Sunday, November 28, 2010

Copy protection

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 copyrighted) (Dell XPS M1210 Battery) .


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 (Dell Studio XPS 1640 Battery) .

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, or only with another device that cannot be easily copied (Dell Studio XPS 1340 Battery) .

The term is also often related to and/or confused with the concept of digital rights management. 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 (Dell Vostro 1710 Battery) .

A more appropriate term is "technological protection measures" (TPMs) , which is often defined as the use of technological tools in order to restrict the use and/or access to a work.

Business rationale

Copy protection is most commonly found on videotapes, DVDs, computer software discs, video game discs and cartridges, and some audio CDs (Sony VGP-BPS13 battery) .

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 (Sony VGP-BPS13/B battery) .

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 it increases 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 (Sony VGP-BPS13/S battery) .

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 (Sony VGP-BPS13A/B battery) .

DRM and license managers sometimes fail, are inconvenient to use, and do not afford the user all of the legal use of the product they have 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 (Sony VGP-BPS13B/B battery) .

Software usage models evolve beyond node locking to floating licenses (where up to N 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) (Sony VGP-BPS13B/B battery) .

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 (Sony VGP-BPL9 battery) .

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 (Sony VGP-BPL11 battery) .

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 (Sony VGP-BPL15 battery) .

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: regardless of any digital restrictions, if music can be heard by the human ear, it can also be recorded (at the very least, with a microphone and tape recorder) (Dell Inspiron E1505 battery) ;

if a film 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 output or headphone jacks) and, once redigitized into an unprotected form, duplicated indefinitely (Dell Latitude E6400 battery) .

Copyingtext-based 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. With basic software and some patience, these techniques can be applied by a typical computer-literate user (HP Pavilion dv6000 Battery) .

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" (Sony Vaio VGN-FZ31S battery) .

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. They can be encrypted in a fashion which is unique for each user's computer, and the decryption system can be made tamper-resistant (see also traitor tracing) (Sony VGN-FZ31S battery) .

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 (Hp pavilion dv6000 battery) .

These were (and are) programmers who as a hobby would defeat copy protection on software, add their alias to the title screen, and then distribute the cracked product to the network of warez BBSes or Internet sites that specialized in distributing unauthorized copies of software (SONY VGN-FZ38M Battery) .

Software copy protection schemes for early computers such as the Apple II and Commodore 64 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' (SONY VGN-FZ31z Battery) .

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 (Sony VGN-FZ31Z Battery) .

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 (SONY VGN-FZ31E Battery) .

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 (SONY VGN-FZ31J Battery) .

By 1980 the first nibble 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 (SONY VGN-FZ31M Battery) .

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 (SONY VGN-FZ31B Battery) .

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 (SONY VGP-BPS13 Battery) .

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 (Dell Inspiron 1320 Battery) .

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 (Dell Inspiron 1320n Battery) .

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 (Dell Inspiron 1464 Battery) .

Floppy disks were replaced by CDs as the preferred method of distribution, and companies like Macrovision and Sony providing copy protection schemes that work by writing data to places on the CD-ROM where a CD-R drive cannot normally write. Such a scheme has been used for the PlayStation and cannot be circumvented easily without the use of a modchip (Dell Inspiron 1564 Battery) .

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?") (Dell Inspiron 1764 Battery) .

This approach can be defeated by users who have the patience to copy the manual with a photocopier, 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 an original (Dell Studio 1450 Battery) .

As a result, user-interactive copy protection of this kind has mostly disappeared.

