In this personal authentication system based on seating pressure, this registration device adjusts parameters through a feature calculation which takes, as teaching data, time-series pressure distribution data on a person to be registered and time-series pressure distribution data on a plurality of other persons, and through an error back propagation method based on differences between the feature calculation results and a teaching signal； and stores the adjusted parameters as personal identification data. This authentication device obtains a personal identification value through a calculation, which uses, as parameters, the personal identification data for each registered person, with respect to the time-series pressure distribution data of a person to be authenticated, and performs authentication. For the feature calculation, calculations for extracting physical features and behavioral features are performed. On the basis of data obtained when a user performs a natural motion, registering of personal identification data or personal authentication can be achieved.
