Patent Publication Number: US-11656882-B2

Title: Instant virtual application launch

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of and claims priority to U.S. patent application Ser. No. 16/790,980 filed Feb. 14, 2020 which is a continuation application of and claims priority to U.S. patent application Ser. No. 15/915,203, filed Mar. 8, 2018, and entitled “Instant Virtual Application Launch,” which is hereby incorporated by reference as to its entirety. 
    
    
     FIELD 
     Aspects described herein generally relate to computer hardware and software, including virtual desktop instances. In particular, one or more aspects of the disclosure relate to computer hardware and software for reducing virtual application launch times by persisting a protocol state of a first receiver instance and sharing the protocol state of the first receiver instance with a second receiver instance. 
     BACKGROUND 
     Enterprise organizations and their employees are increasingly looking for ways to reduce connection time for reestablishing a secure session using virtual desktop instances. As virtual desktops are more frequently adopted and used, it is increasingly important to reduce connection time and the computational cost associated with establishing secure sessions. For example, a single secure session may be used to launch multiple applications. However, such session sharing is not always allowed due to security isolation and/or application compatibility purposes. In another example, enterprise organizations may attempt to reduce launch times by connecting users to a disconnected session rather than establishing a new session. However, this method still has a high computational cost and connection time. There remains an ever-present need to reduce launch times of establishing and reestablishing secure sessions via virtual desktop instances. 
     SUMMARY 
     The following presents a simplified summary of various aspects described herein. This summary is not an extensive overview, and is not intended to identify required or critical elements or to delineate the scope of the claims. The following summary merely presents some concepts in a simplified form as an introductory prelude to the more detailed description provided below. 
     To overcome limitations in the prior art described above, and to overcome other limitations that will be apparent upon reading and understanding the present specification, aspects described herein are directed toward reducing launch time of virtual applications. For example, a protocol state of a first receiver instance during an established secure session may be persisted and shared with a subsequent receiver instance. By persisting the protocol state, the subsequent receiver instance may avoid one or more steps otherwise needed to reestablish the secure session that are computationally expensive. 
     In accordance with one or more embodiments, a computing platform having at least one processor, memory, and a communication interface may establish, by a first virtual desktop instance, a secure session with a virtual delivery agent (VDA), resulting in a protocol state of the first virtual desktop instance. Subsequently, the computing platform may persist, using the first virtual desktop instance, the protocol state. Thereafter, the computing platform may transmit, from the first virtual desktop instance to a second virtual desktop instance, the protocol state. In addition, the computing platform may authenticate, using authentication tokens comprising the protocol state, a connection between the second virtual desktop instance and a gateway device. Further, the computing device may re-establish, after the authenticating, the secure session, wherein the secure session comprises a connection between the VDA and the second virtual desktop instance. 
     In some instances, the computing platform may cause display, during the secure session and via a user device, of a user interface. Further, the computing platform may transmit, to the VDA, a list of virtual channels and user device capabilities. Additionally, the computing platform may launch, via the second virtual desktop instance and during the secure session, one or more additional session features. 
     In some examples, the computing platform may launch the one or more additional session features in response to transmitting, by the VDA, a session reconnect indication to a plurality of virtual channel (VC) modules associated with the VDA. In addition, the computing platform may launch the one or more additional session features in response to launching, by the VDA, a plurality of virtual channels associated with the VC modules. Further, the computing platform may launch the one or more additional session features in response to determining, by the VDA, the user device capabilities. 
     In some instances, the computing platform may launch, via the first virtual desktop instance, at least one of a web link, a published application with content, or a new published application via the first virtual desktop instance. 
     In some examples, the computing platform may launch, by the VDA and responsive to the launching at least one of the web link, the published application with content, or the new published application via the first virtual desktop instance, at least one of the web link, the published application with content, or the new published application. 
     In some instances, the computing platform may perform, prior to the authenticating and by the second virtual desktop instance, a transport reconnect. Further, the computing platform may suspend, by the second virtual desktop instance and for a predetermined period of time, network activity. Additionally, the computing platform may generate, offline, by the second virtual desktop instance, and based on the protocol state of the first virtual desktop instance, a protocol state for the second virtual desktop instance. 
     In some examples, the computing platform may persist the protocol state of the first virtual desktop instance by recording, to a stored file, a network conversation between the first virtual desktop instance and the VDA, wherein the second virtual desktop instance has access to the stored file. 
     In some instances, the secure session may comprise a high definition experience (HDX) session. 
     In some examples, the protocol state may comprise an independent computing architecture (ICA) protocol state, a secure ticket authority (STA) ticket, and a common gateway protocol (CGP) cookie. 
     In some instances, the computing platform may perform, using the second virtual desktop instance and prior to the authenticating the connection between the VDA and the second virtual desktop instance, a transport reconnect. 
     In some examples, the computing platform may generate, using the protocol state of the first virtual desktop instance and for the second virtual desktop instance, a protocol state for the second virtual desktop instance, wherein the generating the protocol state for the second virtual desktop instance is performed offline. 
     In some instances, the protocol state of the first virtual desktop instance may be embedded in the first virtual desktop instance. 
     In some examples, the first virtual desktop instance may comprise an HTML5 receiver hosted and managed by a cloud service, and the second virtual desktop instance may comprise an HTML5 receiver hosted by a client endpoint and managed by the cloud service. 
     In some instances, the computing platform may transmit the protocol state of the first virtual desktop instance by transmitting, from the first virtual desktop instance and to the second virtual desktop instance, an ICA file comprising the protocol state of the first virtual desktop instance. 
     In some examples, the first virtual desktop instance may comprise a first instance of a high definition experience (HDX) software development kit (SDK)-based mobile application, and the second virtual desktop instance may comprise a second instance of the HDX SDK-based mobile application. 
     In some instances, the computing platform may transmit the protocol state of the first virtual desktop instance by transmitting, via one of an operating system (OS) key chain or a mobile device experience (MDX) shared secret vault, the protocol state of the first virtual desktop instance from the first virtual desktop instance to the second virtual desktop instance. 
     In some examples, the first virtual desktop instance may comprise a first instance of HTML5 receiver running in a first browser tab and displaying a first HDX application and the second virtual desktop instance may comprise a second instance of HTML5 receiver running in a second browser tab and displaying a second HDX application. 
     In some instances, the computing platform may transmit the protocol state of the first instance by storing, by the first virtual desktop instance, the protocol state of the first virtual desktop instance to local browser storage and accessing, by the second virtual desktop instance and via the local browser storage, the protocol state of the first virtual desktop instance. 
     These and additional aspects will be appreciated with the benefit of the disclosures discussed in further detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of aspects described herein and the advantages thereof may be acquired by referring to the following description in consideration of the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
         FIG.  1    depicts an illustrative computer system architecture that may be used in accordance with one or more illustrative aspects described herein. 
         FIG.  2    depicts an illustrative remote-access system architecture that may be used in accordance with one or more illustrative aspects described herein. 
         FIG.  3    depicts an illustrative virtualized (hypervisor) system architecture that may be used in accordance with one or more illustrative aspects described herein. 
         FIG.  4    depicts an illustrative cloud-based system architecture that may be used in accordance with one or more illustrative aspects described herein. 
         FIG.  5    depicts an illustrative enterprise mobility management system. 
         FIG.  6    depicts another illustrative enterprise mobility management system. 
         FIG.  7    depicts an illustrative diagram for establishing a remote access secure session at a user device. 
         FIG.  8    depicts an example method for establishing and reestablishing a secure session in accordance with one or more illustrative aspects described herein. 
         FIG.  9    depicts an example method for establishing and reestablishing a secure session via a progressive logon in accordance with one or more illustrative aspects described herein. 
         FIG.  10    depicts an example method for establishing and reestablishing a secure session via an asynchronous launch in accordance with one or more illustrative aspects described herein. 
         FIG.  11    illustrates an example virtual mobile application launch in accordance with one or more illustrative aspects described herein. 
         FIG.  12    illustrates an example virtual launch of HTML5 receiver instances in accordance with one or more illustrative aspects described herein. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of the various embodiments, reference is made to the accompanying drawings identified above and which form a part hereof, and in which is shown by way of illustration various embodiments in which aspects described herein may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope described herein. Various aspects are capable of other embodiments and of being practiced or being carried out in various different ways. 
     As a general introduction to the subject matter described in more detail below, aspects described herein are directed towards reducing launch time of virtual applications. For example, a protocol state of a first receiver instance during an established secure session may be persisted and shared with a subsequent receiver instance. By persisting the protocol state, the subsequent receiver instance may avoid one or more computationally expensive steps previously needed to reestablish the secure session. 
     It is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. Rather, the phrases and terms used herein are to be given their broadest interpretation and meaning. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. The use of the terms “mounted,” “connected,” “coupled,” “positioned,” “engaged” and similar terms, is meant to include both direct and indirect mounting, connecting, coupling, positioning and engaging. 
     Computing Architecture 
     Computer software, hardware, and networks may be utilized in a variety of different system environments, including standalone, networked, remote-access (also known as remote desktop), virtualized, and/or cloud-based environments, among others.  FIG.  1    illustrates one example of a system architecture and data processing device that may be used to implement one or more illustrative aspects described herein in a standalone and/or networked environment. Various network nodes  103 ,  105 ,  107 , and  109  may be interconnected via a wide area network (WAN)  101 , such as the Internet. Other networks may also or alternatively be used, including private intranets, corporate networks, local area networks (LAN), metropolitan area networks (MAN), wireless networks, personal networks (PAN), and the like. Network  101  is for illustration purposes and may be replaced with fewer or additional computer networks. A local area network  133  may have one or more of any known LAN topology and may use one or more of a variety of different protocols, such as Ethernet. Devices  103 ,  105 ,  107 , and  109  and other devices (not shown) may be connected to one or more of the networks via twisted pair wires, coaxial cable, fiber optics, radio waves, or other communication media. 
     The term “network” as used herein and depicted in the drawings refers not only to systems in which remote storage devices are coupled together via one or more communication paths, but also to stand-alone devices that may be coupled, from time to time, to such systems that have storage capability. Consequently, the term “network” includes not only a “physical network” but also a “content network,” which is comprised of the data—attributable to a single entity—which resides across all physical networks. 
     The components may include data server  103 , web server  105 , and client computers  107 ,  109 . Data server  103  provides overall access, control and administration of databases and control software for performing one or more illustrative aspects describe herein. Data server  103  may be connected to web server  105  through which users interact with and obtain data as requested. Alternatively, data server  103  may act as a web server itself and be directly connected to the Internet. Data server  103  may be connected to web server  105  through the local area network  133 , the wide area network  101  (e.g., the Internet), via direct or indirect connection, or via some other network. Users may interact with the data server  103  using remote computers  107 ,  109 , e.g., using a web browser to connect to the data server  103  via one or more externally exposed web sites hosted by web server  105 . Client computers  107 ,  109  may be used in concert with data server  103  to access data stored therein, or may be used for other purposes. For example, from client device  107  a user may access web server  105  using an Internet browser, as is known in the art, or by executing a software application that communicates with web server  105  and/or data server  103  over a computer network (such as the Internet). 