Other software copy protection techniques include:

  • A dongle, a piece of hardware containing an electronic serial number 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 (Dell Studio 1457 Battery) .
  • Rainbow (SafeNet), HASP (Aladdin Knowledge Systems), iLok (Copy Protection) and Matrix Software License Protection System SecuTech's UniKey are popular dongle protection schemes utilizing a USB dongle. For the production of even more restrictive software, a dongle product that supports code porting mechanism is one choice available to software developers (Dell Latitude D610 Battery) .
  • Bus encryption and encrypted code for use in Secure cryptoprocessors. This prevents copying and tampering of programs used in high security environments such as ATMs. 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 (Toshiba NB100 Battery) .
  • A registration 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 (Toshiba Satellite M65 battery) .
  • 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, which requires the user to have a keyfile in the same directory as the program is installed to run it (Toshiba Satellite M60 battery) .
  • A phone activation code, which requires the user to call a number and register the product to receive a computer-specific serial number (Dell Latitude D830 Battery) .
  • Internet product activation, 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 (Dell Latitude D620 Battery) .
  • Microsoft's Windows Genuine Advantage system is a far-reaching example of this.
  • Protection by code morphing or code obfuscation. The Code Morphing is multilevel technology containing hundreds of unique code transformation patterns (Dell Studio 1735 Battery) .
  • In addition this technology includes the special layer that transforms some commands into Virtual Machine commands (like 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 (Dell Inspiron Mini 10 Battery) .

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 in ROM, while others do not, and so some other metric, such as the date and time (to the second) of initialization of the hard disk can be used (Sony VGN-FW11S Battery) .

On machines with Ethernet cards, the MAC address, which is unique and factory-assigned, is a popular surrogate for a machine serial number; however, this address is programmable on modern cards. With the rise of virtualization the practice of locking has to add to these simple hardware parameters to still prevent copying (Sony VGN-FW11M Battery) .

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 Internetproduct activation products allow replacement copies to be issued to registered users or multiple copies to the same license (Dell Studio 1555 battery) .

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 (Dell Latitude E5400 Battery) .

In his 1976 Open Letter to Hobbyists, 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 blacklisting that is used to enhance certain copy protection schemes (Dell Latitude E4200 Battery) .

Copy protection specific to old games

During the 1980s and 1990s, computer games sold on audio cassette and floppy disks 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 (Dell Vostro A840 Battery) .

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 (Dell Inspiron 300M Battery) .

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 used it too, but was later removed by the official v1.4 patch) (Dell Studio 1737 battery) .
  • 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 and 4D Boxing used this technique). Buzz Aldrin's Race Into Space (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 (Dell Inspiron E1505 battery) .
  • 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, 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) (Dell Latitude E6400 battery) ,
  • dialogue spoken by other characters in the game (Wasteland, Dragon Wars), excerpts of the storyline (most Advanced Dungeons and Dragons games and Wing Commander I), or a radio frequency to use to communicate with a character to further a game (Metal Gear Solid) (Dell RM791 battery) .
  • Some sort of code with symbols, not existing on the keyboard or the ASCII code. This code was arranged in a grid, and had to be entered via a virtual keyboard at the request "What is the code at line 3 row 2?". These tables were printed on dark paper (Maniac Mansion, Uplink) (Dell XPS M1530 battery) ,
  • or were visible only through a red transparent layer (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 version of Jet Set Willy—was a card with color sequences at each grid reference that had to be entered before starting the game (Dell XPS M2010 battery) .
  • This also prevented photocopying.
  • The Secret of Monkey Island 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 (Dell Vostro 1000 battery) .
  • 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 system include games from Accolade like Star Control (Acer Aspire One battery) .
  • Zork games such as Beyond Zork and Zork Zero 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 (Toshiba Satellite P10 Battery) .
  • The in-game help function alluded to this form of control with the response "Good luck, Blackbeard" to queries that were unsolvable without the original game materials.
  • The lenslok system used a plastic prismatic device, shipped with the game, which was used to descramble a code displayed on screen (SONY VGN-FZ210CE Battery) .

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 or the Hero's manual of Quest for Glory or a copy of the National Inquisitor newspaper in Zak McKracken) in order to entice gamers to buy the package (Dell Precision M70 Battery) .

