Introduction of Content Protection technologies 林至勇

outline Content Protection Digital Right Management(DRM) Conclusion

Content Protection Technologies Content protection technologies divide into two sections: –Cryptographically-Based Technologies Digital domain ex: Encryption –Signal-Processing Based Technologies analogue domain ex: Digital Watermarking

Cryptographically-Based Technologies DVD Content Scrambling System (CSS) Content Protection for Recordable Media (CPRM) Content Protection for Pre-recorded Media (CPPM) Digital Transmission Content Protection (DTCP) High-Bandwidth Digital Content Protection (HDCP) Content Protection System Architecture (CPSA) Content Protection on the Home Network Broadcast Flag Tamper Resistance

DVD Content Scrambling System (CSS) Objectives: –to protect the content of DVDs from piracy. –to enforce region-based viewing restrictions. Functions: –player-host mutual authentication –data encryption Components of the system (CSS): –DVD itself. –DVD player that reads the disk and delivers the content. –The host (computer, host board, etc).

CSS System Step 1:(Mutual authentication) –The host and the DVD player establish their trustworthiness and negotiate a session key (bus key). Step 2:(Decoding disk key) –The DVD player tries each of several player keys to decode the disk key. The disk key is disk-wide secret. Step 3:(Send disk key and title keys) –The disk key and title keys are encrypted by bus key and sent from the player to the host. Step 4(Sent encrypted data) –The DVD player sends a sector to the host. Step 5(Decode the title key) –The host decodes the title key using the disk key. Step 6:(Decode the encrypted data) –The host decode the sector using the title key and each DVD contains a region code that indicates the region of the world in which it is intended to be viewed.

Content Protection for Recordable Media (CPRM) Developers: –4C Entity(IBM, Intel, Matsushita and Toshiba) Objective: –protect content recorded on a number of physical media types Components of the system: –Key management for interchangeable media –Content encryption –Media based renewability CPRM technology is designed to meet the following criteria: –It meets the content owners ’ requirements for robustness and system renewability. –It is applicable for both audio and video content. –It is equally suitable for implementation on PCs and CE devices. –It is applicable to different media types.

Operates of CPRM System

Content Protection for Pre- recorded Media (CPPM) Developers: –4C Entity Objectives: –protect DVD-Audio. CPPM System: –Encrypt audio content use 56-bit keys, instead of the 40-bit keys used for CSS. –Each licensed decoder model has assigned to it a set of unique device keys that allow it to obtain the Media Key (used to encrypt the audio content) from the MKB and decrypt the audio content. –Watermark contains 4 CCI (copy control information) and Usage Identifier.

Digital Transmission Content Protection (DTCP) Developers: –5C (Hitachi, Intel, Matsushita, Sony and Toshiba) Objectives: –DTCP protect audio/video content from illegal copying, intercepting and tampering as it traverses high performance digital buses, such as the IEEE 1394 or USB. Components of the system: –Authentication and key exchange –Content encryption –Copy control information –System renewability

1394 Content Protection Architecture Content Encryption: M6 or DES cipher Authentication and Key Exchange (AKE):  This includes two authentication levels:  Full authentication: for copy-never content.  Restricted authentication:for copy-one-generation and no-more-copies content.  Three encryption keys:  authentication key:established during authentication to encrypt the exchange key.  exchange key:set up and manage the security of copyrighted content streams.  content key:encrypt the content being exchanged. System renewability Messages (SRMs): delivered via content and new devices to ensures the long term integrity of the system and revoke unauthorized devices. Copy Control Information (CCI): specify whether their content can be duplicated. Encryption Mode Indicator (EMI): copy-freely, copy-never, copyone-generation, or no-more- copies.

High-Bandwidth Digital Content Protection (HDCP) Developers: –Intel, with contributions by Silicon Image. Objectives: –Protect DVI outputs from being copied. –Provide a secure digital link between a video source (PC, DVD, etc) and a display device (television, monitor, projector, etc). Components of the system: –Authentication and key exchange –Content encryption –Device renewability Device renewability –The key revocation list is carried by System Renewability Messages (SRM). –SRMs can be presented to the host in prerecorded or broadcasted content, or received from another compliant device with a newer SRM.

