Television encryption
Encyclopedia
Television encryption, often referred to as "scrambling
", is encryption
used to control access to pay television services, usually cable
or satellite television
services.
The early cable-based Pay TV networks used no security. This led to problems with people connecting to the network without paying. Consequently, some methods were developed to frustrate these self-connectors. The early Pay TV systems for cable television were based on a number of simple measures. The most common of these was a channel-based filter that would effectively stop the channel being received by those who had not subscribed. These filters would be added or removed according to the subscription. As the number of television channels on these cable networks grew, the filter-based approach became increasingly impractical.
Other techniques such as adding an interfering signal to the video or audio began to be used as the simple filter solutions were easily bypassed. As the technology evolved, addressable set-top boxes became common, and more complex scrambling techniques such as digital encryption of the audio or video cut and rotate (where a line of video is cut at a particular point and the two parts are then reordered around this point) were applied to signals.
Encryption was used to protect satellite-distributed feeds for cable television networks. Some of the systems used for cable feed distribution were expensive. As the DTH market grew, less secure systems began to be used. Many of these systems (such as OAK Orion) were variants of cable television scrambling systems that affected the synchronisation part of the video, inverted the video signal, or added an interfering frequency to the video. All of these analogue scrambling techniques were easily defeated.
In France, Canal+
launched a scrambled service in 1984. It was also claimed that it was an unbreakable system. Unfortunately for that company, an electronics magazine, "Radio Plans", published a design for a pirate decoder within a month of the channel launching.
In the USA, HBO was one of the first services to encrypt its signal using the VideoCipher II system. In Europe, FilmNet scrambled its satellite service in September 1986, thus creating one of the biggest markets for pirate satellite TV decoders in the world, because the system that FilmNet used was easily hacked. One of FilmNet's main attractions was that it would screen hard-core porn films on various nights of the week. The VideoCipher II system proved somewhat more difficult to hack, but it eventually fell prey to the pirates.
Analog
and digital
pay television have several conditional access
systems that are used for pay per view (PPV) and other subscriber related services. Originally, analog-only cable TV systems relied on set-top boxes to control access to programming, as television sets originally were not "cable-ready". Analog encryption was typically limited to premium channels such as HBO or channels with adult-oriented content. In those cases, various proprietary video synchronization suppression methods were used to control access to programming. In some of these systems, the necessary synch signal was on a separate subcarrier. Analog set-top boxes have largely been replaced by digital set-top boxes that can directly control access to programming as well as digitally decrypt signals.
VideoCipher II RS (VCII RS)
is the scrambling system that C-Band satellite pay TV channels originally used. A VCII-capable satellite receiver is required to decode VCII channels. VCII has largely been replaced by DigiCipher 2
in North America
. Originally, VCII-based receivers had a separate modem technology for pay-per-view access known as Videopal. This technology became fully integrated in later-generation analog satellite television receivers.
satellite receiver is required to decode DCII channels. In North America, most digital cable
programming is accessed with DigiCipher 2-based set-top boxes.
PowerVu
is another popular digital encryption technology used for non-residential usage. PowerVu was developed by Scientific Atlanta. Other commercial digital encryption systems are Irdeto
(by Irdeto Access), Nagravision
(by Kudelski), Viaccess
(by France Telecom), and Wegener
.
In the US, both DirecTV
and Dish Network
direct broadcast satellite
systems use digital encryption standards for controlling access to programming. DirecTV uses VideoGuard
, a system designed by NDS
. DirecTV has been cracked in the past, which led to an abundance of cracked smartcards being available on the black market. However, a switch to a stronger form of smart card (the P4 card) wiped out DirectTV piracy soon after it was introduced. Since then, no public cracks have become available. Dish Network uses Nagravision (2 and 3) encryption.
In Canada
, both Bell TV and Shaw Direct DBS systems use digital encryption standards. Bell TV, like Dish Network, uses Nagravision for encryption. Shaw Direct uses a DigiCipher 2-based system very similar to that of 4DTV large dish satellite systems.
was originally used for analog satellite television pay channel access in Canada
. It was innovative for its time as it used digital audio
. It has been completely replaced by digital encryption technologies. Oak Orion was used by Sky Channel
in Europe between the years 1982 and 1987. Oak developed related encryption systems for cable TV and broadcast pay TV services such as ON TV
. The Oak systems used a sine wave added to the video signal to interfere with the video sync and relocated audio to a subcarrier
.