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 andDragon Age: Origins provide bonus in-game material that will only be given if one buys the game new (Toshiba Satellite L305 Battery) .

Copy protection methods of recent video game console systems

When Sega's Dreamcast was released September 9, 1999, it came with a newer disc format, called the GD-ROM. Using a modified CD player, one could access the game functionality (Toshiba Satellite T4900 Battery) .

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 (Toshiba PA3399U-2BRS battery) .

The Xbox has a specific function: Non-booting or non-reading from CDs and DVD-Rs 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 (Toshiba Satellite A200 Battery)

(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 copy protection functions by requesting the DVD drive compute the angular distance between specific data sectors on the disc (Toshiba Satellite 1200 Battery) .

A duplicated DVD will return different values than a pressed original would.

The PlayStation 2 has a map file that contains all of the exact positions and file size info of the CD in it. It 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 (Toshiba Satellite M300 Battery) .

This means that if the file is moved inside the limit, it's useless since the game is looking outside the limit for it. And it will not work outside of the limit, thus making any copied disc unusable without a mod chip or the use of FMCB: free memory card boot. FMCB uses your memory card to trick the built-in DVD video software into booting your copied games (WD External HDD ---passport essential (500GB/640GB)) .

Before a copied game can be played, it must have been patched with a free application.

Nintendo's Wii and Nintendo GameCube have their own specialty format for copy protection. It is based on DVD/miniDVD (Game Cube) technology; each disc contains some deliberately placed defects (WD External HDD passport essential (250GB/320GB) .

The exact positions of these defects, which differ for each produced disc, is encoded encrypted in the BCA 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 (WD External HDD ---passport essential SE (750GB/1TB) .

Nevertheless, it can be read using some consumer DVD-ROM drives with a firmware modification or "debug mode".

The PSP, except the PSP Go, uses the Universal Media Disc, a media format similar to a MiniDisc. It holds about 1.2 GB. Although it cannot be copied, one can make an ISO image (a file version of the UMD) on a memory card and play it on custom firmware, which can be installed on the PSP (WD External HDD ---passport elite(250GB/320GB) .

The PlayStation 3 uses Blu-ray BD-ROM discs. In addition to any protection provided by the console itself, the BD-ROM format's specification allows for a ROM-Mark 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 (WD External HDD ---passport elite(500GB/640GB) .

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. (WD External HDD ---passport studio for Mac(320GB/500GB) .

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 (WD External HDD ---passport studio for Mac(500GB/640GB) .

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 (WD External HDD ---Elements series(250GB/320GB) .

Copy protection for videotape

Companies such as Macrovision and Dwight Cavendish provided schemes to videotape 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 (WD External HDD ---Elements SE(500GB/640GB) .

Starting in 1985 with the video release of "The Cotton Club", Macrovision has licensed to publishers a technology that exploits the automatic gain control 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 (WD External HDD ---Elements SE(750GB/1TB) .

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 (WD External HDD --- Elements desktop(500GB/640GB) .

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 had become a popular mainstream hobby, and several music publishers responded by starting to sell some CDs with various copy protection schemes (WD External HDD --- Elements desktop(750GB/1TB) .

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 (WD External HDD --- Elements desktop(1.5 TB/2TB)

(which is effective since copy-protection software is generally written for Microsoft Windows), which has led critics to question the usefulness of such schemes.

CD copy protection is achieved by assuming certain feature levels in the drives (WD External HDD ---passport essential SE (750GB/1TB)--USB 3.0) :

The CD Digital Audio is the oldest CD standard and forms the basic feature set beyond which dedicated audio players need no knowledge. CD-ROM drives additionally need to support mixed mode CDs (combined audio and data tracks) and multi-session CDs (multiple data recordings each superseding and incorporating data of the previous session) (WD External HDD ---passport essential (500GB/640GB) .

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 (WD External HDD ---passport for Mac(320GB/500GB) .

