System and method of controlling access to content using an accessibility API

Disclosed are system and methods for controlling access to content from a user application executing in an isolated environment on a user device. An exemplary method includes intercepting, by a security application, data relating to content in a graphical user interface of the user application using an accessibility application programming interface (API) exposed by an operating system of the user device, and generating a first template associated with the content based on the intercepted data. The template specifies a pattern of elements of the graphical user interface. The method further includes determining a category of the content based on a comparison of the first template with a plurality of previously generated templates; and controlling access to the content of the graphical user interface based on the determined category.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims benefit of priority under 35 U.S.C. 119(a)-(d) to a Russian Application No. 2017109812 filed on Mar. 24, 2017, which is incorporated by reference herein.

FIELD OF TECHNOLOGY

The present disclosure relates generally to the field of computer security, more specifically, to systems and methods of controlling access to content based on templates generated using an accessibility application programming interface (API).

BACKGROUND

In some operating systems (OS), notably in mobile OSs such as Android, in order to ensure security when executing user applications, the operating system organizes an isolated execution environment code (hereinafter, isolated environment) known as a “sandbox”. The isolated environment usually constitutes a controllable set of software and hardware resources accessible to the application for its execution, such as space on the disk or in the memory, the number of processor cores which can be used, and so forth. Moreover, the isolated environment usually either partly emulates the execution of system functions—for example, access to a network (local area or Internet), OS functions, or reading information from data entry devices—or greatly restricts the possibility of their execution—. Applications running in such an isolated environment are not able to read much less write into regions of the RAM of the computing device (e.g., mobile device) which are accessible to or allocated to other applications.

In order to call system functions, a third-party user application needs to request and receive additional authorization. Usually, such authorizations are granted by the user either when installing an application (e.g., in earlier versions of the Android OS) or during the launching or execution of the application (e.g., in later versions of the Android OS and in other OS). Example of such authorizations include: permission to work with text messages (e.g., SMS/MMS messages), permission to access a user's contacts, and permissions to access network services. The volume of actions which an application can perform outside the isolated environment with the help of authorizations is likewise limited. The authorizations themselves are usually of various kinds: those which can be granted to all applications and those which are granted only to a limited group of applications, for example, only the applications constituting the firmware of the computing device or only the applications considered first-party by the OS.

A security application can also be considered a third-party application in this sense and thus limited in its rights within the isolated environment and those additional authorizations granted to it by the user. Therefore, difficulties arise when the security application attempts to analyze data obtained by other foreign applications (for example, from the Internet), since this data cannot be obtained and analyzed by the security application. There are no authorizations for reading the data of other applications in the list of authorizations provided to third-party applications by the operating system, since such authorizations are contrary to the approach of using an isolated environment.

Despite the relative protection of mobile devices against malicious applications (due to the above-described closed nature achieved with the aid of the isolated environment), problems of filtering out unwanted data content obtained by applications on mobile devices are rather serious. For example, parents may want to guard their children against undesirable links, obscene language, and other undesirable information; users may want to guard themselves against phishing, intrusive advertising, and so on; and companies may want their workers to use mobile devices only for business purposes.

Known security system are ineffective because they do not have the ability to receive and process data and content obtained by applications working in isolated environments. Therefore, there is a need to improve a mechanism for a security application to control access to content by user applications executing in an isolated environment on a mobile device.

SUMMARY

The operating systems of modern mobile devices often have subsystems which facilitate the ability for people with disabilities to work with the device. In a number of cases, such subsystems have application programming interfaces (API) which allow outside developers to create applications providing such people with alternative methods of perceiving information (voice reading of screen text, data output to an external device supporting the Braille alphabet, and so forth).

The described system and methods provide a security application that uses this accessibility API to intercept data about content being displayed by another user application, which would be otherwise difficult or impossible to obtain due to the use of isolated environments. The security application generates templates based on the intercepted data, and uses the template to classify the content on the user application as one or more categories of content. The security application may then control access based on the categories of content, for example, by restricting access or blocking display of the content by the user application.

As such, the proposed method makes it possible to identify the category of data received by applications on mobile devices with the use of the application programming interface for users with disabilities. The described technique may advantageously success in scenarios in which the conventional techniques cannot produce information which clearly identifies the content. For example, if a user has received a message in a messenger application (such as WhatsApp®) that contains a direct link to an image in a social network (such as Instagram®) and has opened the link, the content visible to the user and accessible to the functions of that interface might not contain the name of the application, the name of the user profile, or the name of the material.

