Package org.bouncycastle.pqc.crypto.gmss.util

Class WinternitzOTSVerify

  • public class WinternitzOTSVerify
extends java.lang.Object
    This class implements signature verification of the Winternitz one-time signature scheme (OTSS), described in C.Dods, N.P. Smart, and M. Stam, "Hash Based Digital Signature Schemes", LNCS 3796, pages 96–115, 2005. The class is used by the GMSS classes.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int getLog​(int intValue)
      This method returns the least integer that is greater or equal to the logarithm to the base 2 of an integer intValue.
      int getSignatureLength()  
      byte[] Verify​(byte[] message, byte[] signature)
      This method computes the public OTS key from the one-time signature of a message.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • WinternitzOTSVerify

        public WinternitzOTSVerify​(Digest digest,
                           int w)
        The constructor
        Parameters:
        digest - the name of the hash function used by the OTS and the provider name of the hash function
        w - the Winternitz parameter

    • Method Detail

      • getSignatureLength

        public int getSignatureLength()
        Returns:
        The length of the one-time signature

      • Verify

        public byte[] Verify​(byte[] message,
                     byte[] signature)
        This method computes the public OTS key from the one-time signature of a message. This is *NOT* a complete OTS signature verification, but it suffices for usage with CMSS.
        Parameters:
        message - the message
        signature - the one-time signature
        Returns:
        The public OTS key

      • getLog

        public int getLog​(int intValue)
        This method returns the least integer that is greater or equal to the logarithm to the base 2 of an integer intValue.
        Parameters:
        intValue - an integer
        Returns:
        The least integer greater or equal to the logarithm to the base 256 of intValue