Patent Publication Number: US-10311237-B2

Title: Mechanism to synchronize clients in a digital rights management environment

Description:
RELATED APPLICATIONS 
     This application claims priority to Application No. 61/671,634 entitled “Mechanism to Synchronize clients in a Digital Rights Management Environment” filed on Jul. 13, 2012 which is hereby incorporated by reference in its entirety. 
    
    
     FIELD 
     This disclosure relates generally to computer software and more particularly relates to the creation, modification, use, and distribution of electronic content. 
     BACKGROUND 
     A publisher publishes content that may be purchased by users on client devices for consumption. For example, the published content may include media content, electronic application content, and/or other types of content. Upon purchasing the content, the user may receive the content and an embedded electronic license to access the content based on the terms of the license. The electronic license may indicate that the user may access the content for a specified period of time upon which the user&#39;s license to access the content will terminate. Conventional techniques for enforcing the terms of the license involve using the system clock of the client device to determine whether license period has expired and/or whether to continue providing access to the content. However, the system clock of the client device may be compromised and may reflect an inaccurate time thereby allowing the user to continue accessing the content for a period of time that exceeds the terms of the license. 
     SUMMARY OF THE INVENTION 
     Disclosed are embodiments for receiving content for consumption on a client device, the content being associated with a license agreement defining a license period for consumption; determining whether the license period has expired based at least in part on a current time received from a server, the server being separate from the client device; and terminating access to the content based on a determination that the license period has expired. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       These and other features, aspects, and advantages of the present disclosure are better understood when the following Detailed Description is read with reference to the accompanying drawings, where: 
         FIG. 1  is a block diagram depicting exemplary computing devices in an exemplary computing environment for implementing certain embodiments; 
         FIG. 2  is a flow chart illustrating an exemplary method for a license executable for determining if a license period for consumption of content has expired; 
         FIG. 3  is a flow chart illustrating an exemplary method for a license executable for determining whether a license period for consumption of content has expired based on a start time interval; 
         FIG. 4  is a flow chart illustrating an exemplary method for a license executable for determining whether a license period for consumption of content has expired based on a stop time interval; and 
         FIG. 5  is a flow chart illustrating an exemplary method for a license executable for determining whether a license period for consumption content has expired based on probability information. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed are embodiments for a secured source that provides an uncompromised date and time to client devices with access to content associated with a license agreement. The uncompromised date and time may be used by a license executable embedded within the license associated with the content to determine whether a license period for consuming the content on the client device has expired. Users regularly purchase content, such as media, applications, and/or other content, for use on client devices. A publisher of the purchased content associates a license agreement that imposes terms for the consumption of the purchased content. For example, the terms may include a period of use, restrictions on a number of devices from which to consume the content, and/or other license terms for the consumption of the content. An accurate and uncompromised time is provided by a secured source, referred to as a “heartbeat” server, and is used to determine whether consumption of the content is within the period of use according to the license agreement. Determining whether the license period has expired based on the time from the heartbeat server may be more secure than relying on a local system clock of the client device which may be susceptible to modification and being compromised. The embodiments described herein provide for an approach for the publisher of the purchased content to determine the validity of a license for accessing the purchased content using a secured and uncompromised source without overloading the source. 
     In many instances, purchasers of the licensed content may circumvent the terms of the license agreement and consume the content outside of the terms of the license agreement. For example, the license agreement many dictate that the content be consumed up until an expiration time at which point access to the content may be terminated. Savvy purchasers may sometimes manipulate the system clock of the client device to compromise the expiration determination and continue to consume the content well beyond the licensed period. 
     To prevent the consumption of the licensed content outside of the terms of the license, whether use is with an expiration period may be determined based on a current time received from the secured source, i.e, a heartbeat server. The heartbeat server may provide an accurate and uncompromised current time from which a license executable associated with the content may determine whether the licensed period has expired. For example, the license executable may be embedded within the content that periodically computes whether the expiration period has expired based on a current time that is requested from the heartbeat server. 
     A publisher of licensed content may embed a license executable within the licensed content that executes on the client device to determine whether the consumption of the licensed content conforms to the terms of the license agreement. For instance the license executable may determine whether the license period for consuming the licensed content has expired based on a current time received from the heartbeat server. 
