Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Motoji Omori

Makoto Tatebayashi

Toshihisa Nakano

Natsume Matsuzaki

Atsuko Miyaji

Masayuki Kozuka

Kazuhiko Yamauchi

Syunji Harada

A system structured from a management device, a content key distribution device and a plurality of terminals suppresses the data volume of a terminal revocation list (TRL). The management device generates and transmits a TRL formed from data that expresses terminal IDs of all terminals to be invalidated, by only a value and a position of a common bit string in the IDs, to the content key distribution device. Each terminal holds a terminal ID that includes a manufacturer ID and a serial number, and requests the distribution of a content key by sending the terminal ID to the content key distribution device. The content key distribution device refers to the TRL, judges whether the terminal ID transmitted from the terminal is that of an invalidated terminal, and if negative, encrypts and transmits the content key to the terminal.

Encryption communications system

A system structured from a management device, a content key distribution device and a plurality of terminals suppresses the data volume of a terminal revocation list (TRL). The management device generates and transmits a TRL formed from data that expresses terminal IDs of all terminals to be invalidated, by only a value and a position of a common bit string in the IDs, to the content key distribution device. Each terminal holds a terminal ID that includes a manufacturer, ID and a serial number, and requests the distribution of a content key by sending the terminal ID to the content key distribution device. The content key distribution device refers to the TRL, judges whether the terminal ID transmitted from the terminal is that of an invalidated terminal, and if negative, encrypts and transmits the content key to the terminal.

Encrypted data delivery system

A supplier device 70 which supplies title data is equipped with a encryption module 74 for performing an encryption which is substitutive in nature and the user device 90 which uses the title data is equipped with a decryption module 93 for performing a decryption which corresponds to the encryption. The supplier device 70 uses this encryption module 74 to prove its own authorization and authenticate other devices. Similarly, the user device 90 uses this decryption module 93 to prove its own authorization and authenticate other devices.

Communication device which performs two-way encryption authentication in

A 6-digit decimal input value A and a previously prepared 6-digit decimal extension fixed value L are substituted in an extension function f, thereby extending the input value A to a 12-digit decimal value f(A,L). This extended value f(A,L) is bit-agitated with a bit agitation key R. Further, a value C obtained by the bit agitation processing is substituted in a reduction function g, thereby obtaining a 6-digit decimal output value B. Thus, the input value A is extended by the extension processing to be thereafter subjected to the bit agitation processing, whereby safety of secret information can be improved without increasing the number of digits of the input value A. Further, the value obtained by the bit agitation is thereafter reduced, whereby the output value B can be reduced to a number of digits which is applicable to the human memory. Thus, a bit agitator is obtained which is safer than a conventional one and has an excellent user interface.

Bit agitator

A user i calculates authentication application information involving a random-number parameter and transmits it to a sales company A. At the sales company A, the received authentication application information is one-way transformed using a random-number parameter and is transmitted to the user i as authentication challenged information. At the user i, an identification number for credit membership of the user and a password are inputted and the received authentication challenge information is transformed using the password to create authentication response information. Then the identification number of the user i and the authentication response information are transmitted to the sales company A. At the sales company A, the received authentication response information is one-way transformed so that the random-number parameter is cancelled so as to produce authentication reference information. Then the received identification number and the authentication reference information are transmitted to the credit company b. At the credit company b, transformed secret information which is stored in advance is retrieved using the received identification number as a key and it is determined whether the transformed secret information and the authentication reference information are equal. If they are equal, the credit company b transmits to the sales company A authentication information indicating correctness of the user i, and if they are not equal, it transmits authentication information indicating that the user i can not be authenticated as a correct user. At the sales company A, the authentication information transmitted from the credit company b is transmitted to the user i.

Personal authentication method

A 6-digit decimal input value A and a previously prepared 6-digit decimal extension fixed value L are substituted in an extension function f, thereby extending the input value A to a 12-digit decimal value f(A,L). This extended value f(A,L) is bit-agitated with a bit agitation key R. Further, a value C obtained by the bit agitation processing is substituted in a reduction function g, thereby obtaining a 6-digit decimal output value B. Thus, the input value A is extended by the extension processing to be thereafter subjected to the bit agitation processing, whereby safety of secret information can be improved without increasing the number of digits of the input value A. Further, the value obtained by the bit agitation is thereafter reduced, whereby the output value B can be reduced to a number of digits which is applicable to the human memory. Thus, a bit agitator is obtained which is safer than at conventional one and has an excellent user interface.

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Osaka, Japan

Motoji Omori