In one exemplary aspect, a method is provided for controlling access to content from a user application executing in an isolated environment on a user device. The method includes intercepting, by a security application, data relating to content in a graphical user interface of the user application using an accessibility application programming interface (API) exposed by an operating system of the user device, and generating a first template associated with the content based on the intercepted data. The template specifies a pattern of elements of the graphical user interface. The method further includes determining a category of the content based on a comparison of the first template with a plurality of previously generated templates; and controlling access to the content of the graphical user interface based on the determined category.

According to another exemplary aspect, the first template specifies at least one of a relationship, a type, and one or more properties of one or more elements of the graphical user interface of the user application.

According to another exemplary aspect, the step of determining the category of the content based on the comparison of the first template with a plurality of previously generated templates further includes: determining the category of the content as undesirable based on comparison results that indicated the first template is similar to at least one of the previously generated templates whose category has been previously identified as undesirable.

According to another exemplary aspect, at least one of the previously generated templates is associated with a weighting factor.

According to another exemplary aspect, the plurality of previously generated templates are associated with specific versions of the user application, and wherein comparison of the first template with the previously generated templates is performed based on a version of the user application.

According to another exemplary aspect, the determined category of the content specifies a type of the user application in which the content is being displayed, and a type of the content.

According to another exemplary aspect, the method further includes registering, with the operating system, the security application as an accessibility service, wherein the security application is configured to support the accessibility API.

In one further exemplary aspect, a system is provided for controlling access to content from a user application executing in an isolated environment. In this aspect, the system includes a display device configured to render a graphical user interface of the user application, and a processor. The processor is configured to intercept, by a security application, data relating to content in the graphical user interface using an accessibility application programming interface (API) exposed by an operating system of the user device, and generate a first template associated with the content based on the intercepted data. The template specifies a pattern of elements of the graphical user interface. The processor is further configured to determine a category of the content based on a comparison of the first template with a plurality of previously generated templates, and control access to the content of the graphical user interface based on the determined category.

According to another exemplary aspect, a computer-readable medium is provided comprising instructions that comprises computer executable instructions for performing any of the methods disclosed herein.

DETAILED DESCRIPTION

FIG. 1illustrates a block diagram a system for controlling access to content by a user application running in an isolated environment using an accessibility application programming interface (API), according to an exemplary aspect. The system may be deployed on a user device100, such as a desktop computer or a mobile device (e.g., a laptop computer, tablet, smart phone or other portable computing device). The terms “user device” and “mobile device” will be used interchangeably herein. A schematic diagram of an exemplary aspect of a user device100will be described later with reference toFIG. 4.

The user device100may execute one or more user applications150(e.g., Internet browser, text processing application, etc.). Each user application150may be configured to generate, load, and display a graphical user interface on the user device100for interfacing with the user application150. The graphical user interface may contain content152for consumption and/or interaction with the user. Content152of a user application may include any combination of text data, audio data, video data, and any other types of multimedia, and may be provided in a variety of formats, including web pages, web applications, mobile applications, image files (e.g., static and animated GIFs), video files, sound files, streaming video and sound files, and so forth.

In order to protect the user from possible malicious applications, an operating system102of the user device100may be configured to create an isolated environment106, such as a sandbox, for executing each user application150, for example, at the time of launching of the user application150. During their execution in the isolated environment106, the user applications150may try to access various data from files, user input or the Internet, and access various OS services and system resources, or even to other user applications150. The isolated environment106may be configured to restrict data access rights of the user applications150as well as to place limitations on the access to various OS services and system resources.

The system for identifying categories of data on mobile devices with use of an accessibility API designed for developing applications for users with disabilities is part of a security application140(such as an antivirus application) and includes an interception module110and a categorization module120. As used herein, an accessibility API is a set of functions exposed by an operating system and designed for the creation of applications suitable for users with limited abilities. Applications that support an accessibility API are configured to expose information relating to the user interface of the application including both control elements and data contained in the application so as to allow programmatic access (via the accessibility API) by an accessibility application. An accessibility application is an application that provides user interface enhancements to assist users with limited abilities, for example, a screen reader application.