     Receipt of the current time from the heartbeat server can be controlled in various ways to prevent circumvention techniques and/or to avoid burdening communication networks and the heartbeat server. For example to avoid network congestion and heartbeat server overload, requests for current time can be sent only periodically. In one embodiment, the license executable may transmit a request to the heartbeat server if it has not done so for a given period of time. For example, it may transmit a request for the current time if the time period since the last receipt of the current time exceeds a period that corresponds to a start interval, i.e., an interval after which it starts requesting the current time from the heartbeat server. For example, the license executable may compare the time period since the last communication (e.g., 10 days since it last received the current time) with the start interval (e.g., specifying that a current time should be requested if not received in the last 7 days). If the time period since the last communication exceeds the time period corresponding to the start interval (e.g., 10 days exceeds 7 days), then the license executable transmits a request to the heartbeat server to again receive the current time. Upon receipt of the current time from the heartbeat server, the license executable determines whether the licensed period for consumption of the content has expired and if the period has expired, terminates access to the licensed period. 
     In the above example, receipt of the current time is based on requests that are sent or not sent based on locally-stored time. A user might try to continue unauthorized use of content by preventing the request for/receipt of the current time, for example, by manipulating the current time. Various techniques can be used to prevent such circumvention. In one embodiment, the license executable may terminate access to the licensed content if it has not heard from the heartbeat server for a given period of time. For example, it may terminate access if the time of last communication with the heartbeat server exceeds a period that corresponds to a stop interval, i.e., an interval after which it stops waiting for the current time from the heartbeat server and terminates access. For example, the technically savvy purchaser may have prevented communication with the heartbeat server by having terminated access to other devices over a network or by otherwise managing and controlling communication with other devices. For instance, the purchaser may operate the client device in “off-line” mode where there is no network connectivity for communication with any other devices over a network. Thus, no requests, such as a request to the heartbeat server, may be transmitted from the client device and the licensed content may be consumed beyond the terms of the license agreement for an indefinite period of time. A stop interval can be used to prevent such circumvention. For example, a license executable may determine if the time period since the last communication with the heartbeat server exceeds a time period that corresponds to the stop interval and, if so, terminate access to the licensed content. 
     Additional techniques may be used so that a user cannot prevent the request for/receipt of the current time by manipulating the locally stored time. In one embodiment, the license executable may transmit a request to the heartbeat server only occasionally but in a way that is not based on the locally-stored time. For example, determining a frequency for transmitting requests to the heartbeat server may be determined based on a probability function instead of the local clock. A test that determines when to send a request to the heartbeat server may use a probability function. For example, the test may be used so that a request for current time is sent only a percentage of the time that the executable considers sending a request. In some embodiments, the executable may consider sending a request each time the content is accessed but only send a request based on a result of the test. The test may be defined such that the test is passed or is not passed a particular percentage of the time, e.g., 10% of the time the test will pass resulting in a transmission of the request to the heartbeat server. For example, a probability function may be used to mathematically provide a result that can be compared with a threshold or range. As a particular example, the function may result in a value between 0 and 10 where the likelihood that the value will be less than 1 is 10%. To send requests only 10% of the time, the function is executed and a request is sent if the result is less than 1. In one embodiment, a random number generator may be used. The license executable may generate a random number and if the result is within a specified probability range, the license executable transmits a request to the heartbeat server to receive of the current time. 
     These illustrative examples are given to introduce the reader to the general subject matter discussed here and are not intended to limit the scope of the disclosed concepts. The following sections describe various additional embodiments and examples with reference to the drawings in which like numerals indicate like elements. 
       FIG. 1  depicts an exemplary computing environment for performing searches based on search criteria as described herein. The methods and systems disclosed herein are also applicable on other computing systems and environments. The environment shown in  FIG. 1  includes a wired or wireless network  109  connecting various devices  103 ,  104  and  106 . In one embodiment, the network  109  includes the Internet. In other embodiments, other networks, intranets, or combinations of networks may be used. Alternative configurations are possible. 
     As used herein, the term “device” refers to any computing or other electronic equipment that executes instructions and includes any type of processor-based equipment that operates an operating system or otherwise executes instructions. A device will typically include a processor that executes program instructions and may include external or internal components such as a mouse, a CD-ROM, DVD, a keyboard, a display, or other input or output equipment. Examples of devices are personal computers, digital assistants, personal digital assistants, cellular phones, mobile phones, smart phones, pagers, digital tablets, laptop computers, Internet appliances, other processor-based devices, and television viewing devices. Exemplary devices  103  and  106  are respectively used as special purpose computing devices to provide specific functionality offered by their respective applications and by the interaction between their applications. As an example, client device  106  is shown with a display  113  and various input/output devices  116 . A bus, such as bus  119 ,  120  and  123  will typically be included in a device as well. 
