SECURE PRESENTATION OF MEDIA STREAMS IN RESPONSE TO ENCRYPTED CONTENT

• US 20100172498A1
• Filed: 03/17/2010
• Published: 07/08/2010
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: Kaleidescape Incorporated
• Original Assignee: Kaleidescape Incorporated
• Inventors: Hui, Kevin, Collens, Daniel A., Watson, Stephen, Rechsteiner, Paul, Malcolm, Michael A.
• Granted Patent: US 8,280,051 B2
• Time in Patent Office: Days
• US Class Current: 380/237
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
• CPC Class Codes: G09C 5/00 Ciphering apparatus or methods not provided for in the preceding groups, e.g. involving the concealment or deformation of graphic data such as designs, written or printed messages
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: G11B 20/00173 wherein the origin of the content is checked, e.g. determining whether the content has originally been retrieved from a legal disc copy or another trusted source
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: H04L 2209/606 Traitor tracing
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04N 1/32352 Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 2201/3235 Checking or certification of the authentication information, e.g. by comparison with data stored independently

Abstract

Secure presentation of media streams includes encoding the media streams into digital content, encrypting a portion of that digital content, the portion being required for presentation, in which the encrypted version is substantially unchanged in formatting parameters from the clear version of the digital content. Selecting those portions for encryption so there is no change in distribution of the media stream: packetization of the digital data, or synchronization of audio with video portions of the media stream. When encoding the media stream into MPEG-2, refraining from encrypting information by which the video block data is described, packet formatting information, and encrypting the video block data using a block-substitution cipher. A block-substitution cipher can be used to encrypt each sequence of 16 bytes of video data in each packet, possibly leaving as many as 15 bytes of video data in each packet in the clear.

Claims

1. Apparatus comprising:

an input port capable of being coupled to a communication link, the communication link being capable of carrying digital content, the digital content including at least some presentable information and at least some formatting information;

a digital content decoder, the decoder being capable of identifying the presentable information in response to the formatting information; and

a digital content decryptor, the decryptor being capable of decrypting the presentable information in response to a key,

wherein the decryptor is protected by a relatively-higher degree of security than the decoder.

2. Apparatus as in claim 1, wherein the communication link includes at least one of:

a computer network capable of carrying digital content;

or a reader capable of retrieving information in response to physical media, the physical media being capable of carrying digital content.

3. Apparatus as in claim 1, wherein the decoder includes an MPEG decoder.

4. Apparatus as in claim 1, wherein the decoder is included in a first selected set of hardware or software, the first selected set being trusted;

and the decryptor and the key are included in a second selected set of hardware or software, the second selected set being relatively more trusted than the first selected set.

5. Apparatus as in claim 1, wherein the decoder is responsive to the formatting information to present at least some metadata about one or more media streams without the decoder having access to the presentation information.

6. Apparatus as in claim 1, wherein the decoder is responsive to the formatting information to provide at least one of the following functions without the decoder having access to the presentation information:

known playback functions known for media streams;

navigation within the digital content;

content selection within the digital content;

or manipulation of the presentation.

7. Apparatus as in claim 1, wherein the digital content represents a media stream including at least one of:

a movie, animation, sound, still media, a picture, an illustration, a database, a collection of information.

8. Apparatus as in claim 1, wherein the relatively-higher degree of security includes tamper-resistant hardware operating under control of verified software.

9. Apparatus as in claim 1, wherein the digital content represents a first media stream and a second media stream, the decoder being responsive to the formatting information and the decryptor being responsive to a selected key, the selected key providing differential access to selected users to the first media stream and the second media stream.

10. Apparatus as in claim 9, wherein the first media stream includes audio information and the second media stream includes video information;

the first media stream includes information in a first language and the second media stream includes information in a second language;

the first media stream includes presentation information targeted at a first type of audience and the second media stream includes information targeted at a first type of audience.