Copy protection
Overview
 
Copy protection, also known as content protection, copy obstruction, copy prevention and copy restriction, refer to techniques used for preventing the reproduction of software, films, music, and other media, usually for copyright
Copyright
Copyright is a legal concept, enacted by most governments, giving the creator of an original work exclusive rights to it, usually for a limited time...

 reasons.
Media corporations have always used the term copy protection, but critics argue that the term tends to sway the public into identifying with the publishers, who favor restriction technologies, rather than with the users.
Encyclopedia
Copy protection, also known as content protection, copy obstruction, copy prevention and copy restriction, refer to techniques used for preventing the reproduction of software, films, music, and other media, usually for copyright
Copyright
Copyright is a legal concept, enacted by most governments, giving the creator of an original work exclusive rights to it, usually for a limited time...

 reasons.

Terminology

Media corporations have always used the term copy protection, but critics argue that the term tends to sway the public into identifying with the publishers, who favor restriction technologies, rather than with the users. Copy prevention and copy control may be more neutral terms. "Copy protection" is a misnomer for some systems, because any number of copies can be made from an original and all of these copies will work, but only in one computer, or only with one dongle
Dongle
A software protection dongle is a small piece of hardware that plugs into an electrical connector on a computer and serves as an electronic "key" for a piece of software; the program will only run when the dongle is plugged in...

, or only with another device that cannot be easily copied.

The term is also often related to, and confused with, the concept of digital rights management
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...

. Digital rights management is a more general term because it includes all sorts of management of works, including copy restrictions. Copy protection may include measures that are not digital. A more appropriate term may be "technological protection measures" (TPMs), which is often defined as the use of technological tools in order to restrict the use or access to a work.

Business rationale

Copy protection is most commonly found on videotape
Videotape
A videotape is a recording of images and sounds on to magnetic tape as opposed to film stock or random access digital media. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram...

s, DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

s, computer software
Computer software
Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

 discs, video game discs and cartridges, and some audio CDs
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

.

Many media formats are easy to copy using a machine, allowing consumers to distribute copies to their friends, a practice known as "casual copying".

Companies publish works under copy protection because they believe that the cost of implementing the copy protection will be less than the revenue produced by consumers who buy the product instead of acquiring it through casually copying.

Opponents of copy protection argue that people who obtain free copies only use what they can get for free, and would not purchase their own copy if they were unable to obtain a free copy. Some even argue that free copies increase profit; people who receive a free copy of a music CD may then go and buy more of that band's music, which they would not have done otherwise.

Some publishers have avoided copy-protecting their products, on the theory that the resulting inconvenience to their users outweighs any benefit of frustrating "casual copying".

From the perspective of the end user, copy protection is always a cost
Cost
In production, research, retail, and accounting, a cost is the value of money that has been used up to produce something, and hence is not available for use anymore. In business, the cost may be one of acquisition, in which case the amount of money expended to acquire it is counted as cost. In this...

. DRM
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...

 and license managers sometimes fail, are inconvenient to use, and may not afford the user all of the legal use
Fair use
Fair use is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work. In United States copyright law, fair use is a doctrine that permits limited use of copyrighted material without acquiring permission from the rights holders...

 of the product he/she has purchased.

The term copy protection refers to the technology used to attempt to frustrate copying, and not to the legal remedies available to publishers or authors whose copyrights are violated. Software usage models evolve beyond node locking to floating licenses (where a fixed number licenses can be concurrently used across an enterprise), grid computing (where multiple computers function as one unit and so use a common license) and electronic licensing (where features can be purchased and activated online). The term license management refers to broad platforms which enable the specification, enforcement and tracking of software licenses. To safeguard copy protection and license management technologies themselves against tampering and hacking, software anti-tamper methods are used.

Technical challenges

From a technical standpoint, it would seem theoretically impossible to completely prevent users from making copies of the media they purchase, as long as a "writer" is available that can write to blank media. The basic technical fact is that all types of media require a "player" — a CD player, DVD player, videotape player, computer, or video game console
Video game console
A video game console is an interactive entertainment computer or customized computer system that produces a video display signal which can be used with a display device to display a video game...

. The player has to be able to read the media in order to display it to a human. In turn, then, logically, a player could be built that first reads the media, and then writes out an exact copy of what was read, to the same type of media, or perhaps to some other format, such as a file on a hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...

. If to another disk, then the result is an exact duplicate of the copy protected disc.

At a minimum, digital copy protection of non-interactive works is subject to the analog hole
Analog hole
The analog hole is a fundamental and inevitable vulnerability in copy protection schemes for noninteractive works in digital formats which can be exploited to duplicate copy-protected works that are ultimately reproduced using analog means...

: regardless of any digital restrictions, if music
Music
Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...

 can be heard by the human ear, it can also be recorded (at the very least, with a microphone and tape recorder); if a film
Film
A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...

 can be viewed by the human eye, it can also be recorded (at the very least, with a video camera and recorder). In practice, almost-perfect copies can typically be made by tapping into the analog output of a player (e.g. the speaker
Loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...

 output or headphone jacks) and, once redigitized into an unprotected form, duplicated indefinitely. Copying text-based
Text-based
Usually used in reference to a computer application, a text-based application is one whose primary input and output are based on text rather than graphics or sound. This does not mean that text-based applications do not have graphics or sound, just that the graphics or sound are secondary to the...

 content in this way is more tedious, but the same principle applies: if it can be printed or displayed, it can also be scanned and OCRed
Optical character recognition
Optical character recognition, usually abbreviated to OCR, is the mechanical or electronic translation of scanned images of handwritten, typewritten or printed text into machine-encoded text. It is widely used to convert books and documents into electronic files, to computerize a record-keeping...

. With basic software and some patience, these techniques can be applied by a typical computer-literate user.

Since these basic technical facts exist, it follows that a determined individual will definitely succeed in copying any media, given enough time and resources. Media publishers understand this; copy protection is not intended to stop professional operations involved in the unauthorized mass duplication of media, but rather to stop "casual copying".

Copying of information goods which are downloaded (rather than being mass-duplicated as with physical media) can be inexpensively customized for each download, and thus restricted more effectively, in a process known as "traitor tracing
Traitor tracing
Traitor tracing is a copyright infringement detection system which works by tracing the source of leaked files rather than by direct copy protection. The method is that the distributor adds a unique value to each copy given out...

". They can be encrypted in a fashion which is unique for each user's computer, and the decryption system can be made tamper-resistant
Tamper resistance
Tamper resistance is resistance to tampering by either the normal users of a product, package, or system or others with physical access to it. There are many reasons for employing tamper resistance....

.

Copy protection for computer software

Copy protection for early home computer software, especially for games, started a long cat-and-mouse struggle between publishers and crackers
Software cracking
Software cracking is the modification of software to remove or disable features which are considered undesirable by the person cracking the software, usually related to protection methods: copy protection, trial/demo version, serial number, hardware key, date checks, CD check or software annoyances...

. These were (and are) programmers who would defeat copy protection on software as a hobby, add their alias
Pseudonym
A pseudonym is a name that a person assumes for a particular purpose and that differs from his or her original orthonym...

 to the title screen, and then distribute the "cracked" product to the network of warez
Warez
Warez refers primarily to copyrighted works distributed without fees or royalties, and may be traded, in general violation of copyright law. The term generally refers to unauthorized releases by organized groups, as opposed to file sharing between friends or large groups of people with similar...

 BBSes
Bulletin board system
A Bulletin Board System, or BBS, is a computer system running software that allows users to connect and log in to the system using a terminal program. Once logged in, a user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging...

 or Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

 sites that specialized in distributing unauthorized copies of software.

Software copy protection schemes for early computers such as the Apple II and Commodore 64
Commodore 64
The Commodore 64 is an 8-bit home computer introduced by Commodore International in January 1982.Volume production started in the spring of 1982, with machines being released on to the market in August at a price of US$595...

 computers were extremely varied and creative because most of the floppy disk reading and writing was controlled by software, not by hardware; for the IBM-PC these were known as 'booters
PC booter
A PC booter, or booter, is a type of software for home computer era personal computers that was loaded and executed in the bootup of the computer, from a bootable floppy disk, rather than as a regular program; a booter thus bypassed any operating system that might be installed on the hard disk of...

