/**
  * Returns a digest of a specified key
  *
  * @param key the key
  * @return the digest
  */
 public static byte[] generateKeyID(Key key) {
   if (null == key) return null;
   return NDNDigestHelper.digest(key.getEncoded());
 }
 /**
  * Returns a digest of a specified key
  *
  * @param key the key
  * @return the digest
  */
 public static byte[] generateKeyID(byte[] key) {
   return NDNDigestHelper.digest(key);
 }