     As used herein, the term “application” or “service” refers to any program instructions or other functional components that execute on a device. An application or service may reside in the memory of a device that executes the application. As is known to one of skill in the art, such applications may be resident in any suitable computer-readable medium and execute on any suitable processor. For example, as shown the devices  103 ,  104  and  106  each have a computer-readable medium such as memory  126 ,  127  and  129  coupled to processors  133 ,  134  and  136  that execute computer-executable program instructions and/or accesses stored information. Such processors  133 ,  134  and  136  may comprise a microprocessor, an ASIC, a state machine, or other processor, and can be any of a number of computer processors. Such processors include, or may be in communication with, a computer-readable medium which stores instructions that, when executed by the processor, cause the processor to perform the steps described herein. 
     As used herein, the term “server” refers to an application that listens for or otherwise waits for requests or a device that provides one or more such applications that listens for or otherwise waits for requests. Heartbeat server device  103  and the publisher device are examples of a server. A “server device” may be used to provide an accurate and uncompromised current time from a trusted source. For example, the heartbeat server device  103  may include a time service  139  to provide the current time. 
     A computer-readable medium may include, but is not limited to, an electronic, optical, magnetic, or other storage device capable of providing a processor with computer-readable instructions. Other examples include, but are not limited to, a floppy disk, CD-ROM, DVD, magnetic disk, memory chip, ROM, RAM, an ASIC, a configured processor, optical storage, magnetic tape or other magnetic storage, or any other medium from which a computer processor can read instructions. The instructions may include processor-specific instructions generated by a compiler and/or an interpreter from code written in any suitable computer-programming language, including, for example, C, C++, C#, Visual Basic, Java, Python, Perl, JavaScript, and ActionScript. 
     In  FIG. 1 , the heartbeat server device  103  includes a memory  129  that includes the time service  139 . In one embodiment, the time service  139  receives a request from the client device  106  with access to the licensed content  149  and responds with a time stamp  143 . The time stamp  143  includes the current time as maintained by the heartbeat server device  103  that may be used by the client device  106  to determine whether to provide access to the licensed content  149 . For instance, the client device  106  may determine to terminate access to the licensed content  149  if the license period for consuming the content has expired. The client device  106  may use the time stamp  143  to determine whether the license period for consuming the licensed content  149  has expired. The publisher device  104  includes a memory  127  that includes content  140 . The publisher device  104  provides the content  140  to users on client devices  106  if the users agree to the terms included in a license agreement  141  associated with the content  140 . 
     The client device  106  includes a memory  126  that includes a client side application  146  and licensed content  149 . The licensed content  149  may be media content, software applications, documents, and/or any other type of electronic content that the user on the client device  106  has previously agreed to consume according to the terms of license agreement  141  associated with the content  140 . The licensed content  149  may include an embedded license with a Digital Rights Management (“DRM”) executable, i.e. a license executable  153 , which manages the terms for consumption of the licensed content  149 . In one embodiment, the license executable  153  is configured to manage the communication with the heartbeat server device  103  based on the terms of the license agreement  141 . The license executable  153  may define a consumption period for consuming the licensed content  149 , specific devices from which the licensed content  149  may be consumed, and/or any other terms related to the consumption of the licensed content  149 . Additionally, the license executable  153  includes a stop interval  156 , a start interval  159 , and probability function  163 . In one embodiment, the stop interval  156  indicates an amount of time that the client device  106  may operate without communicating with the heartbeat server device  103  to receive the time stamp  143 . The start interval  159  indicates an amount of time that the client device  106  may operate before a communication with the heartbeat server device  103  is initiated to receive the time stamp  143 . The probability function  163  represents a probability that the client device  106  has been in operation without communicating with the heartbeat server device  103  to receive the time stamp  143 . 
     The client side application  146  may be a browser that renders the licensed content  149  on the display  113 . In one embodiment, the client side application  143  renders the content  153  according to the terms of the license  149 . For example, a user operating the client device  106  may purchase access to licensed content  149 , such as a movie. The user may consume the licensed content  149  for a period of time as defined by the license  153 . For instance, the user may have access to the licensed content  149  to watch and/or otherwise consume the licensed content  149  for a period of time as defined by the license  153  embedded with the licensed content  149 . The client side application  146  may monitor the system clock  166  of the client device  106  to determine whether the licensed period has expired. Upon determining that the license period has expired, the client side application  149  terminates access to the content  153 . 