'. The first copy protection was for cassette tapes and consisted of a loader at the beginning of the tape, which read a specially formatted section which followed.

The first protection of floppy disks consisted of changing the address marks, bit slip marks, data marks, or end of data marks for each sector. For example, Apple’s standard sector markings were:
  • D5 AA 96 for the address mark. That was followed by track, sector, and checksum.
  • DE AA EB concluded the address header with what are known as bit slip marks.
  • D5 AA AD was used for the data mark and the end of data mark was another DE AA EB.


Changing any of these marks required changing the software which read the floppy disk, but produced a disk that could not be copied. Some systems used complicated systems that changed the marks by track or even within a track.

By 1980, the first nibble
Nibble
In computing, a nibble is a four-bit aggregation, or half an octet...

 copier, Locksmith, was introduced. These copiers reproduced copy protected floppy disks an entire track at a time, ignoring how the sectors were marked. This was harder to do than it sounds, because Apple disks did not use the index hole to mark the start of a track. Tracks could start anywhere. Nevertheless, Locksmith copied Apple II disks by taking advantage of the sync fields between sectors, which consisted of a long string of FF (hex) bytes between each sector. It found the longest string of FFs, which occurred between the last and first sectors on each track, and began writing the track in the middle of that.

Ironically, Locksmith would not copy itself. The first Locksmith measured the distance between sector 1 of each track. Copy protection engineers quickly figured out what Locksmith was doing and began to use the same technique to defeat it. Locksmith countered by introducing the ability to reproduce track alignment and prevented itself from being copied by embedding a special sequence of nibbles, that if found, would stop the copy process. Henry Roberts (CTO of Nalpeiron), a graduate student in computer science at the University of South Carolina, reverse engineered Locksmith, found the sequence and distributed the information to some of the 7 or 8 people producing copy protection at the time.

For some time, Locksmith continued to defeat virtually all of the copy protection systems in existence. The next advance came from Henry Roberts' thesis on software copy protection, which devised a way of replacing Apple’s sync field of FFs with random appearing patterns of bytes. Because the graduate student had frequent copy protection discussions with Apple’s copy protection engineer, Apple developed a copy protection system which made use of this technique.

Henry Roberts then wrote a competitive program to Locksmith, Back It UP. He devised several methods for defeating that, and ultimately a method was devised for reading self sync fields directly, regardless of what nibbles they contained.

The back and forth struggle between copy protection engineers and nibble copiers continued until the Apple II became obsolete and was replaced by the IBM PC and its clones.

Floppy disks were replaced by CDs as the preferred method of distribution, with companies like Macrovision
Macrovision
Rovi Corporation is a globally operating, US-based company that provides guidance technology, entertainment data, copy protection, industry standard networking and media management technology for digital entertainment devices and services...

 and Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

 providing copy protection schemes that work by writing data to places on the CD-ROM where a CD-R
CD-R
A CD-R is a variation of the Compact Disc invented by Philips and Sony. CD-R is a Write Once Read Many optical medium, though the whole disk does not have to be entirely written in the same session....

 drive cannot normally write. Such a scheme has been used for the PlayStation
PlayStation
The is a 32-bit fifth-generation video game console first released by Sony Computer Entertainment in Japan on December 3, .The PlayStation was the first of the PlayStation series of consoles and handheld game devices. The PlayStation 2 was the console's successor in 2000...

 and cannot be circumvented easily without the use of a modchip
Modchip
A modchip is a small electronic device used to modify or disable built-in restrictions and limitations of computers, specifically videogame consoles...

.

For software publishers, a less expensive method of copy protection is to write the software so that it requires some evidence from the user that they have actually purchased the software, usually by asking a question that only a user with a software manual could answer (for example, "What is the 4th word on the 6th line of page 37?"). This approach can be defeated by users who have the patience to copy the manual with a photocopier
Photocopier
A photocopier is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat...

, and it also suffers from the fact that once crackers circumvent the copy protection on a piece of software, the resulting cracked product is more convenient than the original software, creating a disincentive to buying the original. As a result, user-interactive copy protection of this kind has mostly disappeared.

Other software copy protection techniques include:
  • A dongle
    Dongle
    A software protection dongle is a small piece of hardware that plugs into an electrical connector on a computer and serves as an electronic "key" for a piece of software; the program will only run when the dongle is plugged in...

    , a piece of hardware containing an electronic serial number
    Serial number
    A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...

     that must be plugged into the computer to run the software. This adds extra cost for the software publisher, so dongles are uncommon for games and are found mostly in expensive high-end software packages. Rainbow (SafeNet), HASP (Aladdin Knowledge Systems
    Aladdin Knowledge Systems
    Aladdin Knowledge Systems was a company that produced software for digital rights management and Internet security. The company was by SafeNet Inc, in 2009. Its corporate headquarters are located in Belcamp...

    ), iLok (Copy Protection) and Matrix Software License Protection System UniKey are popular dongle protection schemes utilizing a USB
    Universal Serial Bus
    USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....

     dongle
    Dongle
    A software protection dongle is a small piece of hardware that plugs into an electrical connector on a computer and serves as an electronic "key" for a piece of software; the program will only run when the dongle is plugged in...

    . For the production of even more restrictive software, a dongle product that supports code porting mechanism is one choice available to software developers.
  • Bus encryption
    Bus encryption
    Bus encryption is the use of encrypted program instructions on a data bus in a computer that includes a secure cryptoprocessor for executing the encrypted instructions...

     and encrypted code for use in secure cryptoprocessor
    Secure cryptoprocessor
    A secure cryptoprocessor is a dedicated computer on a chip or microprocessor for carrying out cryptographic operations, embedded in a packaging with multiple physical security measures, which give it a degree of tamper resistance....

    s. This prevents copying and tampering of programs used in high security environments such as ATMs
    Automated teller machine
    An automated teller machine or automatic teller machine, also known as a Cashpoint , cash machine or sometimes a hole in the wall in British English, is a computerised telecommunications device that provides the clients of a financial institution with access to financial transactions in a public...

    . This hardware solution is based on the fact that unlike music, video, and text that must eventually be revealed to users to be heard, viewed, or read, program instructions are needed only by the cryptoprocessor that decrypts and executes them.
  • A product key, a series of letters and numbers that is asked for when running the program. Many computer games use registration keys. The software will refuse to run if the registration key is not typed in correctly, and multiplayer games will refuse to run if another user is online who has used the same registration key.
  • Name & Serial, a name and serial number that is given to the user at the time the software is purchased, and is required to install it.
  • Keyfile
    Keyfile
    A keyfile is a file on a computer which contains encryption or license keys.A common use is web server software running secure socket layer protocols. Server-specific keys issued by trusted authorities are merged into the keyfile along with the trusted root certificates...

    , which requires the user to have a keyfile in the same directory as the program is installed to run it.
  • A phone activation code, which requires the user to call a number and register the product to receive a computer-specific serial number.
  • Internet product activation
    Product activation
    Product activation is a license validation procedure required by some proprietary computer software programs. In one form, product activation refers to a method invented by Ric Richardson and patented by Uniloc where a software application hashes hardware serial numbers and an ID number specific...

    , which requires the user to connect to the Internet, or exchange encrypted files with the vendor, so the software can "call home" and notify the manufacturer who has installed the software and where, and prevent other users from installing the software if they attempt to use the same serial number. Microsoft
    Microsoft
    Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

    's Windows Genuine Advantage
    Windows Genuine Advantage
    Windows Genuine Advantage is an anti-piracy system created by Microsoft that enforces online validation of the licensing of several recent Microsoft Windows operating systems when accessing several services, such as Windows Update, and downloading Windows components from the Microsoft Download...

     system is a far-reaching example of this.
  • Device ID verification, specifically tying a copy of software to a computer or mobile device based on a unique identifier only known to that device (like the IMEA code of a smartphone), a process utilized by Appuware, Inc. for its app piracy prevention scheme.
  • Protection by code morphing
    Code morphing
    Code morphing is one of the approaches to protect software applications from reverse engineering, analysis, modifications, and cracking used in obfuscating software. This technology protects intermediate level code such as compiled from Java and .NET languages rather than binary object code...

     or code obfuscation. The code morphing is multilevel technology containing hundreds of unique code transformation patterns. In addition this technology includes the special layer that transforms some commands into virtual machine
    Virtual machine
    A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...

     commands (like P-Code
    P-Code machine
    In computer programming, a p-code machine, or portable code machine is a virtual machine designed to execute p-code...