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 (WD External HDD ---passport for Mac(640GB/1TB) .

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 (WD External HDD ---My book essential 4 generation(640GB/1TB) .

Some car radios with CD playback, portable CD players, CD players with additional support for data CDs containing MP3 files, and DVD players have had problems with these CDs.

The deviation from the Red Book 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 (WD External HDD ---My book essential 4 generation( 1.5TB/2TB) .

The logo is a trademark owned by Philips and Sony 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 WD External HDD ---My book elite( 1TB/1.5TB) .

In general the audio can always be extracted by applying the principle of the analog hole. Additionally, such programs as IsoBuster may be capable of producing hidden audio files.

Examples of CD copy protection schemes are Cactus Data Shield, Copy Control, and Data Position Measurement WD External HDD ---My book studio(1TB/2TB) .

Copy protection in recent digital media

More recently, publishers of music and films in digital form have turned to encryption 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 WD External HDD ---My book essential 4 generation( 1.5TB/2TB) .

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 of "authorized" players, which allow only "legitimate" uses of the work (usually restricted forms of playback, but no conversion or modification) WD External HDD ---My book elite(640GB/2TB) .

The controversial Digital Millennium Copyright Act 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 Seagate External HDD ---expansion portable (320GB/500GB) .

However, encryption schemes designed for mass-market standardized media such as DVD suffer from the fundamental weakness that once implemented, they can never be changed without breaking the standard. Since consumers are highly unlikely to buy new hardware for the sole purpose of preserving copy protection Seagate External HDD ---expansion portable (750GB/1TB) ,

manufacturers have been prevented from enhancing their DRM technology until recently, with the release of next-generation media such as HD DVD and Blu-ray Disc. This period represents more than enough time for the encryption scheme to be defeated by determined attackers Seagate External HDD ---expansion (1.5TB/2TB) .

For example, the CSS encryption system used on DVD Video was broken within three years of its market release in November 1996 (see DeCSS), 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 Seagate External HDD ---Freeagent Desktop (500GB/1TB)

this would not only provoke a furious backlash amongst consumers, but massively restrict the market that the new DVDs could be sold to. More recent DVDs have attempted to augment CSS with additional protection schemes Seagate External HDD ---Freeagent Desk (1.5TB/2TB) .

Most modern schemes likeARccOS Protection use tricks of the DVD format in an attempt to trip up 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 Seagate External HDD ---Freeagent Go(250GB/320GB) .

The newest generations of optical disc media, HD DVD and Blu-ray Disc, attempt to address this issue. Both formats employ the Advanced Access Content System, 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 Seagate External HDD ---Freeagent Go(500GB/640GB) .

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 ethernetport, to give them the ability to download DRM updates Seagate External HDD ---Freeagent Go(750GB/1TB) .

Blu-ray Disc goes one step further with a separate technique called BD+, 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 Seagate External HDD ---Freeagent Goflex(250GB/320GB) .

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 Seagate External HDD ---Freeagent Goflex(500GB/640GB) .

  • While the copy protection in Zak McKracken and the Alien Mindbenders wasn't 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 Seagate External HDD ---Freeagent Goflex Pro(500GB/750GB) .
  • In case of copied versions of Settlers 3, the iron smelters - who are essential to create weapons - would only produce pig irons, making the players inevitably lose weapons because of the lack ofarmour .
  • Bohemia Interactive Studio developed a unique and very subtle protection system for its game Operation Flashpoint: Cold War Crisis Seagate External HDD ---Freeagent Goflex desktop(1TB/2TB) .

Dubbed FADE, 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 Seagate External HDD ---Freeagent go for Mac(320GB/640GB) .

FADE is also used in ArmA II.