     As mentioned, the system clock  166  may be susceptible to modification by another application. For example, the system clock  166  may be manipulated to reflect an inaccurate time for circumventing one or more actions dependent on an accurate time. Since the system clock  146  may be used to determine whether the license period has expired, the client side application  146  may determine to continue providing access to the licensed content  149  even after the license period has expired because the compromised system clock  166  indicates an inaccurate time. To this end, the license executable  153  may periodically transmit a request to the time service  139  to receive the time stamp  143 . As discussed above, the time stamp  143  includes the current time and thus functions as a trusted and secure source of an accurate time. The license executable  153  may determine whether the license period has expired based on the trusted time included in the time stamp  143  received from the time service  139 . If the license executable  153  determines that the license period has expired, then the license executable  153  may terminate access to the licensed content  149 . 
     In some instances, outbound communications from the client device  106  may be monitored such that any communications to the heartbeat server device  103  or the like may be comprised. For example, the outbound communications may be blocked, rerouted, and/or otherwise compromised such that the client side application  146  fails to communication with the heartbeat server device  103 . In the event that the communications to the heartbeat device  103  are comprised, the license executable  153  may not receive the time stamp  143  from the heartbeat server device  103  and thus may not accurately determine whether the license period for consuming the licensed content  149  has expired. 
     To this end, the publisher of the licensed content  149  may configure the license executable  153  to be signed and protected such that it may not be compromised by another application or service. Any communications between the license executable  153  and the time service  139  may be secured. The license executable  153  is equipped with one or more of the stop interval  156 , the start interval  159 , and the probability function  163  in the license embedded into the licensed content  149 . The stop interval  156  indicates an amount of time that may pass without receiving the time stamp  143  from the time service  139 , as discussed above. The license executable  153  may detect that the amount of time since the last receipt of the time stamp  143  exceeds the stop interval  156  and terminate access to the content  153 . The value of the stop interval  156  may be established by the publisher of the licensed content  149 . For example, the value of the stop interval  149  may correspond to a maximum length of a license period. 
     The start interval  159  indicates an amount of time that may pass before forcing receipt of the time stamp  143  from the time service  139 , as discussed above. The license executable  153  may detect that the amount of time since the last receipt of the time stamp  143  exceeds the start interval  159 . In response, the license executable  153  transmits a request to the time service  139  to receive the time stamp  143 . The license executable  153  may then determine whether the license period has expired based on the current time indicated in the time stamp  143 . 
     The probability function  163  represents a likelihood that a communication to the time service  139  should be transmitted to receive the time stamp  143 . For example, the publisher providing the licensed content  149  may determine that a client device  106  accessing the content  143  should determine whether the license period has expired based on a time stamp  143  provided by the heartbeat server device  103  on a periodic basis. In particular, the probability function  163  may reflect a probability that the expiration needs to be determined from the time stamp  143  provided by the time service  139 . For example, the publisher may establish the probability based on historical and/or empirical evidence of a frequency that the system clock  146  gets compromised. As another example, the publisher may establish the probability based on a load that the heartbeat server device  103  may process. For instance, a probability of “10%” may correspond to the heartbeat server device  103  being able to process 10% of all requests from all client devices  106  that have access to the licensed content  149 . In one embodiment, the probability function  163  may be associated with a random number generator and a mathematical function implemented based on the random number. The probability function  163  may also include a numerical range. In one embodiment, if the result of the mathematical function performed on the random number falls within the numerical range, then a request to receive the time stamp  143  may be forced. For example, the license executable  153  may determine whether the result of the mathematical function is within the numerical range and transmit a request to receive the time stamp  143  if the result is within the numerical range. The license executable  153  may then determine whether the license period has expired based on the current time received in the time stamp  143 . In one embodiment, the license executable  153  may implement the functionality associated with the stop interval  156 , the start interval  159 , and the probability function  163  independently of each other. 
       FIG. 2  is a flowchart that provides one example of the operation of a portion of the client device  106  according to certain embodiments. It is understood that the flowchart of  FIG. 2  provides merely an example of the many different types of functional arrangements that may be employed to implement the operation of the portion of the client device  106 . As an alternative, the flowchart of  FIG. 2  may be viewed as depicting an example of steps of a method implemented in the client device  106  according to one or more embodiments. 