    ). Code obfuscation turns binary code into an undecipherable mess that is not similar to normal compiled code, and completely hides execution logic of the protected code.


Copy protection methods usually tie the installed software to a specific machine by involving some unique feature of the machine. Some machines have a serial number
Serial number
A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...

 in ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...

, while others do not, and so some other metric, such as the date and time (to the second) of initialization of the hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...

 can be used. On machines with Ethernet cards, the MAC address
MAC address
A Media Access Control address is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used for numerous network technologies and most IEEE 802 network technologies, including Ethernet...

, which is factory-assigned and intended to be unique, is a popular surrogate for a machine serial number; however, this address is programmable on modern cards. With the rise of virtualization
Hardware virtualization
Computer hardware virtualization is the virtualization of computers or operating systems. It hides the physical characteristics of a computing platform from users, instead showing another abstract computing platform...

 the practice of locking has to add to these simple hardware parameters to still prevent copying.

These schemes have all been criticized for causing problems for validly licensed users who upgrade to a new machine, or have to reinstall the software after reinitializing their hard disk. Some Internet product activation
Product activation
Product activation is a license validation procedure required by some proprietary computer software programs. In one form, product activation refers to a method invented by Ric Richardson and patented by Uniloc where a software application hashes hardware serial numbers and an ID number specific...

 products allow replacement copies to be issued to registered users or multiple copies to the same license.

Like all software, copy-protection software sometimes contains bugs, whose effect may be to deny access to validly licensed users. Most copy protection schemes are easy to crack, and the resulting cracked software is then more valuable than the non-cracked version, because users can make additional copies.

In his 1976 Open Letter to Hobbyists
Open Letter to Hobbyists
The Open Letter to Hobbyists was an open letter written by Bill Gates, the co-founder of Microsoft, to early personal computer hobbyists, in which Gates expresses dismay at the rampant copyright infringement taking place in the hobbyist community, particularly with regard to his company's...

, Bill Gates complained that "most of you steal your software." However, Gates initially rejected copy protection and said "It just gets in the way."

There is also the tool of software blacklist
Software blacklist
Software blacklisting is a tool used by manufacturers of software and music on CD and DVD to prevent copying.Essentially the software on the disc will audit the user's computer for certain types of virtual CD and CD authoring software, or for debugging software used by warez groups to create...

ing that is used to enhance certain copy protection schemes.

Copy protection specific to XX century games

During the 1980s and 1990s, computer games sold on audio cassette and floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...

s were sometimes protected with a user-interactive method that demanded the user to have the original package or a part of it, usually the manual. Copy protection was activated not at installation but every time the game was executed.

Sometimes the copy protection code was needed not at launch, but at a later point in the game. This helped the gamer to experience the game (e.g. as a demonstration) and perhaps could convince him to buy it by the time the copy protection point was reached.

Several imaginative and creative methods have been employed, in order to be both fun and hard to copy. These include:
  • The most common method ("What is the 13th word on the 7th line of page 22?") was often used at the beginning of each game session, but as it proved to be troublesome and tiring for the players, it declined in popularity (for example, X-COM: UFO Defense
    X-COM: UFO Defense
    UFO: Enemy Unknown is a critically acclaimed strategy video game created by Julian Gollop and published by MicroProse Software in 1993...

     used it too, but was later removed by the official v1.4 patch). A variant of this technique involved matching a picture provided by the game to one in the manual and providing an answer pertaining to the picture (Ski or Die
    Ski or Die
    Ski or Die is a 1990 winter sports game by Electronic Arts for the Amiga, NES, MS-DOS and Commodore 64. It consisted of 5 minigames which could be played individually or in a set sequentially...

    and 4D Boxing used this technique). Buzz Aldrin's Race Into Space
    Buzz Aldrin's Race into Space
    Buzz Aldrin's Race Into Space, frequently abbreviated BARIS, is a space simulation and strategy game for MS-DOS. The player takes the role of Administrator of NASA or head of the Soviet space program with the ultimate goal of being the first side to conduct a successful manned moon landing...

     (in the floppy version but not the CD version) incorporated a copy protection scheme that required the user to input an astronaut's total duration in space (available in the manual) before the launch of certain missions. If the answer was incorrect, the mission would suffer a catastrophic failure.
  • Manuals containing information and hints vital to the completion of the game, like answers to riddles (Conquests of Camelot
    Conquests of Camelot
    Conquests of Camelot: The Search for the Grail is a graphic adventure game released in 1989 by Sierra. It was the first game in the Conquests series designed by Christy Marx and her husband Peter Ledger. The only other game in the series was 1992's Conquests of the Longbow: The Legend of Robin Hood...

    , King's Quest 6), recipes of spells (King's Quest 3), keys to deciphering non-Latin writing systems (Ultima series, see also Ultima writing systems), maze guides (Manhunter), dialogue spoken by other characters in the game (Wasteland, Dragon Wars
    Dragon Wars
    Dragon Wars is a fantasy computer role-playing game developed by Interplay Entertainment in 1989, and distributed by Activision.-Story:The story from the back of the original box:-Development:...

    ), excerpts of the storyline (most Advanced Dungeons and Dragons games and Wing Commander I
    Wing Commander I
    Wing Commander is the first, eponymous game in Chris Roberts' science fiction space simulation franchise. The game was first released for the PC on September 26, 1990 and was later ported to the Amiga, CD32 , Mega-CD and the SNES...

    ), or a radio frequency to use to communicate with a character to further a game (Metal Gear Solid
    Metal Gear Solid
    is a videogame by Hideo Kojima. The game was developed by Konami Computer Entertainment Japan and first published by Konami in 1998 for the PlayStation video game console. It is the sequel to Kojimas early MSX2 computer games Metal Gear and Metal Gear 2: Solid Snake...

    ).
  • Some sort of code with symbols, not existing on the keyboard or the ASCII
    ASCII
    The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...

     code. This code was arranged in a grid, and had to be entered via a virtual keyboard
    Virtual keyboard
    A virtual keyboard is a software component that allows a user to enter characters. A virtual keyboard can usually be operated with multiple input devices, which may include a touchscreen, an actual keyboard and a computer mouse.- Types :...

     at the request "What is the code at line 3 row 2?". These tables were printed on dark paper (Maniac Mansion
    Maniac Mansion
    Maniac Mansion is a 1987 graphic adventure game developed and published by Lucasfilm Games. It was Lucasfilm's first published video game, and it was initially released for the Commodore 64 and Apple II. A comedy horror parody of B movies, it follows teenager Dave Miller as he ventures...

    , Uplink), or were visible only through a red transparent layer (Indiana Jones and the Last Crusade
    Indiana Jones and the Last Crusade: The Graphic Adventure
    Indiana Jones and the Last Crusade: The Graphic Adventure is a graphical adventure game, originally released in 1989 , published by Lucasfilm Games . It was the third game to use the SCUMM engine.-Plot:The plot closely follows, and expands upon, the film of Indiana Jones and the Last Crusade...

    ), making the paper very difficult to photocopy. Another variant of this method—most famously used on the ZX Spectrum
    ZX Spectrum
    The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd...

     version of Jet Set Willy
    Jet Set Willy
    Jet Set Willy is a computer game originally written for the ZX Spectrum home computer. It was published in 1984 by Software Projects and ported to most home computers of the time....

