Index of Encryptions System

[kolorado]

KeyFly is a platform for digital television. In addition to offering security as a CA system, it is a platform that allows new sources of revenues
for pay-TV or free TV operators. The platform has been created to meet new requirements and challenges of digital television, going further than
traditional subscription payment systems, incorporating more flexible business models with no need for permanent subscriptions, value-added services
to free TV, as well as new payment techniques via mobile phones. KeyFly allows different options such as with or without smart card, CAS embedded
into set-top box or into Common Interface CAMs, with or without need for subscription. KeyFly supports different methods for rights management
from traditional pay-TV Systems to Free TV with new value-added services.
KeyFly provides for impulse-purchase of pay-per-view events or subscription periods, which can be paid for via SMS or the internet.
Subscription types cover simple time-based subscriptions to renewable subscription models where the content is requested via mobile
phone or internet.

Users:
Al-Jazeera Sports use KeyFly as one of two simulcrypted encryption services on their European broadcasts
A number of channels on Hotbird including InXtc, 247 Sex TV, Sex Asians and SuperSex TV use KeyFly as one of their encryption formats.
TVE on Hispasat also use this type of encryption.

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DigiCipher 2, or simply DCII, is a digital signal compression standard used on many communications satellite television and audio signals.
The DCII standard was originally developed in 1997 by General Instrument, which is now the Home and Network Mobility division of Motorola.

The original attempt for a North American digital signal encryption and compression standard was DigiCipher 1, which was used most notably
in the now-defunct PrimeStar medium-power DBS system during the early 1990s. The DCII standard predates wide acceptance of DVB-based digital
terrestrial television compression (although not cable or satellite DVB) and therefore is incompatible with the DVB standard.

The primary difference between DigiCipher 2 and DVB lies in how each standard handles SI, or System Information. DigiCipher 2 also relies on
the fact that its signals must be understood in terms of a virtual channel number in addition to the DCII signal's downlink frequency, whereas
DVB signals have no virtual channel number.

Approximately 70% of newer first-generation digital cable networks in North America use the 4DTV/DigiCipher 2 format. The use of DCII is most
prevalent in North American digital cable television set-top boxes. DCII is also used on Motorola's 4DTV digital satellite receiver and Star
Choice's DBS receiver (Star Choice is based in Canada).

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VideoCrypt 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° east.

Three variants of the VideoCrypt system were deployed in Europe: VideoCrypt I for the UK and Irish market and VideoCrypt II for continental Europe.
The third variant, VideoCrypt-S was used on a short-lived BBC Select service. The VideoCrypt-S system differed from the typical VideoCrypt
implementation as it used line shuffle scrambling.

Sky NZ and Sky Fiji may use different versions of the VideoCrypt standard.
Sky NZ used NICAM stereo for many years until abandoning it when the Sky DTH technology started replacing Sky UHF.


The system scrambles the picture using a technique known as Line Cut-and-Rotate. Each line that made up each picture (video frame) is cut at one
of 256 possible "cut points", and the two halves of each line are swapped around for transmission. The series of cutpoints is determined
by a pseudo-random sequence. Channels were decoded using a pseudorandom number generator (PRNG) sequence stored on a smart card (aka Viewing Card).

To decode a channel the decoder would read the smart card to check if the card is authorised for the specific channel. If not, a message would
appear on screen. Otherwise the decoder seeds the card's PRNG with a seed transmitted with the video signal to generate the correct sequence
of cut points.

The system also included a cryptographic element called the Fiat Shamir Zero Knowledge Test. This element was a routine in the smartcard that
would prove to the decoder that the card was indeed a genuine card. The basic model was that the decoder would present the card with a packet
of data (the question) which the card would process and effectively return the result (the answer) to the decoder proving that it was a genuine
card without disclosing any critical information. If the decoder received the wrong result from the card, it was supposed to stop decoding the video.
However a technologically insecure implementation of this otherwise strong cryptographic element made it redundant.

The VideoCrypt-S variant, used by the BBC Select service, was based on line shuffle scrambling. This form of video scrambling changes the order
in which lines are transmitted thus line 20 may be transmitted as line 32. The VideoCrypt-S variant used six blocks of forty seven lines per field.
It had three scrambling formats: full shuffle in which 282 lines were affected; half shuffle, in which every alternate field was scrambled;
and a line delay scramble in which the start position of the video in each line was pseudo-randomly delayed.

The VideoCrypt system was far from secure and a number of hacks were employed.

Card attacks:

* Hackers discovered methods of preventing Sky from killing or deactivating their cards. The simplest of these attacks relied on the fact that
Sky was using EPROM technology for its smartcards at the time. Thus by modifying the decoder to limit the write voltage to the card, it was possible
to stop cards being turned off over the air. Another, known as the KENtucky Fried Chip attack relied on replacing the microcontroller that controlled
the smartcard to decoder interface. This attack relied on blocking packets with the smartcard's identification number. The voltage based attack failed
after Sky changed to smartcards that used EEPROM technology.

