Kabushiki Kaisha Toshiba

Matsushita Electric Industrial Co., Ltd.

Verance Corporation

Panasonic Corporation

Naoki Endoh

Takehisa Kato

Koichi Hirayama

Hisashi Yamada

Makoto Tatebayashi

Toru Kambayashi

Koichiro Akiyama

Kenjiro Endoh

Shuichi Tsujimoto

Taku Katoh

Motoji Ohmori

Hiroaki Unno

Taku Kato

Tadashi Kojima

Yoshihisa Fukushima

Chong U Lee

Toshimitsu Kaneko

Hideo Shimizu

Kenji Shimoda

Shunichi Numazaki

Kamran Moallemi

Kouya Tochikubo

Katherine S Lam

Toshiaki Saisho

Satomi Hori

On a recording medium, first information obtained by enciphering data with the first key and second information obtained by enciphering the first key with each of the predetermined second keys are recorded. A deciphering method is characterized by comprising the steps of inputting the first and second information, deciphering the first key using at least one of the second keys, determining by a specific method that the obtained first key is correct, and then deciphering the data using the first key to obtain the data.

Method and apparatus of enciphering and deciphering data using keys enciphered and deciphered with other keys

A record medium comprises an original data obtained by superimposing a presentation target data, to which an error correction encoding is performed and an identification information.

Record medium, record medium manufacturing device, computer readable record medium on which program is recorded, and data presentation device

A cryptographic communication terminal serving as one of information transmitting and receiving terminals in cryptographic communication includes a cryptographic algorithm storage section for storing one or more types of cryptographic algorithm used for cryptographic communication, and outputting a designated cryptographic algorithm, a key information storage section for storing a key used for cryptographic communication corresponding to the cryptographic algorithm, and outputting a designated key, a control section for designating, with respect to the cryptographic algorithm storage section and the key information storage section, which cryptographic algorithm and key are to be used in the cryptographic communication, and an encryption/decryption section for decrypting received encryption information by using the cryptographic algorithm designated with respect to the cryptographic algorithm storage section and the key designated with respect to the key information storage section, and encrypting information to be transmitted.

Cryptographic communication terminal, cryptographic communication center apparatus, cryptographic communication system, and storage medium

A system () for scrambling digital samples () of multimedia data, including audio and video data samples, such that the content of the samples is degraded but still recognizable, or otherwise provided at a desired quality level. The samples may be in any conceivable compressed or uncompressed digital format, including Pulse Code Modulation (PCM) samples, samples in floating point representation, samples in companding schemes (e.g., &#x3bc;-law and A-law), and other compressed bit streams. The quality level may be associated with a particular signal to noise ratio, or quality level that is determined by objective and/or subjective tests, for example. A number of LSBs can be scrambled in successive samples in successive frames (FRAME A, FRAME B, FRAME C). Moreover, the parameters for scrambling may change from frame to frame. Furthermore, all or part of the scrambling key () can be embedded () in the scrambled data and recovered at a decoder () to be used in descrambling. After descrambling, the scramble key is no longer recoverable because the scramble key itself is scrambled by the descrambler.

Multimedia adaptive scrambling system (MASS)

A source of MPEG2 video data is connected with a dedicated AV device or personal computer by means of an IEEE 1394 interface. A transmission unit in the source has an IEEE 1394 encryption unit and a sending I/F unit. A reception unit varies between the dedicated AV unit and the personal computer. In the reception unit of the dedicated AV device, a receiving I/F unit and a decryptor are integrally incorporated into one semiconductor chip and an MPEG2 decoder is incorporated into one semiconductor chip. In the reception unit of the personal computer, the receiving I/F unit is formed of one semiconductor chip, and the decryptor connected to the I/F unit through a bus, and the MPEG2 decoder are formed of one semiconductor chip. Thus, data before decryption will not appear on the bus, which prevents MPEG2 video data from being taken out of the computer for illegal copying purposes. In addition, the reception unit is made to have a different physical configuration depending on whether it is to be mounted in the dedicated AV device or the personal computer. This will prevent the reception unit (including the decryptor) of the dedicated AV device from being connected in the personal computer in place of its associated reception unit (excluding the decryptor).