    —was a card with color sequences at each grid reference that had to be entered before starting the game. This also prevented photocopying.
  • The Secret of Monkey Island
    The Secret of Monkey Island
    The Secret of Monkey Island is a graphic adventure game developed by Lucasfilm Games and published by the same company after its name was changed to LucasArts. The game spawned a number of sequels, collectively known as the Monkey Island series...

    offered one of the most imaginative protection keys: a rotating wheel with halves of pirate's faces. The game showed a face composed of two different parts and asked when this pirate was hanged on a certain island. The player then had to match the faces on the wheel, and enter the year number that appeared on the island-respective hole. Its sequel had the same concept, but with magic potion ingredients. Other games that employed the code wheel
    Code wheel
    A code wheel is a type of copy protection used on older computer games, often those published in the late 1980s and early 1990s. It evolved from the original "manual protection" system in which the program would require the user to enter a specific word from the manual before the game would start...

     system include games from Accolade like Star Control
    Star Control
    Star Control is a science fiction computer game that was developed by Toys for Bob and published by Accolade in the early 1990s. Star Control still enjoys a cult following...

    .
  • Zork
    Zork
    Zork was one of the first interactive fiction computer games and an early descendant of Colossal Cave Adventure. The first version of Zork was written in 1977–1979 on a DEC PDP-10 computer by Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling, and implemented in the MDL programming language...

    games such as Beyond Zork
    Beyond Zork
    Beyond Zork was an interactive fiction computer game written by Brian Moriarty and released by Infocom in 1987...

    and Zork Zero
    Zork Zero
    Zork Zero: The Revenge of Megaboz is an interactive fiction computer game, written by Steve Meretzky over nearly 18 months and published by Infocom in 1988, with an original retail price of $59.95...

    came with "feelies" which contained information vital to the completion of the game. For example, the parchment found from Zork Zero contained clues vital to solving the final puzzle. However, whenever the player attempts to read the parchment, they are referred to the game package. The in-game help function alluded to this form of control with the response "Good luck, Blackbeard
    Blackbeard
    Edward Teach , better known as Blackbeard, was a notorious English pirate who operated around the West Indies and the eastern coast of the American colonies....

    " to queries that were unsolvable without the original game materials.
  • The Lenslok
    Lenslok
    Lenslok is a copy protection mechanism found in some computer games and other software on the 8bit Atari, Commodore 64, Sinclair ZX Spectrum, Sinclair QL, MSX and Amstrad CPC. The most famous game to use it was Elite for the ZX Spectrum....

     system used a plastic prismatic device, shipped with the game, which was used to descramble a code displayed on screen.


While not strictly a software protection, some game companies offered "value-added" goodies with the package, like funny manuals, posters, comics, storybooks or fictional documentation concerning the game (e.g. the Grail Diary for Indiana Jones or a police cadet notebook with Police Quest
Police Quest
Police Quest is a series of computer games produced and published by Sierra On-Line between 1987 and 1993. The original series was composed of four adventure games, the first three of which were designed by former policeman Jim Walls, with the fourth title designed by former LAPD Chief Daryl F....

or the Hero's manual of Quest for Glory
Quest for Glory
Quest for Glory is a series of hybrid role-playing/adventure computer games designed by Corey and Lori Ann Cole. The series combined humor, puzzle elements, themes and characters borrowed from various legends, puns, and memorable characters, creating a 5-part series of the Sierra stable.Although...

or a copy of the National Inquisitor newspaper in Zak McKracken) in order to entice gamers to buy the package. This trend is re-emerging in modern gaming as an incentive to both buy games and discourage their resale; some games like Forza Motorsport 3
Forza Motorsport 3
Forza Motorsport 3 is a racing video game developed for Xbox 360 by Turn 10 Studios. It was released in October . It is the sequel to Forza Motorsport 2 and the third installment in the Forza Motorsport series...

and Dragon Age: Origins
Dragon Age: Origins
Dragon Age: Origins is a single-player role-playing video game developed by BioWare's Edmonton studio and published by Electronic Arts. It is the first game in the Dragon Age franchise...

provide bonus in-game material that will only be given if one buys the game new.

Copy protection methods of recent video game console systems

When Sega's Dreamcast was released in 1998, it came with a newer disc format, called the GD-ROM
GD-ROM
GD-ROM is the proprietary optical disc format used by the Dreamcast games console, as well as its arcade counterparts and the Sega/Nintendo/Namco Triforce arcade system...

. Using a modified CD player, one could access the game functionality. Using a special swap method could allow reading a GD-ROM game through a CD-ROM just using common MIL-CD (standard CD Boot loading, commonly found on Windows Installation Discs, Linux Live CDs, and others). Dreamcasts sold after October 2000 contain a newer firmware update, not allowing MIL-CD boot.

The Xbox
Xbox
The Xbox is a sixth-generation video game console manufactured by Microsoft. It was released on November 15, 2001 in North America, February 22, 2002 in Japan, and March 14, 2002 in Australia and Europe and is the predecessor to the Xbox 360. It was Microsoft's first foray into the gaming console...

 has a specific function: Non-booting or non-reading from CDs
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

 and DVD-R
DVD-R
DVD-R is a DVD recordable format. A DVD-R typically has a storage capacity of 4.71 GB. Pioneer has also developed an 8.5 GB dual layer version, DVD-R DL, which appeared on the market in 2005....

s as a method of game copy protection. Also, the Xbox is said to use a different DVD file system (instead of UDF). It has been theorized that the discs have a second partition that is read from the outside in (opposite current standards thus making the second partition unreadable in PC DVD drives) which give the tracks the appearance that the disc was spun backwards during manufacture. The Xbox 360
Xbox 360
The Xbox 360 is the second video game console produced by Microsoft and the successor to the Xbox. The Xbox 360 competes with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of video game consoles...

 copy protection functions by requesting the DVD drive compute the angular distance between specific data sectors on the disc. A duplicated DVD will return different values than a pressed original would.

The PlayStation 2
PlayStation 2
The PlayStation 2 is a sixth-generation video game console manufactured by Sony as part of the PlayStation series. Its development was announced in March 1999 and it was first released on March 4, 2000, in Japan...

 has a map file that contains all of the exact positions and file size info of the CD in it, which is stored at a position that is beyond the file limit. The game directly calls the position at where the map file is supposed to be. This means that if the file is moved inside the limit, it is useless since the game is looking outside the limit for it, and the file will not work outside of the limit, making any copied disc unusable without a mod chip or the use of FMCB (free memory card boot). FMCB uses the memory card to trick the built-in DVD video software into booting copied games. Before a copied game can be played, it must have been patched with a free application.

Nintendo's Wii
Wii
The Wii is a home video game console released by Nintendo on November 19, 2006. As a seventh-generation console, the Wii primarily competes with Microsoft's Xbox 360 and Sony's PlayStation 3. Nintendo states that its console targets a broader demographic than that of the two others...

 and Nintendo GameCube
Nintendo GameCube
The , officially abbreviated to NGC in Japan and GCN in other regions, is a sixth generation video game console released by Nintendo on September 15, 2001 in Japan, November 18, 2001 in North America, May 3, 2002 in Europe, and May 17, 2002 in Australia...

 have their own specialty format for copy protection. It is based on DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

/miniDVD (Game Cube) technology; each disc contains some deliberately placed defects. The exact positions of these defects, which differ for each produced disc, is encoded encrypted in the BCA
Burst cutting area
In computing, the burst cutting area or narrow burst cutting area refers to the circular area near the center of a DVD, HD DVD or Blu-ray Disc, where a barcode can be written for additional information such as ID codes, manufacturing information, and serial numbers...

 of each disc. The BCA is readable on most standard DVD-ROM Drives, but consumer burners can reproduce neither the BCA nor the defects. As an additional obfuscation mechanism, the on-disc sector format is a little bit different from normal DVDs. Nevertheless, it can be read using some consumer DVD-ROM drives with a firmware modification or "debug mode".

The PSP
PlayStation Portable
The is a handheld game console manufactured and marketed by Sony Corporation Development of the console was announced during E3 2003, and it was unveiled on , 2004, at a Sony press conference before E3 2004...