The security application140is configured as an accessibility service supporting the accessibility API104exposed by an operating system102. For example, the security application140contains a configuration that declares itself to the operating system102as an accessibility service. The security application140is configured to handle one or more types of accessibility events generated by the operating system102, as described in greater detail below. In one exemplary aspect, the user is asked to install the security application140as a system service of the operating system102on the mobile device for users with limited abilities (i.e., accessibility service). For this, for example in the Android OS versions 7.x and earlier, a user might open the Accessibility system settings tab and select the security application140as one of the providers of this service.

The interception module110is configured to intercept content152pertaining to an application150with which the user is interacting that is being loaded and presented on the display of the mobile device. In the general case, the content represents data which contains elements of the graphic user interface (GUI). The content data represents a file of given format, such as a web page. In one exemplary aspect, the content is loaded by the application from the internal memory of the mobile device. In another exemplary aspect, the content is loaded by the application from the Internet. It should be noted that the user interacts with the application150to view the content152and enter data by means of navigation buttons and/or the touch screen of the mobile device, for example. The application150makes use of graphic interface elements which determine the external appearance of the interface of the application150. Often applications150make use of so-called “themes” containing styles and formatting of the graphic application elements. Moreover, applications150often contain mechanisms for adapting the output of content onto the display of the mobile device, for example depending on the resolution of the display of the mobile device, the orientation of the display of the mobile device (portrait or landscape), and the version of the operating system102under whose control the mobile device is working.

After intercepting the content152pertaining to the application150with which the user is interacting that is being loaded and presented on the display of the mobile device, the interception module110is configured to generate a template of this content. In one exemplary aspect, the template contains a relationship180, a type185, and one or more properties190of the elements of the graphical user interface. In some exemplary aspects, a relationship180associated with an element in the GUI may specify a positional relationship to another element in the GUI based on a graphical distance to the other element. For example, the relationship180may specify one or more graphical coordinates providing an absolute position of the element within the GUI, or graphical coordinates providing a relative position of the element relative to the other element. In some exemplary aspects, the relationship180associated with the element in the GUI may specify a hierarchical relationship to another element in the GUI based on a node hierarchy between elements in the GUI, for example, a child-parent relationship derived from the document object model of HTML elements in a web page. In one exemplary aspect, the type185of an element of the GUI may specify one particular type of content displayed by that element, such as text, images, video. An exemplary template is described in greater detail inFIG. 2.

FIG. 2illustrates a block diagram depicting data related to elements of a graphic user interface intercepted by a security application, according to an exemplary aspect. In one exemplary aspect, the interception module110generates a template specifying a pattern of elements in a graphical user interface based on data intercepted using the accessibility API104. In one exemplary aspect, the intercepted data may be contained in a tree data structure containing node and window information related to the elements in a graphical user interface, although it is understood that other formats and implementations may be used. For sake of illustration,FIG. 2depicts an example tree data structure for a GUI as rendered by a software development inspector application, and annotated with parts of the template.

Using the example of a digital media store application (e.g., Google Play™) application, each content being loaded and presented on the display of the mobile device (hereinafter, a page) has its own structure of elements. There is a page containing a menu and there are pages with elements (books, applications, films). In subsequent navigation, the user can switch to the description of an individual element being presented in digital media store application, and then go to the section of user comments showing their evaluations. In this example, the interception module110identifies the structure of the elements of each page (the content being loaded and shown on the display of the mobile device) where the user ends up in the course of the navigation through the application150. The structure represents a sequence of elements—buttons, text fields, scrollbars, view areas, frames. In one exemplary aspect, the structure contains the presence of sequences of elements or groups of elements (tables, lists). Next, the interception module110identifies (i.e., read) the values and properties of the elements, such as text strings from text fields, colors, font sizes, frames, buttons, checkboxes.

Taking the above into account, the interception module110generates a template based on the content152, the template containing the relationship180, the type185, and the properties190of the elements of the graphic user interface. For example, the template may specify that one particular element has a type185for displaying text (e.g., TextView). The template may further specify the text element has parent-child relationship185with one or more elements, for example, a layout container element identified as a “Badges bar.” The template may specify one or more additional node properties190associated with the text element, for example, the text it contains (e.g., “Simulation”), a resource identifier, class and package information, and control element state information (e.g., not checked, not checkable). In another example, an element of type185“com.android.checkbox” has the property190“checked” with the value “false” and a relationship185relative to the element of type “com.android.button” which is arranged 50 pixels above and 30 pixels to the right.

