code: public static boolean verifySignature(byte[] publicKey, byte[] message, byte[] signature) {
          return curve_sigs.curve25519_verify(SHA512Provider, signature, publicKey, message, message.length) == 0;
      }
docs: Verification of signature
  
  @param publicKey public key of signature
  @param message   message
  @param signature signature of a message
  @return true if signature correct