     Servers and applications may be combined on the same physical machines, and retain separate virtual or logical addresses, or may reside on separate physical machines.  FIG.  1    illustrates just one example of a network architecture that may be used, and those of skill in the art will appreciate that the specific network architecture and data processing devices used may vary, and are secondary to the functionality that they provide, as further described herein. For example, services provided by web server  105  and data server  103  may be combined on a single server. 
     Each component  103 ,  105 ,  107 ,  109  may be any type of known computer, server, or data processing device. Data server  103 , e.g., may include a processor  111  controlling overall operation of the data server  103 . Data server  103  may further include random access memory (RAM)  113 , read only memory (ROM)  115 , network interface  117 , input/output interfaces  119  (e.g., keyboard, mouse, display, printer, etc.), and memory  121 . Input/output (I/O)  119  may include a variety of interface units and drives for reading, writing, displaying, and/or printing data or files. Memory  121  may further store operating system software  123  for controlling overall operation of the data processing device  103 , control logic  125  for instructing data server  103  to perform aspects described herein, and other application software  127  providing secondary, support, and/or other functionality which may or might not be used in conjunction with aspects described herein. The control logic may also be referred to herein as the data server software  125 . Functionality of the data server software may refer to operations or decisions made automatically based on rules coded into the control logic, made manually by a user providing input into the system, and/or a combination of automatic processing based on user input (e.g., queries, data updates, etc.). 
     Memory  121  may also store data used in performance of one or more aspects described herein, including a first database  129  and a second database  131 . In some embodiments, the first database may include the second database (e.g., as a separate table, report, etc.). That is, the information can be stored in a single database, or separated into different logical, virtual, or physical databases, depending on system design. Devices  105 ,  107 , and  109  may have similar or different architecture as described with respect to device  103 . Those of skill in the art will appreciate that the functionality of data processing device  103  (or device  105 ,  107 , or  109 ) as described herein may be spread across multiple data processing devices, for example, to distribute processing load across multiple computers, to segregate transactions based on geographic location, user access level, quality of service (QoS), etc. 
     One or more aspects may be embodied in computer-usable or readable data and/or computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices as described herein. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The modules may be written in a source code programming language that is subsequently compiled for execution, or may be written in a scripting language such as (but not limited to) HyperText Markup Language (HTML) or Extensible Markup Language (XML). The computer executable instructions may be stored on a computer readable medium such as a nonvolatile storage device. Any suitable computer readable storage media may be utilized, including hard disks, CD-ROMs, optical storage devices, magnetic storage devices, and/or any combination thereof. In addition, various transmission (non-storage) media representing data or events as described herein may be transferred between a source and a destination in the form of electromagnetic waves traveling through signal-conducting media such as metal wires, optical fibers, and/or wireless transmission media (e.g., air and/or space). Various aspects described herein may be embodied as a method, a data processing system, or a computer program product. Therefore, various functionalities may be embodied in whole or in part in software, firmware, and/or hardware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like. Particular data structures may be used to more effectively implement one or more aspects described herein, and such data structures are contemplated within the scope of computer executable instructions and computer-usable data described herein. 
     With further reference to  FIG.  2   , one or more aspects described herein may be implemented in a remote-access environment.  FIG.  2    depicts an example system architecture including a computing device  201  in an illustrative computing environment  200  that may be used according to one or more illustrative aspects described herein. Computing device  201  may be used as a server  206   a  in a single-server or multi-server desktop virtualization system (e.g., a remote access or cloud system) configured to provide virtual machines for client access devices. The computing device  201  may have a processor  203  for controlling overall operation of the server and its associated components, including RAM  205 , ROM  207 , Input/Output (I/O) module  209 , and memory  215 . 
     I/O module  209  may include a mouse, keypad, touch screen, scanner, optical reader, and/or stylus (or other input device(s)) through which a user of computing device  201  may provide input, and may also include one or more of a speaker for providing audio output and one or more of a video display device for providing textual, audiovisual, and/or graphical output. Software may be stored within memory  215  and/or other storage to provide instructions to processor  203  for configuring computing device  201  into a special purpose computing device in order to perform various functions as described herein. For example, memory  215  may store software used by the computing device  201 , such as an operating system  217 , application programs  219 , and an associated database  221 . 
     Computing device  201  may operate in a networked environment supporting connections to one or more remote computers, such as terminals  240  (also referred to as client devices). The terminals  240  may be personal computers, mobile devices, laptop computers, tablets, or servers that include many or all of the elements described above with respect to the computing device  103  or  201 . The network connections depicted in  FIG.  2    include a local area network (LAN)  225  and a wide area network (WAN)  229 , but may also include other networks. When used in a LAN networking environment, computing device  201  may be connected to the LAN  225  through a network interface or adapter  223 . When used in a WAN networking environment, computing device  201  may include a modem  227  or other wide area network interface for establishing communications over the WAN  229 , such as computer network  230  (e.g., the Internet). It will be appreciated that the network connections shown are illustrative and other means of establishing a communications link between the computers may be used. Computing device  201  and/or terminals  240  may also be mobile terminals (e.g., mobile phones, smartphones, personal digital assistants (PDAs), notebooks, etc.) including various other components, such as a battery, speaker, and antennas (not shown). 
     Aspects described herein may also be operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of other computing systems, environments, and/or configurations that may be suitable for use with aspects described herein include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network personal computers (PCs), minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. 
     As shown in  FIG.  2   , one or more client devices  240  may be in communication with one or more servers  206   a - 206   n  (generally referred to herein as “server(s)  206 ”). In one embodiment, the computing environment  200  may include a network appliance installed between the server(s)  206  and client machine(s)  240 . The network appliance may manage client/server connections, and in some cases can load balance client connections amongst a plurality of backend servers  206 . 
     The client machine(s)  240  may in some embodiments be referred to as a single client machine  240  or a single group of client machines  240 , while server(s)  206  may be referred to as a single server  206  or a single group of servers  206 . In one embodiment a single client machine  240  communicates with more than one server  206 , while in another embodiment a single server  206  communicates with more than one client machine  240 . In yet another embodiment, a single client machine  240  communicates with a single server  206 . 
     A client machine  240  can, in some embodiments, be referenced by any one of the following non-exhaustive terms: client machine(s); client(s); client computer(s); client device(s); client computing device(s); local machine; remote machine; client node(s); endpoint(s); or endpoint node(s). The server  206 , in some embodiments, may be referenced by any one of the following non-exhaustive terms: server(s), local machine; remote machine; server farm(s), or host computing device(s). 
     In one embodiment, the client machine  240  may be a virtual machine. The virtual machine may be any virtual machine, while in some embodiments the virtual machine may be any virtual machine managed by a Type  1  or Type  2  hypervisor, for example, a hypervisor developed by Citrix Systems, IBM, VMware, or any other hypervisor. In some aspects, the virtual machine may be managed by a hypervisor, while in other aspects the virtual machine may be managed by a hypervisor executing on a server  206  or a hypervisor executing on a client  240 . 
     Some embodiments include a client device  240  that displays application output generated by an application remotely executing on a server  206  or other remotely located machine. In these embodiments, the client device  240  may execute a virtual machine receiver program or application to display the output in an application window, a browser, or other output window. In one example, the application is a desktop, while in other examples the application is an application that generates or presents a desktop. A desktop may include a graphical shell providing a user interface for an instance of an operating system in which local and/or remote applications can be integrated. Applications, as used herein, are programs that execute after an instance of an operating system (and, optionally, also the desktop) has been loaded. 
     The server  206 , in some embodiments, uses a remote presentation protocol or other program to send data to a thin-client or remote-display application executing on the client to present display output generated by an application executing on the server  206 . The thin-client or remote-display protocol can be any one of the following non-exhaustive list of protocols: the Independent Computing Architecture (ICA) protocol developed by Citrix Systems, Inc. of Ft. Lauderdale, Fla.; or the Remote Desktop Protocol (RDP) manufactured by the Microsoft Corporation of Redmond, Wash. 
     A remote computing environment may include more than one server  206   a - 206   n  such that the servers  206   a - 206   n  are logically grouped together into a server farm  206 , for example, in a cloud computing environment. The server farm  206  may include servers  206  that are geographically dispersed while and logically grouped together, or servers  206  that are located proximate to each other while logically grouped together. Geographically dispersed servers  206   a - 206   n  within a server farm  206  can, in some embodiments, communicate using a WAN (wide), MAN (metropolitan), or LAN (local), where different geographic regions can be characterized as: different continents; different regions of a continent; different countries; different states; different cities; different campuses; different rooms; or any combination of the preceding geographical locations. In some embodiments the server farm  206  may be administered as a single entity, while in other embodiments the server farm  206  can include multiple server farms. 
     In some embodiments, a server farm may include servers  206  that execute a substantially similar type of operating system platform (e.g., WINDOWS, UNIX, LINUX, iOS, ANDROID, SYMBIAN, etc.) In other embodiments, server farm  206  may include a first group of one or more servers that execute a first type of operating system platform, and a second group of one or more servers that execute a second type of operating system platform. 
     Server  206  may be configured as any type of server, as needed, e.g., a file server, an application server, a web server, a proxy server, an appliance, a network appliance, a gateway, an application gateway, a gateway server, a virtualization server, a deployment server, a Secure Sockets Layer (SSL) VPN server, a firewall, a web server, an application server or as a master application server, a server executing an active directory, or a server executing an application acceleration program that provides firewall functionality, application functionality, or load balancing functionality. Other server types may also be used. 
     Some embodiments include a first server  206   a  that receives requests from a client machine  240 , forwards the request to a second server  206   b  (not shown), and responds to the request generated by the client machine  240  with a response from the second server  206   b  (not shown.) First server  206   a  may acquire an enumeration of applications available to the client machine  240  and well as address information associated with an application server  206  hosting an application identified within the enumeration of applications. First server  206   a  can then present a response to the client&#39;s request using a web interface, and communicate directly with the client  240  to provide the client  240  with access to an identified application. One or more clients  240  and/or one or more servers  206  may transmit data over network  230 , e.g., network  101 . 
       FIG.  3    shows a high-level architecture of an illustrative desktop virtualization system. As shown, the desktop virtualization system may be single-server or multi-server system, or cloud system, including at least one virtualization server  301  configured to provide virtual desktops and/or virtual applications to one or more client access devices  240 . As used herein, a desktop refers to a graphical environment or space in which one or more applications may be hosted and/or executed. A desktop may include a graphical shell providing a user interface for an instance of an operating system in which local and/or remote applications can be integrated. Applications may include programs that execute after an instance of an operating system (and, optionally, also the desktop) has been loaded. Each instance of the operating system may be physical (e.g., one operating system per device) or virtual (e.g., many instances of an OS running on a single device). Each application may be executed on a local device, or executed on a remotely located device (e.g., remoted). 