  • More recently, Batman: Arkham Asylum 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 Samsung External HDD --G2 protable (250gb/320GB) .
  • The PC version of Grand Theft Auto IV 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 Samsung External HDD --G2 protable (500GB/640GB) .
  • Earthbound has an interesting anti-copying system. 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, the game will freeze and delete all the save files right before the final boss battle Samsung External HDD --S2 protable (160GB/250GB) .
  • In an unauthorized version of the PC edition of Mass Effect, 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 Samsung External HDD --S2 protable (320GB/500GB) .
  • If an unauthorized version of The Sims 2 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 Samsung External HDD --S1 Mini (120GB/160GB) .

Data masking is the process of obscuring (masking) specific data elements within data stores. It ensures that sensitive data is replaced with realistic but not real data. The goal is that sensitive customer information is not available outside of the authorized environment Samsung External HDD --S1 Mini (250GB/320GB) .

Data masking is typically done while provisioning non-production environments so that copies created to support test and development processes are not exposing sensitive information and thus avoiding risks of leaking. Masking algorithms are designed to be repeatable so referential integrity is maintained Samsung External HDD --story station (1TB/1.5TB) .

Common business applications require constant patch and upgrade cycles and require that 6-8 copies of the application and data be made for testing. While organizations typically have strict controls on production systems, data security in non-production instances is often left up to trusting the employee, with potentially disastrous results Samsung External HDD --Story station (1.5TB/2TB) .

Creating test and development copies in an automated process reduces the exposure of sensitive data. Database layout often changes, it is useful to maintain a list of sensitive columns in a without rewriting application code. Data masking is an effective strategy in reducing the risk of data exposure from inside and outside of an organization and should be considered a best practice for curing non-production databases Samsung External HDD ---story station Esata(1TB/1.5TB) .


Effective data masking requires data to be altered in a way that the actual values cannot be determined or reengineered, functional appearance is maintained, so effective testing is possible. Data can be encrypted and decrypted, relational integrity is maintained, security polices can be established and separation of duties between security and administration established Samsung External HDD --G3 station (1TB/1.5TB) .

Common methods of data masking includes: encryption/decryption, shuffling, masking (i.e. numbers letters), substitution (i.e. All female names = Julie), nulling (####) or shuffling (zip code12345 = 53412).

Data Masking Techniques


The Substitution technique replaces the existing data with random values from a pre-prepared dataset Maxtor External HDD --one touch 4 mini (250GB/320GB) .


The Shuffling technique uses the existing data as its own substitution dataset and moves the values between rows in such a way that the no values are present in their original rows Maxtor External HDD --one touch 4 plus (500GB/750GB) .

Number and Date Variance

The Number and Date Variance technique varies the existing values in a specified range in order to obfuscate them. For example, birth date values could be changed within a range of +/- 60 days Maxtor External HDD --one touch 4 plus (1TB/1.5TB) .


The Encryption technique algorythmically scrambles the data. This usually does not leave the data looking realistic and can sometimes make the data larger Maxtor External HDD --black diamond (320GB/500GB) .

Nulling Out Or Deletion

The Nulling Out technique simply removes the sensitive data by deleting it.

Masking Out

The Masking Out technique sanitizes the data by replacing certain specified characters with mask characters. For example, a credit card number might be masked as 4929 1344 XXXX XXXX Maxtor External HDD --cool black(640GB/1TB) .

Row-Internal Synchronization

If a row in a database table contains denormalized data derived from other columns in that row and those columns are masked then the denormalized data row will need to be rebuilt. This technique is called Row-Internal Synchronization Maxtor External HDD --Black diamond (320GB/500GB) .

Table-Internal Synchronization

If a database table contains multiple rows containing identical columns and those columns are masked then the denormalized data rows will need to be set to the same value. This technique is called Table-Internal Synchronization Hitachi External HDD --simple touch (250GB/320GB) .

Table-To-Table Synchronization

If two tables contain the columns with the same denormalized data values and those columns are masked in one table then the second table will need to be updated with the changes. This technique is called Table-To-Table Synchronization Hitachi External HDD --simple touch (320GB/500GB) .

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