To realize unrestrained contents distribution while protecting a copyright without making it necessary to provide any special recording media.

This contents distribution system is provided to select the use condition of contents, to generate a use right script for storing the selected use condition, to encrypt the contents by using a first cryptographic key, to generate a contents package including the data of the encrypted contents and contents information, license control information including the contents information, a second cryptographic key and the use right script and a use ticket including the license control information, to generate authentication data by encrypting arbitrary data by using the second cryptographic key, and to test whether or not the generated authentication data can be correctly decoded by using the second cryptographic key or a third cryptographic key inputted by a user so that use qualification can be authenticated.