Abstract:
Methods and systems for enabling content to be securely and conveniently distributed to authorized users are provided. More particularly, content is maintained in encrypted form on sending and receiving devices, and during transport. In addition, policies related to the use of, access to, and distribution of content can be enforced. Features are also provided for controlling the release of information related to users. The distribution and control of contents can be performed in association with a client application that presents content and that manages keys.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 61/346,819, filed May 20, 2010, the entire disclosure of which is hereby incorporated herein by reference. 
     
    
     COPYRIGHT AUTHORIZATION 
       [0002]    A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
       FIELD 
       [0003]    Methods and apparatuses for providing content are provided. More particularly, methods and systems for enabling content to be securely provided over communication networks are provided. 
       BACKGROUND 
       [0004]    The Internet increasingly provides the means by which content is distributed. However, the Internet is inherently insecure. As a result, it has been difficult for content providers to realize compensation for content distributed over the Internet, particularly using the applications and services running on the Internet collectively known as the World Wide Web, or simply “the Web”. For example, although publishers, including traditional newspaper publishers, have constructed pay walls, which typically require payment of subscription fees to access content, such walls can usually be circumvented without great difficulty. Moreover, because authorized users can easily make and distribute content that is legitimately accessed, illicit copies made from legitimate copies are commonly available. Therefore, with some exceptions, traditional publishers have been largely unsuccessful at realizing compensation in connection with content that is made available over the Internet. 
         [0005]    As alternatives to subscription arrangements, other mechanisms for monetizing the provision of content have been developed. For example, advertising supported content is commonly available on the Internet. One difficulty with advertising supported content has been assigning a value to advertisements associated with content. For example, advertisements are preferably directed to persons who are likely buyers of advertised goods and services. However, accurately targeting consumers of advertised goods and services requires information about their needs and desires. This information can be inferred from search terms entered by the user and/or from content viewed by the user. Internet service providers can also analyze subscriber emails to create profiles that can be sold to advertisers or otherwise used in targeting consumers. Moreover, search terms, viewed content, and other data indicative of a user&#39;s needs or wants can be accumulated over time by advertisers or associated entities. However, such use of private information is often considered objectionable. 
         [0006]    In order to provide privacy and security for Internet activities, various security applications and procedures can be applied. However, the use of security applications is optional, and is not pervasive on the Web. In addition, security is typically implemented using an insufficient number of keys, with the result that cracking one key can often lead to access to large amounts of data. In addition, even when encryption has been applied, such encryption has been isolated. For example, data is frequently stored in unencrypted form both in the cloud and on the computers of end users. In addition, the application of security features, for example to prevent or limit the release of private information, can make many features of the Web inaccessible, because operation of such features is predicated on free access to information. Therefore, the relative lack of privacy and security on the Internet remains a problem, and has adversely affected the electronic distribution of content. 
       SUMMARY 
       [0007]    Embodiments of the present invention are directed to providing methods and systems for enabling content to be securely and conveniently distributed to authorized users, even over insecure networks. In accordance with embodiments of the present invention, a client application is provided for managing the collection of content and keys required to access that content. In accordance with further embodiments of the present invention, the client application participates in implementing access controls related to items of content. These controls enable content providers to condition access to content on receiving consideration for such access and/or to enforce other policies related to the use of and access to content. Moreover, embodiments of the present invention allow different levels of access to content to be provided to different users, and further allow content to be made available for different users on different terms. 
         [0008]    A system in accordance with embodiments of the present invention includes server side components connected to client devices via a communication network, such as the Internet. The server side components can include storage devices on which content is stored. The system can include agents or modules for performing various functions, including synchronization, content management, authentication, match making, taxonomy, billing, and other functions. The client devices included in the system feature a client application. The client application provides an interface through which a user accesses available content. Moreover, the client application maintains metadata concerning content objects, information for fetching or updating content or other information to the user, including targeted advertising. In one aspect, the client application maintains and manages one or more key rings containing keys for enabling access to encrypted content. 
