Patent Publication Number: US-11393300-B2

Title: Secure point of sale terminal and associated methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/782,294, filed Oct. 12, 2017, which is a continuation of U.S. application Ser. No. 15/645,912, filed Jul. 10, 2017, which is a continuation of U.S. application Ser. No. 14/877,909, filed Oct. 7, 2015, which claims the benefit of U.S. Provisional Application No. 62/072,420, filed Oct. 29, 2014, and U.S. Provisional Application No. 62/074,061, filed Nov. 2, 2014, all of which are incorporated by reference in their entirety herein for all purposes. 
    
    
     BACKGROUND 
     Point-of-sale (POS) systems allow users, such as merchants, to offer customers flexibility in completing goods or services sales transactions. However, such systems may not provide a mechanism for secure transactions such as entering a PIN (personal identification number) associated with a credit, debit, EMV, and other payment cards, including cards having embedded integrated circuits for, among other things, authentication. The relative lack of security may lead to identity theft or fraudulent transactions, and ultimately a relatively poor consumer and/or merchant experience. 
     Point of sale terminals need to have a secure operating environment that guarantee unscrupulous people cannot steal sensitive data or hijack the payment processing capabilities of the device. Unfortunately, this results in POS terminals that are closed systems, and have very limited applications that can be used to customize and augment the terminal functionality. In addition, the terminal needs a dedicated PIN pad that needs to be physically protected to meet strict security requirements and needs physical and logical security to isolate sensitive data from the regular operating environment. 
     SUMMARY 
     In one embodiment, a device is provided. The device comprises an input device with an input device user data connection to an input device controller. The device also comprises a multiplexer with a multiplexer control input port, a multiplexer data input port communicatively coupled to the input device controller, a first data output port, and a second data output port. The device also comprises a secure processor with: (i) a control output port communicatively coupled to the multiplexer control input port; and (ii) a secure processor data input port communicatively coupled to the first data output port. The device also comprises a second processor with a second processor data input port communicatively coupled to the second data output port. The multiplexer is configurable between a first state and a second state. The multiplexer data input port is communicatively coupled to the first data output port through the multiplexer when a current state of the multiplexer is the first state. The multiplexer data input port is communicatively coupled to the second data output port through the multiplexer when the current state of the multiplexer is the second state. The current state of the multiplexer is exclusively controlled by the secure processor via the control output port. 
     In another embodiment, an integrated circuit is provided. The integrated circuit comprises a multiplexer with a multiplexer control input port, a multiplexer data input port, a first data output port, and a second data output port. The integrated circuit also comprises an input pin communicatively coupled to the multiplexer data input port. The integrated circuit also comprises a multiplexer control circuit communicatively coupled to the multiplexer control input port. The integrated circuit also comprises an input device data processing circuit communicatively coupled to the first data output port. The integrated circuit also comprises an output pin communicatively coupled to the second data output port. The multiplexer is configurable between a first state and a second state via the multiplexer control circuit. The multiplexer data input is communicatively coupled to the first data output port through the multiplexer when the current state of the multiplexer is the first state. The multiplexer data input is communicatively coupled to the second data output port through the multiplexer when the current state of the multiplexer is the second state. 
     In another embodiment, a method is provided. The method comprises receiving secure data from a user via an input device. The method also comprises routing the secure data to a secure processor using a hardware multiplexer. The method also comprises processing the secure data using the secure processor. The method also comprises receiving non-secure data from the user via the input device. The method also comprises routing the non-secure data to a second processor using the hardware multiplexer. The method also comprises processing the non-secure data using the second processor. The method also comprises altering a routing state of the hardware multiplexer using the secure processor. The routing state of the hardware multiplexer is only controlled by the secure processor. 
