Abstract: A memory card 110 extracts a session key Ks from the data applied onto a data bus BS3 by carrying out a decryption process. An encryption processing unit 1406 encrypts a public encryption key KPcard(1) of memory card 110 based on session key Ks, and applies the encrypted key to a server via data bus BS3. A memory 1412 receives from a server data such as license key Kc, license ID data License-ID and user ID data User-ID encrypted with a public encryption key KPcard(1) differing for each memory card for storage, and receives encrypted content data [Dc]Kc encrypted with license key Kc from data bus BS3 for storage.

Abstract: A memory card (110) includes a memory (1415) to store encrypted content data, a license hold unit (1440) to store at least a portion of license information distributed by a distribution system, a plurality of authentication data hold units (1400.1, 1400.2), 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 (SW2) 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 (110).

Abstract: A memory card (110) conducts an authentication process with a server based on data stored in an authentication data hold unit (1400). The memory card (110) extracts a first session key (Ks1) from a server by a decryption process and a transaction ID from the data applied on a data bus (BS3). The memory card (110) generates a second session key (Ks2) through a session key generation unit (1418), and transmits to the server, as the keys to encrypt content data in receiving decryption of content data, the second session key (Ks2) and a key (KPm(1)) unique to the memory card (110) in an encrypted state with the first session key (Ks1). The transaction ID and the second session key (Ks2) stored in the log memory (1460) are used in the redistribution process.

Abstract: A license server (10) includes a CRL database (306) 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 (315) 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 (315) in distributing content also transmits information for updating the revocation list in the memory card.

Abstract: A cellular phone has distributed encrypted content data and an encrypted content key stored in a memory. The encrypted content key data read out from the memory is decrypted by a decryption processing unit using key data Kp stored in a Kp hold unit, and then applied to a audio reproduction module. A decryption processing unit decrypts encrypted content data read out from the memory using a content key Kc extracted by the decryption processing unit to reproduce content data Dc.

Abstract: A memory card performs decryption processing to extract a session key from data applied from a server to a data bus over a cellular phone network. An encryption processing unit encrypts a public encryption key of memory card based on a session key, and applies the same to the server via data bus. A register receives and stores data such as a decrypted license ID and a user ID from the server, and a memory receives and stores encrypted content data applied from a data bus and encrypted with a license key.

Abstract: A memory card 110 extracts a session key Ks from the data applied onto a data bus BS3 by carrying out a decryption process. An encryption processing unit 1406 encrypts a public encryption key KPcard(1) of memory card 110 based on session key Ks, and applies the encrypted key to a server via data bus BS3. A memory 1412 receives from a server data such as license key Kc, license ID data License-ID and user ID data User-ID encrypted with a public encryption key KPcard(1) differing for each memory card for storage, and receives encrypted content data [Dc]Kc encrypted with license key Kc from data bus BS3 for storage.

Abstract: A memory card 110 extracts a session key Ks from the data applied onto a data bus BS3 by carrying out a decryption process. An encryption processing unit 1406 encrypts a public encryption key KPcard(1) of memory card 110 based on session key Ks, and applies the encrypted key to a server via data bus BS3. A memory 1412 receives from a server data such as license key Kc, license ID data License-ID and user ID data User-ID encrypted with a public encryption key KPcard(1) differing for each memory card for storage, and receives encrypted content data [Dc]Kc encrypted with license key Kc from data bus BS3 for storage.

Abstract: A memory card (110) includes a memory (1415) to store encrypted content data, a license hold unit (1440) to store at least a portion of license information distributed by a distribution system, a plurality of authentication data hold units (1400.1, 1400.2), 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 (SW2) 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 (110).

Abstract: A license server (10) includes a CRL database (306) 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 (315) 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 (315) in distributing content also transmits information for updating the revocation list in the memory card.

Abstract: A memory card (110) conducts an authentication process with a server based on data stored in an authentication data hold unit (1400). The memory card (110) extracts a first session key (Ks1) from a server by a decryption process and a transaction ID from the data applied on a data bus (BS3). The memory card (110) generates a second session key (Ks2) through a session key generation unit (1418), and transmits to the server, as the keys to encrypt content data in receiving decryption of content data, the second session key (Ks2) and a key (KPm(1)) unique to the memory card (110) in an encrypted state with the first session key (Ks1). The transaction ID and the second session key (Ks2) stored in the log memory (1460) are used in the redistribution process.

Abstract: Disclosed is an image processing system including an image input unit, an extraction unit, a plurality of compression process parts and a selection unit to compress a 1-frame image down to a less amount of color information. The image input unit takes in a plurality of frame images per frame. The extraction unit extracts each of the taken-in frame images per unit area of a designated size. The plurality of compression process parts effects compression processes different from each other with respect to pels contained in each unit area. The selection unit selects one compression process part from the plurality of compression process parts for compressing the unit area of the designated size.

Abstract: An image data compression method in which reductions in data amount are achieved by deleting some pixel data. Compression is achieved by performing a reading step to read an image as plural pixel data and a deleting step to delete some of the pixel data. A prediction error calculating step calculates a prediction error that represents the difference between the color value pixel data of a pixel in question and the predicted color value thereof, as predicted by a prescribed prediction method from the pixel data of a pixel adjacent thereto. An area classifying step classifies the pixel data of the entire image area into either an abrupt color change areas type in which the prediction error is large or a nonabrupt color change area in which the prediction error is small. The deleting step is performed only on the pixel data classified in the nonabrupt color change area; deleted-position information is appended to the non-deleted pixel data that indicates the position of a pixel whose data has been deleted.

Abstract: A motion picture reproducing apparatus having a file composed of a header an image track on which image data have been recorded for a predetermined period of time and a sound track on which sound data have been recorded for the predetermined period of time. The image and sound data of the file are provided with track and data identifying numbers by a track identifying section and a data identifying section, respectively, and are outputted to a data synchronizing section. The data synchronizing section reads in order the image data and the sound data on the basis of the control information of the header, synchronizes the image data and the sound data to which the same data identifying numbers have been imparted with reference to the track and data identifying numbers which have been given to the image data and sound data, and outputs the image and sound data to reproduction units.

Abstract: The method comprises a read-out step for reading out the image data from a predetermined recording medium according to a frame unit; an image outputting step for image-outputting the frame data read out in the read-out step; a time measuring step for measuring a reproductive processing time taken from a start of reading out in the read-out step to an end of outputting of an image in the image outputting step according to a frame unit; a predicting step for predicting an image output time of next frame data to be reproduced next to the frame data on the basis of the reproductive processing time measured in the time measuring step; a detecting step for detecting an image output time set per frame data from the image data; and a determining step for determining next frame data to be reproduced next to the frame data in accordance with the image output time predicted in the predicting step and the image output time detected in the detecting step.

Abstract: A video data reproducing apparatus and method therefor having a file controller section for controlling video data recorded on a first recording medium at random positions, and further, having a second recording medium for recording the video data in a serial manner. The apparatus includes a decision section for judging whether to select the video data of either the first recording medium or the second recording medium. A first reading section reads out the data of the first recording medium through the file controller section when the first recording medium is selected by the decision section, and a second reading section reads out the video data to a buffer memory from the second recording medium, without any intervention of the file controller section, when the second recording medium is selected by the decision section.