1、 ETSI TS 103 162 V1.1.1 (2010-10)Technical Specification Access, Terminals, Transmission and Multiplexing (ATTM); Integrated Broadband Cable and Television Networks;K-LAD Functional SpecificationETSI ETSI TS 103 162 V1.1.1 (2010-10)2Reference DTS/ATTM-003012 Keywords CA, cable ETSI 650 Route des Luc
2、ioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice Individual copies of the present document can be downloaded from: htt
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6、d the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2010. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTM, TIPHONTM, the TIPHON logo and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM is a Trade Ma
7、rk of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. LTE is a Trade Mark of ETSI currently being registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Associatio
8、n. ETSI ETSI TS 103 162 V1.1.1 (2010-10)3Contents Intellectual Property Rights 4g3Foreword . 4g31 Scope 5g32 References 5g32.1 Normative references . 5g32.2 Informative references 5g33 Definitions and abbreviations . 6g33.1 Definitions 6g33.2 Abbreviations . 6g34 Introduction 7g34.1 Overview 7g34.2
9、Descrambling Algorithm Requirements . 7g35 Functional Diagram 8g36 Functional Requirements 10g36.1 Key Ladder Functions 10g36.1.1 CA Key Ladder . 10g36.1.2 Challenge Response 10g36.1.3 Key Ladder Ciphers 11g36.1.4 CW Alignment 11g36.2 Time Constraints 11g36.3 Driver API 11g36.4 Secret Chipset Key Ob
10、fuscation . 11g37 Root Key Derivations . 11g37.1 Introduction 11g37.2 Functional Requirements 12g38 Extensions 13g38.1 Introduction 13g38.2 Additional Key Levels 13g38.3 Additional Security Operations 13g3History 14g3ETSI ETSI TS 103 162 V1.1.1 (2010-10)4Intellectual Property Rights IPRs essential o
11、r potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Ess
12、ential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI
13、. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Specification (TS) has been produced by ETSI Technical Committee Acc
14、ess, Terminals, Transmission and Multiplexing (ATTM). ETSI ETSI TS 103 162 V1.1.1 (2010-10)51 Scope The present document defines the key ladder and cryptographic requirements for security functionality to be embedded within a television receivers chipset (e.g. SOC). The use of a standard key ladder
15、ensures that any television receiving device may receive television content from any television distribution network regardless of the network security solution in use. 2 References References are either specific (identified by date of publication and/or edition number or version number) or non-spec
16、ific. For specific references, only the cited version applies. For non-specific references, the latest version of the reference document (including any amendments) applies. Referenced documents which are not found to be publicly available in the expected location might be found at http:/docbox.etsi.
17、org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity. 2.1 Normative references The following referenced documents are necessary for the application of the present document. 1 ISO/IEC 13818-1 (2007): Inf
18、ormation technology - Generic coding of moving pictures and associated audio information: Systems“. 2 ETSI ETR 289: “Digital Video Broadcasting (DVB); Support for use of scrambling and Conditional Access (CA) within digital broadcasting systems“. 3 ETSI TS 102 825-5: “Digital Video Broadcasting (DVB
19、); Content Protection and Copy Management (DVB-CPCM); Part 5: CPCM Security Toolbox“. 4 ISO/IEC 18033-3 (2005): Information technology - Security techniques - Encryption algorithms - Part 3: Block ciphers. 5 FIPS-197 (AES): “Specification for the Advanced Encryption Standard Federal Information Proc
20、essing Standards (FIPS)“ Publication 197, November 26, 2001. 2.2 Informative references The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. i.1 DVB-CSA - DVB BlueBook A125 (2008)/(Document
21、 a125_CSA3_dTR101289.v1.2.1): “Support for use of the DVB Scrambling Algorithm version 3 within digital broadcasting systems“. ETSI ETSI TS 103 162 V1.1.1 (2010-10)63 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: Au
22、thentication key (A): a 16-byte key derived from K2 that is used by the challenge-response mechanism NOTE: A can be used either to authenticate the sink device through a traditional challenge-response, or used by the sink device to authenticate messages from the source device by deriving a key for a
23、 CBC-MAC or similar symmetric message authentication algorithm. control word: key used to descramble the video, either 8 or 16 bytes Dk(Y): used to denote the data Y decrypted with key K Ek(Y): used to denote the data Y encrypted with key K ESCK: encrypted secret chipset key which is the value physi
24、cally stored in the chipsets OTP NOTE: It has to be at least as large as the SCK. The ESCK would be typically uneditable and unreadable after manufacture. Key 1 (K1): 16-byte key used to decrypt the CW Key 2 (K2): 16-byte key used to decrypt K1 Key Ladder Root Key, or Root Key (K3): 16-byte private
25、key used by each compliant chipset at the root of the key ladder, it is used to decrypt K2 NOTE: In chipsets that implement an extended key ladder with n levels, the root key at the highest level of the key ladder will be denoted by Kn. PID: Packet ID of a component elementary stream within a progra
26、m carried in an MPEG-2 transport stream public ID: 8-byte Public Identifier of the sink device chipset, including elements indicating the manufacturer and model as well as a globally unique identifier for the chipset instance within that model SCK: secret chipset key which is unique to each complian
27、t chipset NOTE: It has to be at least 16-bytes. In initial chipset deployments that lack the root key derivation mechanism, the SCK may also serve as the key ladder root key K3. In this case the SCK shall be exactly 16 bytes. vendor ID: value of at least 8 bits that will be used to identify CA vendo
28、rs, network operators, and other entities using a compliant chipset 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: AES Advanced Encryption Standard CPU Central Processing Unit CW Control Word DES Data Encryption Security DVB-CSA2 Digital Video Broadcas
29、ting-Common Scrambling Algorithm ILA Industry Licensing Authority MPEG Motion Picture Equipment Group OTP One Time Programmable memory SOC System On Chip SCK Secret Chipset Key STB Set Top Box TDES Triple DESETSI ETSI TS 103 162 V1.1.1 (2010-10)74 Introduction 4.1 Overview The present document is a
30、specification for enabling and securing the delivery of content descrambling keys from a source device to a sink device. The basis of the present document is a three-step key ladder and challenge-response authentication scheme in which the base key derivation inputs are protected within the one time
31、 programmable memory (OTP) of the sink devices hardware (e.g. chipset). The key ladder is used primarily for the delivery of content descrambling keys while the challenge-response mechanism is used for checking the integrity and authenticity of sink devices as well as messages arriving from an compl
32、iant source device. The present document is intended for chipset manufacturers who choose to implement the key ladder functionality in their chipsets. This key ladder specification is designed to support the dynamic substitution and replacement of either sink or source device in a manner that mainta
33、ins the security and integrity of the underlying content distribution network. The specification enables the portability of sink devices between content distribution networks by permitting the field upgradeability of sink devices to work with previously unknown source devices. The specification also
34、 enhances the capability of networks to upgrade their source devices without disrupting the capabilities of already fielded sink devices. While the source device is expected to be a key management system such as a traditional Conditional Access System or Digital Rights Management solution deployed b
35、y a content distribution network, and the sink device is expected to be a secure content consumption device such as a STB or television, the present document is not limited to only supporting these particular types of devices. The present document is derived from an existing technical solution alrea
36、dy deployed in existing hardware systems and is designed to be backwards compatible with these existing implementations. The key derivation component of the present document enables cross-network portability by allowing network specific inputs to be securely reprogrammed in the field. The modificati
37、on of one of these system inputs may occur on the fly, and is sufficient to enable a sink device to function securely on a new network, using a new root key for the key ladder. The present document does not specify how content arrives to the sink device descrambler, only that the sink devices descra
38、mbler shall recognize the scrambling algorithm utilized by the contents network distribution system. The present document does not specify conformance and robustness rules for chipset hardware nor interoperability or certification requirements. Such rules are beyond the scope of the current specific
39、ation and are expected to be the responsibility of an Industry Licensing Authority (ILA). It is recognized that effective and safe implementation and deployment of content security systems based on the mechanisms described in the present document will require a complete security infrastructure that
40、can deal with business, security, intellectual property , documentation and trusted information distribution issues. The description of such an infrastructure and the organizations which will administer it (i.e. an ILA) is outside of the scope of the present document. As the present document is expe
41、cted to be implemented in the chipset hardware of a sink devices, a universal separable security specification would also require that the sink devices hardware implement all standardized scrambling algorithms that it might ever encounter. To ensure universal portability of compliant sink device har
42、dware between networks, a finite set of scrambling algorithms shall be implemented in these devices. Use of additional scrambling algorithms is permitted, but is not defined in the present document. 4.2 Descrambling Algorithm Requirements The present document defines the key ladder, authentication m
43、echanism, and cryptographic requirements of a compliant chipset implementation. ETSI ETSI TS 103 162 V1.1.1 (2010-10)8Except where explicitly noted, the following requirements are specific to Version 1 of the present document. To be backwards compatible, future versions of the present document shall
44、 support these initial requirements but may also support additional future requirements, such as DVB-CSA3 i.1. A compliant chipset shall include an MPEG-2 transport processor as defined by 1. A compliant chipset shall include an MPEG-2 transport stream component descrambler utilizing an open, standa
45、rd descrambling algorithm. At a minimum, Version 1 requires support for two content descrambling algorithms (transport stream ciphers): DVB CSA2 2; AES 128 Bit Cipher optimized for handling MPEG2 TS 3) used in CBC mode only: - Chaining Mode is set to CBC and is therefore not required to implement RC
46、BC chaining mode. The authentication mechanism and the key ladder structure protecting the descrambling key within the descrambler of the transport processor chipset shall utilize two standardized block ciphers: TDES (Triple-DES as specified in 4); and AES (as specified in 5). 5 Functional Diagram F
47、igure 1 presents the functional design of the Version 1 key ladder embedded within the transport processor/descrambler chipset of the sink device, and depicts the key ladders relationship with the drivers and dependent applications executed by the Main CPU, the content descrambler, and the other sin
48、k device functions. Figure 1 does not represent the chipsets actual hardware architecture. ETSI ETSI TS 103 162 V1.1.1 (2010-10)9OMS Drivers128 bits for AES). 4. The compliant chipset shall be configurable as to whether or not the software may use clear control words. If clear control words are allo
49、wed, the compliant chipset shall allow the software to switch back and forth freely, without reset between clear control words and control words from the key ladder. If the compliant chipset supports descrambling of multiple streams simultaneously, then it shall be possible to use clear and encrypted control words simultaneously. Forbidding the use of clear control words will be configurable, one-time, in the form of on-chip OTP both by the chipset vendor as well as software programmable at the time of device (e.g. STB) manufacturin