Referring back toFIG. 1, the interception module110is configured to provide the generated template to the categorization module120. It should be noted that in one exemplary aspect the categorization module120is a module (part) of the security application140. In another exemplary aspect, the categorization module120is implemented on a remote server or as a cloud service.

In one exemplary aspect, the categorization module120is configured to maintain a set of templates previously created on the basis of the content whose categories have been identified.

In the context of the present disclosure, the category of a content is a set of properties containing at least the type of application150during the navigation of which the content has been loaded and displayed, and the type of the content itself. As described earlier, the type of the application150can be a web browser, a messenger, a social network application, applications for distribution of media content (Google Play, Samsung Apps™), applications for viewing video streams from the Internet, applications for viewing video broadcasts from the Internet, multimedia players, and so forth. In some exemplary aspects, the type of the content can include the entire screen of an application, the comment section, the message exchange section, a content section typical of the particular application (description of video material on YouTube®, description of an application in Google Play, description of a film in an online movie theater), and so forth.

In one exemplary aspect, the set of templates of content whose category has been previously identified is stored in a database160or other storage module or device. In one exemplary aspect, the set of templates is generated with the use of the accessibility API for known applications, known types of applications and known types of content.

It should be noted that the template may (or may not) depend on the version of the application in which the content was downloaded and displayed (with the release of a new application version, the structure of the elements of the graphic interface and the template as a whole may change), and therefore in one exemplary aspect, the database160stores records about versions of applications and their corresponding templates. Thus, for example, if the database160contains a template of a particular web browser application (e.g., Google Chrome™) version 9.12, the categorization module120can clearly determine from this template the web browser application of the corresponding version. However, with the release of version 9.13, the web browser application in some cases (for example, if a control element has been added, if the external appearance of a window or font style has been changed) will no longer be clearly determined from the template by the categorization module120. Nevertheless, the categorization module120will assign the web browser application version 9.13 to the browser type.

In one exemplary aspect, the templates can have at least one weighting factor (for example, the popularity of known applications or the popularity of content within an application, such as the popularity of a video on YouTube) in order to speed up the determination of categories by the categorization module120. In this case, the categorization module120selects templates from the database160in accordance with the weighting factors. Thus, for example, user applications150from a digital media store or platform marketplace may have popularity ratings, such as most downloaded, most highly-rated, etc. In accordance with the mentioned ratings, the database160for templates may store weighting factors of popularity. The categorization module120selects N (e.g., 1000) templates of the most popular applications and compares them to the generated template obtained from the interception module110. In another example, it is possible to select M each (such as 10) of the most popular templates of the most popular types of applications. For example, the categorization module120may compare 10 of the most popular templates of message exchange programs (e.g., or top 10 templates of browsers, or top 100 templates of games) to the generated template obtained from the interception module110.

Furthermore, the categorization module120uses a set of comparison rules against which the template received from the interception module110is compared to templates whose categories have been identified. In some exemplary aspects, the rules can be trusted or deterministic, i.e., clearly identifying the content. In another exemplary aspect, the rules can be probabilistic, i.e., identifying the content with a probability, making use of methods for identifying the degree of similarity of templates known in the prior art. The rules in turn may be determined for individual templates or for groups of templates.

In one exemplary aspect, with the use of the rules the categorization module120identifies not only the type of application, but also the application itself (such as its name and version). In the general case, the comparison rules are kept in the database160.

Furthermore, in one exemplary aspect, the categorization module120selects a set of unsafe or undesirable categories reflecting the presence of information in the content which may be undesirable for various groups of users. Such information may include sexual content with age restrictions, alcohol, tobacco, narcotics, violence, profanity, weapons, and other objectionable content.

As an example, let us consider the above-described digital media store application (e.g., Google Play). The content of this application might have been analyzed previously by methods known in the prior art. For example, the pages of applications (or books) presented for installation have been analyzed. For the pages of popular applications of each type in the digital media store application, templates have been created, and categories, determined. The categorization module120compares the template obtained from the interception module110with the mentioned most popular templates. As a result of the comparison, it is found that the user wants to download, from the digital media store application, an application which is distributing or advertising sexual content. As a result, steps may be taken preventing the application from getting onto the mobile device of the user. For example, the security application140may block the downloading and installing of an application.

