Patent attributes
In the conventional technique for mainly performing access control, an entity (an individual) which provides information cannot grasp a state of use of personal information. In the conventional technique for encrypting stored data, a decryption key is always required when personal data is used and the personal data is not protected once decrypted. The invention constitute a system such that a purchase history is collected according to an anonymous ID and a response from a member card or an agent server is required for operation for associating the anonymous ID with a personal ID. Personal data itself is not encrypted but stored in a plain text with the personal ID and the anonymous ID as keys such that the anonymous ID is regenerated every time the anonymous ID is associated with the personal ID on a server side. At this point, the anonymous ID serving as a collection key for the purchase history, which is accumulated concurrently, is also regenerated.