         [0009]    Methods in accordance with embodiments of the present invention include the delivery of content to recipient client devices in encrypted form. More particularly, when a user composes a document or other content, a new encryption key, in particular a content key, is applied to encrypt that document. The document is then stored on the client device of the author in encrypted form. In addition, metadata related to the document can be encrypted using the content encryption key. If the author decides to provide the content to another user, the encrypted or unencrypted header and metadata information associated with the document can be encrypted using a permissions key. Next, the recipients of the document are identified, and a public key for the recipient is requested. The permissions key and the content key are then encrypted by the public key of the recipient. The recipient is then provided with a copy of the document package, including the encrypted content, the encrypted content key, metadata related to the content, and the associated content and permissions keys. Where the content is provided to multiple recipients, a separate document package is created for each recipient, with each individual document package having elements encrypted using the recipient&#39;s public key. 
         [0010]    Upon receipt at the client device of the content, the recipient&#39;s private key is applied to remove the delivered data from the wrapper created using the recipient&#39;s public key. The encrypted document is stored in the object store on the client device. More particularly, a container that contains the encrypted content, metadata, and a permissions key for content is stored in the object store. The content key is added to the key ring maintained by the client application on the client device. This key ring can be associated with a particular collection of data objects, also referred to herein as a concert. Accordingly, it can be appreciated that content is delivered to client devices in encrypted form. In addition, it can be appreciated that content is stored on client devices in encrypted form. In accordance with further embodiments of the present invention, a user of a client device has no direct access to the key ring associated with the encrypted content or the individual keys of that key ring. Instead, access to the keys of a key ring can only be made through a client application that holds the user&#39;s private key. Direct access to the private key is prevented by the client application and by client side system keys. Accordingly, policies established by authors and/or publishers regarding encrypted content can be enforced, including policies that prevent or restrict uncompensated distribution of the content. 
         [0011]    In order to access content included in a concert on a client device, the client application applies a client side system key for the subject concert to access the required content key stored as part of that concert&#39;s key ring. The client side system key can be a symmetric key that is protected with the user&#39;s private key. Moreover, the user need not be cognizant of the client side system keys used to access that user&#39;s concert key rings. The content key can then be applied by the client application to decrypt the content and any header information or other metadata that was also encrypted using the content key. The encrypted content and other information can then be displayed to the user of the client device through the client application. Although the user of a client device can enable the content key, the user has no direct access to that key. In addition, the user is not required to manage content keys. 
         [0012]    In accordance with still other aspects of embodiments of the present invention, at least some portion of the content or metadata related to the content may be available in unencrypted form. For example, metadata comprising a synopsis of a document or other content and information identifying the author and/or publisher of the document can be made publicly available. Even data that is publicly available can be stored in encrypted form using a key that is well known to the system. If, after viewing the publicly available information, a person is interested in obtaining a complete copy of the document, that person can arrange for appropriate payment or other consideration, and in return receive access rights to that content. 
         [0013]    Additional advantages and features of embodiments of the present invention will become more readily apparent from the following description, particularly when taken together with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  depicts elements of a system for providing content in accordance with embodiments of the present invention; 
           [0015]      FIG. 2  depicts other elements of a system for providing content in accordance with embodiments of the present invention; 
           [0016]      FIG. 3  is a block diagram depicting components of a system for providing content in accordance with embodiments of the present invention; 
           [0017]      FIG. 4  illustrates aspects of a process for composing a document in accordance with embodiments of the present invention; 
           [0018]      FIG. 5  illustrates aspects of a process for reading a document in accordance with embodiments of the present invention; 
           [0019]      FIG. 6  illustrates aspects of a process for forwarding a document in accordance with embodiments of the present invention; 
           [0020]      FIG. 7  illustrates aspects of a process for requesting an encryption key in accordance with embodiments of the present invention; 
           [0021]      FIG. 8  illustrates aspects of a process for assembling a document in accordance with embodiments of the present invention; 
           [0022]      FIG. 9  illustrates a process for generating a key for a concert key ring in accordance with embodiments of the present invention; 
           [0023]      FIGS. 10-13  illustrate different security procedures that may be implemented for accessing content in accordance with embodiments of the present invention; 
           [0024]      FIGS. 14-18  illustrate different options for storing concert information in accordance with embodiments of the present invention; 
           [0025]      FIG. 19  illustrates an example system architecture in accordance with embodiments of the present invention; and 
           [0026]      FIG. 20  is an example of a user interface in accordance with embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]      FIG. 1  illustrates aspects of a system  100  for providing content in accordance with embodiments of the present invention. In general, the system  100  includes one or more client devices  104  interconnected to a content system server  108  by a communication network  112 . A client device  104 , as will be described in greater detail elsewhere herein, may comprise a general purpose computer, such as, but not limited to, a laptop or desktop personal computer. The communication network  112  may comprise one or more networks, including the Internet. The content system server  108  may comprise one or more devices that perform functions in support of the provision of content to client devices  104  over the communication network  112 . 