Another example of the determining of a category is the situation which occurs when communicating with an unknown contact through a messenger application (e.g., “WhatsApp®”). The categorization module120can determine from the template received from the interception module110that the user is communicating through the messenger application with an unknown number. The messenger application itself can be identified with a high degree of probability from the style (format) of the chat window. However, the telephone number (displayed at the top in place of the contact name) will be present in the template. This element clearly indicates that the number is not among the user's contacts, and so the communication is occurring with an unknown party. Such a communication may be blocked afterwards, since such contacts are categorized as unsafe or undesirable, for example in the context of parental control for children using a mobile device.

FIG. 3illustrates a flowchart for a method300for identifying categories of data using an accessibility API, according to an exemplary aspect.

The method300begins at step302, in which the security application140, which includes at least the interception module110, registers as a system service for users with limited abilities of the operating system on the mobile device. In one exemplary aspect, the security application140also includes the categorization module120. In another exemplary aspect, the categorization module120is implemented on a remote server or as a cloud service.

In step304, the interception module110intercepts data relating to content in a graphical user interface of an user application using an accessibility API exposed by the operating system of the user device. For example, the interception module110using the application programming interface designed for creating of applications for users with disabilities is used to intercept content being downloaded and presented on the display of the mobile device relating to an application with which the user is interacting. The content may represent data which contains elements of a graphic user interface. In one exemplary aspect, the content is downloaded by the application from the internal memory of the mobile device. In another variant embodiment, the content is downloaded by the application from the Internet.

In one exemplary aspect, the interception module110may use one or more event handlers of the security application140registered with the accessibility API104to intercept various types of events generated during execution of the user applications150, such as: pressing/holding down of an element of the graphic user interface (GUI) of the user application150; shifting of focus to another element of the GUI of the user application150; selecting of an object in an element of the GUI containing a list of objects (such as changing a selected element in ListBox or RadioButtonGroup); changing of text in an element of the GUI of the user application150; displaying a window (main or dialog window) of the user application150on the screen of the user device100.

In step306the interception module110generates a template of the mentioned content based on the intercepted data. The template specifies a pattern of elements of the graphical user interface. The template contains the relationship180, the type185and the properties190of the elements of the graphic user interface. For example, in cases where the intercepted data is formatted as a tree data structure, the interception module110may iteratively walk through the nodes in the tree data structure, read each node, and create the template based on the properties observed in the nodes.

For example, the interception module110may generate one or more templates of content from a photo-sharing application (e.g., Instagram®) executing on the user device. The interception module110may generate a first template corresponding to content from a “newsfeed” view of the photo-sharing application, which includes a continuous listing of other users' recent photos and videos. If the user clicks or taps on a picture from the newsfeed view, the photo-sharing application renders and displays a detailed view of that picture. In response to this change in the GUI, which the accessibility API detects and triggers events for, the interception module110may generate a second template for content in the second, detailed view of the photo-sharing application. Say the user scrolls down the detailed view of the picture and moves to a comments section of the view. The interception module110may generate a third template for this section of the GUI. It is noted that if any or all of these templates for the photo-sharing application were previously generated, when the user then subsequently opens any page or view in the photo-sharing application, the interception module110can determine which previous template can be applied.

In step308the interception module110provides the generated template to the categorization module120. In cases where the categorization module120is implemented on a remote server or as a cloud service, the security application140transmits the generated template to the categorization module120over a network.

In step310the categorization module120determines a category of the content based on a comparison of the generated template with a plurality of previously generated templates. In one exemplary aspect, the categorization module120is used to compare the generated template with a set of templates previously formed with the use of the mentioned application programming interface of templates whose categories have been identified (e.g., as unsafe), and on the basis of the results of the comparison at least one category of the mentioned content is identified (e.g., as unsafe). In the context of the present disclosure, the category of the content is a set of properties containing at least the type of the application150during whose navigation the content was downloaded and displayed, and the type of the content itself.

In the general case, the set of templates of content whose categories have been previously identified is kept in the database160. In the context of the present disclosure, the set of templates is formed with the use of the application programming interface designed for creating of applications for users with limited abilities for known applications, known types of applications, and known types of content.