     A computer device  301  may be configured as a virtualization server in a virtualization environment, for example, a single-server, multi-server, or cloud computing environment. Virtualization server  301  illustrated in  FIG.  3    can be deployed as and/or implemented by one or more embodiments of the server  206  illustrated in  FIG.  2    or by other known computing devices. Included in virtualization server  301  is a hardware layer that can include one or more physical disks  304 , one or more physical devices  306 , one or more physical processors  308 , and one or more physical memories  316 . In some embodiments, firmware  312  can be stored within a memory element in the physical memory  316  and can be executed by one or more of the physical processors  308 . Virtualization server  301  may further include an operating system  314  that may be stored in a memory element in the physical memory  316  and executed by one or more of the physical processors  308 . Still further, a hypervisor  302  may be stored in a memory element in the physical memory  316  and can be executed by one or more of the physical processors  308 . 
     Executing on one or more of the physical processors  308  may be one or more virtual machines  332 A-C (generally  332 ). Each virtual machine  332  may have a virtual disk  326 A-C and a virtual processor  328 A-C. In some embodiments, a first virtual machine  332 A may execute, using a virtual processor  328 A, a control program  320  that includes a tools stack  324 . Control program  320  may be referred to as a control virtual machine, Dom0, Domain 0, or other virtual machine used for system administration and/or control. In some embodiments, one or more virtual machines  332 B-C can execute, using a virtual processor  328 B-C, a guest operating system  330 A-B. 
     Virtualization server  301  may include a hardware layer  310  with one or more pieces of hardware that communicate with the virtualization server  301 . In some embodiments, the hardware layer  310  can include one or more physical disks  304 , one or more physical devices  306 , one or more physical processors  308 , and one or more physical memory  316 . Physical components  304 ,  306 ,  308 , and  316  may include, for example, any of the components described above. Physical devices  306  may include, for example, a network interface card, a video card, a keyboard, a mouse, an input device, a monitor, a display device, speakers, an optical drive, a storage device, a universal serial bus connection, a printer, a scanner, a network element (e.g., router, firewall, network address translator, load balancer, virtual private network (VPN) gateway, Dynamic Host Configuration Protocol (DHCP) router, etc.), or any device connected to or communicating with virtualization server  301 . Physical memory  316  in the hardware layer  310  may include any type of memory. Physical memory  316  may store data, and in some embodiments may store one or more programs, or set of executable instructions.  FIG.  3    illustrates an embodiment where firmware  312  is stored within the physical memory  316  of virtualization server  301 . Programs or executable instructions stored in the physical memory  316  can be executed by the one or more processors  308  of virtualization server  301 . 
     Virtualization server  301  may also include a hypervisor  302 . In some embodiments, hypervisor  302  may be a program executed by processors  308  on virtualization server  301  to create and manage any number of virtual machines  332 . Hypervisor  302  may be referred to as a virtual machine monitor, or platform virtualization software. In some embodiments, hypervisor  302  can be any combination of executable instructions and hardware that monitors virtual machines executing on a computing machine. Hypervisor  302  may be Type  2  hypervisor, where the hypervisor executes within an operating system  314  executing on the virtualization server  301 . Virtual machines may then execute at a level above the hypervisor. In some embodiments, the Type  2  hypervisor may execute within the context of a user&#39;s operating system such that the Type  2  hypervisor interacts with the user&#39;s operating system. In other embodiments, one or more virtualization servers  301  in a virtualization environment may instead include a Type  1  hypervisor (not shown). A Type  1  hypervisor may execute on the virtualization server  301  by directly accessing the hardware and resources within the hardware layer  310 . That is, while a Type  2  hypervisor  302  accesses system resources through a host operating system  314 , as shown, a Type  1  hypervisor may directly access all system resources without the host operating system  314 . A Type  1  hypervisor may execute directly on one or more physical processors  308  of virtualization server  301 , and may include program data stored in the physical memory  316 . 
     Hypervisor  302 , in some embodiments, can provide virtual resources to operating systems  330  or control programs  320  executing on virtual machines  332  in any manner that simulates the operating systems  330  or control programs  320  having direct access to system resources. System resources can include, but are not limited to, physical devices  306 , physical disks  304 , physical processors  308 , physical memory  316 , and any other component included in virtualization server  301  hardware layer  310 . Hypervisor  302  may be used to emulate virtual hardware, partition physical hardware, virtualize physical hardware, and/or execute virtual machines that provide access to computing environments. In still other embodiments, hypervisor  302  may control processor scheduling and memory partitioning for a virtual machine  332  executing on virtualization server  301 . Hypervisor  302  may include those manufactured by VMWare, Inc., of Palo Alto, Calif.; the XENPROJECT hypervisor, an open source product whose development is overseen by the open source XenProject.org community; HyperV, VirtualServer or virtual PC hypervisors provided by Microsoft, or others. In some embodiments, virtualization server  301  may execute a hypervisor  302  that creates a virtual machine platform on which guest operating systems may execute. In these embodiments, the virtualization server  301  may be referred to as a host server. An example of such a virtualization server is the XENSERVER provided by Citrix Systems, Inc., of Fort Lauderdale, Fla. 
     Hypervisor  302  may create one or more virtual machines  332 B-C (generally  332 ) in which guest operating systems  330  execute. In some embodiments, hypervisor  302  may load a virtual machine image to create a virtual machine  332 . In other embodiments, the hypervisor  302  may execute a guest operating system  330  within virtual machine  332 . In still other embodiments, virtual machine  332  may execute guest operating system  330 . 
     In addition to creating virtual machines  332 , hypervisor  302  may control the execution of at least one virtual machine  332 . In other embodiments, hypervisor  302  may present at least one virtual machine  332  with an abstraction of at least one hardware resource provided by the virtualization server  301  (e.g., any hardware resource available within the hardware layer  310 ). In other embodiments, hypervisor  302  may control the manner in which virtual machines  332  access physical processors  308  available in virtualization server  301 . Controlling access to physical processors  308  may include determining whether a virtual machine  332  should have access to a processor  308 , and how physical processor capabilities are presented to the virtual machine  332 . 
     As shown in  FIG.  3   , virtualization server  301  may host or execute one or more virtual machines  332 . A virtual machine  332  is a set of executable instructions that, when executed by a processor  308 , may imitate the operation of a physical computer such that the virtual machine  332  can execute programs and processes much like a physical computing device. While  FIG.  3    illustrates an embodiment where a virtualization server  301  hosts three virtual machines  332 , in other embodiments virtualization server  301  can host any number of virtual machines  332 . Hypervisor  302 , in some embodiments, may provide each virtual machine  332  with a unique virtual view of the physical hardware, memory, processor, and other system resources available to that virtual machine  332 . In some embodiments, the unique virtual view can be based on one or more of virtual machine permissions, application of a policy engine to one or more virtual machine identifiers, a user accessing a virtual machine, the applications executing on a virtual machine, networks accessed by a virtual machine, or any other desired criteria. For instance, hypervisor  302  may create one or more unsecure virtual machines  332  and one or more secure virtual machines  332 . Unsecure virtual machines  332  may be prevented from accessing resources, hardware, memory locations, and programs that secure virtual machines  332  may be permitted to access. In other embodiments, hypervisor  302  may provide each virtual machine  332  with a substantially similar virtual view of the physical hardware, memory, processor, and other system resources available to the virtual machines  332 . 
     Each virtual machine  332  may include a virtual disk  326 A-C (generally  326 ) and a virtual processor  328 A-C (generally  328 .) The virtual disk  326 , in some embodiments, is a virtualized view of one or more physical disks  304  of the virtualization server  301 , or a portion of one or more physical disks  304  of the virtualization server  301 . The virtualized view of the physical disks  304  can be generated, provided, and managed by the hypervisor  302 . In some embodiments, hypervisor  302  provides each virtual machine  332  with a unique view of the physical disks  304 . Thus, in these embodiments, the particular virtual disk  326  included in each virtual machine  332  can be unique when compared with the other virtual disks  326 . 
     A virtual processor  328  can be a virtualized view of one or more physical processors  308  of the virtualization server  301 . In some embodiments, the virtualized view of the physical processors  308  can be generated, provided, and managed by hypervisor  302 . In some embodiments, virtual processor  328  has substantially all of the same characteristics of at least one physical processor  308 . In other embodiments, virtual processor  308  provides a modified view of physical processors  308  such that at least some of the characteristics of the virtual processor  328  are different than the characteristics of the corresponding physical processor  308 . 
     With further reference to  FIG.  4   , some aspects described herein may be implemented in a cloud-based environment.  FIG.  4    illustrates an example of a cloud computing environment (or cloud system)  400 . As seen in  FIG.  4   , client computers  411 - 414  may communicate with a cloud management server  410  to access the computing resources (e.g., host servers  403   a - 403   b  (generally referred herein as “host servers  403 ”), storage resources  404   a - 404   b  (generally referred herein as “storage resources  404 ”), and network resources  405   a - 405   b  (generally referred herein as “network resources  405 ”)) of the cloud system. 
     Management server  410  may be implemented on one or more physical servers. The management server  410  may run, for example, CLOUDPLATFORM by Citrix Systems, Inc. of Ft. Lauderdale, Fla., or OPENSTACK, among others. Management server  410  may manage various computing resources, including cloud hardware and software resources, for example, host computers  403 , data storage devices  404 , and networking devices  405 . The cloud hardware and software resources may include private and/or public components. For example, a cloud may be configured as a private cloud to be used by one or more particular customers or client computers  411 - 414  and/or over a private network. In other embodiments, public clouds or hybrid public-private clouds may be used by other customers over an open or hybrid networks. 
     Management server  410  may be configured to provide user interfaces through which cloud operators and cloud customers may interact with the cloud system  400 . For example, the management server  410  may provide a set of application programming interfaces (APIs) and/or one or more cloud operator console applications (e.g., web-based or standalone applications) with user interfaces to allow cloud operators to manage the cloud resources, configure the virtualization layer, manage customer accounts, and perform other cloud administration tasks. The management server  410  also may include a set of APIs and/or one or more customer console applications with user interfaces configured to receive cloud computing requests from end users via client computers  411 - 414 , for example, requests to create, modify, or destroy virtual machines within the cloud. Client computers  411 - 414  may connect to management server  410  via the Internet or some other communication network, and may request access to one or more of the computing resources managed by management server  410 . In response to client requests, the management server  410  may include a resource manager configured to select and provision physical resources in the hardware layer of the cloud system based on the client requests. For example, the management server  410  and additional components of the cloud system may be configured to provision, create, and manage virtual machines and their operating environments (e.g., hypervisors, storage resources, services offered by the network elements, etc.) for customers at client computers  411 - 414 , over a network (e.g., the Internet), providing customers with computational resources, data storage services, networking capabilities, and computer platform and application support. Cloud systems also may be configured to provide various specific services, including security systems, development environments, user interfaces, and the like. 