         [0028]    More particularly, a content system server  108  in accordance with embodiments of the present invention can include one or more firewalls  116 , gateways  120 , edge server clusters  124  and core servers  126 . An edge server cluster  124  and/or core server  126  provided as part of a content system server  108  can include one or more databases  128 , data warehouse/reporting engines or modules  132 , and accounting data collection engines or modules  136 . The content system server  108  can additionally include analytics  140 , accounting  144 , and customer contact  148  engines or modules. Although the various components of the content system server  108  are depicted in  FIG. 1  as discrete pieces of interconnected hardware, it should be appreciated that embodiments of the present invention are not limited to such configurations. For example, a content system server  108  can be implemented using one or a small number of server computer devices. A content system server  108  can also be distributed among a number of different devices, various functions performed by the content system server  108  can be distributed among such devices, and the devices making up the content system server  108  can be distributed among different locations. 
         [0029]      FIG. 2  illustrates another view the content distribution system  100  in accordance with embodiments of the present invention, and in particular illustrates additional aspects of the client device  104 . The client device  104  executes a client application or concert application  204 . The client application  204  can function to retrieve content from the content system server  108  via the communication network  112 , to enable access to that content, and to enforce rules associated with that content. The client application  204  can also function to prepare content for delivery from the client device  104  to other client devices  104  and/or the content system server  108 . The client application  204  can also control the collection and release of information, such as demographic information regarding a user associated with the client device  104 , interests of the user associated with the client device  104  or other personal information. In accordance with embodiments of the present invention, content can be maintained in an object store  208  on or associated with the client device  104 . Moreover, in accordance with embodiments of the present invention, and as will be described in greater detail elsewhere herein, content  206  is stored in the object store  208  in encrypted form. Content  206  can be maintained in the object store  208  as part of one or more groupings, referred to herein as concerts  212 . Moreover, access to content  206  can be through an associated concert  212 . Each concert  212  can include various information or concert content  216 , such as content object metadata (e.g., digital rights management (DRM) information, history, analytics, identities of parent objects, child objects, etc.), pointers to content objects, permission keys  218 , object keys, and object type information. Each concert  212  is also associated with an access key, which can be in the form of a client side system key  234 . In addition, different concerts  212  can access or share the same items of content  206 . 
         [0030]    The client device  104  also includes a public key ring  220 , one or more content (concert) key rings  224 , and a private key ring  228 . The public key ring  220  can maintain public keys or encryption keys  222  that the client device  104  uses to encrypt information to be sent to other client devices  104  or to a content system server  108 . The public keys  222  can be distributed by the content system server  108  to a client device  104  when requested by the client device  104 . The content key ring  224  can be encrypted, and can comprise access or content keys  226  for decrypting items of content  206  maintained in the object store  208 . Where there are multiple content key rings  224  associated with a client device  104 , the different content key rings  224  can comprise concert key rings that are grouped according to the concert  212  to which they pertain. The private key ring  228  can include the private keys  230  needed to decrypt messages sent to the client device  104  using the corresponding public keys. In accordance with embodiments of the present invention, the user of the client device  104  does not have direct access to the content keys  226  maintained in the content key ring  224  or the private keys  230  maintained in the private key ring  228 . Instead, the content key ring  224  and the private key ring  228  are encrypted and accessed using hidden or system keys  234  that only the client application  204  can access. Therefore, access to the content  224  and private  228  key rings must be made through the client application  204 , allowing policies regarding distribution and/or use of content  206  established by an author, publisher, or other authority to be enforced. Moreover, the client side system key may be a symmetric key that is protected by the user&#39;s private key. 
         [0031]      FIG. 3  is a block diagram depicting components of a system  100  for providing content in accordance with embodiments of the present invention. More particularly, additional components of the client device  104  and content system server  108  are illustrated. In general, the client device  104  can comprise a general purpose computer, smart phone, or other device capable of supporting communications over a communication network  112 , and of running a suitable version of the client application  204 . The server system  108  may comprise one or more server computers capable of communication over a communication network  112 , and of running a suitable server application  302 . In general, the client device  104  and server system  108  include a processor  304 , memory  308 , data storage  312 , and a communication or network interface  316 . In addition, the client device  104  and/or server system  108  can include one or more user input devices  320 , such as a keyboard and a pointing device, and one or more user output devices  324 , such as a display and a speaker. 