     In another embodiment, another method is provided. The method comprises receiving secure data from a user via an input pin of an integrated circuit. The method also comprises routing the secure data to an input device data processing circuit using a hardware multiplexer. The method also comprises processing the secure data using the input device data processing circuit. The method also comprises receiving non-secure data from the user via the input pin. The method also comprises routing the non-secure data to an output pin of the integrated circuit using the hardware multiplexer. The method also comprises altering a routing state of the hardware multiplexer using the secure processor. The routing state of the hardware multiplexer is only be controlled by the secure processor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates two architectures for a client device in a secure POS platform that are in accordance with one or more example embodiments. 
         FIG. 2  illustrates an example network architecture for a secure POS platform in accordance with one or more example embodiments. 
         FIG. 3  illustrates an example component architecture for certain components of the secure POS platform shown in  FIG. 2  in accordance with one or more example embodiments. 
         FIG. 4  illustrates a diagram of an example computer system for certain components of the secure POS platform shown in  FIG. 2  in accordance with one or more example embodiments. 
         FIG. 5  illustrates a flow diagram of an example method for operating a secure POS platform in accordance with one or more example embodiments. 
         FIG. 6  illustrates a diagram of an example client device for a secure POS platform operating in a non-secure mode in accordance with one or more example embodiments. 
         FIG. 7  illustrates a diagram of an example client device for a secure POS platform operating in a secure mode in accordance with one or more example embodiments. 
         FIGS. 8A-8D  illustrate diagrams of example device architectures for client devices for a secure POS platform in accordance with one or more example embodiments. 
         FIG. 9  illustrates a flow diagram of an example method for operating a secure POS platform in accordance with one or more example embodiments. 
         FIG. 10  illustrates a ladder diagram of communications between a secure processor and application processor for conducting a secure transaction that is in accordance with one or more example embodiments. 
         FIG. 11  illustrates another ladder diagram of communications between a secure processor, multiplexer, and second input device, for conducting a secure transaction that is in accordance with one or more example embodiments. 
         FIG. 12  illustrates another ladder diagram of communications between a secure processor, application processor, and server, for conducting a secure transaction that is in accordance with one or more example embodiments. 
         FIG. 13  illustrates another flow diagram of an example method for operating a secure POS platform in accordance with one or more example embodiments. 
         FIG. 14  illustrates another ladder diagram of communications for operating a secure POS platform in accordance with one or more example embodiments. 
         FIG. 15  illustrates an upper view of an example cover for a POS or client device in accordance with one or more example embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference now will be made in detail to embodiments of the disclosed invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the present technology, not as a limitation of the present technology. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present technology without departing from the scope thereof. For instance, features illustrated or described as part of one embodiment may be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present subject matter covers all such modifications and variations within the scope of the appended claims and their equivalents. 
     Described herein are systems and methods for providing secure POS (point-of-sale) platforms and associated methods. Certain embodiments of the systems and methods described herein may facilitate providing a secure POS platform to provide secure interactions with local services and/or third-party applications during one or more POS transactions (e.g., financial transactions, login sessions, etc.) at physical and/or remote locations. Further, certain embodiments of the systems and methods may also provide or otherwise facilitate secure communication with a user of the POS platform. 
     POS transactions on a POS platform may influence the selection of data communication channels within the secure POS platform, where these data communication channels may be used to process the data associated with one or more POS transactions. For example, a merchant may use a POS platform to complete a transaction with a customer who may have placed an order for goods or services (e.g., purchasing milk, etc.), where the merchant or the customer may swipe a credit card to complete the transaction. Based upon the type of transaction, the POS platform may choose one or more data channels to access one or more processors within the POS platform to complete the transaction. For example, if the transaction involves secure data, such as credit card information or a personal identification number (PIN) a secure channel may be used; whereas if the transaction involves unsecure data, such as the entry of a quantity of milk to be purchased, a non-secure channel may be used. The one or more data channels can be used to process or otherwise complete the transaction. 