* Commercial pirates completely reverse engineered the Sky smartcard, removed the access control routines and created working pirate smartcards using
different microcontroller types (typically the PIC16C84) to that used by Sky.

* Hackers also discovered, (after the commercial pirate code became public) ways of switching on "dead" cards using a computer and smartcard interface
by sending a properly formatted and addressed activation packet to the card. Variations on this attack also allowed existing subscriber cards to be
upgraded to more expensive subscription packages. This attack was known as the "Phoenix Hack" after the mythical bird that could bring itself
back to life.

Datastream attacks

* Other successful hacks involved sampling the datastream between the card and the decoder, for example you could record a movie and store the
decoder information so that people could then use it to decode the same movie that they recorded earlier with a decoder and "dummy" card (the dummy
smartcard was an interface that received the synchronised decryption seeds from a computer). The attack was known as the Delayed Data Transfer hack
and it worked because the conditional access data, decoder addressing and encrypted keys, were on the video lines that are recorded by normal VCRs
and the data rate, unlike that of Teletext, was slow enough to allow the data to be recorded with the encrypted video.

Decoder card datastream attacks

* The most successful hack on the VideoCrypt system is the "McCormac Hack" devised by John McCormac. This attack involved broadcasting the
decryption keys from the decoder-card data live so that other decoders could use it to watch the encrypted channels effectively sharing a card
with several decoders. This particular attack is extremely dangerous if the internet is used to redistribute the decryption keys since a single
card can be used, virtually, in a multitude of decoders. Card Sharing is an implementation of the McCormac Hack.

Brute force

* As desktop computing power increased, such a simple system was always inherently vulnerable to brute force 'image-processing' attacks.
* Even without any information at all about the cutpoint sequence, adjacent lines in a picture can be 'correlated' to find the best match,
and the picture reconstructed.
* The Brute force method will not work for all pictures, but is an interesting proof-of-concept.
* Markus Kuhn's Antisky.c program from 1994 is an early example of such an attack.
* More recently it has been shown that, using detailed knowledge of the way colour is transmitted in analogue TV systems, 'perfect' r
econstruction could be achieved for many scenes.
* Cheap PC TV cards (~£40) with particular chipsets (e.g: Brooktree) were capable of descrambling the image in near real time
(sound was delayed to match). This was made possible with software such as MoreTV or hVCPlus and a reasonably fast PC. The picture
quality was on par with an old VHS videotape, with some colour distortion depending on PC performance.


These issues have become far less of a problem when Sky introduced Sky Digital which uses the VideoGuard system which so far has not been beaten.
Although, the analog UHF option is still available.

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Conax is a company that designs conditional access systems for digital television. Based in Oslo, Norway, Conax has subsidiaries in the USA,
India and Germany and sales & support offices in Russia, Singapore, China, South Korea, Brazil, and Canada.

Between 1986 and 1992 the core of Conax was formed as a research team in Telenor's Research and Development department. The technology, including
one of the world's first pay-TV smart cards, was put into large-scale operation from 1992. In 1994 Telenor Conax was established as an independent
company within the Telenor group.

The company is today owned 90% by Telenor, the leading telecom, IT and media company in Norway and 10% by Telenor Venture II ASA, a new fund
of TeleVenture, with its main areas of interest within mobile communications, broadband and new media and internet.

Open and Interoperable by sticking to a non-proprietary and open solution, Conax allows the possibility of “freedom of choice” in technology.
This is achieved by:

* A fully open, fair and non-discriminatory licensing policy for STB manufacturers to include support for Conax CAS in the STB
* Digital Video Broadcasting (DVB) and OpenCable compliant transmission format
* DVB SimulCrypt compliance on both transmission and receiver (STB) sides
* Detachable security module using an ISO 7816 compatible smart card
* Supply of Common Interface Conditional Access Modules (CAMs) and CableCards (option)
* Using a standard over-the-air STB loader such as the Euroloader or other non-proprietary STB loader controlled by the operator

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Videocipher I

This was the first version of the Videocipher system that was first demonstrated by Linkabit in 1983.

Also known as Videocipher IB, this variation on Videocipher was commonly used by sports backhauls.
CBS used this system from 1987 to the mid-1990's to encrypt its transmissions to affiliates on the T
elstar 301 and Telstar 302 satellites.

In Canada, the CTV television network also used this technology on its network feeds. With this system
the video is scrambled by means of re-ordering the video scan lines, while all audio remains in the clear.
This system was discontinued in the early 2000s.