     Certain clients  411 - 414  may be related, for example, different client computers creating virtual machines on behalf of the same end user, or different users affiliated with the same company or organization. In other examples, certain clients  411 - 414  may be unrelated, such as users affiliated with different companies or organizations. For unrelated clients, information on the virtual machines or storage of any one user may be hidden from other users. 
     Referring now to the physical hardware layer of a cloud computing environment, availability zones  401 - 402  (or zones) may refer to a collocated set of physical computing resources. Zones may be geographically separated from other zones in the overall cloud of computing resources. For example, zone  401  may be a first cloud datacenter located in California, and zone  402  may be a second cloud datacenter located in Florida. Management server  410  may be located at one of the availability zones, or at a separate location. Each zone may include an internal network that interfaces with devices that are outside of the zone, such as the management server  410 , through a gateway. End users of the cloud (e.g., clients  411 - 414 ) might or might not be aware of the distinctions between zones. For example, an end user may request the creation of a virtual machine having a specified amount of memory, processing power, and network capabilities. The management server  410  may respond to the user&#39;s request and may allocate the resources to create the virtual machine without the user knowing whether the virtual machine was created using resources from zone  401  or zone  402 . In other examples, the cloud system may allow end users to request that virtual machines (or other cloud resources) are allocated in a specific zone or on specific resources  403 - 405  within a zone. 
     In this example, each zone  401 - 402  may include an arrangement of various physical hardware components (or computing resources)  403 - 405 , for example, physical hosting resources (or processing resources), physical network resources, physical storage resources, switches, and additional hardware resources that may be used to provide cloud computing services to customers. The physical hosting resources in a cloud zone  401 - 402  may include one or more computer servers  403 , such as the virtualization servers  301  described above, which may be configured to create and host virtual machine instances. The physical network resources in a cloud zone  401  or  402  may include one or more network elements  405  (e.g., network service providers) comprising hardware and/or software configured to provide a network service to cloud customers, such as firewalls, network address translators, load balancers, virtual private network (VPN) gateways, Dynamic Host Configuration Protocol (DHCP) routers, and the like. The storage resources in the cloud zone  401 - 402  may include storage disks (e.g., solid state drives (SSDs), magnetic hard disks, etc.) and other storage devices. 
     The example cloud computing environment shown in  FIG.  4    also may include a virtualization layer (e.g., as shown in  FIGS.  1 - 3   ) with additional hardware and/or software resources configured to create and manage virtual machines and provide other services to customers using the physical resources in the cloud. The virtualization layer may include hypervisors, as described above in  FIG.  3   , along with other components to provide network virtualizations, storage virtualizations, etc. The virtualization layer may be as a separate layer from the physical resource layer, or may share some or all of the same hardware and/or software resources with the physical resource layer. For example, the virtualization layer may include a hypervisor installed in each of the virtualization servers  403  with the physical computing resources. Known cloud systems may alternatively be used, e.g., WINDOWS AZURE (Microsoft Corporation of Redmond Wash.), AMAZON EC2 (Amazon.com Inc. of Seattle, Wash.), IBM BLUE CLOUD (IBM Corporation of Armonk, N.Y.), or others. 
     Enterprise Mobility Management Architecture 
       FIG.  5    represents an enterprise mobility technical architecture  500  for use in a “Bring Your Own Device” (BYOD) environment. The architecture enables a user of a mobile device  502  to both access enterprise or personal resources from a mobile device  502  and use the mobile device  502  for personal use. The user may access such enterprise resources  504  or enterprise services  508  using a mobile device  502  that is purchased by the user or a mobile device  502  that is provided by the enterprise to the user. The user may utilize the mobile device  502  for business use only or for business and personal use. The mobile device  502  may run an iOS operating system, an Android operating system, or the like. The enterprise may choose to implement policies to manage the mobile device  502 . The policies may be implemented through a firewall or gateway in such a way that the mobile device  502  may be identified, secured or security verified, and provided selective or full access to the enterprise resources (e.g.,  504  and  508 .) The policies may be mobile device management policies, mobile application management policies, mobile data management policies, or some combination of mobile device, application, and data management policies. A mobile device  502  that is managed through the application of mobile device management policies may be referred to as an enrolled device. 
     In some embodiments, the operating system of the mobile device  502  may be separated into a managed partition  510  and an unmanaged partition  512 . The managed partition  510  may have policies applied to it to secure the applications running on and data stored in the managed partition  510 . The applications running on the managed partition  510  may be secure applications. In other embodiments, all applications may execute in accordance with a set of one or more policy files received separate from the application, and which define one or more security parameters, features, resource restrictions, and/or other access controls that are enforced by the mobile device management system when that application is executing on the mobile device  502 . By operating in accordance with their respective policy file(s), each application may be allowed or restricted from communications with one or more other applications and/or resources, thereby creating a virtual partition. Thus, as used herein, a partition may refer to a physically partitioned portion of memory (physical partition), a logically partitioned portion of memory (logical partition), and/or a virtual partition created as a result of enforcement of one or more policies and/or policy files across multiple applications as described herein (virtual partition). Stated differently, by enforcing policies on managed applications, those applications may be restricted to only be able to communicate with other managed applications and trusted enterprise resources, thereby creating a virtual partition that is not accessible by unmanaged applications and devices. 
     The secure applications may be email applications, web browsing applications, software-as-a-service (SaaS) access applications, Windows Application access applications, and the like. The secure applications may be secure native applications  514 , secure remote applications  522  executed by a secure application launcher  518 , virtualization applications  526  executed by a secure application launcher  518 , and the like. The secure native applications  514  may be wrapped by a secure application wrapper  520 . The secure application wrapper  520  may include integrated policies that are executed on the mobile device  502  when the secure native application  514  is executed on the mobile device  502 . The secure application wrapper  520  may include meta-data that points the secure native application  514  running on the mobile device  502  to the resources hosted at the enterprise (e.g.,  504  and  508 ) that the secure native application  514  may require to complete the task requested upon execution of the secure native application  514 . The secure remote applications  522  executed by a secure application launcher  518  may be executed within the secure application launcher  518 . The virtualization applications  526  executed by a secure application launcher  518  may utilize resources on the mobile device  502 , at the enterprise resources  504 , and the like. The resources used on the mobile device  502  by the virtualization applications  526  executed by a secure application launcher  518  may include user interaction resources, processing resources, and the like. The user interaction resources may be used to collect and transmit keyboard input, mouse input, camera input, tactile input, audio input, visual input, gesture input, and the like. The processing resources may be used to present a user interface, process data received from the enterprise resources  504 , and the like. The resources used at the enterprise resources  504  by the virtualization applications  526  executed by a secure application launcher  518  may include user interface generation resources, processing resources, and the like. The user interface generation resources may be used to assemble a user interface, modify a user interface, refresh a user interface, and the like. The processing resources may be used to create information, read information, update information, delete information, and the like. For example, the virtualization application  526  may record user interactions associated with a graphical user interface (GUI) and communicate them to a server application where the server application will use the user interaction data as an input to the application operating on the server. In such an arrangement, an enterprise may elect to maintain the application on the server side as well as data, files, etc. associated with the application. While an enterprise may elect to “mobilize” some applications in accordance with the principles herein by securing them for deployment on the mobile device  502 , this arrangement may also be elected for certain applications. For example, while some applications may be secured for use on the mobile device  502 , others might not be prepared or appropriate for deployment on the mobile device  502  so the enterprise may elect to provide the mobile user access to the unprepared applications through virtualization techniques. As another example, the enterprise may have large complex applications with large and complex data sets (e.g., material resource planning applications) where it would be very difficult, or otherwise undesirable, to customize the application for the mobile device  502  so the enterprise may elect to provide access to the application through virtualization techniques. As yet another example, the enterprise may have an application that maintains highly secured data (e.g., human resources data, customer data, engineering data) that may be deemed by the enterprise as too sensitive for even the secured mobile environment so the enterprise may elect to use virtualization techniques to permit mobile access to such applications and data. An enterprise may elect to provide both fully secured and fully functional applications on the mobile device  502  as well as a virtualization application  526  to allow access to applications that are deemed more properly operated on the server side. In an embodiment, the virtualization application  526  may store some data, files, etc. on the mobile device  502  in one of the secure storage locations. An enterprise, for example, may elect to allow certain information to be stored on the mobile device  502  while not permitting other information. 
     In connection with the virtualization application  526 , as described herein, the mobile device  502  may have a virtualization application  526  that is designed to present GUIs and then record user interactions with the GUI. The virtualization application  526  may communicate the user interactions to the server side to be used by the server side application as user interactions with the application. In response, the application on the server side may transmit back to the mobile device  502  a new GUI. For example, the new GUI may be a static page, a dynamic page, an animation, or the like, thereby providing access to remotely located resources. 
     The secure applications  514  may access data stored in a secure data container  528  in the managed partition  510  of the mobile device  502 . The data secured in the secure data container may be accessed by the secure native applications  514 , secure remote applications  522  executed by a secure application launcher  518 , virtualization applications  526  executed by a secure application launcher  518 , and the like. The data stored in the secure data container  528  may include files, databases, and the like. The data stored in the secure data container  528  may include data restricted to a specific secure application  530 , shared among secure applications  532 , and the like. Data restricted to a secure application may include secure general data  534  and highly secure data  538 . Secure general data may use a strong form of encryption such as Advanced Encryption Standard (AES) 128-bit encryption or the like, while highly secure data  538  may use a very strong form of encryption such as AES 256-bit encryption. Data stored in the secure data container  528  may be deleted from the mobile device  502  upon receipt of a command from the device manager  524 . The secure applications (e.g.,  514 ,  522 , and  526 ) may have a dual-mode option  540 . The dual mode option  540  may present the user with an option to operate the secured application in an unsecured or unmanaged mode. In an unsecured or unmanaged mode, the secure applications may access data stored in an unsecured data container  542  on the unmanaged partition  512  of the mobile device  502 . The data stored in an unsecured data container may be personal data  544 . The data stored in an unsecured data container  542  may also be accessed by unsecured applications  546  that are running on the unmanaged partition  512  of the mobile device  502 . The data stored in an unsecured data container  542  may remain on the mobile device  502  when the data stored in the secure data container  528  is deleted from the mobile device  502 . An enterprise may want to delete from the mobile device  502  selected or all data, files, and/or applications owned, licensed or controlled by the enterprise (enterprise data) while leaving or otherwise preserving personal data, files, and/or applications owned, licensed or controlled by the user (personal data). This operation may be referred to as a selective wipe. With the enterprise and personal data arranged in accordance to the aspects described herein, an enterprise may perform a selective wipe. 