Leitch Technology
Leitch Viewguard is an analog encryption standard used primarily by broadcast TV networks in North America
. Its method of scrambling is by re-ordering the lines of video (Line Shuffle), but leaves the audio intact. Terrestrial broadcast CATV systems in Northern Canada used this conditional access system for many years. It is only occasionally used today on some satellite circuits because of its similarity to D2-MAC and B-MAC
.
B-MAC
B-MAC has not been used for DTH applications since PrimeStar
switched to an all-digital delivery system in the mid-1990s.
VideoCrypt
VideoCrypt is an analog cut and rotate scrambling system with smartcard based conditional access system. It was used in the 1990s by several European satellite broadcasters, mainly British Sky Broadcasting
. It was also used by Sky New Zealand (Sky-NZ). One version of Videocrypt (VideoCrypt-S) had the capability of scrambling sound. A soft encryption option was also available where the encrypted video could be transmitted with a fixed key and any VideoCrypt decoder could decode it.
delayed by either 0 nS
, 902 nS, or 1804 nS. First used in 1984 by French channel Canal Plus, it was widely compromised after the December 1984 issue of "Radio Plans" magazine printed decoder plans.
of a frequency (circa 93.750 KHz) to the video signal. This interfering signal was approximately six times the frequency of the horizontal refresh. It had an optional sound scrambling using Spectrum Inversion. Used in the UK by BBC for its world service broadcasts and by the now defunct UK movie channel "Premiere".
. It was one of the first smart card based systems to be compromised.
Nagravision
An older Nagravision system for scrambling analog satellite and terrestrial television programs was used in the 1990s, for example by the German pay-TV broadcaster Premiere. In this line-shuffling system, 32 lines of the PAL TV signal are temporarily stored in both the encoder and decoder and read out in permuted order under the control of a pseudorandom number generator. A smartcard security microcontroller (in a key-shaped package) decrypts data that is transmitted during the blanking intervals of the TV signal and extracts the random seed value needed for controlling the random number generation. The system also permitted the audio signal to be scrambled by inverting its spectrum at 12.5 KHz using a frequency mixer.
Scrambler
In telecommunications, a scrambler is a device that transposes or inverts signals or otherwise encodes a message at the transmitter to make the message unintelligible at a receiver not equipped with an appropriately set descrambling device...
", is encryption
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
used to control access to pay television services, usually cable
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
or satellite television
Satellite television
Satellite television is television programming delivered by the means of communications satellite and received by an outdoor antenna, usually a parabolic mirror generally referred to as a satellite dish, and as far as household usage is concerned, a satellite receiver either in the form of an...
services.
History
Pay television exists to make revenue from subscribers, and sometimes those subscribers do not pay. The prevention of piracy on cable and satellite networks has been one of the main factors in the development of Pay TV encryption systems.The early cable-based Pay TV networks used no security. This led to problems with people connecting to the network without paying. Consequently, some methods were developed to frustrate these self-connectors. The early Pay TV systems for cable television were based on a number of simple measures. The most common of these was a channel-based filter that would effectively stop the channel being received by those who had not subscribed. These filters would be added or removed according to the subscription. As the number of television channels on these cable networks grew, the filter-based approach became increasingly impractical.
Other techniques such as adding an interfering signal to the video or audio began to be used as the simple filter solutions were easily bypassed. As the technology evolved, addressable set-top boxes became common, and more complex scrambling techniques such as digital encryption of the audio or video cut and rotate (where a line of video is cut at a particular point and the two parts are then reordered around this point) were applied to signals.
Encryption was used to protect satellite-distributed feeds for cable television networks. Some of the systems used for cable feed distribution were expensive. As the DTH market grew, less secure systems began to be used. Many of these systems (such as OAK Orion) were variants of cable television scrambling systems that affected the synchronisation part of the video, inverted the video signal, or added an interfering frequency to the video. All of these analogue scrambling techniques were easily defeated.