Videocipher I (VCI) system was initially considered for use by HBO in the 1980's. HBO tested VCI extensively,
but was ultimately rejected in favor of Videocipher II.

* HBO use of VCI would have required descramblers for home satellite viewers. Thus VCI was determined
to be too expensive for consumer use.

The Leitch Viewguard scrambling system used for satellite feeds as well used the same video line re-ordering
as well, while also leaving the audio intact. ABC and Fox used Viewguard as well on their analog network feeds
to their affiliate stations shortly before switching to digital satellite distribution in 2005 (for ABC) and
2004 (for Fox).

Videocipher II

This was the first consumer scrambling system. It began testing in 1985 on HBO satellite transponders on
Satcom 3R and Galaxy 1 and entered full use in January 1986 by HBO, and within two years was used by a majority
of major cable television programmers. However, lapses in its security enabled some cable pirates to modify the
descrambler to receive free programming. Beginning in 1991, programmers began to phase out the VCII system in
favor of the highly secure Videocipher II Plus (RS) system. The system was fully phased out in 1993. Originally
sold as a stand-alone decoder box that consisted of a fully electronic decoder and the actual descrambler module,
some satellite system manufacturers began to manufacturer their receivers with the module installed. This system
works by encrypting both audio (in digital sound) and video. A Videocipher II decoder is still capable of decoding
only the video portion of a Videocipher II Plus.

Furthermore, in the late eighties and early nineties, VideoCipher II modules that had been pirated, began to
receive constant Electronic Counter Measures (ECM) "Keys" which would roll over every month. Later on, keys
began to roll constantly for pay per view channels and HBO.

A company called Magna Systems would fax monthly keys to satellite dealers and the dealers would distriubute
the keys to their customers. Magna Systems warned that programmers would begin rolling keys every few days.

In response to the increasing frequency of key changes, enterprising pirates devised more efficient means
of delivering the new keys to the hacked boxes. Among these contraptions included "VMS" modems which when
added to the Videocipher module allowed them to dial into a bulletin board system and download the updated keys.

After HBO left the VideoCipher II datastream in favor of the more secure VideoCipher II Plus (RS) datastream,
other programmers followed suit. Having a VideoCipher II module was no longer worth anything unless the viewer wanted to watch adult/XXX programming with no audio.

Some viewers who had both cable and satellite found a way to marry audio and video. Viewers found a way to get
audio from a cable line and video from satellite with their VideoCipher II and push both to their VCRs and TVs.

Due to the advanced VideoCipher II Plus datastream, video may appear to "flicker" or struggle on an old
VideoCipher II module. If the module has a newer pirate chip installed, flickering may or may not be a problem.

Videocipher II+/RS
In 1992, following years of security breaches with the Videocipher II system, the Videocipher II Plus
became standard. In 1993, all VCII programming was phased out. This is a higher-security system with two variants.
The Videocipher-RS system (RS for Renewable Security) is the Videocipher II Plus system with a slot in the back
of the decoder module to where a card could be inserted to upgrade the security if the VCII Plus system were ever
breached.

Technological obsolescence

General Instrument discontinued production of VC II+ RS modules in 1998 in favor of its DigiCipher system.
Over the next ten years, broadcasters migrated to digital transmission delivery and discontinued their analog
feeds. In October 2008, it was announced by Motorola that their authorization center would no longer authorize
any new decoders after December 31, 2008, and that the current remaining analog Videocipher channels would
switch entirely to digital transmission after that same date.

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EuroCrypt is a conditional access system for Multiplexed Analogue Components-encoded analogue satellite television.
It had several versions (M, S and S2). It supported receivers with card slots and those with embedded keys.
Its most widespread use was in Scandinavia, where the only EuroCrypt protected broadcasts remained until
July 2006 (in France, they stopped in 1998).

It was also hacked with pirate cards, which was popular in many countries in Europe, especially in order to
watch English language channels such as Filmnet Plus and TV1000. EuroCrypt evolved into the Viaccess system
for digital television.

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VideoGuard (sometimes referred to simply as NDS), produced by NDS, is a digital encryption system for use
with conditional access television broadcasting. It is used almost exclusively on digital satellite television
systems operated by News Corporation, which owns the majority of NDS. Its two most widely used implementations
are BSkyB's Sky Digital in the United Kingdom and Ireland and DirecTV in the United States, the former of
which adopted the system in 1998. Several other broadcasters around the world use the VideoGuard system,
including Hot (Israel), Yes (Israel), Viasat (Scandinavia), SKY Italia (Italy), Sky Network Television
(New Zealand), Foxtel (Australia), Tata Sky & Hathway (DVB-C) (India), Astro, D Smart (Turkey),
TotalTV (Balkan), ONO (Spain), Canadian Broadcasting Corporation (Canada), China Central Television
(China) and Telewizja Polska (Poland).