     Although a bulk of the disclosure is directed to a POS platform used to facilitate a financial transaction between an owner of the terminal and another party, the approaches described herein are more broadly applicable to any device that is used to handle both secure and non-secure data. For example, an A™ may include an account management system and may also include an application for ordering stamps or other applications that do not require the receipt of secure data from the user. As another example, a tablet computer may include core applications that are used to interact with financial institutions or ecommerce systems while other applications can be added to the device that do not require the use of secure information. Any of these and similar devices can benefit from some of the approaches described herein. 
     POS Platform Overview 
     As shown in  FIG. 1 , secure POS platform  100  may include a number of hardware components including input device controller (IDC)  102 , multiplexer (MUX)  104 , secure processor (SP)  106 , and application processor (AP)  108 . Throughout this specification, a touch screen will be used as an exemplary input device such that the input device controller may be referred to as a touch controller (TC). However, as mentioned previously, the input device controller could be a controller for any number of input devices or user interfaces such as a keypad, audio interface, or wireless interface. The above are only examples of components that may be included in a secure POS platform, such as  100 , and other components may also be included. 
     Referring to  FIG. 1 , there is shown an example schematic view of a secure POS platform  100  in accordance with one or more example embodiments. In  FIG. 1 , secure POS platform  100  can include one or more components, such as  102 ,  104 ,  106 , and  108  that are internal to associated client device  120 , which can be a merchant POS device. Client device  120  may be operated by a user  110  entering various information for a purchase transaction via an associated input device associated with the client device  120  to facilitate a purchase transaction. The input device could be a touch screen integrated with the client device  120 . The input device could be a multiuse input device such that it is used for both secure operations and normal (non-secure) operations. Secure POS platform  100  may evaluate whether the certain user inputs via the multiuse input device are associated with either secure operations or normal (non-secure) operations. An example of a secure operation is entering a PIN. An example of a non-secure operation is entering a quantity of an item to be purchased via the same touch screen. 
     The hardware components, such as  102 ,  104 , and  106 , may be interconnected to provide various functions in response to certain actions performed by user  110  with respect to client device  120 , such as inputting information via an associated input device or user interface. The hardware components can be implemented as individual integrated circuits (ICs) on a main board of client device  120 . However, MUX  104  and SP  106  could also be implemented on a single application specific integrated circuit (ASIC) while IDC  102  and AP  108  are kept as separate ICs. The chip comprising MUX  104  and SP  106  could then be used as a “secure chip” in a chip set comprising the secure chip, IDC  102 , and AP  108 . As will be described later, integrating MUX  104  and SP  106  onto a single chip provides certain benefits in that IDC  102  and AP  108  could be commercially available ICs that are broadly available beyond the more limited market for specialized secure POS hardware. In other words, an application processor chip and peripheral controller chip could be standard devices for the control of peripherals and running applications generally, and do not need to be augmented in any manner to realize the security benefits of some of the approaches described herein. Any of the functions performed by SP  106  that are disclosed in this specification could be executed on the secure chip. For example, tamper detection circuitry implemented on the secure chip could receive a tamper indication from a tamper sensor and clear a memory implemented on the secure chip to protect encryption keys or other secure information stored on the secure chip. 
     AP  108  can be a standard processor used to implement an operating system for client device  120 . For example, AP  108  can run the Android OS™). In general, the AP can maintain full control over the client device  120  while the device is running applications that don&#39;t require secure information. For example, the main application run by the AP  108  could be the standard merchant-facing retail checkout application used to accept inputs regarding a customer&#39;s order and tally the total of a specific purchase transaction. As another example, the main application run by AP  108  could be a restaurant server&#39;s ordering application used to input orders taken by the server. AP  108  can operate with a cache and main memory that are physically separate from the memory used by SP  106 . This configuration provides certain benefits in that certain attacks may use a processor to write instructions to memory for later execution and exploitation of a secure program running on the same processor, or may use the processor to read and illicitly obtain data from the memory which was utilized and left over by a secure program using the same memory. These kinds of vulnerabilities can be avoided by not allowing the AP to have access to the same memory as the SP. 