In France, Canal+
Canal+
Canal+ is a French premium pay television channel launched in 1984. It is 80% owned by the Canal+ Group, which in turn is owned by Vivendi SA. The channel broadcasts several kinds of programming, mostly encrypted...
launched a scrambled service in 1984. It was also claimed that it was an unbreakable system. Unfortunately for that company, an electronics magazine, "Radio Plans", published a design for a pirate decoder within a month of the channel launching.
In the USA, HBO was one of the first services to encrypt its signal using the VideoCipher II system. In Europe, FilmNet scrambled its satellite service in September 1986, thus creating one of the biggest markets for pirate satellite TV decoders in the world, because the system that FilmNet used was easily hacked. One of FilmNet's main attractions was that it would screen hard-core porn films on various nights of the week. The VideoCipher II system proved somewhat more difficult to hack, but it eventually fell prey to the pirates.
Cable and early satellite television encryption
Analog television
Analog television is the analog transmission that involves the broadcasting of encoded analog audio and analog video signal: one in which the message conveyed by the broadcast signal is a function of deliberate variations in the amplitude and/or frequency of the signal...
and digital
Digital television
Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...
pay television have several conditional access
Conditional access
Conditional Access is the protection of content by requiring certain criteria to be met before granting access to this content...
systems that are used for pay per view (PPV) and other subscriber related services. Originally, analog-only cable TV systems relied on set-top boxes to control access to programming, as television sets originally were not "cable-ready". Analog encryption was typically limited to premium channels such as HBO or channels with adult-oriented content. In those cases, various proprietary video synchronization suppression methods were used to control access to programming. In some of these systems, the necessary synch signal was on a separate subcarrier. Analog set-top boxes have largely been replaced by digital set-top boxes that can directly control access to programming as well as digitally decrypt signals.
VideoCipher II RS (VCII RS)
Videocipher
VideoCipher is a brand name of analog scrambling and de-scrambling equipment for cable and satellite television invented primarily to keep consumer Television receive-only satellite equipment from receiving TV programing except on a subscription basis. It was invented in 1983 by Linkabit...
is the scrambling system that C-Band satellite pay TV channels originally used. A VCII-capable satellite receiver is required to decode VCII channels. VCII has largely been replaced by DigiCipher 2
DigiCipher 2
DigiCipher 2, or simply DCII, is a proprietary standard format of digital signal transmission and encryption with MPEG-2 signal video compression used on many communications satellite television and audio signals...
in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. Originally, VCII-based receivers had a separate modem technology for pay-per-view access known as Videopal. This technology became fully integrated in later-generation analog satellite television receivers.
- VideoCipher I (deprecated)
- VideoCipher II (deprecated)
- VideoCipher II+
- VideoCipher II RS (Renewable Security)
Digital cable and satellite television encryption
DigiCipher 2 is General Instrument's proprietary video distribution system. DCII is based upon MPEG-2. A 4DTV4DTV
4DTV is the name of a Television receive-only consumer satellite television tuner technology manufactured by Motorola for use with large-diameter parabolic satellite dish antennas on the C and Ku frequency bands on multiple satellites...
satellite receiver is required to decode DCII channels. In North America, most digital cable
Digital cable
Digital cable is a generic term for any type of cable television distribution using digital video compression or distribution. The technology was originally developed by Motorola.-Background:...
programming is accessed with DigiCipher 2-based set-top boxes.
PowerVu
PowerVu
PowerVu is a conditional access system for digital television developed by Scientific Atlanta. It is used for professional broadcasting, notably by Retevision, Bloomberg Television, Discovery Channel, AFRTS and American Forces Network...
is another popular digital encryption technology used for non-residential usage. PowerVu was developed by Scientific Atlanta. Other commercial digital encryption systems are Irdeto
Irdeto
Irdeto B.V. is a global software security and media technology company with dual headquarters in Hoofddorp, Netherlands and Beijing, China. It is a subsidiary of multinational media group Naspers...
(by Irdeto Access), Nagravision
Nagravision
Nagravision is a company of the Kudelski Group that develops conditional access systems for cable and satellite television. The name is also used for their main products, the Nagravision encryption systems.-Digital systems:...