In one exemplary aspect, the templates can have a weighting factor to speed up the determination of the categories by the categorization module120. In this case, the categorization module120selects templates from the database in accordance with the weighting factors. Furthermore, the categorization module120uses a set of comparison rules by which the template received from the interception module110is compared to templates whose categories have been identified. In one aspect, the rules can be trusted (clearly identifying the content). In another aspect, the rules can be probable (identifying the content with a probability, making use of methods for identifying the degree of similarity of templates known in the prior art). The rules in turn may be determined for individual templates or for groups of templates. In the general case, the comparison rules are stored in the database160.

At step312, the security application140controls access to the content of the graphical user interface based on the determined category. For example, responsive to determining that content in the graphical user interface is classified as unsuitable for children, the security application140may block the user application from visiting undesirable links or displaying obscene language. In another example, responsive to determining that the content in the GUI is classified as unsafe, the security application140may flag the user application150for phishing or for intrusive advertising. In another example, responsive to determining that the content in the GUI is classified as non-business-related, the security application140may block a mobile device from installing a non-business related user application, or accessing non-business related websites. Other techniques for blocking access to content in a user application executing in an isolated environment are described in greater detail in a commonly owned U.S. Pat. No. 9,536,101, which is incorporated by reference herein.

FIG. 4is a diagram illustrating an example computer system on which aspects of systems and methods for controlling access to content in a user application using an accessibility API may be implemented in accordance with an exemplary aspect. As shown, the computer system20(which may be a personal computer or a server) includes a central processing unit21, a system memory22and a system bus23connecting the various system components, including the memory associated with the central processing unit21. As will be appreciated by those of ordinary skill in the art, the system bus23may comprise a bus memory or bus memory controller, a peripheral bus, and a local bus that is able to interact with any other bus architecture. The system memory may include permanent memory (ROM)24and random-access memory (RAM)25. The basic input/output system (BIOS)26may store the basic procedures for transfer of information between elements of the computer system20, such as those at the time of loading the operating system with the use of the ROM24.

The computer system20, may also comprise a hard disk27for reading and writing data, a magnetic disk drive28for reading and writing on removable magnetic disks29, and an optical drive30for reading and writing removable optical disks31, such as CD-ROM, DVD-ROM and other optical media. The hard disk27, the magnetic disk drive28, and the optical drive30are connected to the system bus23across the hard disk interface32, the magnetic disk interface33and the optical drive interface34, respectively. The drives and the corresponding computer information media are power-independent modules for storage of computer instructions, data structures, program modules and other data of the computer system20.

An exemplary aspect comprises a system that uses a hard disk27, a removable magnetic disk29and a removable optical disk31connected to the system bus23via the controller55. It will be understood by those of ordinary skill in the art that any type of media56that is able to store data in a form readable by a computer (solid state drives, flash memory cards, digital disks, random-access memory (RAM) and so on) may also be utilized.

The computer system20has a file system36, in which the operating system35, may be stored, as well as additional program applications37, other program modules38, and program data39. A user of the computer system20may enter commands and information using keyboard40, mouse42, or any other input device known to those of ordinary skill in the art, such as, but not limited to, a microphone, joystick, game controller, scanner, etc. Such input devices typically plug into the computer system20through a serial port46, which in turn is connected to the system bus, but those of ordinary skill in the art will appreciate that input devices may be also be connected in other ways, such as, without limitation, via a parallel port, a game port, or a universal serial bus (USB). A monitor47or other type of display device may also be connected to the system bus23across an interface, such as a video adapter48. In addition to the monitor47, the personal computer may be equipped with other peripheral output devices (not shown), such as loudspeakers, a printer, etc.

Computer system20may operate in a network environment, using a network connection to one or more remote computers49. The remote computer (or computers)49may be local computer workstations or servers comprising most or all of the aforementioned elements in describing the nature of a computer system20. Other devices may also be present in the computer network, such as, but not limited to, routers, network stations, peer devices or other network nodes.

Network connections can form a local-area computer network (LAN)50and a wide-area computer network (WAN). Such networks are used in corporate computer networks and internal company networks, and they generally have access to the Internet. In LAN or WAN networks, the personal computer20is connected to the local-area network50across a network adapter or network interface51. When networks are used, the computer system20may employ a modem54or other modules well known to those of ordinary skill in the art that enable communications with a wide-area computer network such as the Internet. The modem54, which may be an internal or external device, may be connected to the system bus23by a serial port46. It will be appreciated by those of ordinary skill in the art that said network connections are non-limiting examples of numerous well-understood ways of establishing a connection by one computer to another using communication modules.