     MUX  104  is a hardware multiplexer that receives control inputs from SP  106  and routes data received from IDC  102  to one or more data channels based on those control inputs. The data could be routed through transistors that turn on or off in response to control signals. MUX  104  could be an IC with one or more control pins, one or more input pins and at least two output pins. In approaches where MUX  104  and SP  106  were implemented on a single chip, MUX  104  could be a block of analog circuitry on the secure chip controlled by a digital output from SP  106 . In such approaches, MUX  104  and SP  106  could exchange information via interconnects in the IC. 
     In one embodiment, illustrated by the region of  FIG. 1  indicated by reference number  10 , a secure transaction process can be implemented using the hardware components shown in  FIG. 1 . For example, when user  110  interacts with an input device or user interface associated with client device  120 , IDC  102  can transmit certain user inputs to MUX  104 . In certain instances, when secure POS platform  100  detects or prompts user entry of secure data (e.g., a user entering PIN information) via the input device or user interface associated with client device  120 , the operation is treated as a secure transaction and/or operation. In this instance, SP  106  can control the flow of secure data through MUX  104 . 
       FIG. 1  illustrates another example schematic view of a secure POS platform which is illustrated by the region of  FIG. 1  indicated by reference number  20 , which is in accordance with one or more example embodiments. In the embodiment shown  20 , entry of data that may be considered non-secure (normal mode) can be facilitated via the hardware components, such as  102 ,  104 ,  106 , and  108  of client device  120 , such that data passes from a peripheral to AP  108 . For example, IDC  102  may communicate user inputs to MUX  104 , such as when user  110  interacts with an associated input device or user interface. MUX  104  can then pass the information received from this interaction to AP  108 . AP  108  may then perform transactions and/or operations that may be considered non-secure. In addition, entry of data that may be considered secure can be facilitated via the same hardware components, such as  102 ,  104 ,  106 , and  108  of client device  120 . However, the data from the peripheral will now be routed to SP  106  instead of AP  108 . For example, under the control of SP  106 , MUX  104  will route input data from the peripheral to SP  106 . SP  106  may then perform operations on the data that may be considered secure. IDC  102  may be completely unaware as to which processor the input data is being routed to. 
     Example Network Architecture 
     Referring now to  FIG. 2 , there is shown an example network architecture of a secure POS platform  200  according to certain embodiments of the disclosure. The network architecture of the secure POS platform  200  may include one or more client devices  120 . Client devices  120  can communicate via a network with back-end servers  140 , remote services servers  160 , and control servers  180 . Each of the components in network architecture of the secure POS platform  200  are discussed in more detail below. 
     The one or more client devices  120  may be a merchant POS device, a laptop computer, a desktop computer, another device with computer functionalities, or any combination thereof and/or other types of devices associated with a merchant at various locations. For example, a client device, such as  120  may be a POS terminal provided by First Data Corporation of Atlanta, Georgia. Other examples of client device  120  may be purpose-built POS equipment, a self-service kiosk, a smart phone, a tablet, a wearable computer device, or an e-reader operating a mobile operating system, such as Android OS™). An example hardware architecture of a particular client device that can be used in place of client device  120  is illustrated and described in  FIG. 6  below. 
     In  FIG. 2 , each client device  120  may communicate with one or more remote services servers  160  via a client API, which may be used to access the services and functionalities provided by the remote services servers  160 . Each of the client devices  120  may also communicate with the one or more remote services servers  160  via one or more networks  130 . The one or more remote services servers  160  may be one or more independent computer systems, such as the computer system  400  of  FIG. 4 . In some embodiments, the one or more remote services servers  160  may be a cloud-based computer system, where no on-premise servers are required, which may reduce relative cost and complexity of hardware, installation, and ongoing maintenance and administration. 
