In the present invention, there is provided a data processing device, including: a first memory configured to store identification information for identification of video data in association with a feature included in the video data; a second memory configured to store the feature included in the video data in association with the identification information for identification of the video data; a first reader configured to read out the identification information stored in the first memory based on a feature included in input video data; a second reader configured to read out the feature stored in the second memory based on the identification information read out by the first reader; and a checker configured to compare the feature included in the input video data with the feature read out by the second reader to determine whether or not the input video data matches video data whose feature is stored in the second memory.