Broadcast Flag Objective : –Prevent broadcast content being recorded and then distributed over the internet from websites and other sources Main idea – a bit in the transport layer of a digital broadcast would assert that the content should not be distributed on the Internet

Signal-Processing Based Technologies Macrovision Digital watermarking for copy control Pattern Recognition (Fingerprinting)

Macrovision the grandfather of copy protection technologies, at least 20 years old. Main idea : out-of-specification television signal that most TVs are oblivious to, but most recorders are confused by –detailed technical differences between TVs and VHS recorders two versions: –noise pulse uses a high noise pulse in the vertical blanking interval to confuse the recorder ’ s automatic gain control –inverts 5 cycles of the 11 cycle per-line color burst signal to confuse the recorder ’ s color synchronization Macrovision asserts that about 90% of the VCRs are sensitive to these tricks, and no TVs are.

Digital watermarking for copy control digital watermarking can survive the analogue path. record control: A compliant recorder with an analogue or unencrypted digital input should refuse to record content marked “ do not copy ” playback control: If a player is playing a disc in the clear but finds a watermark of any kind, it should refuse to play. Playback control is a second layer of defense if the content escapes from the encrypted domain. The 4C group picked the Verance watermark for copy control on DVD-Audio. The industry consensus video watermark has not yet been picked The Secure Digital Music Initiative (SDMI), before it collapsed, had the idea of using two watermarks for protecting music: a robust watermark to indicate whether music was protected, and a fragile watermark that would disappear if the music was compressed. The idea was if music was detected with the robust watermark but without the fragile watermark, it would indicate that the content might have been compressed to make an unauthorized copy over the Internet.

Pattern Recognition (Fingerprinting) Watermarks can also be used as recognition algorithms to identify a piece of content. a statistical process and by necessity inexact, and the library of content that needs to be interrogated may be on the order of millions of pieces Complexity, performance is problem Not really considered for identification purposes.

Content Protection System Architecture (CPSA)

 CPRM for protecting content stored on recordable media such as DVD or Flash  CPPM for protecting pre-recorded DVD-Audio content  CSS for protecting pre-recorded DVD-Video content  DTCP for protecting content during for protecting content during digital transmission over 1394 digital transmission over 1394 and USB and USB  HDCP for protecting content moving for protecting content moving across high-bandwidth interfaces across high-bandwidth interfaces to digital displays to digital displays  Conditional Access for protected distribution of premium content via cable or satellite  4C/Verance Watermark for embedding and reading watermark CMI in audio content  A video watermarking scheme, to be selected by the DVD CCA

DVB-CPT-Cfp CPCM Consumer domain architecture

IBM Response to DVB-CPT-Cfp CPCM : xCP Relationship of xCP Cluster to the Copy Protection System Architecture

Content protection toward DRM Creation Waterfall Pay for possession Limited re-use rights available Creation Life-cycle Pay for usage, not possession Share the rights, revenue Require trusted services to validate rights and trades

eBook eMusic eImage eVideo eLearning … Rights Metadata Rights Language Package Protected Content Identify Content Describe Content Make Business Model Codify Rules Package Content/Rules Distribute Protected Content Consume Content Digital Watermarking Encryption Tools Content ID Content Metadata Content Super-Distribution Transfer Workflow of Digital Content Offering 智慧資產創造管理使用 內容 1. 創造 3. 儲存、 4. 交易 9. 使用 權力 2. 創造 5. 描述 6. 授權、 7. 保護、 8. 追蹤

eBook eMusic eImage eVideo eLearning … Rights Metadata Rights Language Package Protected Content Identify Content Describe Content Make Business Model Codify Rules Package Content/Rules Distribute Protected Content Consume Content Digital Watermarking Encryption Tools Content ID Content Metadata Content Digital Object Identifier ; Uniform Resource Identifiers Interoperability of Data in E-Commerce Systems ONline Information eXchange XrML,ODRL,XMCL & 2rdd MPEG-21 Digital Item Identification & Description MPEG-21 Digital Item Declaration MPEG-21 Rights Expression Language & Rights Data Dictionary DRM Standards: MPEG-21. Electronic Book eXchange (EBX). Open eBook Forum (OeBF). TV anytime. Open Mobile Alliance (OMA). Secure Digital Music Initiative (SDMI). IMS Global Learning Consortium (IMS). Super-Distribution Transfer Workflow of Digital Content Offering

Conclusion new technologies are being invented every day. It will form a menu of content protection technologies. Content protection toward digital right management (DRM)