The present invention is made to provide an information distribution system capable of securely storing digitized personal information in an encrypted state in a storage section and securely transferring/disclosing the stored digitized information only to a particular third person via a network. Communication of the information is securely performed in the encrypted state between information terminals connected to the communication network (between a client and a server or between peer-to-peer client terminals). An information terminal which has created information encrypts the original information by a common key generated upon communication and stores the information in a secure storage of one of the information terminals connected to the communication network while maintaining the encrypted state. Further, the system creates a mechanism for authenticating a person having a particular authority for viewing the encrypted information and index information having an encrypted common key and link information indicating the location of the information for supply to a user.