CD key
Encyclopedia
A product key, also known as a Software key, is a specific software-based key for a computer program. It certifies that the copy of the program is original. Activation
is sometimes done offline by entering the key, or with software like Windows XP
online activation is required to prevent multiple people using the same key. Not all software has a product key, as some publishers may choose to use a different method to protect their copyright, or in some cases such as open source software, copyright protection is not used.
Computer games use product keys to verify that the game has not been illegally copied; for example, one could not play Battle.net
powered games such as Diablo II
or StarCraft
online without an original/unique product key. Likewise, one is not allowed to play online with two identical product keys at the same time.
Product keys consist of a series of numbers and/or letters. This sequence is typically entered by the user during the installation of computer software, and is then passed to a verification function in the program. This function manipulates the key sequence according to a mathematical algorithm
and attempts to match the results to a set of valid solutions.
as these keys can be distributed. The overall effectiveness of product keys in enforcing software copyrights requires further study. In addition with improved communication from the rise of the Internet
more sophisticated attacks on Keys such as cracks
(removing the need for a key) and CD key generators
have become common.
Because of this, software publishers are increasingly turning to alternative methods of verifying that keys are both valid and uncompromised. One method, product validation, assigns a product key based on a unique feature of the purchaser's computer hardware (such as its MAC address
), which cannot be as easily duplicated since it depends on the user's hardware. Other newer methods may involve requiring periodical validation of the CD key with an internet server (for games with an online component, such as Battle.net
, this is done whenever the user signs in). The validation can then be performed on the server side, preventing cracks tampering with it (as they do on the client side). The server can also keep a blacklist
of all CD keys known to be invalid or which have explicitly been banned, and deny them access.
, in that it uses uncompromising digital procedures to enforce the license agreement.
Product keys also present new ways for distribution to go wrong. If a product is shipped with missing or invalid keys, then the CD itself is useless. For example, all copies of Splinter Cell: Pandora Tomorrow originally shipped to Australia without CD keys.
a CD key caught running cracks or, in some cases (such as Valve Software's Steam content delivery system), cheats. This results in a permanent ban. Players who wish to continue use of the software must repurchase it. This has inevitably led to criticism over the motivations of enforcing permanent bans.
Particularly controversial is the situation which arises when multiple products' keys are bound together. If products have dependencies on other products (as is the case with expansion pack
s), it is common for companies to ban all bound products. For example, if a fake CD key is used with an expansion pack, the server may ban legitimate CD keys from the original game. Similarly, with Valve's Steam service, all products the user has purchased are bound into the one account. If this account is banned, every product will be rendered unusable.
This "multi-ban" is highly controversial, since it bans users from products which they have legitimately purchased and used.
.) However, individual cases may not be given any attention.
A common cause of false positives (as with the World of Warcraft case above) is users of unsupported platforms. For example, users of Linux
can run Windows applications through compatibility layers such as Wine
and Cedega. These environments sometimes appear to the server as cracks, resulting in a ban.
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...
is sometimes done offline by entering the key, or with software like Windows XP
Windows XP
Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
online activation is required to prevent multiple people using the same key. Not all software has a product key, as some publishers may choose to use a different method to protect their copyright, or in some cases such as open source software, copyright protection is not used.
Computer games use product keys to verify that the game has not been illegally copied; for example, one could not play Battle.net
Battle.net
Battle.net is a gaming service provided by Blizzard Entertainment. Battle.net was launched in November 30, 1996 with the release of Blizzard's action-RPG Diablo. Battle.net was the first online gaming service incorporated directly into the games that make use of it, in contrast to the external...
powered games such as Diablo II
Diablo II
Diablo II is a dark fantasy/horror-themed hack and slash, with elements of the role playing game and dungeon crawl genres. It was released for Windows and Mac OS in 2000 by Blizzard Entertainment, and was developed by Blizzard North. It is a direct sequel to the 1996 hit PC game, Diablo.Diablo II...
or StarCraft
StarCraft
StarCraft is a military science fiction real-time strategy video game developed by Blizzard Entertainment. The first game of the StarCraft series was released for Microsoft Windows on 31 March 1998. With more than 11 million copies sold worldwide as of February 2009, it is one of the best-selling...
online without an original/unique product key. Likewise, one is not allowed to play online with two identical product keys at the same time.
Product keys consist of a series of numbers and/or letters. This sequence is typically entered by the user during the installation of computer software, and is then passed to a verification function in the program. This function manipulates the key sequence according to a mathematical algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
and attempts to match the results to a set of valid solutions.
Effectiveness
Standard key generation, where product keys are generated mathematically, is not completely effective in stopping copyright infringement of softwareCopyright infringement of software
Copyright infringement of software=The copyright infringement of software refers to several practices which involve the unauthorized copying of computer software. Copyright infringement of this kind varies globally...
as these keys can be distributed. The overall effectiveness of product keys in enforcing software copyrights requires further study. In addition with improved communication from the rise of the 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...
more sophisticated attacks on Keys such as cracks
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...
(removing the need for a key) and CD key generators
Keygen
A license or product key generator is a computer program that generates a product licensing key, serial number, or some other registration information necessary to activate for use a software application.-Software licensing:...
have become common.