     Beginning with step  203 , the client device  106  receives content  143  for consumption on the client device  106 . The content  143  may be received from a publisher of the content  143  and may comprise media content, software application content, and/or any other content  143 . The received content  143  is associated with a license agreement that defines a license period for consumption on the client device  106 . Additionally, the content  143  may include an embedded license executable  153  that may be configured with a stop interval  156 , a start interval  159  and a probability function  163  for accurately determining when the license period expires. 
     Next, in step  206 , the client device  106  determines whether the license period for consuming the licensed content  149  expired based on an input from the heartbeat server  103  ( FIG. 1 ). The input from the heartbeat server  103  is the time stamp  143  ( FIG. 1 ) that indicates the accurate and uncompromised current time. In one embodiment, the client device  106  may request the input from the heartbeat server  103  if the time since receipt of the last input from the heartbeat server  103  exceeds a period that corresponds to the start interval  159 . If the time since the last input exceeds the period, then the client device  106  transmits a request to the heartbeat server  103  to receive the time stamp  143 . The client device  106  then determines whether the license period for consumption of the licensed content  149  is expired based on the time indicated in the time stamp  143 . If the license period has expired, then the client device  106  advances to step  209  and terminates access to the licensed content  149 . A timeout period maybe associated with step  206  if the license period is not expired based on the input from the heartbeat server  103 . 
     Returning to step  206 , the client device may also request input from the heartbeat server  103  based on the probability function  163 . In one embodiment, the probability function  163  represents a likelihood that the client device  106  needs an input from the heartbeat server  103 . For example, the probability function  163  may correspond to a random number with which the client device  106  implements a function to produce a result. If the result from the function is within a specified range of numbers, then the client device  106  may transmit a request to the heartbeat server  103  to receive the time stamp  143 . The range may be specified by the publisher of the licensed content  149 . For example, the larger the range, the higher the likelihood that the client device  106  transmits a request to the heartbeat server  103  because the result from the function is more likely to fall within the range. Similarly, the smaller the range, the smaller the likelihood that the client device  106  transmits a request to the heartbeat server  103  because the result from the function is less likely to fall within the range. The client device  106  then determines whether the license period for consumption of the licensed content  149  is expired based on the time indicated in the time stamp  143 . If the license period has expired, then the client device  106  advances to step  209  and terminates access to the licensed content  149 . A timeout period maybe associated with step  206  if the license period is not expired based on the input from the heartbeat server  103 . 
     Additionally, returning to step  206 , the license executable  153  may also determine whether the license period expired based on input from the heartbeat server  106  using the stop interval  156 . The stop interval  156  represents a maximum amount of time that the client device  106  may operate without receiving an input from the heartbeat server  103 . The client device  106  determines the time of receipt of the last input from the heartbeat server  103  and if the time of the last input exceeds the stop interval  159 , the client device  106  advances to step  209  and terminates access to the licensed content  149 . 
       FIG. 3  is a flowchart that provides one example of the operation of a portion of the license executable  153  provided by a publisher of licensed content  149  according to certain embodiments. It is understood that the flowchart of  FIG. 3  provides merely an example of the many different types of functional arrangements that may be employed to implement the operation of the portion of the license executable  153  as described herein. As an alternative, the flowchart of  FIG. 3  may be viewed as depicting an example of steps of a method implemented in the client device  106  according to one or more embodiments. Additionally or alternatively, the flowchart of  FIG. 3  may also be viewed as providing one example of the operation of the client side application  146 . 
     Beginning with step  303 , the licensed executable  153  identifies the start interval  159 . As discussed above, the start interval  159  indicates an amount of time that may elapse until the license executable  153  is updated with the time stamp  143 . In one embodiment, the license executable  153  may identify the start interval  159  from the license agreement embedded with the licensed content  149 . The start interval  159  may be an amount of time indicated in seconds, hours, days, and/or other period of time. 