     The network architecture of the secure POS platform  200  may also include one or more back-end servers  140 . The one or more back-end servers  140  may be coupled to the one or more remote services servers  160  via a respective or single back-end API  145 . The back-end API  145  may be an application programming interface for the one or more back-end servers  140  to supplement the services provided by the one or more remote services servers  160 . The one or more back-end servers  140  may communicate with the one or more remote services servers  160  via network  130  as well. The one or more back-end servers  140 , and/or the remote services servers  160  may be configured to handle financial transactions by authorizing or declining transactions. Each of the back-end servers  140  may be one or more independent computer systems, such as the computer system  400  of  FIG. 4 , for performing back-end processes for purchase transactions. 
     The secure POS platform  200  may also include one or more control servers  180 . Each of the control servers  180  may provide secure communication sessions between a customer support representative (e.g., user  190 ) and one or more client devices (e.g., client devices  120 ). The one or more control servers  180  may be one or more independent computer systems, such as the computer system  400  of  FIG. 4 . 
     The one or more networks  130  may be a system for communication. Each of the networks  130  may encompass a variety of mediums of communication, such as wired communication for one part and wireless communication for another part. The one or more networks  130  may be part of the Internet. 
     For example, a network, such as  130 , may include an Ethernet or other wire-based network or a wireless NIC (WNIC) or wireless adapter for communicating with a wireless network, such as a WI-Fl network. The network  130  may include any suitable network for any suitable communication interface. As an example and not by way of limitation, the network channel may include an ad hoc network, a personal area network (PAN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), or one or more portions of the Internet or a combination of two or more of these networks. One or more portions of one or more of these networks may be wired or wireless. As another example, the network may be a wireless PAN (WPAN) (such as, for example, a BLUETOOTH WPAN), a WI-Fl network, a WI-MAX network, a 3G or 4G network, a cellular telephone network (such as, for example, a Global System for Mobile Communications (GSM) network). 
     In one embodiment, the one or more networks  130  may use standard communications technologies and/or protocols. Thus, each network  130  may include links using technologies such as Ethernet, 802.11, worldwide interoperability for microwave access (WiMAX), 3G, 4G, CDMA, digital subscriber line (DSL), etc. Similarly, the networking protocols used on the network may include multiprotocol label switching (MPLS), the transmission control protocol/Internet protocol (TCP/IP), the User Datagram Protocol (UDP), the hypertext transport protocol (HTTP), the simple mail transfer protocol (SMTP), and the file transfer protocol (FTP). The data exchanged over the network may be represented using technologies and/or formats including the hypertext markup language (H™ L) and the extensible markup language (XML). In addition, all or some of links may be encrypted using conventional encryption technologies such as secure sockets layer (SSL), transport layer security (TLS), and Internet Protocol security (IPsec). 
     Example Architecture for Secure POS Platform Components 
     Turning to  FIG. 3 , there is shown a diagrammatic representation of an example internal architecture  300  of certain components of secure POS platform  200  shown in  FIG. 2  in accordance with one or more embodiments of the disclosure. The example internal architecture  300  may interact with one or more users (e.g., user  110 ) operating one or more client devices (e.g., client device  120 ) communicating with one or more control servers (e.g., control server  180 ). 
     The client device  120  may include a client operating system  214 , at least one point-of-sale application (e.g., POS application  216 ), and one or more applications (e.g., application(s)  218 ). Additionally, client device  120  may be configured to provide a number of services via internal modules. For example, client device  120  may include a PIN pad module  220 , support module  222 , a security module  224 , and/or screenshot module  226 . 
     Each of the modules can operate individually and independently of other modules. Some or all of the modules can be combined as one module. A single module can also be divided into sub-modules, each performing a separate method operation or method operations of the single module. The modules can share access to a memory space. One module can access data accessed by or transformed by another module. The modules can be considered “coupled” to one another if they share a physical connection or a virtual connection, directly or indirectly, allowing data accessed or modified from one module to be accessed in another module. In some approaches, the SP  106  will include separate modules that do not share access to the same memory space as the modules operating on AP  108 . In addition, in certain approaches client device  120  will include two operating systems, one operating on SP  106  and one operating on AP  108 . 