Because of this, software publishers are increasingly turning to alternative methods of verifying that keys are both valid and uncompromised. One method, product validation, assigns a product key based on a unique feature of the purchaser's computer hardware (such as its 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 cannot be as easily duplicated since it depends on the user's hardware. Other newer methods may involve requiring periodical validation of the CD key with an internet server (for games with an online component, such as Battle.net
Battle.net
Battle.net is a gaming service provided by Blizzard Entertainment. Battle.net was launched in November 30, 1996 with the release of Blizzard's action-RPG Diablo. Battle.net was the first online gaming service incorporated directly into the games that make use of it, in contrast to the external...
, this is done whenever the user signs in). The validation can then be performed on the server side, preventing cracks tampering with it (as they do on the client side). The server can also keep a blacklist
Blacklist
A blacklist is a list or register of entities who, for one reason or another, are being denied a particular privilege, service, mobility, access or recognition. As a verb, to blacklist can mean to deny someone work in a particular field, or to ostracize a person from a certain social circle...
of all CD keys known to be invalid or which have explicitly been banned, and deny them access.
Controversy
Some of the most effective CD key protection is very controversial, due to inconvenience, strict enforcement, harsh penalties and, in some cases, false positives. CD key protection has been likened to Digital Rights ManagementDigital 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...
, in that it uses uncompromising digital procedures to enforce the license agreement.
Inconvenience
Product keys are somewhat inconvenient for end users. Not only do they need to be entered whenever a program is installed, but the user must also be sure not to lose them. Loss of a product key usually means the software is useless once uninstalled.Product keys also present new ways for distribution to go wrong. If a product is shipped with missing or invalid keys, then the CD itself is useless. For example, all copies of Splinter Cell: Pandora Tomorrow originally shipped to Australia without CD keys.
Enforcement and penalties
There are many cases of permanent bans enforced by companies detecting usage violations. It is common for an online system to immediately blacklistBlacklist
A blacklist is a list or register of entities who, for one reason or another, are being denied a particular privilege, service, mobility, access or recognition. As a verb, to blacklist can mean to deny someone work in a particular field, or to ostracize a person from a certain social circle...
a CD key caught running cracks or, in some cases (such as Valve Software's Steam content delivery system), cheats. This results in a permanent ban. Players who wish to continue use of the software must repurchase it. This has inevitably led to criticism over the motivations of enforcing permanent bans.
Particularly controversial is the situation which arises when multiple products' keys are bound together. If products have dependencies on other products (as is the case with expansion pack
Expansion pack
An expansion pack, expansion set, or supplement is an addition to an existing role-playing game, tabletop game or video game. These add-ons usually add new game areas, weapons, objects, and/or an extended storyline to a complete and already released game...
s), it is common for companies to ban all bound products. For example, if a fake CD key is used with an expansion pack, the server may ban legitimate CD keys from the original game. Similarly, with Valve's Steam service, all products the user has purchased are bound into the one account. If this account is banned, every product will be rendered unusable.
This "multi-ban" is highly controversial, since it bans users from products which they have legitimately purchased and used.
False positives
Bans are enforced by servers immediately upon detection of cracks or cheats, usually without human intervention. Sometimes, legitimate users are wrongly deemed in violation of the license, and banned. In large cases of false positives, they are sometimes corrected (as happened in World of WarcraftWorld of Warcraft
World of Warcraft is a massively multiplayer online role-playing game by Blizzard Entertainment. It is the fourth released game set in the fantasy Warcraft universe, which was first introduced by Warcraft: Orcs & Humans in 1994...
.) However, individual cases may not be given any attention.
A common cause of false positives (as with the World of Warcraft case above) is users of unsupported platforms. For example, users of 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...
can run Windows applications through compatibility layers such as Wine
Wine (software)
Wine is a free software application that aims to allow computer programs written for Microsoft Windows to run on Unix-like operating systems. Wine also provides a software library, known as Winelib, against which developers can compile Windows applications to help port them to Unix-like...
and Cedega. These environments sometimes appear to the server as cracks, resulting in a ban.
Recovery of Keys
A key recovery program is a program that is designed to read and decrypt and/or de-obfuscate the key to its original state. When the key is returned to its original state, it may be used to reinstall its corresponding software.See also
- Product activationProduct activationProduct 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...
- License managerLicense managerA 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...
- KeygenKeygenA license or product key generator is a computer program that generates a product licensing key, serial number, or some other registration information necessary to activate for use a software application.-Software licensing:...
- Volume license keyVolume license keyVolume License Key is a term used by many computer software companies to denote the product key used when installing software licensed under volume licensing, which allows a single product key to be used for multiple installations....
- Cryptographic hash functionCryptographic hash functionA cryptographic hash function is a deterministic procedure that takes an arbitrary block of data and returns a fixed-size bit string, the hash value, such that an accidental or intentional change to the data will change the hash value...
- Biometric passportBiometric passportA biometric passport, also known as an e-passport or ePassport, is a combined paper and electronic passport that contains biometric information that can be used to authenticate the identity of travelers...
- Serial numberSerial numberA serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...