     In step  306 , the license executable  153  determines whether the time since the last communication with the heartbeat server  103  exceeds a time that corresponds to the start interval  159 . In one embodiment, the license executable  153  and/or the client side application  146  may maintain a record of a last receipt of the time stamp  143  from the time service  139 . If the time since the last receipt of the time stamp  143  exceeds the time corresponding to the start interval  159 , then the license executable  153  advances to step  309 . The license executable  153  may only advance to step  309  if the time of last communication exceeds the time that corresponds to the start interval  159 . A time out call may be associated with step  306  in the event that the time of last communication does not exceed the time that corresponds to the start interval  159 . For instance, a certain amount of time may elapse when the license executable  153  does not advance to step  309  because the time of last communication does not exceed the time that corresponds to the start interval  159 . In this instance, the license executable  153  may stop the approach described in  FIG. 3 . Alternatively or additionally, the license executable  153  may determine that the license period for accessing the licensed content  149  is valid if the time of last communication does not exceed the time that corresponds to the start interval  159  and stop the approach described in  FIG. 3 . In another embodiment, if the license executable  153  determines that the last communication does not exceed the time that corresponds to the start interval  159 , then the license executable  153  may determine whether the license period for accessing the licensed content  149  is valid based on the stop interval  156  and/or the probability function  163  as discussed with respect to  FIG. 2  and  FIG. 4 . 
     In step  309 , the license executable  153  transmits a communication request to the time service  139 . Then, in response, the license executable  153  receives the time stamp  166  in step  313 . In one embodiment, the time stamp  143  includes the current time from the heartbeat server device  103 . The current time of the time stamp  143  represents a trusted and accurate time that has not been compromised. In step  316 , the license executable  153  determines whether the license period for accessing the licensed content  149  has expired based on the time received in the time stamp  143 . If the license executable  153  determines that the license period has expired, then the license executable  153  advances to step  319  and terminates access to the licensed content  149 . Returning to step  316 , if the license executable  153  determines that the license period has not expired, then the license executable  153  returns to step  303  and may optionally restart from step  303 . 
       FIG. 4  is a flowchart that provides one example of the operation of a portion of the license executable  153  provided by a publisher of the licensed content  149  according to certain embodiments. It is understood that the flowchart of  FIG. 4  provides merely an example of the many different types of functional arrangements that may be employed to implement the operation of the portion of the license executable  153  as described herein. As an alternative, the flowchart of  FIG. 4  may be viewed as depicting an example of steps of a method implemented in the client device  106  ( FIG. 1 ) according to one or more embodiments. Additionally or alternatively, the flowchart of  FIG. 3  may also be viewed as providing one example of the operation of the client side application  146 . 
     Beginning with step  403 , the license executable  153  identifies the stop interval  156 . As discussed above, the stop interval  156  represents an amount of time that may pass without receiving the time stamp  166  from the time service  139 . In one embodiment, the license executable  153  may identify the stop interval  156  from the license agreement embedded with the licensed content  149 . The stop interval  156  may be an amount of time indicated in seconds, hours, days, and/or other period of time. 
     Then, in step  406 , the license executable  153  determines whether the last communication with the heartbeat server  103  exceeds a time that corresponds to the stop interval  156 . In one embodiment, the license executable  153  and/or the client siden application  146  may maintain a record of a last receipt of the time stamp  143  from the time service  139 . If the time of last receipt of the time stamp  143  exceeds the time that corresponds to the stop interval  156 , then the license executable  153  advances to step  409 . The license executable  153  may only advance to step  409  if the time of last communication exceeds the time that corresponds to the stop interval  156 . A time out call may be associated with step  406  in the event that the time of last communication does not exceed the time that corresponds to the stop interval  156 . Then, in step  409 , the license executable  153  terminates access to the licensed content  149 . 
       FIG. 5  is a flowchart that provides one example of the operation of a portion of the license executable  153  provided by a publisher of licensed content  149  according to certain embodiments. It is understood that the flowchart of  FIG. 5  provides merely an example of the many different types of functional arrangements that may be employed to implement the operation of the portion of the license executable  153  as described herein. As an alternative, the flowchart of  FIG. 5  may be viewed as depicting an example of steps of a method implemented in the client device  106  according to one or more embodiments. Additionally or alternatively, the flowchart of  FIG. 4  may also be viewed as providing one example of the operation of the client side application  146 . 
     Beginning with step  503 , the license executable  153  identifies the probability function  163 . As discussed above, the probability function  163  corresponds to a probability that a request to the heartbeat server  103  should be transmitted. In one embodiment, the license executable  153  may identify the probability function  163  from the license agreement embedded with the licensed content  149 . The probability function  163  may be associated with any function, such as a random number generator, a mathematical function based on the random number, and/or any other function. Additionally, the probability function  163  may be associated with a numerical range, as discussed above. 