     The mobile device  502  may connect to enterprise resources  504  and enterprise services  508  at an enterprise, to the public Internet  548 , and the like. The mobile device  502  may connect to enterprise resources  504  and enterprise services  508  through virtual private network connections. The virtual private network connections, also referred to as microVPN or application-specific VPN, may be specific to particular applications (as illustrated by microVPNs  550 , particular devices, particular secured areas on the mobile device (as illustrated by O/S VPN  552 ), and the like. For example, each of the wrapped applications in the secured area of the mobile device  502  may access enterprise resources through an application specific VPN such that access to the VPN would be granted based on attributes associated with the application, possibly in conjunction with user or device attribute information. The virtual private network connections may carry Microsoft Exchange traffic, Microsoft Active Directory traffic, HyperText Transfer Protocol (HTTP) traffic, HyperText Transfer Protocol Secure (HTTPS) traffic, application management traffic, and the like. The virtual private network connections may support and enable single-sign-on authentication processes  554 . The single-sign-on processes may allow a user to provide a single set of authentication credentials, which are then verified by an authentication service  558 . The authentication service  558  may then grant to the user access to multiple enterprise resources  504 , without requiring the user to provide authentication credentials to each individual enterprise resource  504 . 
     The virtual private network connections may be established and managed by an access gateway  560 . The access gateway  560  may include performance enhancement features that manage, accelerate, and improve the delivery of enterprise resources  504  to the mobile device  502 . The access gateway  560  may also re-route traffic from the mobile device  502  to the public Internet  548 , enabling the mobile device  502  to access publicly available and unsecured applications that run on the public Internet  548 . The mobile device  502  may connect to the access gateway via a transport network  562 . The transport network  562  may use one or more transport protocols and may be a wired network, wireless network, cloud network, local area network, metropolitan area network, wide area network, public network, private network, and the like. 
     The enterprise resources  504  may include email servers, file sharing servers, SaaS applications, Web application servers, Windows application servers, and the like. Email servers may include Exchange servers, Lotus Notes servers, and the like. File sharing servers may include ShareFile servers, and the like. SaaS applications may include Salesforce, and the like. Windows application servers may include any application server that is built to provide applications that are intended to run on a local Windows operating system, and the like. The enterprise resources  504  may be premise-based resources, cloud-based resources, and the like. The enterprise resources  504  may be accessed by the mobile device  502  directly or through the access gateway  560 . The enterprise resources  504  may be accessed by the mobile device  502  via the transport network  562 . 
     The enterprise services  508  may include authentication services  558 , threat detection services  564 , device manager services  524 , file sharing services  568 , policy manager services  570 , social integration services  572 , application controller services  574 , and the like. Authentication services  558  may include user authentication services, device authentication services, application authentication services, data authentication services, and the like. Authentication services  558  may use certificates. The certificates may be stored on the mobile device  502 , by the enterprise resources  504 , and the like. The certificates stored on the mobile device  502  may be stored in an encrypted location on the mobile device  502 , the certificate may be temporarily stored on the mobile device  502  for use at the time of authentication, and the like. Threat detection services  564  may include intrusion detection services, unauthorized access attempt detection services, and the like. Unauthorized access attempt detection services may include unauthorized attempts to access devices, applications, data, and the like. Device management services  524  may include configuration, provisioning, security, support, monitoring, reporting, and decommissioning services. File sharing services  568  may include file management services, file storage services, file collaboration services, and the like. Policy manager services  570  may include device policy manager services, application policy manager services, data policy manager services, and the like. Social integration services  572  may include contact integration services, collaboration services, integration with social networks such as Facebook, Twitter, and LinkedIn, and the like. Application controller services  574  may include management services, provisioning services, deployment services, assignment services, revocation services, wrapping services, and the like. 
     The enterprise mobility technical architecture  500  may include an application store  578 . The application store  578  may include unwrapped applications  580 , pre-wrapped applications  582 , and the like. Applications may be populated in the application store  578  from the application controller  574 . The application store  578  may be accessed by the mobile device  502  through the access gateway  560 , through the public Internet  548 , or the like. The application store  578  may be provided with an intuitive and easy to use user interface. 
     A software development kit  584  may provide a user the capability to secure applications selected by the user by wrapping the application as described previously in this description. An application that has been wrapped using the software development kit  584  may then be made available to the mobile device  502  by populating it in the application store  578  using the application controller  574 . 
     The enterprise mobility technical architecture  500  may include a management and analytics capability  588 . The management and analytics capability  588  may provide information related to how resources are used, how often resources are used, and the like. Resources may include devices, applications, data, and the like. How resources are used may include which devices download which applications, which applications access which data, and the like. How often resources are used may include how often an application has been downloaded, how many times a specific set of data has been accessed by an application, and the like. 
       FIG.  6    is another illustrative enterprise mobility management system  600 . Some of the components of the mobility management system  500  described above with reference to  FIG.  5    have been omitted for the sake of simplicity. The architecture of the system  600  depicted in  FIG.  6    is similar in many respects to the architecture of the system  500  described above with reference to  FIG.  5    and may include additional features not mentioned above. 
     In this case, the left hand side represents an enrolled mobile device  602  with a client agent  604 , which interacts with gateway server  606  (which includes Access Gateway and application controller functionality) to access various enterprise resources  608  and services  609  such as Exchange, Sharepoint, public-key infrastructure (PKI) Resources, Kerberos Resources, Certificate Issuance service, as shown on the right hand side above. Although not specifically shown, the mobile device  602  may also interact with an enterprise application store (StoreFront) for the selection and downloading of applications. 
     The client agent  604  acts as the UI (user interface) intermediary for Windows apps/desktops hosted in an Enterprise data center, which are accessed using the High-Definition User Experience (HDX)/ICA display remoting protocol. The client agent  604  also supports the installation and management of native applications on the mobile device  602 , such as native iOS or Android applications. For example, the managed applications  610  (mail, browser, wrapped application) shown in the figure above are all native applications that execute locally on the mobile device  602 . Client agent  604  and application management framework of this architecture act to provide policy driven management capabilities and features such as connectivity and SSO (single sign on) to enterprise resources/services  608 . The client agent  604  handles primary user authentication to the enterprise, normally to Access Gateway (AG)  606  with SSO to other gateway server components. The client agent  604  obtains policies from gateway server  606  to control the behavior of the managed applications  610  on the mobile device  602 . 
     The Secure InterProcess Communication (IPC) links  612  between the native applications  610  and client agent  604  represent a management channel, which may allow a client agent to supply policies to be enforced by the application management framework  614  “wrapping” each application. The IPC channel  612  may also allow client agent  604  to supply credential and authentication information that enables connectivity and SSO to enterprise resources  608 . Finally, the IPC channel  612  may allow the application management framework  614  to invoke user interface functions implemented by client agent  604 , such as online and offline authentication. 
     Communications between the client agent  604  and gateway server  606  are essentially an extension of the management channel from the application management framework  614  wrapping each native managed application  610 . The application management framework  614  may request policy information from client agent  604 , which in turn may request it from gateway server  606 . The application management framework  614  may request authentication, and client agent  604  may log into the gateway services part of gateway server  606  (also known as NETSCALER ACCESS GATEWAY). Client agent  604  may also call supporting services on gateway server  606 , which may produce input material to derive encryption keys for the local data vaults  616 , or may provide client certificates which may enable direct authentication to PM protected resources, as more fully explained below. 
     In more detail, the application management framework  614  “wraps” each managed application  610 . This may be incorporated via an explicit build step, or via a post-build processing step. The application management framework  614  may “pair” with client agent  604  on first launch of an application  610  to initialize the Secure IPC channel  612  and obtain the policy for that application. The application management framework  614  may enforce relevant portions of the policy that apply locally, such as the client agent login dependencies and some of the containment policies that restrict how local OS services may be used, or how they may interact with the managed application  610 . 
     The application management framework  614  may use services provided by client agent  604  over the Secure IPC channel  612  to facilitate authentication and internal network access. Key management for the private and shared data vaults  616  (containers) may be also managed by appropriate interactions between the managed applications  610  and client agent  604 . Vaults  616  may be available only after online authentication, or may be made available after offline authentication if allowed by policy. First use of vaults  616  may require online authentication, and offline access may be limited to at most the policy refresh period before online authentication is again required. 
     Network access to internal resources may occur directly from individual managed applications  610  through Access Gateway  606 . The application management framework  614  may be responsible for orchestrating the network access on behalf of each managed application  610 . Client agent  604  may facilitate these network connections by providing suitable time limited secondary credentials obtained following online authentication. Multiple modes of network connection may be used, such as reverse web proxy connections and end-to-end VPN-style tunnels  618 . 
     The Mail and Browser managed applications  610  have special status and may make use of facilities that might not be generally available to arbitrary wrapped applications. For example, the Mail application  610  may use a special background network access mechanism that allows it to access an Exchange server  608  over an extended period of time without requiring a full AG logon. The Browser application  610  may use multiple private data vaults  616  to segregate different kinds of data. 
     This architecture may support the incorporation of various other security features. For example, gateway server  606  (including its gateway services) in some cases may not need to validate active directory (AD) passwords. It can be left to the discretion of an enterprise whether an AD password may be used as an authentication factor for some users in some situations. Different authentication methods may be used if a user is online or offline (i.e., connected or not connected to a network). 
     Step up authentication is a feature wherein gateway server  606  may identify managed native applications  610  that are allowed to have access to highly classified data requiring strong authentication, and ensure that access to these applications is only permitted after performing appropriate authentication, even if this means a re-authentication is required by the user after a prior weaker level of login. 
     Another security feature of this solution is the encryption of the data vaults  616  (containers) on the mobile device  602 . The vaults  616  may be encrypted so that all on-device data including files, databases, and configurations are protected. For on-line vaults, the keys may be stored on the server (gateway server  606 ), and for off-line vaults, a local copy of the keys may be protected by a user password or biometric validation. If or when data is stored locally on the mobile device  602  in the secure container  616 , it may be preferred that a minimum of AES 256 encryption algorithm be utilized. 
     Other secure container features may also be implemented. For example, a logging feature may be included, wherein security events happening inside a managed application  610  may be logged and reported to the backend. Data wiping may be supported, such as if or when the managed application  610  detects tampering, associated encryption keys may be written over with random data, leaving no hint on the file system that user data was destroyed. Screenshot protection may be another feature, where an application may prevent any data from being stored in screenshots. For example, the key window&#39;s hidden property may be set to YES. This may cause whatever content is currently displayed on the screen to be hidden, resulting in a blank screenshot where any content would normally reside. 
     Local data transfer may be prevented, such as by preventing any data from being locally transferred outside the application container, e.g., by copying it or sending it to an external application. A keyboard cache feature may operate to disable the autocorrect functionality for sensitive text fields. SSL certificate validation may be operable so the application specifically validates the server SSL certificate instead of it being stored in the keychain. An encryption key generation feature may be used such that the key used to encrypt data on the mobile device  602  is generated using a passphrase or biometric data supplied by the user (if offline access is required). It may be XORed with another key randomly generated and stored on the server side if offline access is not required. Key Derivation functions may operate such that keys generated from the user password use KDFs (key derivation functions, notably Password-Based Key Derivation Function 2 (PBKDF2)) rather than creating a cryptographic hash of it. The latter makes a key susceptible to brute force or dictionary attacks. 
