/// <summary>
 /// DES decryption.
 /// </summary>
 /// <param name="source"></param>
 /// <param name="key"></param>
 /// <returns></returns>
 public static byte[] FastDecrypt(ArraySegment <byte> source, byte[] key)
 {
     return(SymmetricAlgorithmHelper.Decrypt <DES>(source, key));
 }
 /// <summary>
 /// Create a DES key.
 /// </summary>
 /// <returns></returns>
 public static byte[] FastCreateKey()
 {
     return(SymmetricAlgorithmHelper.CreateKey <DES>());
 }