     In step  506 , the license executable  153  implements the function according to the probability function  163 . For example, the function may call for generating a random number, as known in the art. Additionally, the function may also call for a mathematical function defined by the probability function  163  that is to be implemented based on the generated random number. The license executable  153  implements the probability function  163  and generates a result. 
     Then, in step  509 , the license executable  153  may determine whether the result of the function associated with probability function  163  indicates that a communication should be transmitted to the heartbeat server  103 . For example, the license executable  153  may determine whether the result of the function defined by the probability function  163  (i.e., the random number and/or the result of some other mathematical function based on the random number) falls within a number range associated with the probability function  163 . In one embodiment, a smaller range may correspond to a smaller probability that the random number and/or the result of the other mathematical function falls within the numerical range. Similarly, a larger range may correspond to a larger probability that the random number and/or the result of the other mathematical function falls within the numerical range. 
     If the license executable  153  determines that the probability function  163  indicates that a communication should be transmitted to the heartbeat server  103 , then the license executable  153  advances to step  513 . If the license executable  153  determines that the probability function  163  indicates that a communication to the heartbeat server  103  is not needed, the license executable  153  returns to step  503  to restart the process. For example, the result of the mathematical function and/or the random number may fall outside of the numerical range indicating that the communication to the heartbeat server  103  is probably not necessary. 
     In step  513 , the license executable  153  transmits a communication request to the heartbeat server  103 . Then, in response, the license executable  153  receives the time stamp  143  in step  516 . In one embodiment, the time stamp  143  includes the current time from the heartbeat server device  103 . The current time of the time stamp  143  represents a trusted and accurate time that has not be compromised. In step  519 , the license executable  153  determines whether the license period for accessing the licensed content  149  has expired based on the time received in the time stamp  143 . If the license executable  153  determines that the license period has expired, then the license executable  153  advances to step  523  and terminates access to the licensed content  149 . Returning to step  519 , if the license executable  153  determines that the license period has not expired, then the license executable  153  returns to step  503  and may optionally restart from step  503 . 
     GENERAL 
     Numerous specific details are set forth herein to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter may be practiced without these specific details. In other instances, methods, apparatuses or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure claimed subject matter. 
     Some portions are presented in terms of algorithms or symbolic representations of operations on data bits or binary digital signals stored within a computing system memory, such as a computer memory. These algorithmic descriptions or representations are examples of techniques used by those of ordinary skill in the data processing arts to convey the substance of their work to others skilled in the art. An algorithm is a self-consistent sequence of operations or similar processing leading to a desired result. In this context, operations or processing involves physical manipulation of physical quantities. Typically, although not necessarily, such quantities may take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared or otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, numerals or the like. It should be understood, however, that all of these and similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless specifically stated otherwise, it is appreciated that throughout this specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” and “identifying” or the like refer to actions or processes of a computing device, such as one or more computers or a similar electronic computing device or devices, that manipulate or transform data represented as physical electronic or magnetic quantities within memories, registers, or other information storage devices, transmission devices, or display devices of the computing platform. 
     The system or systems discussed herein are not limited to any particular hardware architecture or configuration. A computing device can include any suitable arrangement of components that provide a result conditioned on one or more inputs. Suitable computing devices include multipurpose microprocessor-based computer systems accessing stored software that programs or configures the computing system from a general purpose computing apparatus to a specialized computing apparatus implementing one or more embodiments of the present subject matter. Any suitable programming, scripting, or other type of language or combinations of languages may be used to implement the teachings contained herein in software to be used in programming or configuring a computing device. 
     Embodiments of the methods disclosed herein may be performed in the operation of such computing devices. The order of the blocks presented in the examples above can be varied—for example, blocks can be re-ordered, combined, and/or broken into sub-blocks. Certain blocks or processes can be performed in parallel. 
     The use of “adapted to” or “configured to” herein is meant as open and inclusive language that does not foreclose devices adapted to or configured to perform additional tasks or steps. Additionally, the use of “based on” is meant to be open and inclusive, in that a process, step, calculation, or other action “based on” one or more recited conditions or values may, in practice, be based on additional conditions or values beyond those recited. Headings, lists, and numbering included herein are for ease of explanation only and are not meant to be limiting. 
     While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.