In order to make real time and the avoidance of risk compatible according to the contents of processing by an application, an index ID applying module applies an index computed utilizing streams before and after stream data to the stream data, computes the index again according to a stream that varies every moment, applies an index computed based upon the index of the stream data to the result of the processing of the stream data according to a predetermined procedure and outputs it. An application that receives the result of the processing and the index of the result of the processing switches processing depending upon the index.