Cheating Prevention in Multi-Player Online Games (Dissertation Sample)

Cheating prevention in multi-player online games
Introduction
Yan describes cheating as any behavior in which a player is involved to gain advantage in an online game, if according to the rules of the game the advantage taken is unfair to his fellow peers.
In most of the multiplayer online games, cheating is reportedly rampant though difficult to make a measurement of this. Players, sometimes at a price to pay, get to the Internet and other "darknets" to obtain methodologies which are requisite for cheating in multiplayer online games.
Traditionally, gaming developers put cheats in the game code to reward players in the computer games. As the game was running, one could activate the cheats by pressing and entering a special code. Some of the privileges given to the players included rising a player’s statistics to give stronger impression, being issued unlimited lives or going up some levels.
Causing "grief" to other players is one of the reasons why some players will cheat. "Griefers" is the name given to such type of villain players. Harassing other players as they play the game is their only purpose. Some claim that they do so in order to make the game a bit more interesting as they proceed to complete the game. This seems to be done just to cause misery to other players. Some of this behavior is facilitated by the game rules such as the use of the online chart platform although some players use other means such as use of cheating exploits to steal virtual items of another player.
Cheats implementation
Information security and game rules enforcing are the server’s responsibility in a client server multiplayer model. Clients will run equal codes in the peer to peer game model, though they are still susceptible to almost all of the cheat types found in the client server model. The peer to peer model has also depreciated in favor of the client server model as high speed networks are being adopted everywhere.
Game developers as well as other types of developers are adopting the maxim of "Never trust client" and influences the design of the client server game model. This means that if by any means information is sent from a client breaks the rules or mechanics of the game, then the server doesn’t accept that information and also, unless information is requisite and fair for the game, no information should be sent to the client. As an example, all information about clients will be synchronized to all of the clients if a server does not check data integrity and enforce rules. Though the server can be very fast, a wall hack program will get to show where all the players are, what state they are in reference to ammo, weapons, health etc and which team they are on in the game.
Also, erroneous and altered data from a client will allow a player to manipulate the server, manipulate clients and break rules of the game. (Baughman, 2001)
Modification of game code
Despite there being End User License Agreements which forbid modification, most of the cheats are implemented through modification of game code. Although game software are distributed in binary only versions which make it harder for code modification, reverse engineering has made it possible. Also, editing of game data files can be done separately from the main program hence game software forced to implement circumvent protection.
Map hacks and wall hacks will often perform through modification of software. An analysis and change in memory of the game’s state can be done with some of these cheats which includes giving infinite health and ammo. Also, a software used legitimately outside gaming can perform the role of a cheat when used in a game. Auto clickers and program accelerators are examples of these.
Modification of system software
Some cheats will modify underlying system components rather than game code modification in which a 3rd party protection system or even the game itself can detect. A good example of this is a primitive wall hack that modifies the graphics driver to ignore checking of depth and draw all objects to the screen. From one user to another, there are a large number of system drivers that are different making it a bit difficult to detect driver or system modification.
Data manipulation and tampering
Tampering and/or manipulation of data can circumvent the security of a game’s software in real time while it is on transit from the server to the client or vice versa. As an example, wall hacks can cause interception resulting in active manipulation or also be passive in the case of Ghosting as an example. Via an external communication proxy or the client machine itself, a player can employ the above methodology. Aim bots are other examples of cheats which can perform the above methodology. (Gautier, 1999)
Anti-cheating methods
Many facets of cheating in multiplayer online games make the creating of a system to deal with cheating a bit difficult. However, cheating preventing technologies have been created and are continuously developed by game developers and affiliate software developers. Popular games like World of Warcraft, Quake and Team Fortress 2 have employed such counter measures with working anti cheat software such as Valve Anti-Cheat, GameGuard and PunkBuster.
A patch to the game can get rid of bug exploits, although not all firm’s force updates or patches on the users, leaving the job to the individual users.
Checksums
Client data file checksums are among the common methodologies to prevent cheating. An example is the MD5 sum calculated on the client computer against the game data file, and such type of checksums should be reported to the server before a client can join the game. The calculated checksum will be affected by the changes resulting from a cheater modifying a data file to gain advantage over others and subsequently lead to automatic denial of the client to join the server as an unknown checksum is detected. A game server can automatically ban someone attempting to cheat by use of a downloaded cheating package from the net, if a certain hacked data file checksum is detected by the server during connection.
A data file is held in a "file open" state after the data file has been checked to ensure that no other software can copy or rename a checked file in the multitasking system as the current game progresses. These files are closed once the game ends, till the next check in.
Someone who is attempting to cheat and who has downloaded a cheating package from the Internet may possibly be automatically banned by game servers, if certain well-known hacked datafile checksums are detected by the server during the connection attempt.
A data file is held in a "file open" state once it has been checked in order to prevent renaming or copying of the file afterwards on the multitasking system as the game continues. Until the next check in the files are closed when the gaming session ends. This however only works on file lock enforcing systems. Disabling of the file locking could be done via modification of the system’s libraries without this being noticed within the program. Client’s substitution of the calculated checksum with the original data checksum is another problem arising with this approach. (Dunnigan, 2004)
Custom built data file storage
Storing game data in a private custom built datafile format is another way in which game developers prevent hacking with their ability to strip directory structures and file names but does not otherwise encrypt data. Two files are visible with this approach, one large file of several gigabyte’ size containing data for all sounds, maps, textures, objects, etc. The second file with a mere megabytes’ size contains the datafile and directory structure of the game to facilitate data access to the larger file.
These data structures are sometimes studied by hackers to be able to write unpackers that convert the database into an easily editable datafile and directory structure...