(by Kudelski), Viaccess
Viaccess
Viaccess is a conditional access system developed by France Télécom. There are six versions in use today, Viaccess PC2.3, Viaccess PC2.4, Viaccess PC2.5, Viaccess PC2.6, Viaccess PC3.0 and Viaccess PC4.0....
(by France Telecom), and Wegener
Wegener
Wegener may refer to:* Alfred Wegener , German geologist and meteorologist**Alfred Wegener Institute for Polar and Marine Research**Wegener Canyon, undersea canyon**Mount Wegener, Antarctic mountain in the Read Mountains in the Shackleton Range...
.
In the US, both DirecTV
DirecTV
DirecTV is an American direct broadcast satellite service provider and broadcaster based in El Segundo, California. Its satellite service, launched on June 17, 1994, transmits digital satellite television and audio to households in the United States, Latin America, and the Anglophone Caribbean. ...
and Dish Network
Dish Network
Dish Network Corporation is the second largest pay TV provider in the United States, providing direct broadcast satellite service—including satellite television, audio programming, and interactive television services—to 14.337 million commercial and residential customers in the United States. Dish...
direct broadcast satellite
Direct broadcast satellite
Direct broadcast satellite is a term used to refer to satellite television broadcasts intended for home reception.A designation broader than DBS would be direct-to-home signals, or DTH. This has initially distinguished the transmissions directly intended for home viewers from cable television...
systems use digital encryption standards for controlling access to programming. DirecTV uses VideoGuard
VideoGuard
VideoGuard , produced by NDS, is a digital encryption system for use with conditional access television broadcasting. It is used on digital satellite television systems - some of which are operated by News Corporation, which owns about half of NDS...
, a system designed by NDS
NDS Group
NDS Group Plc. is a developer of pay TV technology. NDS was established in 1988 as an Israeli start up company. It was acquired by News Corporation in 1992. The company is currently headquartered in Staines, United Kingdom...
. DirecTV has been cracked in the past, which led to an abundance of cracked smartcards being available on the black market. However, a switch to a stronger form of smart card (the P4 card) wiped out DirectTV piracy soon after it was introduced. Since then, no public cracks have become available. Dish Network uses Nagravision (2 and 3) encryption.
In Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, both Bell TV and Shaw Direct DBS systems use digital encryption standards. Bell TV, like Dish Network, uses Nagravision for encryption. Shaw Direct uses a DigiCipher 2-based system very similar to that of 4DTV large dish satellite systems.
Oak Industries
Oak OrionOak Orion
The Oak Orion scrambling system was a form of television encryption developed by Oak Industries in the early 1980s.It was mainly used for encrypting the satellite feeds of American and Canadian television services transmitted by Cancom via the Anik satellites, first on Anik B, and later on Anik D1...
was originally used for analog satellite television pay channel access in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. It was innovative for its time as it used digital audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...
. It has been completely replaced by digital encryption technologies. Oak Orion was used by Sky Channel
Sky Channel
Sky Channel can refer to any of the following.* In Europe, Sky Channel was a satellite television channel that was broadcast in the 1980s, it went on to become Sky1....
in Europe between the years 1982 and 1987. Oak developed related encryption systems for cable TV and broadcast pay TV services such as ON TV
ON-TV
ON-TV, also known as National Subscription Television, was a subscription television service launched in 1977 by Oak Industries, Norman Lear's Chartwell Enterprises and Jerry Perenchio. Oak was a manufacturer of satellite and pay-TV decoders and equipment...
. The Oak systems used a sine wave added to the video signal to interfere with the video sync and relocated audio to a subcarrier
Subcarrier
A subcarrier is a separate analog or digital signal carried on a main radio transmission, which carries extra information such as voice or data. More technically, it is an already-modulated signal, which is then modulated into another signal of higher frequency and bandwidth...
.
Leitch TechnologyLeitch TechnologyLeitch Technology Corporation was a Canadian corporation based in Toronto, Ontario specializing in the design and manufacture of equipment for the broadcast television and video post-production industries....