     Further, one or more initialization vectors may be used in encryption methods. An initialization vector will cause multiple copies of the same encrypted data to yield different cipher text output, preventing both replay and cryptanalytic attacks. This will also prevent an attacker from decrypting any data even with a stolen encryption key. Further, authentication then decryption may be used, wherein application data is decrypted only after the user has authenticated within the application. Another feature may relate to sensitive data in memory, which may be kept in memory (and not in disk) only when it&#39;s needed. For example, login credentials may be wiped from memory after login, and encryption keys and other data inside objective-C instance variables are not stored, as they may be easily referenced. Instead, memory may be manually allocated for these. 
     An inactivity timeout may be implemented, wherein after a policy-defined period of inactivity, a user session is terminated. 
     Data leakage from the application management framework  614  may be prevented in other ways. For example, if or when a managed application  610  is put in the background, the memory may be cleared after a predetermined (configurable) time period. When backgrounded, a snapshot may be taken of the last displayed screen of the application to fasten the foregrounding process. The screenshot may contain confidential data and hence should be cleared. 
     Another security feature may relate to the use of an OTP (one time password)  620  without the use of an AD (active directory)  622  password for access to one or more applications. In some cases, some users do not know (or are not permitted to know) their AD password, so these users may authenticate using an OTP  620  such as by using a hardware OTP system like SecurID (OTPs may be provided by different vendors also, such as Entrust or Gemalto). In some cases, after a user authenticates with a user ID, a text may be sent to the user with an OTP  620 . In some cases, this may be implemented only for online use, with a prompt being a single field. 
     An offline password may be implemented for offline authentication for those managed applications  610  for which offline use is permitted via enterprise policy. For example, an enterprise may want StoreFront to be accessed in this manner In this case, the client agent  604  may require the user to set a custom offline password and the AD password is not used. Gateway server  606  may provide policies to control and enforce password standards with respect to the minimum length, character class composition, and age of passwords, such as described by the standard Windows Server password complexity requirements, although these requirements may be modified. 
     Another feature may relate to the enablement of a client side certificate for certain applications  610  as secondary credentials (for the purpose of accessing PM protected web resources via the application management framework micro VPN feature). For example, a managed application  610  may utilize such a certificate. In this case, certificate-based authentication using ActiveSync protocol may be supported, wherein a certificate from the client agent  604  may be retrieved by gateway server  606  and used in a keychain. Each managed application  610  may have one associated client certificate, identified by a label that is defined in gateway server  606 . 
     Gateway server  606  may interact with an enterprise special purpose web service to support the issuance of client certificates to allow relevant managed applications to authenticate to internal PKI protected resources. 
     The client agent  604  and the application management framework  614  may be enhanced to support obtaining and using client certificates for authentication to internal PM protected network resources. More than one certificate may be supported, such as to match various levels of security and/or separation requirements. The certificates may be used by the Mail and Browser managed applications  610 , and ultimately by arbitrary wrapped applications  610  (provided those applications use web service style communication patterns where it is reasonable for the application management framework to mediate HTTPS requests). 
     Application management client certificate support on iOS may rely on importing a public-key cryptography standards (PKCS) 12 BLOB (Binary Large Object) into the iOS keychain in each managed application  610  for each period of use. Application management framework client certificate support may use a HTTPS implementation with private in-memory key storage. The client certificate may not be present in the iOS keychain and may not be persisted except potentially in “online-only” data value that is strongly protected. 
     Mutual SSL or TLS may also be implemented to provide additional security by requiring that a mobile device  602  is authenticated to the enterprise, and vice versa. Virtual smart cards for authentication to gateway server  606  may also be implemented. 
     Both limited and full Kerberos support may be additional features. The full support feature relates to an ability to do full Kerberos login to Active Directory (AD)  622 , using an AD password or trusted client certificate, and obtain Kerberos service tickets to respond to HTTP Negotiate authentication challenges. The limited support feature relates to constrained delegation in Citrix Access Gateway Enterprise Edition (AGEE), where AGEE supports invoking Kerberos protocol transition so it can obtain and use Kerberos service tickets (subject to constrained delegation) in response to HTTP Negotiate authentication challenges. This mechanism works in reverse web proxy (aka corporate virtual private network (CVPN)) mode, and when HTTP (but not HTTPS) connections are proxied in VPN and MicroVPN mode. 
     Another feature may relate to application container locking and wiping, which may automatically occur upon jail-break or rooting detections, and occur as a pushed command from administration console, and may include a remote wipe functionality even when a managed application  610  is not running. 
     A multi-site architecture or configuration of enterprise application store and an application controller may be supported that allows users to be serviced from one of several different locations in case of failure. 
     In some cases, managed applications  610  may be allowed to access a certificate and private key via an API (for example, OpenSSL). Trusted managed applications  610  of an enterprise may be allowed to perform specific Public Key operations with an application&#39;s client certificate and private key. Various use cases may be identified and treated accordingly, such as if or when an application behaves like a browser and no certificate access is required, if or when an application reads a certificate for “who am I,” if or when an application uses the certificate to build a secure session token, and if or when an application uses private keys for digital signing of important data (e.g. transaction log) or for temporary data encryption. 
     Instant Virtual Application Launch 
       FIG.  7    depicts an illustrative diagram for establishing a remote access secure session at a user device  705 . To begin, the user device  705  may comprise a mobile computing device, such as a mobile device, a laptop computer, and the like. The user device  705  may publish a query to establish a secure session using a virtual desktop instance, such as an instance of CITRIX™ Secure Browser or an instance of CITRIX RECEIVER™. The query may pass through a firewall  725  and to a gateway computing platform  710 . The gateway computing platform may comprise, for example, a Netscalar Gateway. 
     The gateway computing platform  710  may establish a connection with a storefront  715 , which may enumerate applications and/or to authenticate the user device  705 . The storefront  715  may also register, with a desktop delivery controller (DDC), a user device token, and may establish a connection with a virtual delivery agent (VDA)  720  for purposes of initiating a brokering process. The VDA  720  may comprise application virtualization software such as XENAPP® or XENDESKTOP®. The VDA may comprise one of a plurality of VDAs and/or terminal servers to which the user device  705  is load balanced. The VDA  720  may encrypt, using an encryption service, user device credentials and then store the user device credentials. The VDA  720  may also generate, using the user device credentials, a logon ticket. The VDA  720  may return the logon ticket to the storefront. 
     The storefront  715  may establish a connection with a secure ticket authority (STA) service  730 , which may be used to store identification information for the VDA  720 . The STA service  730  may comprise, for example, a server. The STA service  730  may issue a STA ticket which may be used for subsequent authentication attempts. For example, the STA ticket may be used to reference an IP address of the VDA  720  and a port number of the VDA  720 . The storefront  715  may also generate an Independent Computing Architecture (ICA) file, and may make the ICA file available to the user device  705 . In some examples, the ICA file may comprise the secure ticket authority (STA) ticket and the logon ticket described above. The ICA file may comprise a name of a requested application or virtual desktop and may comprise an address of the gateway computing platform  710 . 
     The gateway computing device  710  may also establish a connection with the VDA  720 . For example, the gateway computing device  710  may pass requests and authentication credentials from the user device  705  to the VDA  720 . 
       FIG.  8    depicts an example method  800  for establishing and reestablishing a secure session in accordance with one or more illustrative aspects described herein. Referring to  FIG.  8   , at step  805 , a secure session may be pre-launched between a first receiver instance and a virtual delivery agent (VDA). The first receiver instance may be, for example, a first virtual desktop instance such as an instance of an HTML5 receiver instance or an instance of a secure browser. In some examples, the first receiver instance may be based on an endpoint client device, and in other examples, the first receiver instance may be hosted by a cloud service. The pre-launch may begin by using the first receiver instance to retrieve information associated with an application, such as INTERNET EXPLORER™. For example, the user device may publish, using the first receiver instance, a query to establish a secure session. The query may pass through a firewall and to a gateway computing platform, which will subsequently authenticate the first receiver instance and perform connection brokering with the VDA. For example, the gateway computing platform may transmit, through the firewall and to a storefront, an active directory (AD) logon token. The storefront may use the AD logon token to enumerate applications and/or to authenticate the user device. After receiving the AD logon token, the storefront may register, with a desktop delivery controller (DDC), a user device token, and may initiate a brokering process with the VDA. As part of the brokering, the VDA may receive user device credentials, such as the AD logon token. Using an encryption service, the VDA may encrypt and store the user device credentials. The VDA may also generate, using the user device credentials, a logon ticket. The VDA may return the logon ticket to the storefront. The VDA may also transmit, to the storefront, an internet protocol (IP) address of the VDA and port details of the VDA. The storefront may store, in a STA service, the IP address and the port details of the VDA. The STA service may issue a STA ticket, and may transmit the STA ticket to the storefront. 
     The STA ticket may be used to reference an IP address of the VDA and a port number of the VDA. For example, when the user device attempts to reconnect to the VDA, it may not know the address of the VDA. In this example, the user device may connect to gateway computing platform and may provide the gateway computing platform with the STA ticket. The STA ticket may be exchanged across a common gateway protocol (CGP) from the user device to the gateway computing platform and may act as an authentication token between the user device and the gateway computing platform. The STA ticket may conceal internal details of the VDA. In some examples, the gateway computing platform may transmit, via the ICA file and to the user device, the STA ticket. During subsequent requests to reestablish the secure session between the user device and the VDA, the user device may use the STA ticket to circumvent the process of brokering between the storefront and the VDA. In response to receiving the STA ticket, the STA computing platform may transmit, to the gateway computing platform, the IP address and port for the VDA. 
     After brokering to the VDA, the storefront may generate an Independent Computing Architecture (ICA) file, and may make the ICA file available to the user device. For example, the ICA file may comprise a protocol state for the first receiver instance and a plurality of authentication tokens. For example, the ICA file may comprise one or more of the STA ticket, the logon ticket, the name of a requested application or virtual desktop, an address of the gateway, and the like. The ICA file may be stored at the user device. The ICA file may be removed after use. The ICA file may also contain configuration information for connecting to different servers, and may link to the application and/or a server desktop environment. The first receiver instance may then begin to establish a connection with the VDA. For example, the first receiver instance may first establish a websocket connection to provide duplex communication channels over a single transmission control protocol (TCP) connection. The first receiver instance may then establish, via a gateway computing platform and with the VDA, an ICA connection. The ICA connection may be established via an ICA handshake, which may comprise a six way handshake between the gateway computing platform and the VDA. Establishing the ICA connection may also comprise validating the STA ticket. Once the STA ticket is validated, the gateway computing platform may use the IP address and the port details of the VDA to connect the user device to the VDA. In some examples, the gateway computing platform may retrieve a refresh STA ticket from the STA service that may be used to reauthorize a connection in case of network disruption. The VDA may receive, from the gateway computing platform, the request to establish the secure session. In some examples, the VDA may already have identified the user device. For example, the gateway communication platform may transmit, to the VDA, the identity of the user device. Along with the request to establish the secure session, the VDA may receive the logon ticket, which the VDA may use to resolve the user device credentials in the encryption service and to validate the user device. The VDA may transmit, to one of a credential provider filter such as CITRIX™ Credential Provider Filter, or a credential provider such as MICROSOFT™ Credential Provider, the user device credentials. 