Since the majority of content provided by companies like BSkyB requires subscription, VideoGuard protects that
content by encrypting both standard subscription channels and pay-per-view movies and events. Access flags can
be downloaded to the subscriber's card either over the air (via 'hidden' data streams) or by using the box's
built in modem, thereby allowing rapid changing of channel packages and ordering of events.

Already in use in America since 1997, the VideoGuard system was introduced to the UK by NDS in 1998 with
the launch of Sky Digital, replacing the VideoCrypt system in use on Sky's analogue broadcasts. To date,
despite widespread piracy of the US DirecTV service between 1997 and 2002, the implementation in the UK
has remained secure, although various pay per view flaws have been identified. Even these flaws are related
merely to the circuitry of the Set-Top Box (STB), rather than the NDS card. It is suspected that the version
initially used by Sky Digital was either insecure or close to being broken, as a software update rolled out
to all boxes required replacement of the BSkyB subscriber's viewing card. Even so, wholesale card replacements
are rare, currently having occurred just once during the life of the Sky Digital system, in 2003.

While most commonly used to protect pay-TV, VideoGuard is also used by numerous non-subscription
broadcasters to enforce geographic rights restrictions. Videoguard has been used by the BBC, ITV,
and Channel 4 to restrict non-UK viewing, although in recent years these broadcasters have moved
to broadcasting FTA on the more geographically restricted footprint of the Astra 2D satellite which
is mainly, although not entirely, focused on the UK and Ireland. In some cases, encryption is still
used on some versions of ITV and Channel 4 services where rights issues or a lack of capacity on the
Astra 2D satellite are an issue.

A further example is British television channel Five and its spin off channels (Five US, Fiver and the +1 versions)
which still use this 'Free To View' encryption mode to prevent these channels being viewed outside the UK for
copyright reasons. Five has also made a single free-to-air version of its primary channel available in
Free-to-Air format via Astra 2D. This feed sometimes carries an apology caption to black out programming
where rights issues remain.

Many broadcasters choose to pair their cards, meaning that a paired (also called "married") card can be used
only in a specific broadcaster-supplied STB, or by using the serial number from said receiver with one of the
reverse-engineered solutions. In the case of Sky Digital, all cards are married to a particular set top box,
although almost all non-premium channels will still allow viewing even if the box and card are not paired.
Other channels, such as Sky's sports and movie channels, cannot be viewed unless the viewing card is being
used in its specifically paired set top box.

Reverse Engineering

Videoguard is unusual in that legitimate external CAM modules are not available, the encryption system instead
being built in to the hardware and firmware of platform-supplied set top boxes. However, several groups have
managed to reverse-engineer VideoGuard to the point where a legitimate subscriber's card can be utilised in
third-party receivers to decrypt those channels which that subscriber is authorised to view. A software
CAM emulator exists for the DreamBox & Triple-Dragon Linux-powered satellite receivers, along with the
Diablo, Dragon and T-Rex Conditional Access modules. None of the reverse-engineered solutions are able
to "update" the card, meaning the legitimate card needs to be returned to official Sky receiver for a
few hours (or overnight) to be refreshed.

Currently the Dreambox CCcam emulator will allow updates to be written to a valid NDS card.

The new Darkbox HD has now been tested with official Sky cards and has been found to work with them

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Basic Interoperable Scrambling System, usually known as BISS, is a satellite signal scrambling system
developed by the European Broadcasting Union and a consortium of hardware manufacturers.

Prior to its development, "ad-hoc" or "Occasional Use" satellite news feeds were transmitted without
any encryption. This allowed anyone with the correct equipment to view the program material.
Using BISS the transmission is protected by a 12 digit "session key" that is agreed by the transmitting
and receiving parties prior to transmission. The key is entered into both the encoder and decoder ,
this key then forms part of the encryption of the digital TV signal and only receivers with the correct
key will decrypt the signal. The system, however, is insecure.

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Irdeto provides solutions for digital content protection in digital TV, IPTV and mobile environments.
The company's dual headquarters are located in Hoofddorp near Amsterdam and in Beijing. Irdeto provides
both smart card and software-based conditional access systems for pay TV, supporting cable, satellite,
terrestrial, MMDS and IPTV operators. In addition, the company offers chip- and software-based solutions
for mobile media and TV based on the following standards: S-DMB, T-DMB, DVB-H, OMA 1, OMA 2.

Irdeto is a subsidiary of media group Naspers (JSE: NPN), which also includes a group of pay TV sister
companies in Africa, Europe and Asia. As a primary supplier to these companies since the early days of
digital TV, Irdeto plays a vital role within this group. Nevertheless, more than 75% of Irdeto's revenue
comes from companies outside the group since the 1990s.