Field Detail

• PRECOMP_NAME

  public static final java.lang.String PRECOMP_NAME

  See Also:

  Constant Field Values

Constructor Detail

• WNafUtil

  public WNafUtil()

Method Detail

• configureBasepoint

  public static void configureBasepoint​(ECPoint p)

• generateCompactNaf

  public static int[] generateCompactNaf​(java.math.BigInteger k)

• generateCompactWindowNaf

  public static int[] generateCompactWindowNaf​(int width,
                                               java.math.BigInteger k)

• generateJSF

  public static byte[] generateJSF​(java.math.BigInteger g,
                                   java.math.BigInteger h)

• generateNaf

  public static byte[] generateNaf​(java.math.BigInteger k)

• generateWindowNaf

  public static byte[] generateWindowNaf​(int 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[].

• getNafWeight

  public static int getNafWeight​(java.math.BigInteger k)

• getWNafPreCompInfo

  public static WNafPreCompInfo getWNafPreCompInfo​(ECPoint p)

• getWNafPreCompInfo

  public static WNafPreCompInfo getWNafPreCompInfo​(PreCompInfo preCompInfo)

• getWindowSize

  public static int getWindowSize​(int bits)

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

  Parameters:

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

  Returns:

  the window size to use

• getWindowSize

  public static int getWindowSize​(int bits,
                                  int maxWidth)

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

  Parameters:

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

  maxWidth - the maximum window width to return

  Returns:

  the window size to use

• getWindowSize

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

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

  Parameters:

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

  windowSizeCutoffs - a monotonically increasing list of bit sizes at which to increment the window width

  Returns:

  the window size to use

• getWindowSize

  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 - the bit-length of the scalar to multiply by

  windowSizeCutoffs - a monotonically increasing list of bit sizes at which to increment the window width

  maxWidth - the maximum window width to return

  Returns:

  the window size to use

• precompute

  public static WNafPreCompInfo precompute​(ECPoint p,
                                           int minWidth,
                                           boolean includeNegated)

• precomputeWithPointMap

  public static WNafPreCompInfo precomputeWithPointMap​(ECPoint p,
                                                       ECPointMap pointMap,
                                                       WNafPreCompInfo fromWNaf,
                                                       boolean includeNegated)