         [0032]    The processor  304  may include any processor capable of performing instructions encoded in software or firmware. In accordance with other embodiments of the present invention, the processor  304  may comprise a controller or application specific integrated circuit (ASIC) having or capable of performing instructions encoded in logic circuits. The memory  308  may be used to store programs or data, including data comprising content  206 . As examples, the memory  308  may comprise RAM, SDRAM, or other solid state memory. Alternatively or in addition, data storage  312  may be provided. The data storage  312  may generally include storage for programs and data. For example, the data storage  312  may store various data and applications. For instance, with respect to a client device  104 , data storage  312  may provide storage for a client application  204 , object store  208 , concerts  212  and concert contents  216 , and the public key ring  220 . Data storage  312  associated with a client device  104  can also provide storage for a content key ring  224  and the private key ring  228  for the client device  104 . In addition, operating system  328  instructions, an email application  330 , other communication applications  332 , or other applications and data can be stored in data storage  312 . The data storage  312  associated with the server system  108  can include the content database  128 , data warehouse  132 , analytics information  140 , accounting information  144 , and various indices  334 , for example for use in connection with the storage and organization of content  206 , user information, and other information. Instructions related to the server system  108  operating system  328  may also be stored in data storage  312  of the server system  108 . 
         [0033]    Data storage  312  may comprise fixed data storage, such as one or more internal hard disk drives, or logical partitions. In accordance with still other embodiments, external data storage  336  can be interconnected to the client device  104 , for example via a communication interface  316 . The external data storage  336  can provide data storage for some or all of the system  100  applications and data associated with a particular user. Accordingly, external data storage  336  can provide for storage of a client application  204 , object store  208 , concerts  212  and concert contents  216 , key rings  220 ,  224 ,  228  and/or any other applications or data. Particular examples of external data storage  336  include external hard disk drives, universal serial bus (USB) drives, including flash drives, or other external data storage or memory devices. 
         [0034]      FIG. 4  is a flowchart depicting aspects of a process for composing content  206 , in this example a document, in accordance with embodiments of the present invention. At step  404 , a user, for example a user of a client device  104 , composes a document or other content  206 . When the content is ready for sending or is at least partially created, a new content encryption key  226  is requested (step  408 ). At step  412 , the document is assembled. Assembly of the document can include associating header information with the document. In accordance with embodiments of the present invention, some of the header information can be encrypted along with the contents of the document, while other portions of the header data will not be encrypted using the content key  226  that is applied to the document contents. If the document will be sent to other users, public encryption keys  222  for those other users are requested (step  416 ). After obtaining the required key or keys  222  or  226 , the document is encrypted (step  420 ). 
         [0035]    At step  424 , the created document is added to a concert  212 . In particular, content object metadata is added to the concert or concerts  212  to which the document is assigned. In addition, the content key  226  requested at step  408  is added to the content key ring  224  of the user (step  428 ). At step  432 , the encrypted document is queued for storage and/or delivery. In accordance with embodiments of the present invention, documents and other content are stored in an object store  208  in encrypted form. Therefore, storage can include storing the document, as encrypted using the content key  226 , on data storage  312  associated with the client device  104 . As described in greater detail elsewhere herein, for a document that is to be sent to another client device  104  or a server device  108 , the content key  226  is encrypted using the recipient&#39;s public key  230 . A document package comprising the encrypted content  206 , the encrypted content key  226 , and header or other information (which can be encrypted using the public key  230  of a user of the recipient device  104  and/or  108 ), metadata associated with the document (either unencrypted or encrypted with a permissions key  218  and/or the content key  226 ), the permissions key  218 , and the encrypted content key  226  can then be delivered to a recipient device, for example across a public network. 