     Once an ICA connection, including a connection containing a plurality of virtual channels, is established and once the first receiver instance and VDA are initialized, the first receiver instance may begin to render the secure session and the VDA may host the secure session. The secure session may comprise a high definition experience (HDX) session. 
     After the user device connects to the VDA, the VDA may register, with the user device, a reconnect cookie. In one example, the reconnect cookie may comprise a CGP cookie. Following a possible network disruption, this may allow the user device to reestablish the secure session with the VDA without causing session interruption. For example, following a network disruption, the user device may be able to recreate and reauthorize the network connection by providing, to the gateway computing platform, the refresh STA ticket as previously explained. The user device may then securely reattach to the secure session by providing, to the VDA, the CGP cookie. Thus the user device may reattach to the session without resupplying the user device credentials to one of a credential provider filter or a credential provider. The user device may reattach to the session without performing full re-authentication with the VDA&#39;s authentication subsystem. The gateway computing platform may retrieve a new refresh STA ticket from the STA service. The VDA may generate a new CGP cookie. The new refresh STA ticket and CGP cookie may then be returned to the user device via a CGP handshake protocol, so they can be used following a possible future network disruption. 
     At step  810 , after performing the session pre-launch, the first receiver instance may persist the protocol state for the first receiver instance, established at step  805 , for the first receiver instance. For example, the first receiver instance may record internal protocol state variables comprising the ICA state, such as a framing state, a basic encryption state, a secure ICA encryption state, ICA reducer (compression) state, negotiated ICA capabilities state, and the like. In another example, the first receiver instance may record a network protocol conversation between the first receiver instance and the VDA hosting the pre-launch secure session. The first receiver instance may make the recorded network protocol conversation open to subsequent receiver instances. In this example, the first receiver instance may also record the plurality of authentication tokens. The plurality of authentication tokens may include, for example, a refresh secure ticket authority (STA) ticket that may be used to authenticate the first receiver instance to a gateway computing platform, such as a Netscalar Gateway. The plurality of authentication tokens may also include, for example, a common gateway protocol (CGP) cookie, which may be used for re-authentication and re-attachment to the secure session. 
     In some examples, the first receiver instance may persist the protocol state for the first receiver instance until the end of the ICA handshake. For example, the first receiver instance may persist the protocol state for the first receiver instance until the end of the ICA handshake because, assuming that the ICA protocol network conversation does not include one or more keep alive packets, after the pre-launch the secure session will be stale. In this example, recording until the end of the ICA handshake may be sufficient to establish the protocol modules and capabilities. The first receiver instance may ignore ICA packets transmitted after the ICA handshake because they may not be relevant to a new receiver instance. 
     In other examples, the first receiver instance may record the entire network protocol conversation between the first receiver instance and the VDA. In these examples, the protocol state for the first receiver instance may be shared locally on the user device as opposed to being sent over a network. 
     At step  815 , once the first receiver instance has persisted the protocol state, a user device may receive an instruction to launch the secure session comprising one of a web link, a published application with content, a new published application, and the like. For example, if a user is attempting to access content in a secure browser, the user may provide a user input to the user device comprising a uniform resource locator (URL). In another example, the user may be attempting to launch a new HDX template application on a mobile device, and may provide a user input to the mobile device requesting that the mobile device launch the new HDX template application from a mobile device springboard. In yet another example, the user may provide a user input to the user device comprising an instruction to launch a new HTML5 published application or to launch a new published application from an application store. For example, the user may attempt to launch MICROSOFT WORD™ MICROSOFT EXCEL™, and the like. 
     At step  820 , once the user device attempts to access the secure session, the first receiver instance may share, with a second receiver instance, the protocol state for the first receiver instance persisted above at step  810 . The first receiver instance may share the protocol state for the first receiver instance by performing one of a plurality of sharing and caching optimizations of the ICA file, determined at step  805 , between the first receiver instance and the second receiver instance. 
     For example, the first receiver instance and the second receiver instance may comprise instances of a secure browser service, such as CITRIX™ Secure Browser, or HTML5 receiver. The first receiver instance may comprise an HTML5 receiver instance hosted and managed by a cloud service, and the second receiver instance may comprise an HTML5 receiver instance hosted by a client endpoint and managed by the cloud service. The first receiver instance may send, to the second receiver instance, the protocol state for the first receiver instance in the ICA file determined above at step  805 . In this example, the first receiver instance may send, to the second receiver instance, the protocol state for the first receiver instance each time the second receiver instance attempts to establish the secure session. The ICA file may be sent, via a one way transmission, to the second receiver instance. Once the second receiver instance receives the protocol state for the first receiver instance, the second receiver instance may cache the protocol state for the first receiver instance. Once the protocol state for the first receiver instance is cached at the second receiver instance, the first receiver instance may send the protocol state of the first receiver instance when there is an update or change to the first receiver instance and may not otherwise send the protocol state of the first receiver instance to the second receiver instance. Once cached, the protocol state of the first receiver instance may be embedded into the second receiver instance. In some examples, the protocol state of the first receiver instance may also be embedded into the first receiver instance. 
     In another example, the first receiver instance and the second receiver instance may comprise instances of HDX software development kit (SDK) mobile applications. The HDX SDK mobile applications may be signed by a shared profile and the first receiver instance may share, with the second receiver instance and via an operating system (OS) key chain, the protocol state of the first receiver instance. Alternatively, the HDX SDK mobile applications may be managed with one of mobile application management (MAM), mobile device management (MDM), or a combination of MDM and MAM, and the first receiver instance may share, with the second receiver instance and via a mobile device experience (MDX) secret vault, the protocol state of the first receiver instance. The second receiver instance may then access, via the MDX secret vault, the protocol state of the first receiver instance and any associated authentication tokens. Sharing of the protocol state of the first receiver instance between HDX mobile applications is illustrated and described below further with regard to  FIG.  11   . 
     In yet another example, the first receiver instance and the second receiver instance may comprise instances of HTML5 receivers running in different browser tabs. For example, a user may attempt to launch different content in each of two HTML5 receivers running in different tabs of INTERNET EXPLORER™. In this example, the first receiver instance may store, using local browser storage, the protocol state of the first receiver instance and any associated authentication tokens. The second receiver instance may then access the protocol state of the first receiver instance and the associated authentication tokens. The second receiver instance may comprise one of a new instance of an HTML5 receiver or an existing HTML receiver instance in a browser tab that may be brought into focus. Sharing of the protocol state of the first receiver instance between instances of HTML receivers running in different browser tabs is illustrated and described further below with regard to  FIG.  12   . 
     At step  825 , after receiving the protocol state of the first receiver instance, the second receiver instance may perform a transport reconnect, and may be re-authenticated to the gateway computing platform and secure session. The second receiver instance may perform the transport reconnect and authentication process via the CGP and using the authentication tokens. For example, the second receiver instance may use the refresh STA ticket for authorization to the gateway computing platform and may use the CGP cookie to re-authenticate and to re-attach to the pre-created session, established at step  805 . The second receiver instance may perform the transport reconnect prior to authentication of the connection between the VDA and the second virtual desktop instance. 
     At step  830 , the second receiver instance may suspend network activity for a predetermined period of time. This may include suspension of the CGP. 
     At step  835 , once the network activity has been suspended at step  830 , the second receiver instance may perform, using the protocol state of the first receiver instance, an in-application recreation of the protocol state of the first receiver instance, resulting in a protocol state of the second receiver instance. For example, the second receiver instance may recreate the ICA state generated at step  805  from the protocol state of the first receiver instance. This recreation of the protocol state of the first receiver instance may be performed from memory of the user device, and may be placed in storage. To generate the protocol state of the second receiver instance, the second receiver instance may read host-to-client protocol comprising the protocol state of the first receiver instance and may drop client-host responses. By generating the protocol state of the second receiver instance offline, the protocol state stored at the VDA may remain unaffected. This method may avoid multiple roundtrip network latency of presentation-level protocol negotiation and may reduce HDX session reconnect processing time. 
     For example, to generate the protocol state of the second receiver instance, the second receiver instance may read from the ICA file generated above at step  810 , and the second receiver instance may throw away the corresponding write operations. This may allow the second receiver instance to simulate communication and negotiation with a network by communicating with a recorded network conversation. The second receiver instance may then use this recorded network conversation to create the protocol state of the second receiver instance. This may reduce the computing cost of generating the protocol state of the second receiver instance. 
     In some examples, such as when the first receiver instance comprises an instance of HTML5 receiver, the first receiver instance may embed, within itself, the protocol state of the first receiver instance. In these examples, when a user downloads, to a user device, a second instance of the HTML5 receiver, the protocol state for the first receiver instance may already be embedded. 
     At step  840 , after creation of the protocol state for the second receiver instance at step  835 , the second receiver instance may resume normal network activity and the CGP protocol. The second receiver may then continue normal communication with the session at the VDA. The communication between the second receiver and the session may involve presentation level protocols such as ICA or ICA Virtual Channels tunneled over CGP. The communication between the second receiver and the session may allow user interaction with the session and/or exchange of data. The communication between the second receiver and the session may further modify the ICA state at the second receiver. 
     At step  845 , after resuming normal network activity and the CGP at step  840 , the second receiver instance may reset an ICA reducer compression state via a new ICA protocol command. The second receiver instance may also reset an ICA stack protocol header overhead, which may depend on a type of transport used. In some examples, the transport may comprise an enlightened data transport (EDT). In other examples, the transport may comprise a transmission control protocol (TCP). Resetting the ICA reducer compression state and the ICA stack protocol header may be performed in parallel, and the reset may not affect logon time. 
     At step  850 , the requested content (such as a web link, published application with content, new published application, or the like) may be launched via the second receiver instance. 
     Although steps  805 - 850  are shown in one example order in  FIG.  8   , steps  805 - 850  need not all be performed in the order specified and some steps may be omitted or changed in order. The method  800  may be a recursive method that continuously repeats. The method  800  may be repeated in full or in part. 
       FIG.  9    depicts an example method  900  for establishing and reestablishing a secure session via a progressive logon in accordance with one or more illustrative aspects described herein. The example method  900  may comprise an extended version of the method  800 , described above. Referring to  FIG.  9   , at step  905 , a secure session may be pre-launched between a first receiver instance and a virtual delivery agent VDA. Actions performed at step  905  may be similar to those described above with regard to step  805 . 
     At step  910 , after performing the session pre-launch, the first receiver instance may persist the protocol state for the first receiver instance, established at step  805 , for the first receiver instance. Actions performed at step  910  may be similar to those described above with regard to step  810 . 