, except the PSP Go
PSP Go
The PSP Go is a version of the PlayStation Portable handheld game console manufactured by Sony. It was released on October 1, 2009 in American and European territories, and on November 1 in Japan. It was revealed prior to E3 2009 through Sony's Qore VOD service...

, uses the Universal Media Disc
Universal Media Disc
The Universal Media Disc is an optical disc medium developed by Sony for use on their PlayStation Portable handheld gaming and multimedia platform...

, a media format similar to a MiniDisc
MiniDisc
The disc is permanently housed in a cartridge with a sliding door, similar to the casing of a 3.5" floppy disk. This shutter is opened automatically by a mechanism upon insertion. The audio discs can either be recordable or premastered. Recordable MiniDiscs use a magneto-optical system to record...

. It holds about 1.2 GB. Although it cannot be copied, one can make an ISO image
ISO image
An ISO image is an archive file of an optical disc, composed of the data contents of every written sector of an optical disc, including the optical disc file system...

 (a file version of the UMD) on a memory card and play it on custom firmware, which can be installed on the PSP.

The PlayStation 3
PlayStation 3
The is the third home video game console produced by Sony Computer Entertainment and the successor to the PlayStation 2 as part of the PlayStation series. The PlayStation 3 competes with Microsoft's Xbox 360 and Nintendo's Wii as part of the seventh generation of video game consoles...

 uses Blu-ray BD-ROM
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...

 discs. In addition to any protection provided by the console itself, the BD-ROM format's specification allows for a ROM-Mark
ROM-Mark
In computing, ROM Mark or BD-ROM Mark is a serialization technology designed to guard against mass production piracy or the mass duplication and sale of unauthorized copies of pre-recorded Blu-ray Discs...

 which cannot be duplicated by consumer-level recorders. The BD-ROM format, in addition, has a notably large file size in the neighborhood of 40-50 gigabytes per game, making it unwieldy for online file-sharing, a major method of video game copying.

Proposed general purpose copy protection methods

There is another protection method that is not out yet, US Patent Office for Application Number 11678137. Each and every copy of a protected program gets its own internal intelligence, interpretable only by itself, which includes time of program creation, etc., etc.. Each copy of the game or program must be compiled or otherwise created at the time of purchase. Also, the maker must keep track of a subset of each and every instance of the newly created specialty software in case the user emails in for new keys, say for a reinstall. Perhaps even the purchasers name would be encoded and included as part of the intelligence. The number of permissible occurrences of requests for new key codes, say, 5 times, can be controlled by the program maker. If someone cracks the code for that particular copy of the program, still, it will work only for that copy, and only in the time frame that the internal intelligence says it can be installed.

Copy protection for videotape

Companies such as Macrovision
Macrovision
Rovi Corporation is a globally operating, US-based company that provides guidance technology, entertainment data, copy protection, industry standard networking and media management technology for digital entertainment devices and services...

 and Dwight Cavendish provided schemes to videotape
Videotape
A videotape is a recording of images and sounds on to magnetic tape as opposed to film stock or random access digital media. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram...

 publishers making copies unusable if they were created with a normal VCR. All major videotape duplicators licensed Macrovision or similar technologies to copy protect video cassettes for their clients or themselves.

Starting in 1985 with the video release of "The Cotton Club
The Cotton Club (film)
The Cotton Club is a 1984 crime-drama, centered on a famed Harlem jazz club of the 1930s, the Cotton Club.The movie was co-written and directed by Francis Ford Coppola, choreographed by Henry LeTang, and starred Richard Gere, Diane Lane, and Gregory Hines...

", Macrovision has licensed to publishers a technology that exploits the automatic gain control
Automatic gain control
Automatic gain control is an adaptive system found in many electronic devices. The average output signal level is fed back to adjust the gain to an appropriate level for a range of input signal levels...

 feature of VCRs by adding pulses to the vertical blanking sync signal. These pulses do not affect the image a consumer sees on his TV, but do confuse the recording-level circuitry of consumer VCRs. This technology, which is aided by U.S. legislation mandating the presence of automatic gain-control circuitry in VCRs, is said to "plug the analog hole" and make VCR-to-VCR copies impossible, although an inexpensive circuit is widely available that will defeat the protection by removing the pulses. Macrovision has patented methods of defeating copy prevention, giving it a more straightforward basis to shut down manufacture of any device that descrambles it than often exists in the DRM world.

Copy protection for audio CDs

By 2000, Napster
Napster
Napster is an online music store and a Best Buy company. It was originally founded as a pioneering peer-to-peer file sharing Internet service that emphasized sharing audio files that were typically digitally encoded music as MP3 format files...

 had become a popular mainstream hobby, and several music publishers responded by starting to sell some CDs with various copy protection schemes. Most of these are playback restrictions that aim to make the CD unusable in computers with CD-ROM drives, leaving only dedicated audio CD players for playback. This does not, however, prevent such a CD from being copied via analogue connections or by ripping the CD under operating systems such as Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

 (which is effective since copy-protection software is generally written for Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

), which has led critics to question the usefulness of such schemes.

CD copy protection is achieved by assuming certain feature levels in the drives: The CD Digital Audio
Red Book (audio CD standard)
Red Book is the standard for audio CDs . It is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.The first edition of the Red Book was released in 1980 by Philips and Sony; it was adopted by the Digital Audio Disc...

 is the oldest CD standard and forms the basic feature set beyond which dedicated audio players need no knowledge. CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

 drives additionally need to support mixed mode CDs
Enhanced CD
Enhanced CD, also known as CD Extra and CD Plus, is a certification mark of the Recording Industry Association of America for various technologies that combine audio and computer data for use in both Compact Disc and CD-ROM players....

 (combined audio and data tracks) and multi-session CDs (multiple data recordings each superseding and incorporating data of the previous session).

The play preventions in use intentionally deviate from the standards and intentionally include malformed multisession data or similar with the purpose of confusing the CD-ROM drives to prevent correct function. Simple dedicated audio CD players would not be affected by the malformed data since these are for features they do not support — for example, an audio player will not even look for a second session containing the copy protection data.

In practice, results vary wildly. CD-ROM drives may be able to correct the malformed data and still play them to an extent that depends on the make and version of the drive. On the other hand, some audio players may be built around drives with more than the basic intelligence required for audio playback. Some car radios with CD playback, portable CD players, CD players with additional support for data CDs containing MP3
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...

 files, and DVD players have had problems with these CDs.

The deviation from the Red Book
Red Book (audio CD standard)
Red Book is the standard for audio CDs . It is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.The first edition of the Red Book was released in 1980 by Philips and Sony; it was adopted by the Digital Audio Disc...

 standard that defines audio CDs required the publishers of these copy-protected CDs to refrain from using the official CDDA logo on the discs or the cases. The logo is a trademark
Trademark
A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...

 owned by Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

 and Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

 and licensed to identify compliant audio discs only. To prevent dissatisfied customers from returning CDs which were misrepresented as compliant audio CDs, such CDs also started to carry prominent notices on their covers.

In general the audio can always be extracted by applying the principle of the analog hole
Analog hole
The analog hole is a fundamental and inevitable vulnerability in copy protection schemes for noninteractive works in digital formats which can be exploited to duplicate copy-protected works that are ultimately reproduced using analog means...

. Additionally, such programs as IsoBuster
IsoBuster
-External links:*...

 may be capable of producing hidden audio files.

Examples of CD copy protection schemes are Cactus Data Shield
Cactus Data Shield
Cactus Data Shield is a form of CD/DVD copy protection for audio compact discs developed by Midbar Tech now owned by Macrovision. It has been used extensively by EMI and BMG and their subsidiaries...

, Copy Control
Copy Control
Copy Control was the generic name of a copy prevention system, used from 2001 until 2006 on several digital audio disc releases by EMI Group and Sony BMG Music Entertainment in several regions...

, and Data Position Measurement
Data Position Measurement
Data Position Measurement is a copy protection mechanism that operates by measuring the physical location of data on an optical disc. Stamped CDs are perfect clones and always have the data at the expected location, while a burned copy would exhibit physical differences. DPM detects these...

