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AssigneeSanyo Electric Co., Ltd.
InventorsYoshihiro Hori, Takatoshi Yoshikawa
Estimating the term…
A controller of a reproduction terminal determines whether a block read from a memory card is an encrypted block or a non-encrypted block, and then applies the read block to a content decrypting circuit. The controller stops supplying the block to the content decrypting circuit when a predetermined number of non-encrypted blocks are continuously read from the memory card. Consequently, reproduction of the encrypted content data can be stopped if the encrypted content data includes a continuous non-encrypted portion in which the number of non-encrypted blocks is equal to or larger than a predetermined non-zero number.
A reproducing device for decrypting and reproducing encrypted content data divided into a plurality of blocks formed of an encrypted block including encrypted data and a non-encrypted block including non-encrypted data, comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Involving video stream decryption: by partially decrypting, e.g. decrypting a video stream that has been partially encrypted
Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity: protecting distributed…
Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer: to…
Television signal recording: using static stores, e.g. storage tubes or semiconductor memories
Term ended 17 Dec 2023 (estimated)
1. Field of the Invention
The present invention relates to a reproduction device for decrypting and reproducing encrypted data obtained by a data distribution system, which can secure a copyright relating to copied information.
2. Description of the Background Art
FIG. 1 is a schematic diagram showing a concept of a data distribution system;
FIG. 2 is a schematic view showing a concept of another data distribution system;
FIG. 3 shows characteristics of data, information and others for communication in the data distribution systems shown in FIGS. 1 and 2;
Embodiments of the invention will now be described with reference to the drawings. The same or similar parts or portions bear the same reference numbers in the figures, and description thereof will not be repeated.
FIG. 1 is a schematic diagram showing a concept of a whole structure of a data distribution system, from which encrypted content data is obtained by a cellular phone provided with a music reproducing function according to the invention.
Description will now be given by way of example on a data distribution system distributing digital music data to a memory card 110 of each user via a cellular phone network will be described as an example, and a data distribution system distributing digital music data to personal computers on the internet. However, as will become apparent from the following description, the present invention is not limited to such a case. The present invention is applicable to the distribution of other copyrighted materials, i.e., content data such as video data, image data, text data and programs, and further applicable.