         [0036]      FIG. 5  illustrates aspects of a process for reading a document or other content  206  in accordance with embodiments of the present invention. Initially, at step  504 , an instruction to open the document is received. The document that is opened can be a document that is opened for the first time, or an existing document in a concert  212  on the client device  104  being used to open the document that has previously been accessed. At step  508 , a determination is made as to whether the document has been seen before. If it has been seen before, the client application  204  requests the content key  226  for that document from the content key ring  224  for the concert  212  that includes the document (step  512 ). In particular, for a document that has been seen before, decryption of content on the client device  104  includes the client application  204  applying the user&#39;s private key  230  to access a permissions key  218 , which in turn enables access to the required content key  226  included in the content key ring  224 . If the document has not been seen before, the accessible information is decrypted using the user&#39;s private key  222  (step  516 ). The content key  226  for the document is extracted by the client application  204  and is added to the content key ring  224 , and metadata and permissions (as established by the associated permissions key  218 ) are stored in the content properties store included as part of the concert information  216  (step  520 ). Accordingly, whether extracting the content key  226  from the header or obtaining the content key  226  from the content key ring  224 , the client application  204  can be required to apply the user&#39;s private key  230 . After extracting the content key  226  from document header information, or after obtaining the content key  226  from the content key ring  224 , the client application applies the required content decryption key  226  to decrypt the document in memory (step  524 ). Following decryption, the content key  226  in memory is overwritten (step  528 ), and the document is displayed by the client application  204  (step  532 ). Because access and display of the document is through the client application  204 , actions that the user can take with respect to the document can be limited as determined by permissions associated with the document. 
         [0037]    At step  536 , a determination is made as to whether the document is to be saved. If the document is not to be saved, the memory is overwritten, the content key  226  is deleted from the content key ring  224 , and metadata and permissions associated with that content  206  are deleted from the concert contents or properties store  216 , and any other concert object metadata related to the document is deleted (step  540 ). If the document is to be saved, the content key  226  for the document is requested from the content key ring  224  (step  544 ) and the document is encrypted in memory (step  548 ). The encrypted document is then saved or resaved in the object store  208  (step  552 ). At step  556 , metadata related to the document is updated. The memory is then overwritten, to remove any unencrypted versions or portions of the document from the memory (step  560 ). 
         [0038]      FIG. 6  illustrates aspects of a process for forwarding a document or other content  206  in accordance with embodiments of the present invention. Initially, at step  604 , the user opens (reads) a document using a client device  104 , for example as described in connection with  FIG. 5 . At step  608 , the user composes a forward message in memory. In preparation for sending the message, the client application  204  running on the client device  104  requests a new content encryption key  226  (step  612 ). The document is assembled (step  616 ), and public encryption keys  222  for the recipient or recipients are requested (step  620 ). The document is next encrypted (step  624 ), and is added to the concert or concerts  212  to which the document is assigned (step  628 ). At step  632 , the content key  226  is added to the content key ring  224  of the user. The encrypted document is then queued for storage and/or delivery (step  636 ). 
         [0039]      FIG. 7  illustrates aspects of a process for requesting a content encryption key  226  in accordance with embodiments of the present invention. In response to a request for a content encryption key  226  (step  704 ), an encryption algorithm is selected (step  708 ). As can be appreciated by one of skill in the art, some encryption algorithms are more suited to particular types of encrypted content than others. In addition, different encryption algorithms may be selected based on the level of security deemed necessary for the content  206  being encrypted. In view of these various considerations, embodiments of the present invention support multiple encryption algorithms. After an algorithm is selected, a content key  226  is generated (step  712 ) and the strength of that key  226  is tested (step  716 ). If the content key  226  is determined to be weak, a new content key  226  is generated (step  712 ), and that new key  226  is again tested (step  716 ). Once an approved key  226  has been generated, it is returned to the client application  204  (step  720 ). Returning the approved key (step  712 ) can include placing the content key  226  one of the key rings on the client device  104 . The version of the content key  226  in memory is then overwritten (step  716 ). 
         [0040]      FIG. 8  illustrates aspects of a process for assembling a document or other content  206  in accordance with embodiments of the present invention. At step  804 , metadata that is to be encrypted with a document or content key  226  is collected. Metadata for encryption can include, for example, citations, or metadata that is not required until the document is actually viewed, such as information relating to the resolution of graphical elements of the document. At step  808 , the document and related metadata is encrypted using the unique content key  226 . At step  812 , metadata that is part of the document header but that may not be encrypted using the content key  226  is collected. Examples of metadata that may not be encrypted can include a synopsis that the author or other authority desires to make public, the author, size of the document, creation date, etc. The header for the document, including the content key  226  required to access the document, is then encrypted with a permissions key  218  (step  816 ). At this point, the document and the associated information can be sent to the content system server  108 . 