.

Copy protection in recent digital media

More recently, publishers of music and films in digital form have turned to 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...

 to make copying more difficult. CSS, which is used on DVDs, is a famous example of this. It is a form of copy protection that uses 40-bit encryption. Copies will not be playable since they will be missing the key, which is not writable on DVD-R or DVD-RW discs. With this technique, the work is encrypted using a key only included in the firmware
Firmware
In electronic systems and computing, firmware is a term often used to denote the fixed, usually rather small, programs and/or data structures that internally control various electronic devices...

 of "authorized" players, which allow only "legitimate" uses of the work (usually restricted forms of playback, but no conversion or modification). The controversial Digital Millennium Copyright Act
Digital Millennium Copyright Act
The Digital Millennium Copyright Act is a United States copyright law that implements two 1996 treaties of the World Intellectual Property Organization . It criminalizes production and dissemination of technology, devices, or services intended to circumvent measures that control access to...

 provides a legal protection for this in the US, that would make it illegal to distribute "unauthorized" players—which was supposed to eliminate the possibility of building a DVD copier. However, encryption schemes designed for mass-market standardized media such as DVD suffer from the fundamental weaknesses that consumers have physical access to the devices containing the keys, and once implemented, the copy-protection scheme can never be changed without breaking the forward compatibility
Forward compatibility
Forward compatibility or upward compatibility is a compatibility concept for systems design, as e.g. backward compatibility. Forward compatibility aims at the ability of a design to gracefully accept input intended for later versions of itself...

 of older devices (or the backward compatibility
Backward compatibility
In the context of telecommunications and computing, a device or technology is said to be backward or downward compatible if it can work with input generated by an older device...

 of newer media). Since consumers are highly unlikely to buy new hardware for the sole purpose of preserving copy protection, manufacturers have been prevented from enhancing their DRM technology until recently, with the release of next-generation media such as HD DVD
HD DVD
HD DVD is a discontinued high-density optical disc format for storing data and high-definition video.Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format...

 and Blu-ray Disc
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...

. This period represents more than enough time for the encryption scheme to be defeated by determined attackers. For example, the CSS encryption system used on DVD Video was broken within three years of its market release in November 1996 (see DeCSS
DeCSS
DeCSS is a computer program capable of decrypting content on a commercially produced DVD video disc. Before the release of DeCSS, there was no way for computers running a Linux-based operating system to play video DVDs....

), but has not been changed since, because doing so would immediately render all DVD players sold prior to the change incapable of reading new DVDs—this would not only provoke a backlash amongst consumers, but also restrict the market that the new DVDs could be sold to. More recent DVDs have attempted to augment CSS with additional protection schemes. Most modern schemes like ARccOS Protection
ARccOS Protection
ARccOS is a copy-protection system made by Sony that is used on some DVDs. Designed as an additional layer to be used in conjunction with Content Scramble System , the system deliberately creates corrupted sectors on the DVD, which cause copying software to produce errors .Despite being promoted...

 use tricks of the DVD format in an attempt to defeat copying programs, though it is noted that any scheme must stay within the bounds of the DVD Video format, limiting the possible avenues of protection—and making it easier for hackers to learn the innards of the scheme and find ways around it.

The newest generations of optical disc media, HD DVD
HD DVD
HD DVD is a discontinued high-density optical disc format for storing data and high-definition video.Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format...

 and Blu-ray Disc
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...

, attempt to address this issue. Both formats employ the Advanced Access Content System
Advanced Access Content System
The Advanced Access Content System is a standard for content distribution and digital rights management, intended to restrict access to and copying of the "next generation" of optical discs and DVDs. The specification was publicly released in April 2005 and the standard has been adopted as the...

, which provides for several hundred different decryption keys (for the varying models of players to hit the market), each of which can be invalidated ("revoked") should one of the keys be compromised. Revoked keys simply will not appear on future discs, rendering the compromised players useless for future titles unless they are updated to fix the issue. For this reason, all HD-DVD players and some Blu-ray players include an ethernet
Ethernet physical layer
The Ethernet physical layer is the physical layer component of the Ethernet family of computer network standards.The Ethernet physical layer evolved over a considerable time span and encompasses quite a few physical media interfaces and several magnitudes of speed...

 port, to give them the ability to download DRM updates. Blu-ray Disc goes one step further with a separate technique called BD+
BD+
BD+ is a component of the Blu-ray Disc Digital Rights Management system. It was developed by Cryptography Research Inc. and is based on their Self-Protecting Digital Content concept...

, a virtual machine that can execute code included on discs to verify, authorize, revoke, and update players as the need arises. Since the protection program is on the disc rather than the player, this allows for updating protection programs within BD's working life by simply having newer programs included on newer discs.

Notable copy protection payloads

Over time, software publishers (especially in the case of videogames) became creative about crippling the software in case it was illegally copied. These games would initially show that the copy was successful, but eventually render themselves unplayable via subtle methods.
  • Superior Soccer had no outward signs of copy protection, but if it decided it was illegally copied, it would make the soccer ball in the game invisible, making it impossible to play the game.
  • While the copy protection in Zak McKracken and the Alien Mindbenders
    Zak McKracken and the Alien Mindbenders
    Zak McKracken and the Alien Mindbenders is a graphical adventure game, originally released in October 1988 , published by LucasArts . It was the second game to use the SCUMM engine, after Maniac Mansion...

    was not hidden as such, the repercussions of missing the codes was unusual: the player would end up in jail (permanently), and the police officer would give a lengthy and condescending speech about software copying.
  • In case of copied versions of Settlers 3, the iron smelters - who are essential to create weapons - would only produce pig iron
    Pig iron
    Pig iron is the intermediate product of smelting iron ore with a high-carbon fuel such as coke, usually with limestone as a flux. Charcoal and anthracite have also been used as fuel...

    s, making the players inevitably lose weapons because of the lack of armour
    Armour
    Armour or armor is protective covering used to prevent damage from being inflicted to an object, individual or a vehicle through use of direct contact weapons or projectiles, usually during combat, or from damage caused by a potentially dangerous environment or action...

    .
  • Bohemia Interactive Studio
    Bohemia Interactive Studio
    Bohemia Interactive , also referred to as Bohemia Interactive Studio , is an independent computer and console game developer based in Prague, Czech Republic...

     developed a unique and very subtle protection system for its game Operation Flashpoint: Cold War Crisis. Dubbed FADE
    FADE
    FADE is digital rights management software developed by Macrovision. It operates by detecting if a game has been pirated, and initially allows the player to use the game normally but eventually and gradually degrades certain game features over a time, eventually rendering it unplayable.- How It...

    , if it detects an unauthorized copy, it does not inform the player immediately but instead progressively corrupts aspects of the game (such as reducing the weapon accuracy to 0) to the point that it eventually becomes unplayable. The message "Original discs don't FADE" will eventually appear if the game is detected as being an unauthorized copy. FADE is also used in ArmA II. They continued these methods in Take On Helicopters
    Take On Helicopters
    Take On Helicopters is a helicopter game from independent Czech development studio Bohemia Interactive. The game will feature two large open world terrains based upon real-world terrain-data. Campaign will take place on a 3,800 square kilometer terrain around Seattle...

