window width to use for a scalar multiplication of the given size.

Parameters

bits:int: the bit-length of the scalar to multiply by
windowSizeCutoffs:int[]: a monotonically increasing list of bit sizes at which to increment the window width
maxWidth:int: the maximum window width to return

Returns:int

the window size to use

getWNafPreCompInfo	back to summary
public static WNafPreCompInfo getWNafPreCompInfo(ECPoint p)

getWNafPreCompInfo	back to summary
public static WNafPreCompInfo getWNafPreCompInfo(PreCompInfo preCompInfo)

precompute	back to summary
public static WNafPreCompInfo precompute(final ECPoint p, final int minWidth, final boolean includeNegated)

precomputeWithPointMap	back to summary
public static WNafPreCompInfo precomputeWithPointMap(final ECPoint p, final ECPointMap pointMap, final WNafPreCompInfo fromWNaf, final boolean includeNegated)

resizeTable	back to summary
private static ECPoint[] resizeTable(ECPoint[] a, int length)

trim	back to summary
private static byte[] trim(byte[] a, int length)

trim	back to summary
private static int[] trim(int[] a, int length)

public abstract Class WNafUtil

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail