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Conditional access

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Conditional access (CA) is a term commonly used in relation to software and to digital television systems. Conditional access is that ‘just-in-time’ evaluation to ensure the person who is seeking access to content is authorized to access the content. Said another way, conditional access is a type of access management. Access is managed by requiring certain criteria to be met before granting access to the content.

In software

Conditional access is a function that lets you manage people’s access to the software in question, such as email, applications, and documents. It is usually offered as SaaS (Software-as-a-Service) and deployed in organizations to keep company data safe. By setting conditions on the access to this data, the organization has more control over who accesses the data and where and in what way the information is accessed.

When setting up conditional access, access can be limited to or prevented based on the policy defined by the system administrator. For example, a policy might require access is available from certain networks, or access is blocked when a specific web browser is requesting the access.

In digital television

Under the Digital Video Broadcasting (DVB) standard, conditional access system (CAS) standards are defined in the specification documents for DVB-CA (conditional access), DVB-CSA (the common scrambling algorithm) and DVB-CI (the Common Interface).[1] These standards define a method by which one can obfuscate a digital-television stream, with access provided only to those with valid decryption smart-cards. The DVB specifications for conditional access are available from the standards page on the DVB website.

This is achieved by a combination of scrambling and encryption. The data stream is scrambled with a 48-bit secret key, called the control word. Knowing the value of the control word at a given moment is of relatively little value, as under normal conditions, content providers will change the control word several times per minute. The control word is generated automatically in such a way that successive values are not usually predictable; the DVB specification recommends using a physical process for that.

In order for the receiver to unscramble the data stream, it must be permanently informed about the current value of the control word. In practice, it must be informed slightly in advance, so that no viewing interruption occurs. Encryption is used to protect the control word during transmission to the receiver: the control word is encrypted as an entitlement control message (ECM). The CA subsystem in the receiver will decrypt the control word only when authorised to do so; that authority is sent to the receiver in the form of an entitlement management message (EMM). The EMMs are specific to each subscriber, as identified by the smart card in his receiver, or to groups of subscribers, and are issued much less frequently than ECMs, usually at monthly intervals. This being apparently not sufficient to prevent unauthorized viewing, TPS has lowered this interval down to about 12 minutes. This can be different for every provider, BSkyB uses a term of 6 weeks. When Nagravision 2 was hacked, Digital+ started sending a new EMM every three days to make unauthorized viewing more cumbersome.

The contents of ECMs and EMMs are not standardized and as such they depend on the conditional access system being used.[2]

The control word can be transmitted through different ECMs at once. This allows the use of several conditional access systems at the same time, a DVB feature called simulcrypt, which saves bandwidth and encourages multiplex operators to cooperate. DVB Simulcrypt is widespread in Europe; some channels, like the CNN International Europe from the Hot Bird satellites, can use 7 different CA systems in parallel.

The decryption cards are read, and sometimes updated with specific access rights, either through a conditional-access module (CAM), a PC card-format card reader meeting DVB-CI standards, or through a built-in ISO/IEC 7816 card reader, such as that in the Sky Digibox.

Several companies provide competing CA systems; ABV, VideoGuard, Irdeto, Nagravision, Conax, Viaccess, Synamedia, Mediaguard (a.k.a. SECA) are among the most commonly used CA systems.

Due to the common usage of CA in DVB systems, many tools to aid in or even directly circumvent encryption exist. CAM emulators and multiple-format CAMs exist which can either read several card formats or even directly decrypt a compromised encryption scheme. Most multiple format CAMs and all CAMs that directly decrypt a signal are based on reverse engineering of the CA systems. A large proportion of the systems currently in use for DVB encryption have been opened to full decryption at some point, including Nagravision, Conax, Viaccess, Mediaguard (v1) as well as the first version of VideoGuard.

Conditional access in North America

In Canada and United States, the standard for conditional access is provided with CableCARDs whose specification was developed by the cable company consortium CableLabs.

Cable companies in the United States are required by the Federal Communications Commission to support CableCARDs. Standards exist for two-way communication (M-card), but satellite television has separate standards. Next-generation approaches in the United States eschew such physical cards and employ schemes using downloadable software for conditional access such as DCAS.

The main appeal of such approaches is that the access control may be upgraded dynamically in response to security breaches without requiring expensive exchanges of physical conditional-access modules. Another appeal is that it may be inexpensively incorporated into non-traditional media display devices such as portable media players.

Conditional access systems

Conditional access systems include:

Analog systems

Digital systems

CA ID Name Developed by Introduced (year) Security Notes
0x4AEB Abel Quintic Abel DRM Systems 2009 Secure
0x4AF0 , 0x4AF2 , 0x4B4B ABV CAS ABV International Pte. Ltd 2006 Secure (Farncombe Certified) CA,DRM,Middleware & Turnkey Solution Provider For DTH, DVBT/T2, DVBC, OTT, IPTV, VOD,Catchup TV, Audience Measurement System, EAD etc.
0x4AFC Panaccess Panaccess Systems GmbH 2010 Secure (Farncombe Certified) CA for DVB-S/S2, DVB-T/T2, DVB-C, DVB-IP, OTT, VOD, Catchup etc.
0x4B19 RCAS or RIDSYS cas RIDSYS, INDIA 2012 Secure CA for DVB-C, IPTV, OTT, VOD, Catchup etc.
0x4B30, 0x4B31 ViCAS Vietnam Multimedia Corporation (VTC) Unknown Secure (Farncombe Certified)
0x4800 Accessgate Telemann Unknown
0x4A20 AlphaCrypt AlphaCrypt Unknown
N/A B-CAS ARIB STD-B25 (Multi-2) Association of Radio Industries and Businesses (ARIB) 2000 CA for ISDB. Used in Japan only
0x1702, 0x1722, 0x1762 reserved for various non-BetaResearch CA systems Formally owned by BetaTechnik/Beta Research (subsidiary of KirchMedia). Handed over to TV operators to handle with their CA systems. Unknown
0x1700 – 0x1701, 0x1703 – 0x1721, 0x1723 – 0x1761, 0x1763 – 0x17ff, 0x5601 – 0x5604 VCAS DVB Verimatrix Inc. 2010
0x2600


0x2610

BISS


BISS-E

European Broadcasting Union 2002


2018

Compromised, BISS-E secure
0x27A0-0x27A4 ICAS (Indian CAS) ByDesign India Private Limited 2015 Advanced Embedded Secure
0x4900 China Crypt CrytoWorks (China) (Irdeto) Unknown
0x22F0 Codicrypt Scopus Network Technologies (now part of Harmonic) Unknown Secure
0x4AEA Cryptoguard Cryptoguard AB 2008 Secure
0x0B00 Conax Contego Conax AS Unknown Secure
0x0B00 Conax CAS 5 Conax AS Unknown Compromised Pirate cards has existed
0x0B00 Conax CAS 7.5 Conax AS Unknown Secure
0x0B00, 0x0B01, 0x0B02, 0x0BAA Conax CAS 7 Conax AS Unknown Compromised Cardsharing
0x0B01, 0x0B02, 0x0B03, 0x0B04, 0x0B05, 0x0B06, 0x0B07 Conax CAS 3 Conax AS Unknown Compromised Pirate cards has existed
0x4AE4 CoreCrypt CoreTrust(Korea) 2000 S/W & H/W Security CA for IPTV, Satellite, Cable TV and Mobile TV
0x4347 CryptOn CryptOn Unknown
0x0D00, 0x0D02, 0x0D03, 0x0D05, 0x0D07, 0x0D20 Cryptoworks Philips CryptoTec Unknown Partly compromised (older smartcards)
0x4ABF CTI-CAS Beijing Compunicate Technology Inc. Unknown
0x0700 DigiCipher and DigiCipher II Jerrold/GI/Motorola 4DTV 1997 Compromised DVB-S2 compatible, used for retail BUD dish service and for commercial operations as source programming for cable operators.

Despite the Programming Center shut down its consumer usage of DigiCipher 2 (as 4DTV) on August 24, 2016, it is still being used for cable headends across the United States, as well as on Shaw Direct in Canada.

0x4A70 DreamCrypt Dream Multimedia 2004 Proposed conditional access system used for Dreambox receivers.
0x4A10 EasyCas Easycas Unknown
0x2719,0xEAD0 InCrypt Cas S-Curious Research & Technology Pvt. Ltd., Equality Consultancy Services Unknown
0x0464 EuroDec Eurodec Unknown
0x5448 Gospell VisionCrypt GOSPELL DIGITAL TECHNOLOGY CO., LTD. Unknown Secure
0x5501 Griffin Nucleus Systems, Ltd. Unknown
0x5581 Bulcrypt Bulcrypt 2009 Used in Bulgaria and Serbia
0x0606 Irdeto 1 Irdeto 1995 Compromised
0x0602, 0x0604, 0x0606, 0x0608, 0x0622, 0x0626, 0x0664, 0x0614 Irdeto 2 Irdeto 2000
0x0692 Irdeto 3 Irdeto 2010 Secure
0x4AA1 KeyFly SIDSA 2006 Partly compromised (v. 1.0)
0x0100 Seca Mediaguard 1 SECA 1995 Compromised
0x0100 Seca Mediaguard 2 (v1+) SECA 2002 Partly compromised (MOSC available)
0x0100 Seca Mediaguard 3 SECA 2008
0x1800, 0x1801, 0x1810, 0x1830 Nagravision Nagravision 2003 Compromised
0x1801 Nagravision Carmageddon Nagravision Unknown Combination of Nagravision with BetaCrypt
0x1702, 0x1722, 0x1762, 0x1801 Nagravision Aladin Nagravision Unknown
0x1801 Nagravision 3 - Merlin Nagravision 2007 Secure
0x1801 Nagravision - ELK Nagravision Circa 2008 IPTV
0x4A02 Tongfang Tsinghua Tongfang Company 2007 Secure
0x4AD4 OmniCrypt Widevine Technologies 2004
0x0E00 PowerVu Scientific Atlanta 1998 Compromised Professional system widely used by cable operators for source programming
0x0E00 PowerVu+ Scientific Atlanta 2009
0x1000 RAS (Remote Authorisation System) Tandberg Television Unknown Professional system, not intended for consumers.
0x4AC1 Latens Systems Latens 2002
0xA101 RosCrypt-M NIIR 2006
0x4A60, 0x4A61, 0x4A63 SkyCrypt/Neotioncrypt/Neotion SHL AtSky/Neotion[3] 2003
Unknown T-crypt Tecsys Unknown
0x4A80 ThalesCrypt Thales Broadcast & Multimedia[4] Unknown Viaccess modification. Was developed after TPS-Crypt was compromised.[5]
0x0500 TPS-Crypt France Telecom Unknown Compromised Viaccess modification used with Viaccess 2.3
0x0500 Viaccess PC2.3, or Viaccess 1 France Telecom Unknown
0x0500 Viaccess PC2.4, or Viaccess 2 France Telecom 2002
0x0500 Viaccess PC2.5, or Viaccess 2 France Telecom Unknown
0x0500 Viaccess PC2.6, or Viaccess 3 France Telecom 2005
0x0500 Viaccess PC3.0 France Telecom 2007
0x0500 Viaccess PC4.0 France Telecom 2008
Unknown Viaccess PC5.0 France Telecom 2011 Secure
Unknown Viaccess PC6.0 France Telecom 2015
0x0930, 0x0942 Synamedia VideoGuard 1 NDS (now part of Synamedia) 1994 Partly compromised (older smartcards)
0x0911, 0x0960 Synamedia VideoGuard 2 NDS (now part of Synamedia) 1999 Secure
0x0919, 0x0961, 0x09AC Synamedia VideoGuard 3 NDS (now part of Synamedia) 2004 Secure
0x0927, 0x0963, 0x093b, 0x09CD Synamedia VideoGuard 4 NDS (now part of Synamedia) 2009 Secure
0x56D0 Onnet CA/DRM Onnet Systems India Pvt. Ltd. 2021 Secure CA/DRM, IPTV Middleware, OTT, Interactive Services, STB Middleware, AR/VR
0x4AD0, 0x4AD1 X-Crypt XCrypt Inc. 2010 Secure
0x4AE0, 0x4AE1, 0x7be1 DRE-Crypt Cifra 2004 Secure
Unknown PHI CAS RSCRYPTO 2016 Secure

See also

References

  1. ^ "Security". DVB. Retrieved 2022-12-05.
  2. ^ https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.1852-1-201701-I!!PDF-E.pdf [bare URL PDF]
  3. ^ "Skycrypt". 2008-01-17. Retrieved 2008-08-28.
  4. ^ "What means ThalesCrypt? - AfterDawn". www.afterdawn.com.
  5. ^ "TPSCrypt". 2008-01-17. Retrieved 2008-08-28.
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