MEDIA ENCRYPTION DEVICE, MEDIA ENCRYPTION AND DECRYPTION DEVICE, METHOD OF MEDIA ENCRYPTION, AND METHOD OF MEDIA ENCRYPTION AND DECRYPTION

摘要

In a media encryption device, a dynamic image compression unit (101) compresses video data and generates compressed video data which includes a header storing basic information of the video data and macroblock data storing the variable-length code of the video data. An encryption processing determination unit (102) identifies as encryption portions the leading portion of each header in the compressed video data and the portion extending from the tail end of a slice header to the head of the macroblock data, and an encryption processing unit (103) encrypts the identified portions while generating encrypted portion information indicative of the encrypted portions.