     The client device  120  may include additional, fewer, or different modules for various applications. Conventional components such as network interfaces, security functions, load balancers, failover servers, management and network operations consoles, and the like are not shown so as to not obscure the details of the system. 
     The operating system  214  may be an operating system of the client device  120 , such as Android™ or iOS™ or any other operating system that may be suitable for a point-of-sale system. The operating system  214  may be an open or closed format. 
     The POS application  216  may contain modules executable on the client device  120  to perform point-of-sale services (e.g., Clover™, or any other POS services). The POS application(s)  216  may run on the AP  108 . The POS application  216  may include a timecards module, a self-serve module, a register module, a store inventory module, or any combination thereof. The one or more applications, such as  218 , may include applications that may be built-in or may be provided by third-party applications. For example, one or more applications  218  may include a register module, which may be configured to provide an interface for a merchant to facilitate sales transactions in a business. The register module may have bar code scanner functionality, check-out functionality, payment functionality, or any combination thereof. It is understood that the register module is one of many possible modules that may exist within one or more application(s)  218  executing on respective client devices  120 , and that other modules may be implemented. The application(s)  218  may run on the AP  108 . 
     Client device(s)  120  may include applications that are built-in or provided by third-party entities. For example, application(s)  218  may include a register module, which may be configured to provide an interface for an operator of the merchant/business to facilitate sales transactions. The register module may have bar code scanner functionality, check-out functionality, payment functionality, or any combination thereof. Application(s)  218  may also include screenshot module  226 , which may be configured to communicate with operating system  214  to request screenshots of client device(s)  120 . A screenshot may be a screen capture of client device(s)  120  at a certain instance. The captured screenshots may be sent to control server  180  for viewing by user  190 . An administrator or other users may choose the interval value to allow for continuous viewing of the screenshots. For example, every 1 millisecond, screenshot module  226  may capture a screenshot of client device(s)  120 . Screenshot module  226  may send the captured screenshots to control server  180  so user  190  may view actions taken at the client device(s)  120  by user  110 . The interval may be within a predetermined threshold time value. The predetermined threshold time value may be selected to allow consecutive viewing of the screenshots (similar to a video) by user  190 . The predetermined threshold may determine the number of screenshots taken each second resulting in continuous viewing by the user  190 . An interval value higher than the threshold may result in flickering while being viewed by the user  190 . An Interval value lower than the threshold may result in continuous viewing but may impact performance since more screenshots may be taken each second. 
     The PIN pad module  220  may be configured to allow a user (e.g., user  110 ) to interact with a particular client device, such as  120 . PIN pad module  220  may allow customers to enter information associated with a transaction, such as a sales transaction. PIN pad module  220  may be configured to operate with either a touch screen or a physical PIN pad system, for example, the First Data ® FD-40 device provided by First Data Corporation of Atlanta Georgia, associated with client device  120 . PIN pad module  220  may be configured to operate in a secure or insecure mode. A secure mode may be a mode that may require heightened security when entering information (e.g., payment authentication information). In other approaches, PIN pad module  220  may be configured to operate in the same manner whether it is in secure or insecure mode while alternate modules in the device adjust their characteristics to reflect the current mode of device  120 . 
     PIN pad module  220  may be configured to operate with operating system  214  in a secure mode even if operating system  214  is an open format (e.g., Windows™, and Android™). The information may be related to a debit card or a credit card, or a gift card, or any other form of information related to a point-of-sale system. For example, a customer (e.g., user  110 ) may be purchasing a product from a business using a debit card. The customer may enter a code associated with the debit card in order to facilitate or otherwise complete the transaction. 
