Partial encryption techniques for media data
First Claim
1. A method for encrypting media data, said method comprising:
- identifying a media file having media data to be encrypted, the media data being arranged in frames;
examining the media data in the media file to locate frame boundaries for the frames within the media data;
dividing each of the frames into a plurality of blocks;
retrieving encryption parameters to be utilized; and
encrypting each of the blocks in accordance with the encryption parameters.
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Accused Products
Abstract
Improved techniques to partially encrypt media files are disclosed. The encryption serves to cryptographically secure only a portion of the media data within a media file, while the remaining portion of the media data is not cryptographically secured. Although only partial encryption is used, the portion being encrypted serves to substantially disrupt usefulness of other parts of the media file which are not encrypted. In other words, the partial encryption renders the media file substantially unusable by unauthorized users. In one embodiment, the partial encryption is performed by a host device and thereafter the partially encrypted media file is delivered to a client device. The client device, if authorized, can subsequently decrypt the partially encrypted media file and utilize (e.g., play) the media file. However, since the media files are only partially encrypted, the decryption is likewise also only partial, which makes decryption faster and less resource intensive.
409 Citations
24 Claims
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1. A method for encrypting media data, said method comprising:
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identifying a media file having media data to be encrypted, the media data being arranged in frames;
examining the media data in the media file to locate frame boundaries for the frames within the media data;
dividing each of the frames into a plurality of blocks;
retrieving encryption parameters to be utilized; and
encrypting each of the blocks in accordance with the encryption parameters. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for encrypting media data, said method comprising:
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identifying a media file having media data to be encrypted, the media data being arranged in frames;
examining the media data in the media file to locate frame boundaries for the frames within the media data;
dividing each of the frames into a plurality of blocks; and
encrypting only a portion of the media data pertaining to each of the blocks. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A method for decrypting media data, said method comprising:
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identifying a media file having encrypted media data to be decrypted and unencrypted media data that requires no decryption, the media data being arranged in frames;
retrieving encryption parameters associated with the media file;
examining the media data in the media file to locate frame boundaries for the frames within the media data;
dividing each of the frames into a plurality of blocks; and
decrypting each of the blocks in accordance with the encryption parameters. - View Dependent Claims (18, 19, 20, 21)
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22. A portable media device, comprising:
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a memory device for storage of a media file, the media file including encrypted media data and unencrypted media data;
a media output device that outputs media data; and
a controller operatively connected to said memory device and said media output device, said controller operates to;
(i) receive a play request from a user to play the media file, (ii) obtain a cryptographic key and encryption parameters associated with the media file, (iii) decrypt only the encrypted media data within the media file in accordance with the cryptographic key and the encryption parameters; and
(iv) outputting the resulting media data so as to play the media file for the user. - View Dependent Claims (23)
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24. A computer readable medium including at least computer program code for encrypting media data, said computer readable medium comprising:
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computer program code for identifying a media file having media data to be encrypted, the media data being arranged in frames;
computer program code for examining the media data in the media file to locate frame boundaries for the frames within the media data;
computer program code for dividing each of the frames into a plurality of blocks; and
computer program code for encrypting only a portion of the media data pertaining to each of the blocks.
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Specification