         [0041]    At step  820 , recipients of the document are identified, and the content system server  108  can request the public key  222  for each recipient of the document (step  824 ). The header information which has been encrypted using the appropriate permissions key  218 , and the document or content key  226 , is then wrapped with the recipient&#39;s public key  222  and appended to the encrypted document (step  828 ). The document is then delivered to the recipient client device  104  (step  832 ). Accordingly, a holder of the private key that is the pair to the public key  222  can access the header information, and can access the content key  226  by applying an appropriate private key  230 , but can only perform actions enabled by the permissions key  218 . 
         [0042]      FIG. 9  illustrates aspects of a process for managing content keys  226 . In general, content keys  226  are stored in encrypted key rings that are each associated with a concert or grouping of content  212 . Accordingly, at step  904 , a concert  212  is created. At step  908 , a key for the content (concert) key ring  224  is generated. At step  912 , a determination may be made as to whether a content key  226  for a content object  206  associated with the concert  212  is available for encryption. If the content key  226  is available for encryption, that content key  226  is encrypted using the key for the content key ring  224  (i.e., the content key ring  224  for the applicable concert  212 ) (step  916 ). 
         [0043]    At step  920 , a determination may be made as to whether there is a need to access a content object  206  included in a concert  212 . If there is a need to access content  206 , the necessary system key  234  is applied to obtain the content key  226  for the required content from the content key ring that includes that content key  226  (step  924 ). Application of the system key  234  can include the client application  204  using the private key  230  to access the system key  234 . The content  206  can then be displayed to the user through the client application  204  (step  928 ). At step  932 , a determination may be made as to whether access to the concert  212  should be discontinued. If access is continued, the process returns to step  912 . Alternatively, the process may end. 
         [0044]      FIGS. 10-13  illustrate different security procedures that may be implemented for accessing content stored as part of an object store  208  and associated with one or more concerts  212  in accordance with embodiments of the present invention. A first level of security is implemented by the process illustrated in  FIG. 10 . According to that process, the client application or concert application  204  is started (step  1004 ). The concert store or concert  212  to mount is then selected (step  1008 ), and a password for that concert store is entered (step  1012 ). Upon entry of the password, the content  206  can be accessed, and work on that content begun (step  1016 ). 
         [0045]    In  FIG. 11 , a next level of security is illustrated. Initially, the client application or concert application  204  is started (step  1104 ), the concert store to mount is selected (step  1108 ), and the required password is entered by the user (step  1112 ). Accordingly, steps  1104  through  1112  generally correspond to steps  1004  to  1012 . At step  1116 , a challenge question is displayed to the user. The user&#39;s response is entered at step  1120 . If the proper response is entered, the content  206  can be accessed, and work can be begun (step  1124 ). 
         [0046]    In  FIG. 12 , a further level of security that can be implemented is illustrated. Initially, at step  1204 , the client application or concert application  204  is started, the concert store to mount is selected (step  1208 ), and the user enters a required password (step  1212 ). At step  1216 , the system requests that the user enter a key file name. Various options may then be implemented. For example, the user may enter the key file name (step  1220 ) for content  206  immediately accessible to the client device  104 , and access to that content may be granted and work begun (step  1224 ). As an alternative, the user may enter the names of multiple key files (step  1228 ), and access to that content can be grated and work begun (step  1232 ). As still another option, after the request for a key file name has been made, the user may mount a removable volume (step  1236 ) and then enter the name of the key file or files for the desired content (step  1240 ). Access to the desired content  206  can then be granted, and work begun (step  1244 ). 
         [0047]    In  FIG. 13 , a further level of security is implemented. Initially, at step  1304 , the client application or concert application  204  is started, the concert store to mount is selected (step  1308 ) and the user enters a required password (step  1312 ). At step  1316 , the client application  204  requests that the user enter the key file name for the requested content  206 . In response to the request, different procedures may be supported. For example, the user may insert a smart card (step  1320 ) containing a key or other required information. In addition, the user may then enter a personal identification number or password (step  1324 ). As an alternative, in response to the request for a key file name, the user may insert a PIN encrypted disk (step  1328 ), and additionally enter the PIN (step  1332 ). After entering the PIN at steps  1324  or  1332 , the user may enter the required key file name (step  1336 ) or the names of multiple key files (step  1340 ). The desired content  206  can then be accessed, and work begun (step  1344 ). 
