To solve the problems of conventional data distribution and billing methods: that, when data are purchased through a network, a customer must pay for the purchase of a data recording medium, register in a credit company, and pay separately for the data, in which case the operation of registering individual information is required even if payment is made without the intervention of a credit company, making the customer continue to feel insecure, fearing that the individual information may leak or be put to use without permission; and that complicated operations must be done for each data provider, resulting in inconvenience and confusion.

A data provider who permits only customers authenticated by use of an ID for authentication to download data sells the data, with the fee of the data included in the fee of a data-recording medium containing the ID for authentication, and collects the fee of the data.