CONTENT ENCRYPTING METHOD, CONTENT ENCRYPTING DEVICE AND COMPUTER PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a content encrypting method capable of encrypting content to the extent that contents of the content can be confirmed without extremely deteriorating the compression rate of the content.

SOLUTION: An I frame 10 divided into a block is extracted from a moving image file in an MPEG format, at least one processing range 12 formed by a matrix of a blocks 11 is set in the extracted I frame 10, a random number obtained from stream encryption with a random number generation key defined as an input is used to generate an encryption key 13 showing a rule for rearranging the blocks 11 included in the processing range 12, and the blocks 11 included in the processing range 12 are rearranged in each processing range 12 to thereby encrypt content.

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