Patent ID: 8407477

Claim:
An information distribution system, comprising: a plurality of information terminals connected to a communication network, wherein at least one information terminal of the plurality of information terminals comprises a common key generating section adapted to generate a common key for performing an encryption communication between the at least one information terminal and another information terminal via the communication network; an original information encrypting section adapted to encrypt original information owned by any one of the plurality of information terminals based on the common key; a section adapted to store a public key and a private key to encrypt the common key; a common key encrypting section adapted to encrypt the common key with the public key; a common key extracting section adapted to extract the encrypted common key with the private key; a decryption processing section adapted to decrypt encrypted information of the original information encrypted by the at least one information terminal based on the extracted common key; an encrypted signature generating section adapted to generate an encrypted signature using the private key; and a secure transport core having a program for achieving the encryption communication installed therein, at least one information terminal of the other information terminals of the plurality of information terminals comprises a secure storage including an original information storing section adapted to store the encrypted original information encrypted by the at least one information terminal of the plurality of information terminals in an encrypted state; an authorized terminal authenticating section adapted to authenticate an authorized information terminal of the plurality of information terminals that is authorized to view the original information by an information terminal that owns the encrypted original information; a link information generating section adapted to generate link information for linking encrypted information of the common key to the encrypted information of the original information; an index information generating section adapted to generate index information for disclosing the link information and the encrypted information of the original information to the at least one information terminal of the plurality of information terminals and the authorized information terminal, wherein the at least one information terminal of the other information terminals of the plurality of information terminals provides the index information to the authorized information terminal; and a secure transport core having a program for performing an encryption communication of information transmitted/received via the communication network installed therein, and the authorized information terminal decrypts the index information with a private key of the authorized information terminal to extract the common key, and decrypts, using the common key, the encrypted information of the original information, based on the link information.