Encyclopedia of Computer Science and Technology

118 CORBA“activation” or “validation,” as with Microsoft Windowsand Office products. The online validation process canforestall the use of valid but duplicated serial numbers(see digital rights management and software piracyand counterfeiting).Hackers and cyber-libertarians have often argued thatthe problem of software piracy has been overrated, andthat allowing the copying of software would enable morepeople who would not otherwise buy programs to try themout. Once someone likes the program, they might buy itnot only for legitimacy of ownership, but in order to getaccess to the technical support and regular upgrades thatare often required for complex business software packages.For less expensive software, an alternative channel (seeshareware) allows for a “try before you buy” distributionof software.Further ReadingAldrich, John. “Implementing Simple Copy Protection: TechnicalOverview.” Available online. URL: http://www.codeproject.com/win32/simplecopyprotection.asp?df=100&foru mid=4250&exp=0&select=878288. Accessed September 6, 2007.Gilmore, John. “What’s Wrong with Copy Protection.” February16, 2001. Available online. URL: http://www.toad.com/gnu/whatswrong.html. Accessed September 6, 2007.Wikipedia. “Copy Protection.” Available online. URL: http://en.wikipedia.org/wiki/Copy_protection. Accessed September6, 2007.CORBA (Common Object Request BrokerArchitecture)CORBA (Common Object Request Broker Architecture) is astandardized way to specify how different applications (onthe same or different machines) can call upon the servicesof database objects (see database and object-orientedprogramming). The CORBA standard is defined by theObject Management Group (OMG), a consortium of morethan 700 companies or organizations, including the majorplayers in distributed database technology.Structure and UsageCreating a CORBA application involves three basic steps.First, specifications are provided using an interface definitionlanguage (IDL) that specifies in generic terms whatservices an object will provide. An IDL compiler then createsa “skeleton” interface that the developer can fill in withactual code for a class for that object in a programming language(such as Java).To use CORBA, a client application accesses an ObjectRequest Broker (ORB), which is software that locates thereferenced object on the network (thus the program doesnot need to know or keep track of specific locations). TheORB sends the request to the object, which processes it andreturns the results, which are then sent back to the clientapplication.The intent of CORBA is to make objects implementedby different vendors fully interoperable (able to call oneanother using the same syntax). While CORBA 1.0 did notcompletely meet this goal, CORBA 2.0 explicitly providedfor a protocol called IIOP (Internet Inter-ORB Protocol)that, if adhered to, does make brokers (ORBs) and objectsinteroperable across vendors and programming languages.CORBA 3 adds a new CORBA Component Model (CCM)and specifications that, among other things, provide forbetter negotiation with firewalls, a problem that had madeCORBA hard to use in Web development.Corba ServicesIn addition to the interfaces defined for particular objects,CORBA provides a number of services that apply to allobjects. These services include creating, moving/copying,or removing objects; allowing more readable names forobjects; concurrency and transaction control; setting propertiesfor objects; and sending queries to objects.A competing framework for distributed object computingis COM/DCOM (Common Object Model/DistributedCommon Object Model, now supplanted by .NET (seeMicrosoft.net). A simpler (though possibly less secure)way to connect programs running on different machines isto use the Simple Object Access Protocol (see soap).Further ReadingBolton, Fintan. Pure CORBA. Indianapolis: Sams, 2001.“Introduction to CORBA” [Java implementation]. Availableonline. URL: http://java.sun.com/developer/onlineTraining/corba/corba.html. Accessed September 4, 2007.McHale, Ciaran. “CORBA Explained Simply, 2007.” Availableonline. URL: http://www.ciaranmchale.com/corba-explainedsimply/.Accessed September 4, 2007.counterterrorism and computersCounterterrorism is the effort to detect, identify, and neutralizeterrorist groups and prevent attacks. Not surprisingly,information technology plays a part in every phaseof this effort—and sometimes even becomes part of thebattlefield.Intelligence and SurveillanceThe Web and other Internet services are an important partof the battle against terrorism, not least because terroriststhemselves are beginning to use online tools effectively(see cyberterrorism). The Internet inherently allows forconsiderable anonymity (see anonymity and the Internet).However, any online activity leaves traces, howevervirtual, and surveillance, intelligence, and forensic techniquesare being adapted to this new medium (see computerforensics).By putting so much material online, terrorists are exposingthemselves to the increasingly sophisticated data miningand “semantic Web” tools that are being developed.These tools can, for example, identify material likely to beof interest (and summarize it) and even analyze the relationshipbetween individuals or groups based on their writingor verbal communications. Of course such results muststill be reviewed and acted upon by trained human analysts.Further, surveillance tools that are deployed too widely orindiscriminately are liable to raise privacy concerns.