         [0048]      FIGS. 14-18  illustrate different options for storing concert information. More particularly, in  FIG. 14 , data storage  312  that is local to the client system  104  can contain all of the object data in an object or volume file store  208 , concert object metadata and keys in associated concerts  212 , a log file database  1404 , and the client application  204 . 
         [0049]    In  FIG. 15 , the object store  208 , concerts  212 , and a log file database  1404  are stored on data storage  312   b  comprising a second data drive that is separate from a first data device comprising the data storage  312   a  on which the client application  204  is stored. For example, the first data drive may comprise a first hard disk drive or flash drive that is internal to the client device  104 , while the second data drive may comprise a second hard disk drive or flash drive that is also internal to the client device  104 . For example, the object store  208 , concerts  212 , and log file database  1404  may be stored on a second internal hard drive provided as part of the client device  104 . In accordance with embodiments of the present invention, the log file data base  1404  can contain a record indicating the concerts  212  that particular content objects  206  are shared with, version information, or other information related to the organization and maintenance of content  206  within the concerts  212 . 
         [0050]    In  FIG. 16 , an object store  208 , concerts  212 , and a log file database  1404  are stored on data storage  312  comprising a local disk drive of a client device  104 , together with the client application  204 . In addition, a second object store  208 , other concerts  212 , and a log file database  1404  associated with those other concerts  212  are stored on data storage  336  comprising a removable USB drive. 
         [0051]    In  FIG. 17 , the client application  204  is stored on data storage  212  comprising a local disk drive of a client device  104 . The object store  208 , concerts  212 , and log file database  1404  are all on data storage  336  comprising a removable USB drive. 
         [0052]    In  FIG. 18 , data storage  212  comprising a local disk drive of the client device  104  contains operating system software  304 , but does not contain the client application  204 , an object store  208 , or concerts  212 . Instead, those components are all stored on data storage  336  comprising a removable USB drive. 
         [0053]      FIG. 19  illustrates an example system  100  architecture in accordance with embodiments of the present invention. In particular, the content system server  108  can be implemented as a core server  126  operating in cooperation with a plurality of edge servers  124 . The core server  126  can implement various content distribution functions, including security and key management, directory update, search, cache management, analytics, match making, taxonomy and backup functions. In addition, the core server  126  can perform various administrative functions, such as data center management, call center management, billing and accounting. The edge servers  124  can also provide security and key management. In addition, edge servers  124  can implement synchronization agents, auto updates, content management, manage plug-ins, caching, directory and message authentication. Client devices  104  included in the system  100  implement security and key management. In addition, collaboration, commerce, media and article builder functions and services can be supported. Moreover, different content and functionality can be accessed through different modules and services. 
         [0054]      FIG. 20  illustrates an embodiment of a user interface  2000  that may be presented to a user, for example by a display included in or associated with a client device  104 . The user interface  2000  and other user interfaces described herein may be visual display presented in a window on a user&#39;s display device. In some embodiments, the client application  204  renders the user interfaces for display and receives user input through one or more user input devices (e.g., selectable buttons, menus, icons, etc.). However, in other embodiments, the content system server  108  may render the user interfaces as multimedia document sent to the client  104  and displayed as a document in the client application  204 . Further, selections by the user in the multimedia document may cause the generation of requests that are sent to the content system server  108  from the client  104 . 
         [0055]    The user interface  2000  provides a window  2002  that can be a first information window for the client application  204 . The window  2002  can include a display area  2004  for displaying content  206 . In addition, a search field  2006  can be included through which a user can search for content. Further, the window  2002  can include a second display area  2008  that can display a set of user-selectable folders  2010  that organize the user&#39;s content. The window  2002  can include further user-selectable devices (e.g., the menu bar  2012  or menus  2014 ) for receiving user selections. 
         [0056]    Although certain examples provided herein discuss the encryption of and operations related to content  206  comprising documents, embodiments of the present invention are not limited to use in association with documents. Instead, any form of content, information, data or the like capable of being stored on and exchanged by computers or like devices can comprise content for purposes of the present disclosure. 
         [0057]    The foregoing discussion of the invention has been presented for purposes of illustration and description. Further, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, within the skill or knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain the best mode presently known of practicing the invention and to enable others skilled in the art to utilize the invention in such or in other embodiments and with various modifications required by the particular application or use of the invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.