     At step  915 , once the first receiver instance has persisted the protocol state, a user device may receive an instruction to launch the secure session comprising one of a web link, a published application with content, a new published application, and the like. Actions performed at step  915  may be similar to those described above with regard to step  815 . 
     At step  920 , once the user device attempts to access the secure session, the first receiver instance may share, with a second receiver instance, the protocol state for the first receiver instance persisted above at step  910 . Actions performed at step  920  may be similar to those described above with regard to step  820 . 
     At step  925 , after receiving the protocol state of the first receiver instance, the second receiver instance may perform a transport reconnect, and be re-authenticated to the gateway computing platform and secure session. Actions performed at step  925  may be similar to those described above with regard to step  825 . 
     At step  930 , the second receiver instance may suspend network activity for a predetermined period of time. Actions performed at step  930  may be similar to those described above with regard to step  830 . 
     At step  935 , once the network activity has been suspended at step  930 , the second receiver instance may perform, using the protocol state of the first receiver instance, an in-application recreation of the protocol state of the first receiver instance, resulting in a protocol state of the second receiver instance. Actions performed at step  935  may be similar to those described above with regard to step  835 . 
     At step  940 , after creation of the protocol state for the second receiver instance at step  935 , the second receiver instance may resume network activity and the CGP protocol. Actions performed at step  940  may be similar to those described above with regard to step  840 . 
     At step  945 , after resuming normal network activity and the CGP protocol at step  940 , the second receiver instance may reset an ICA reducer compression state via a new ICA protocol command. The second receiver instance may also reset an ICA stack protocol header overhead, which may depend on a type of transport used. Actions performed at step  945  may be similar to those described above with regard to step  845 . 
     At step  950 , the requested content (such as a web link, published application with content, new published application, or the like) may be launched via the second receiver instance. Actions performed at step  950  may be similar to those described above with regard to step  850 . 
     At step  952 , the second receiver instance may determine whether all protocol states of the first receiver instance were persisted. In some examples, various virtual channel (VC) capabilities and states depending on a user device type and/or a local environment may not be persisted. If all protocol states of the first receiver instance were persisted, the second receiver instance may proceed to step  954  to initiate a full logon. If the protocol states of the first receiver instance were not all persisted, the second receiver instance may proceed to step  955  to initiate a progressive logon. 
     At step  954 , the second receiver instance may establish and display the web link, published application with content, or published application launched above at step  950 . For example, the second receiver instance may load all features associated with the secure session. The method  900  may then proceed to step  975  to determine whether another attempt to reestablish the secure session is received. 
     At step  955 , the second receiver instance may initiate the progressive logon by establishing a display and may prompt for initial user input via the user device. For example, the user may have access to keyboard, mouse, and basic display functions via the second receiver instance. 
     At step  960 , the second receiver instance may transmit, to the VDA, a list of virtual channels and capabilities of the user device. For example, the user device may be associated with an audio virtual channel, a multimedia virtual channel, a touch virtual channel, a Thinwire graphics virtual channel, an independent software vendor (ISV) virtual channel, and the like. The second receiver may also load, depending on capabilities of the second receiver instance, a plurality of VC modules associated with the virtual channels. 
     At step  965 , the VDA may transmit, to hosts of the VC modules, a session reconnect event. 
     At step  970 , the virtual channels may be reopened and their capabilities may be renegotiated over their respective VC protocols. This may allow the second receiver instance to progressively logon to additional HDX features beyond the display and initial prompt for user input. For example, this may allow the second receiver instance to launch features such as client device mapping (CDM), universal serial bus (USB), multimedia features, audio features, printing capability, drag and drop features, and the like. The VDA may also determine, based on the transmission at step  960 , the user device capabilities. By loading basic features upfront at step  955 , the method described herein may improve user interactions with desktop virtualization programs and decrease delay time caused by initial loading of platform and/or receiver specific features. 
     At step  975 , a determination may be made regarding whether another receiver instance is attempting to connect to the secure session. If not, the method  900  may end. If so, the method  900  may return to step  915 , and a user may attempt to launch the web link, the published application with content, or the new published application. In some examples, the first receiver instance may attempt to reestablish the secure session. In other examples, a new receiver instance may attempt to reestablish the secure session. 
     Although steps  905 - 975  are shown in one example order in  FIG.  9   , steps  905 - 975  need not all be performed in the order specified and some steps may be omitted or changed in order. The method  900  may be a recursive method that continuously repeats. The method  900  may be repeated in full or in part. 
       FIG.  10    depicts an example method  1000  for establishing and reestablishing a secure session via an asynchronous launch in accordance with one or more illustrative aspects described herein. The example method  1000  may comprise an extended version of the method  800 , described above. Referring to  FIG.  10   , at step  1005 , a secure session may be pre-launched between a first receiver instance and a virtual delivery agent VDA. Actions performed at step  1005  may be similar to those described above with regard to step  805 . 
     At step  1010 , after performing the session pre-launch, the first receiver instance may persist the protocol state for the first receiver instance, established at step  1005 , for the first receiver instance. Actions performed at step  1010  may be similar to those described above with regard to step  810 . 
     At step  1015 , once the first receiver instance has persisted the protocol state, a user device may receive an instruction to launch the secure session comprising one of a web link, a published application with content, a new published application, and the like. Actions performed at step  1015  may be similar to those described above with regard to step  815 . 
     At step  1017 , the VDA may determine whether an asynchronous launch should be performed. This may depend on capabilities of the device, anticipated connection time, the content to be loaded, and the like. If an asynchronous launch should be performed, the VDA may proceed to step  1020  to launch the web link, the published application with content, or the new published application. For example, the VDA may launch the content in parallel with the process of re-establishing the secure session. If an asynchronous launch should not be performed, the method  1000  may proceed to step  1025  without performing the methods described at step  1020 . 
     At step  1020 , prior to re-establishing the secure session, initially established at step  1005 , between a second receiver instance and the VDA, content, such as a web page, may be loaded in a backend of the user device. In this example, the content may load before the second receiver instance establishes the secure session. In some examples, the VDA may securely prelaunch a secure session, such as an HDX session, along with an initial application with optional content. The VDA may also connect to the gateway computing platform based on a brokering instruction to prepare for a secure session. In this example, the VDA may not wait for the second receiver instance to connect to the gateway computing platform before establishing a connection with the gateway computing platform. As a result, the secure session may have already launched and loaded the content by the time the second receiver instance re-establishes the secure session with the VDA. For example, a user may attempt to load a web page via a second instance of an internet browser. The VDA may load the web page in the secure session. Then, by the time the second instance of the internet browser actually establishes the secure session with the VDA, the web page may already be loaded. Launching the content at step  1020  may be responsive to launching the secure session at step  1015 . 
     At step  1025 , once the user device attempts to access the secure session, the first receiver instance may share, with a second receiver instance, the protocol state for the first receiver instance persisted above at step  1010 . Actions performed at step  1025  may be similar to those described above with regard to step  810 . 
     At step  1030 , after receiving the protocol state of the first receiver instance, the second receiver instance may perform a transport reconnect, and be re-authenticated to the gateway computing platform and secure session. Actions performed at step  1030  may be similar to those described above with regard to step  825 . 
     At step  1035 , the second receiver instance may suspend network activity for a predetermined period of time. Actions performed at step  1035  may be similar to those described above with regard to step  830 . 
     At step  1040 , once the network activity has been suspended at step  1035 , the second receiver instance may perform, using the protocol state of the first receiver instance, an in-application recreation of the protocol state of the first receiver instance, resulting in a protocol state of the second receiver instance. Actions performed at step  1040  may be similar to those described above with regard to step  835 . 
     At step  1045 , after creation of the protocol state for the second receiver instance at step  1040 , the second receiver instance may resume network activity and the CGP protocol. Actions performed at step  1045  may be similar to those described above with regard to step  840 . 
     At step  1050 , after resuming normal network activity and the CGP protocol at step  1045 , the second receiver instance may reset an ICA reducer compression state via a new ICA protocol command. The second receiver instance may also reset an ICA stack protocol header overhead, which may depend on a type of transport used. Actions performed at step  1050  may be similar to those described above with regard to step  845 . 
     At step  1053 , the VDA may determine whether the web link, the published application with content, or the new published app launched by the user at step  1015  have been launched on the VDA. If they have not been launched at the VDA, the method may proceed to step  1055  to launch the web link, the published application with content, or the new published application at step  1055 . If they were previously launched at step  1020 , the method  1000  may end. 
     Although steps  1005 - 1055  are shown in one example order in  FIG.  10   , steps  1005 - 1055  need not all be performed in the order specified and some steps may be omitted or changed in order. The method  1000  may be a recursive method that continuously repeats. The method  1000  may be repeated in full or in part. 
       FIG.  11    illustrates an example virtual mobile application launch, as described above at step  820  and in accordance with one or more illustrative aspects described herein. For example, a user may want to establish, using a mobile device  1140 , a secure session and launch multiple applications. These applications may comprise instances of HDX SDK mobile applications, such as first instance of HDX mobile application  1110  and a second instance HDX mobile application  1120 . In this example, the first instance of HDX mobile application  1110  may share, with the second instance of HDX mobile application  1120 , and via an OS key chain or an MDX shared secret vault  1130 , a protocol state of the first instance and a plurality of authentication tokens used to establish a connection between the first instance of HDX mobile application  1110  and a gateway computing platform or VDA. The first instance of the HDX mobile application  1110  may share the protocol state of the first instance and the plurality of authentication tokens via a transmission  1250 . The second instance of the HDX mobile application  1120  may generate, based on the protocol state of the first HDX mobile application, a protocol state of the second HDX mobile application, and may use the protocol state of the second HDX mobile application to re-establish the secure session. The HDX SDK mobile applications may be managed with one of mobile application management (MAM), mobile device management (MDM), or a combination of MDM and MAM. The HDX SDK mobile applications may be signed by a shared profile. 
       FIG.  12    illustrates an example virtual launch of HTML5 receiver instances, as described above at step  820  and in accordance with one or more illustrative aspects described herein. For example, a user may be interacting with a browser  1240 . The user may be working within a first browser tab using a first HTML5 receiver instance  1210 . In response to a request to launch a second instance of HTML5 receiver  1220  in a second browser tab, the first HTML5 receiver instance may store, via a communication  1350 , a protocol state of the first HTML5 receiver instance  1210  and authentication tokens associated with the protocol state of the first HTML5 receiver instance  1210  in a local browser storage  1230 . The second HTML5 receiver instance may then access the protocol state of the first HTML5 receiver instance and the associated authentication tokens. The second HTML5 receiver instance may comprise one of a new instance of an HTML5 receiver or an existing HTML receiver instance in a browser tab that may be brought into focus. The second HTML5 receiver  1220  instance may generate, based on the protocol state of the first HTML5 receiver instance, a protocol state of the second HTML5 receiver, and may use the protocol state of the second HTML5 receiver to re-establish the secure session. 
     Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are described as example implementations of the following claims.