def combine_iv_ciphertext(iv, message)
      message.force_encoding('BINARY') if message.respond_to?(:force_encoding)
      iv.force_encoding('BINARY')      if iv.respond_to?(:force_encoding)
      iv + message
    end
def combine_iv_ciphertext(iv, message)
      message.force_encoding('BINARY') if message.respond_to?(:force_encoding)
      iv.force_encoding('BINARY')      if iv.respond_to?(:force_encoding)
      iv + message
    end
Prepend the initialization vector to the encoded message.

 @api private