Leitch Viewguard is an analog encryption standard used primarily by broadcast TV networks in North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. Its method of scrambling is by re-ordering the lines of video (Line Shuffle), but leaves the audio intact. Terrestrial broadcast CATV systems in Northern Canada used this conditional access system for many years. It is only occasionally used today on some satellite circuits because of its similarity to D2-MAC and B-MAC
B-MAC
B-MAC is a form of analog video encoding, specifically a type of B-MAC is a form of analog video encoding, specifically a type of B-MAC is a form of analog video encoding, specifically a type of (Multiplexed Analogue Components (MAC) encoding. MAC encoding was designed in the mid 80s for use with...
.
B-MACB-MACB-MAC is a form of analog video encoding, specifically a type of B-MAC is a form of analog video encoding, specifically a type of B-MAC is a form of analog video encoding, specifically a type of (Multiplexed Analogue Components (MAC) encoding. MAC encoding was designed in the mid 80s for use with...
B-MAC has not been used for DTH applications since PrimeStarPrimeStar
PrimeStar was a U.S. direct broadcast satellite broadcasting company formed in 1991 by a consortium of cable television system operators. PrimeStar was the first medium-powered DBS system in the United States but slowly declined in popularity with the arrival of DirecTV in 1994 and Dish Network in...
switched to an all-digital delivery system in the mid-1990s.
VideoCryptVideoCryptVideoCrypt is a cryptographic, smartcard-based conditional access television encryption system that scrambles analogue pay-TV signals. It was introduced in 1989 by News Datacom and was used initially by Sky TV and subsequently by several other broadcasters on the SES Astra satellites at 19.2°...
VideoCrypt is an analog cut and rotate scrambling system with smartcard based conditional access system. It was used in the 1990s by several European satellite broadcasters, mainly British Sky BroadcastingBritish Sky Broadcasting
British Sky Broadcasting Group plc is a satellite broadcasting, broadband and telephony services company headquartered in London, United Kingdom, with operations in the United Kingdom and the Ireland....
. It was also used by Sky New Zealand (Sky-NZ). One version of Videocrypt (VideoCrypt-S) had the capability of scrambling sound. A soft encryption option was also available where the encrypted video could be transmitted with a fixed key and any VideoCrypt decoder could decode it.
RITC Discret 1
RITC Discret 1 is a system based on horizontal line delay and audio scrambling. Each line of video was pseudorandomlyPseudorandomness
A pseudorandom process is a process that appears to be random but is not. Pseudorandom sequences typically exhibit statistical randomness while being generated by an entirely deterministic causal process...
delayed by either 0 nS
Nanosecond
A nanosecond is one billionth of a second . One nanosecond is to one second as one second is to 31.7 years.The word nanosecond is formed by the prefix nano and the unit second. Its symbol is ns....
, 902 nS, or 1804 nS. First used in 1984 by French channel Canal Plus, it was widely compromised after the December 1984 issue of "Radio Plans" magazine printed decoder plans.
SATPAC
SATPAC was used by the European channel FilmNet. It interfered with the horizontal and vertical synchronisation signals and transmitted a signal containing synchronisation and authorisation data on a separate subcarrier. The system was first used in September 1986 and saw many upgrades as it was easily compromised by pirates. By September 1992, FilmNet changed to D2-MAC EuroCrypt.Telease MAAST / Sat-Tel SAVE
Added an interfering sine waveSine wave
The sine wave or sinusoid is a mathematical function that describes a smooth repetitive oscillation. It occurs often in pure mathematics, as well as physics, signal processing, electrical engineering and many other fields...
of a frequency (circa 93.750 KHz) to the video signal. This interfering signal was approximately six times the frequency of the horizontal refresh. It had an optional sound scrambling using Spectrum Inversion. Used in the UK by BBC for its world service broadcasts and by the now defunct UK movie channel "Premiere".
Payview III
Used by German/Swiss channel Teleclub in the early 1990s, this system employed various methods such as video inversion, modification of synchronisation signals, and a pseudo line delay effect.D2-MAC EuroCrypt
Conditional Access system using the D2-MAC standard. Developed mainly by France Telecom, the system was smartcard based. The encryption algorithm in the smartcard was based on DESData Encryption Standard
The Data Encryption Standard is a block cipher that uses shared secret encryption. It was selected by the National Bureau of Standards as an official Federal Information Processing Standard for the United States in 1976 and which has subsequently enjoyed widespread use internationally. It is...
. It was one of the first smart card based systems to be compromised.