Digital data reproduction device

A conditional access broadcast system for realizing conditional access while maintaining the safety level is disclosed. A contract management device at a broadcast station side delivers a reception contract information containing at least a contract information for controlling decryption of encrypted contents information delivered from a broadcast station by broadcast and a reception device ID in correspondence, which is encrypted using a master key which is commonly provided with respect to all the broadcast reception devices. At each broadcast reception device, whether or not to give a channel key for decrypting the encrypted contents information to the decryption unit is controlled according to the contract information for own broadcast reception device which is acquired from the encrypted reception contract information.

Broadcast reception device and contract management device using common master key in conditional access broadcast system

In an embodiment, a copy-guard system is provided that includes a decoding section for decoding digital data, which is encoded and error-correction-coded, from an information recording medium in which key information encoded for the digital data is recorded, an encoded digital data acquisition section for acquiring digital data encoded by error-correcting the digital data decoded by the decoding section, a detection section for detecting an error position and an error symbol value of the encoded digital data, identification information detection section for detecting an identification information representing whether the information recording medium is original or copied and which is replaced with a part of the digital data encoded and error-correction-coded, based on the error position and the error symbol value detected by the detection section, a determination section for determining whether a copy of the information recording medium is protected, and a copy protection section.

Copy-guard system and information recording medium used in the same system

This invention protects the unauthorized copy of multimedia data, recorded on an information recording medium, by using electronic watermark information and key information. The electronic watermark information embedded in the multimedia data is extracted by an electronic watermark extraction unit on the decryption system side. A disk key is obtained using the electronic watermark information and a part master key. The multimedia data is decrypted using the resultant disk key.

Copy protection apparatus and information recording medium used in this copy protection apparatus

A transmission apparatus 100 includes a secret key storage unit 103 that stores three secret keys K1, K2 and K3, a secret key selection unit 104 that selects one secret key Ks from the secret keys, a message generation unit 106 for generating a message M used as a carrier for indicating a secret key, an encryption module 105 for generating a cryptogram Ca by encrypting the generated message M using the secret key Ks, an encryption module 107 for generating a cryptogram Cm by encrypting the message M using the message M itself as the secret key, and two transmission units 111 and 112 for transmitting the cryptograms Ca and Cm to the reception apparatus 200 to indicate the selected secret key Ks. The reception apparatus 200 includes a decryption module, such as 221, for generating decrypted data Mi by decrypting the cryptogram Ca using a secret key Ki out of the three secret keys, and a decryption module, such as 222, for generating decrypted data Mii by decrypting the cryptogram Cm using the decrypted data Mi, and authorizes that the secret key Ki has been selected when the decrypted data Mi matches the decrypted data Mii.

Secret key transfer method which is highly secure and can restrict the

In an encrypted transmission system composed of one transmission apparatus 10 and twenty-eight reception apparatuses A1-G4 that are classified into seven groups A-G, two secret key exclusively selected out of a total of fourteen secret keys are distributed beforehand to each group. The transmission apparatus 10 encrypts the same message M using one of the two secret keys distributed to each group and sends each group a message M encrypted with one of the group's secret keys. The reception apparatuses each decrypt the received cryptogram separately using each of the secret keys assigned to the of group to which each reception apparatus belongs, judge whether either of the two decryption results conforms to a predetermined rule, and specify the correct decryption result.

Encrypted communication system that limits the damage caused when a

An information processing system includes a first information processing apparatus and a second information processing apparatus arranged separate from the first information processing apparatus and capable of exchanging a signal with the first information processing apparatus. The first information processing apparatus includes a first key generator for generating a first key, and a first encrypting unit for encrypting data using the first key generated by the first key generator to generate first encrypted information. The second information processing apparatus includes a second key storage unit for storing a second key, and a second encrypting unit for encrypting the first key using the second key stored in the second storage unit to generate second encrypted information. The first information processing apparatus further includes a correlation storage unit for storing the first encrypted information generated by the first encrypting unit and the second encrypted information generated by the second encrypting unit, the first encrypted information being correlated with the second encrypted information.

Growing community of inventors

Tokyo, Japan

Naoki Endoh