    , where the screen would blur and distort when playing a pirated copy.
  • More recently, Batman: Arkham Asylum
    Batman: Arkham Asylum
    Batman: Arkham Asylum is a 2009 action-adventure stealth video game based on DC Comics' Batman developed for PlayStation 3, Xbox 360, Mac OS X and Microsoft Windows. It was developed by Rocksteady Studios and published by Eidos Interactive in conjunction with Warner Bros. Interactive Entertainment...

    implemented a copy protection system where the game disables Batman's glide system and various other features, rendering the players to be unable to continue beyond a certain point.
  • Many games use the "code checksumming" technique to prevent alteration of code to bypass other copy protection. Important constants for the game - such as the accuracy of the player's firing, the speed of their movement, etc. - are not included in the game but calculated from the numbers making up the machine code
    Machine code
    Machine code or machine language is a system of impartible instructions executed directly by a computer's central processing unit. Each instruction performs a very specific task, typically either an operation on a unit of data Machine code or machine language is a system of impartible instructions...

     of other parts of the game. If the code is changed, the calculation yields a result which no longer matches the original design of the game and the game plays improperly. Exile is known to have used this technique but it is a common technique in general usage.
  • The PC version of Grand Theft Auto IV
    Grand Theft Auto IV
    Grand Theft Auto IV is a 2008 open world action video game published by Rockstar Games, and developed by British games developer Rockstar North. It has been released for the PlayStation 3 and Xbox 360 video game consoles, and for the Windows operating system...

    has a copy protection that swings the camera as though the player was drunk. If the player entered a vehicle it will automatically throttle, making it difficult to steer. It also damages the vehicle, making it vulnerable to collisions and bullets.
  • In Earthbound
    Earthbound
    Earthbound may refer to:*EarthBound , a role-playing video game series for Nintendo**Mother , a Japan-only game that was to be called Earth Bound in the US...

    , unauthorized copies of the game will trigger a checksum that makes random encounters appear much more often than in an authorized copy, and if the player progresses through the game without giving up (or cracks this protection), a second checksum code will activate before the final boss battle, freezing the game and deleting all the save files.
  • In an unauthorized version of the PC edition of Mass Effect
    Mass Effect
    Mass Effect is an action role-playing game developed by BioWare for the Xbox 360 and Microsoft Windows by Demiurge Studios. The Xbox 360 version was released worldwide in November 2007 published by Microsoft Game Studios...

    , the game save mechanism would not work and the in-game galactic map would cause the game to crash. As the galactic map is needed to travel to different sections of the game, the player would be stuck in the first section of the game.
  • If an unauthorized version of The Sims 2
    The Sims 2
    The Sims 2 is a strategic life simulation computer game developed by Maxis and published by Electronic Arts. It is the sequel to the best-selling computer game, The Sims, which debuted on February 4, 2000. It was first released on September 14, 2004 for Microsoft Windows. A port to Apple Mac OS X...

     was used, the Build Mode would not work properly. Walls would not be able to be built on the player's property, which prevents the player from building any custom houses. Some furniture and clothing selections would not be available too.
  • A March 2009 update to the BeeJive IM iPhone app included special functionality for users of the pirated version: the screen would read "PC LOAD LETTER
    PC Load Letter
    PC LOAD LETTER is a technology meme, originally a printer error message, which has grown into popular culture as a reference to a confusing or inappropriate error message.-Explanation:...

    " whenever the user tried to establish a connection to any IM service, then quickly switch to a YouTube
    YouTube
    YouTube is a video-sharing website, created by three former PayPal employees in February 2005, on which users can upload, view and share videos....

     clip from the movie Office Space
    Office Space
    Office Space is a 1999 American comedy film satirizing work life in a typical 1990s software company. Written and directed by Mike Judge, it focuses on a handful of individuals fed up with their jobs portrayed by Ron Livingston, Jennifer Aniston, Gary Cole, David Herman, Ajay Naidu, and Diedrich...

    .
  • Red Alert 2 has a copy protection, where if an illegal version of it is detected, the player's entire base would be destroyed within 30 seconds of the player joining a match.
  • The DS version of Michael Jackson: The Experience has a copy protection system where vuvuzela noises are heard as the music is playing, no visible notes, making the game impossible to play, & the game freezing upon the player pausing it.
  • Older versions of Autodesk 3ds Max use a dongle
    Dongle
    A software protection dongle is a small piece of hardware that plugs into an electrical connector on a computer and serves as an electronic "key" for a piece of software; the program will only run when the dongle is plugged in...

     for copy protection; if it is missing, the program will randomly corrupt the points of the user's model during usage, destroying their work.
  • Older versions of CDRWIN
    CDRWIN
    CDRWIN is a CD/DVD burning software for Microsoft Windows developed by Golden Hawk Technology company.Once popular, CDRWIN's usage has diminished due to the bundling of limited versions of other software packages, such as Nero Burning ROM and Roxio Easy CD Creator, with new computers and optical...

     used a serial number for initial copy protection. However, if this check was bypassed, a second hidden check would activate causing a random factor to be introduced into the CD burning process, producing corrupted "coaster" disks.
  • Terminate, a BBS terminal package, would appear to operate normally if cracked but would insert a warning that a pirated copy was in use into the IEMSI login packet it transmitted, where the sysop
    SysOp
    A sysop is an administrator of a multi-user computer system, such as a bulletin board system or an online service virtual community. It may also be used to refer to administrators of other Internet-based network services....

     of any BBS the user called could clearly read it.
  • Ubik's Musik, a music creation tool for the Commodore 64
    Commodore 64
    The Commodore 64 is an 8-bit home computer introduced by Commodore International in January 1982.Volume production started in the spring of 1982, with machines being released on to the market in August at a price of US$595...

    , would transform into a Space Invaders
    Space Invaders
    is an arcade video game designed by Tomohiro Nishikado, and released in 1978. It was originally manufactured and sold by Taito in Japan, and was later licensed for production in the United States by the Midway division of Bally. Space Invaders is one of the earliest shooting games and the aim is to...

     game if it detected that a cartridge-based copying device had attempted to interrupt it. This combined copy protection and an easter egg
    Easter egg
    Easter eggs are special eggs that are often given to celebrate Easter or springtime.The oldest tradition is to use dyed or painted chicken eggs, but a modern custom is to substitute chocolate eggs, or plastic eggs filled with confectionery such as jelly beans...

    , as the message that appears when it occurs is not hostile ("Plug joystick in port 1, press fire, and no more resetting/experting!")
  • The Amiga version of Bomberman
    Bomberman
    Bomberman is a strategic, maze-based computer and video game franchise originally developed by Hudson Soft. The original game was published in 1983 and new games in the series are still being published to this day. Today, the commercially successful Bomberman is featured in over 70 different games...

     featured a multitap
    Multitap
    A multitap is a video game console peripheral that increases the number of controller ports available to the player, allowing additional controllers to be used in play...

     peripheral that also acted as a dongle
    Dongle
    A software protection dongle is a small piece of hardware that plugs into an electrical connector on a computer and serves as an electronic "key" for a piece of software; the program will only run when the dongle is plugged in...

    . Data from the multitap was used to calculate the time limit of each level. If the multitap was missing, the time limit would be calculated as 0, causing the level to end immediately.
  • Never Mind, a puzzle game for the Amiga, contained code that caused any pirated version of the game to behave as a demo. The game would play three levels sampled from throughout the game, and then give the message "You have completed three levels; however there are 100 levels to complete on the original disc."
  • While not a destructive payload. In Spyro: Year of the Dragon
    Spyro: Year of the Dragon
    Spyro: Year of the Dragon is a platform game, developed by Insomniac Games and published by Sony Computer Entertainment for the PlayStation video game console. The game was released in North America on October 23, 2000 and in Europe on November 10, 2000...

