Fujitsu Corporation

Sanyo Electric Co., Ltd.

Hitachi, Ltd.

Renesas Electronics Corporation

Masataka Takahashi

Takayuki Hasebe

Yoshihiro Hori

Toshiaki Hioki

Takahisa Hatakeyama

Takeaki Anazawa

Tadaaki Tonegawa

Miwa Kanamori

Shigeki Furuta

Takatoshi Yoshikawa

Hiroshi Takemura

Makoto Yoshioka

A memory card () stores access restriction information (AC) to a license information hold unit () arranged in a TRM area. Access restriction information (AC) has information for example of a frequency of reproduction allowed and a number of licenses owned. A controller () in reproducing and transferring content initially confirms access restriction information (AC) and thereafter effects reproduction and transfer and after the reproduction and transfer are effected updates access restriction information (AC), as required, for storage in a license information hold unit ().

Data distribution system and recording device for use therein

A memory card () includes a memory () to store encrypted content data, a license hold unit () to store at least a portion of license information distributed by a distribution system, a plurality of authentication data hold units (), each storing a plurality of authentication data that are authenticated respectively by a plurality of public authentication keys KPma, KPmb common to the distribution system, and a switch (SW) to selectively provide the data from the plurality of authentication data hold units outside of said recording apparatus according to a request external to the memory card ().

Content data storage

A memory card () conducts an authentication process with a server based on data stored in an authentication data hold unit (). The memory card () extracts a first session key (Ks) from a server by a decryption process and a transaction ID from the data applied on a data bus (BS). The memory card () generates a second session key (Ks) through a session key generation unit (), and transmits to the server, as the keys to encrypt content data in receiving decryption of content data, the second session key (Ks) and a key (KPm()) unique to the memory card () in an encrypted state with the first session key (Ks). The transaction ID and the second session key (Ks) stored in the log memory () are used in the redistribution process.

Memory card and data distribution system using it

A license server () includes a CRL database () holding a revocation list recording therein classes predetermined corresponding respectively to a memory device, such as a memory card, and a content reproduction circuit, such as a cellular phone, that are subjected to revocation of distributing, reproducing and transferring content data. A distribution control unit () suspends an operation distributing content data if the distribution is addressed to a class listed on the revocation list. The revocation list is also held in the memory card and distribution control unit () in distributing content also transmits information for updating the revocation list in the memory card.

Data distribution system and recording device and data provision device used therefor

Growing community of inventors

Ishikawa, Japan

Masataka Takahashi