| 主权项 |
1. A video processing device for encrypting a compressed video signal from an elementary bit stream, the video processing device comprising:
a machine that includes: a key storage device for storing at least one encryption key; and an encryption processing device, coupled to the key storage device, that retrieves the at least one encryption key from the key storage device, and that encrypts the elementary bit stream into at least one partially encrypted elementary bit stream, wherein first portions of the at least one partially encrypted elementary bit stream are encrypted and second portions of the at least one partially encrypted elementary bit stream are unencrypted, wherein the encryption processing device applies a first of a plurality of encryption methods for encrypting the first portions of a first block size and applies a second of the plurality of encryption methods for encrypting the first portions of a second block size that is less than the first block size. |