     A Character named Zoe will tell the player outside the room containing the balloon to Midday Garden Home and several other areas that they are using a pirated copy. However this has no impact on the gameplay itself and just proves to be a minor annoyance.
  • The Atari Jaguar
    Atari Jaguar
    The Atari Jaguar is a video game console that was released by Atari Corporation in 1993. It was the last to be marketed under the Atari brand until the release of the Atari Flashback in 2004. It was designed to surpass the Mega Drive/Genesis, Super Nintendo Entertainment System, and the Panasonic...

     console would freeze at startup and play the sound of an enraged jaguar snarling if the inserted cartridge failed the initial security check.
  • The Lenslok
    Lenslok
    Lenslok is a copy protection mechanism found in some computer games and other software on the 8bit Atari, Commodore 64, Sinclair ZX Spectrum, Sinclair QL, MSX and Amstrad CPC. The most famous game to use it was Elite for the ZX Spectrum....

     copy protection system gave an obvious message if the lens-coded letters were entered incorrectly, but if the user soft-reset the machine, the areas of memory occupied by the game would be flooded with the message "THANK YOU FOR YOUR INTEREST IN OUR PRODUCT. NICE TRY. LOVE BJ/NJ" to prevent the user examining leftover code to crack the protection.
  • An update to the sandbox game Garry's Mod
    Garry's Mod
    Garry's Mod is a sandbox physics game using the Source engine. Garry's Mod has been available on Steam's content delivery service since November 29, 2006...

     enabled a copy protection mechanism that outputs the error "Unable to shade polygon normals" if the game detects that it is pirated. The error also includes the user's Steam ID as an error ID, meaning that pirates can be identified by their Steam account when asking for help about the error on the Internet.
  • The Atari version of Alternate Reality: The Dungeon would have the player's character attacked by two unbeatable "FBI Agents" if it detected a pirated version. The FBI agents would also appear when restoring a save which was created by a pirated version, even if the version restoring the save was legal.
  • VGA Planets
    VGA Planets
    VGA Planets is a graphical, multi-player, space strategy war game. The game simulates combat in space between galactic scale empires. The game emphasizes colonization of space and the development of the planets that you find, colonize or conquer. Development of these resources determines what kind...

    , a play-by-BBS strategy game, contained code in its server which would check all clients' submitted turns for pirated registration codes. Any player deemed to be using an illegal copy, or cheating in the game, would have random forces destroyed throughout the game by an unbeatable enemy called "The Tim Continuum" (after the game's author, Tim Wissemann). A similar commercial game, Stars!
    Stars!
    Stars! is a complex turn-based computer game based around the management of planets and fleets of spaceships following the 4X game model...

    , would issue empty turn updates for players with invalid registration codes, meaning that none of their orders would ever be carried out.
  • On a copied version of the original PC version of Postal, as soon as the game was started the player character would immediately shoot himself in the head.


The usage of copy protection payloads which lower playability of a game without making it clear that this is a result of copy protection is now generally considered unwise, due to the potential for it to result in unaware players with pirated copies spreading word-of-mouth that a game is of low quality. The authors of FADE
FADE
FADE is digital rights management software developed by Macrovision. It operates by detecting if a game has been pirated, and initially allows the player to use the game normally but eventually and gradually degrades certain game features over a time, eventually rendering it unplayable.- How It...

 explicitly acknowledged this as a reason for including the explicit warning message.

See also

  • Alcohol 120%
  • Aladdin Knowledge Systems
    Aladdin Knowledge Systems
    Aladdin Knowledge Systems was a company that produced software for digital rights management and Internet security. The company was by SafeNet Inc, in 2009. Its corporate headquarters are located in Belcamp...

  • BD+
    BD+
    BD+ is a component of the Blu-ray Disc Digital Rights Management system. It was developed by Cryptography Research Inc. and is based on their Self-Protecting Digital Content concept...

  • Broadcast flag
    Broadcast flag
    A broadcast flag is a set of status bits sent in the data stream of a digital television program that indicates whether or not the data stream can be recorded, or if there are any restrictions on recorded content...

  • Bus encryption
    Bus encryption
    Bus encryption is the use of encrypted program instructions on a data bus in a computer that includes a secure cryptoprocessor for executing the encrypted instructions...

  • CD-Cops
    CD-Cops
    CD-Cops is the first CD-ROM protection that uses the geometry of the CD-ROM media rather than a hidden "mark". It was invented in 1996 by Danish Link Data Security, known for its Cops Copylock key-diskette security used in the 1990s by Lotus 1-2-3.-Overview:...

  • CI+
  • Daemon Tools
    Daemon Tools
    Daemon Tools is a disk image emulator and optical disc authoring program for Microsoft Windows. Daemon Tools was originally a furtherance in the development of another program, Generic SafeDisc emulator, and incorporated all of its features. The program claims to be able to defeat most copy...

  • Code morphing
    Code morphing
    Code morphing is one of the approaches to protect software applications from reverse engineering, analysis, modifications, and cracking used in obfuscating software. This technology protects intermediate level code such as compiled from Java and .NET languages rather than binary object code...

  • Code obfuscation
  • Digital rights management
    Digital rights management
    Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...

  • Digital watermarking
    Digital watermarking
    Digital watermarking is the process of embedding information into a digital signal which may be used to verify its authenticity or the identity of its owners, in the same manner as paper bearing a watermark for visible identification. In digital watermarking, the signal may be audio, pictures, or...

  • Encryption software
    Encryption software
    Encryption software is software whose main task is encryption and decryption of data, usually in the form of files on hard drives and removable media, email messages, or in the form of packets sent over computer networks.-Security:...

  • Extended Copy Protection
    Extended Copy Protection
    Extended Copy Protection is a software package developed by the British company First 4 Internet, and sold as a copy protection or digital rights management scheme for Compact Discs...

  • Floating licensing
    Floating licensing
    Floating licensing is a software licensing approach in which a limited number of licenses for a software application are shared among a larger number of users over time. When an authorized user wishes to run the application they request a license from a central license server. If a license is...

  • Game Jackal
    Game Jackal
    Game Jackal is a PC application developed by Antiguan-based company SlySoft that allows users to play PC game titles without the need for the game's media to be in the CD-ROM or DVD-ROM drive...

  • Game-altering device
  • iLok (Copy Protection)
  • Libcrypt
    Libcrypt
    Libcrypt is a copy protection mechanism developed by Sony for use in their PlayStation systems. The protection consists of a two-stage verification algorithm: the first stage attempts to validate the game disc as an original PlayStation disc; following that, a checksum is then calculated from the...

  • License manager
    License manager
    A license manager is a software management tool used by software vendors or by end-user organizations to control where and how software products are able to run. License managers protect software vendors from losses due to software piracy and enable end-user organizations to enforce compliance with...

  • List of license managers
  • Product activation
    Product activation
    Product activation is a license validation procedure required by some proprietary computer software programs. In one form, product activation refers to a method invented by Ric Richardson and patented by Uniloc where a software application hashes hardware serial numbers and an ID number specific...

  • Protect Software
    Protect Software
    Protect Software is a globally operating, Germany based company that develops and markets licensing, access control and secure distribution technologies for creative works. This includes digital media and computer software...

  • Rob Northen copylock
    Rob Northen copylock
    Rob Northen Copylock is a copy-protection system to prevent disk duplication with standard floppy disk drives on the Amiga, Atari ST and PC-DOS platforms...

  • SafeDisc
    SafeDisc
    SafeDisc is a CD/DVD copy protection and digital rights management program for Windows applications and games. Created by Macrovision Corporation, it aims to prevent the copying of discs for casual or commercial use....

  • SafeNet
  • Secure cryptoprocessor
    Secure cryptoprocessor
    A secure cryptoprocessor is a dedicated computer on a chip or microprocessor for carrying out cryptographic operations, embedded in a packaging with multiple physical security measures, which give it a degree of tamper resistance....

  • SecuROM
    SecuROM
    SecuROM is a CD/DVD copy protection and digital rights management product developed by Sony DADC. SecuROM aims to resist home media duplication devices, professional duplicators, and attempts at reverse engineering software. It is most often used for commercial computer games running under the...

  • Software anti-tamper
  • Sony BMG CD copy protection scandal
  • StarForce
    StarForce
    StarForce is a software copy protection mechanism developed by Protection Technology, which claims that products protected with StarForce are difficult to reverse engineer.- Product families :Currently known official versions of StarForce include:...

  • TAGES
    TAGES
    Tagès is a software copy protection system, jointly developed, at first, by MPO and the Thales Group starting in 1999...

  • Tamper resistance
    Tamper resistance
    Tamper resistance is resistance to tampering by either the normal users of a product, package, or system or others with physical access to it. There are many reasons for employing tamper resistance....

  • Trusted Computing
    Trusted Computing
    Trusted Computing is a technology developed and promoted by the Trusted Computing Group. The term is taken from the field of trusted systems and has a specialized meaning. With Trusted Computing, the computer will consistently behave in expected ways, and those behaviors will be enforced by...

  • Vendor lock-in
    Vendor lock-in
    In economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs...

  • Watermark detection

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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