An information receiving apparatus receives identification information and encrypted identification information and makes a comparison between them to allow prevention of illegal utilization of contents data. Also, a data storage apparatus can record contents data encrypted by a content key and the content key so that the contents data can be reproduced on other apparatuses to improve versatility. Moreover, a management apparatus can manage the contents data in the data storage apparatus to allow other apparatuses to utilize it. And also, an information regulating apparatus can verify a signature on available data to prevent illegal utilization of the contents data. Furthermore, the data storage apparatus can store the content key, its handling policies, the contents data encrypted by the content key and its license conditions information so as to safely provide the contents data. In addition, an information recording apparatus can select favorite contents data and store it on the data storage apparatus. Furthermore, the information receiving apparatus can prevent utilization of provision-prohibited contents data by a provision prohibition list.