     Support module  222  may be configured to provide a user (e.g., user  190 ) to control client device  120  for performing maintenance or guidance activities. For example, user  190  may be at least one of a manager, a customer support personnel, or an administrator of the POS network, or any other person responsible for maintenance or guidance activities. For example, customer support personnel (e.g., user  190 ) may take control of client device  120  to assist the merchant (e.g., user  110 ) in debugging/resolving one or more issues with client device  120  or to answer questions about that device. It may also be used by a manager who may provide guidance and support for an employee at client device  120 . For example, a merchant (e.g., user  110 ) may contact a customer service representative (e.g., user  190 ) to report an issue with a client device (e.g., client device  120 ). 
     Security module  224  may be configured to handle payment transaction information, including a PIN or a card number. In one example embodiment, security module  224  may operate in a secure mode and may comply with one or more industry standards for secure transactions. For example, Payment Card Industry (PCI) as a governing body for payment security may provide one or more guidelines and/or rules to follow when implementing a secure sales transaction. For example, operating a physical PIN pad may allow for better control for implementing secure sales transaction. However, operating a touch screen PIN pad may present challenges. In one embodiment, PIN pad module  220  may operate a touch screen PIN pad that allows a user to enter the PIN of their debit card. Security module  224  may be configured to operate with one or more processing units to implement secure sales transactions. For example, a client device, such as  120 , may be configured to operate using a processing unit that may be dedicated for secure operations and an insecure processing unit dedicated for insecure operations. Secure operations may be, for example, swiping a credit card, entering a PIN for a debit card, or any other operation related to executing a secure transaction. Insecure operations include any operation that may be related to using client device  120  without handling secure data. For example, during a sales transaction, if a customer swipes his or her credit card, security module  224  may select a secure processing unit to complete the transaction. In a particular class of implementations, the selection of the secure processor units may involve the security module initiating a transition in the control signal or signals that are provided to MUX  104 . Although the above example is presented with two processing units, other combinations of secure and insecure processors may be envisioned. For example, a single processing unit may be divided into two areas, one secure and one insecure, or a plurality of processing units may be separated into secure or insecure processor groups. 
     Security module  224  may be implemented independent of operating system  214 . For example, this may allow developers to work independently from the firmware of operating system  214 , which may allow for better code control. Security module  224  may also be implemented using a physically separate memory from the other modules. Security module  224  may execute its instructions using SP  106  and a physically separate memory from the memory used by AP  108 . As mentioned above, in certain approaches PIN pad module  220 , and other modules in device  120 , do not require information as to whether the device is operating in a secure or non-secure mode. 
     Control server  180  may include operating system  230 , at least one point-of-sale application (e.g., POS application  232 ), and at least one application (e.g., application(s)  234 ). Additionally, control server  180  may be configured to provide a number of services via internal modules. For example, control server  180  may include control module  236 . The description of operating system  230 , the at least one point-of-sale application (e.g., POS application  232 ), and at least one application (e.g., application(s)  234 ) may be substantially similar to the description of operating system  214 , the at least one point-of-sale application (e.g., POS application  216 ), and the one or more applications (e.g., application(s)  218 ), respectively, of the client device  120 . 
     Example Computing Device Architectures 
     In the example of  FIG. 4 , the computer system  400  may include a processor  302 , a main memory  306 , a non-volatile memory  310 , and a network interface device  312 . Various common components (e.g., cache memory) are omitted for illustrative simplicity. The computer system  400  is intended to illustrate example sub-components of the secure POS platform depicted in  FIGS. 2-3 . The computer system  400  may be of any applicable known or convenient type. The sub-components of the computer system  400  may be coupled together via a bus  330  or through some other known or convenient device. 
     This disclosure contemplates the computer system  400  taking any suitable physical form. As an example and not by way of limitation, the computer system  400  may be an embedded computer system, a custom built device and/or platform, a system-on-chip (SOC), a single-board computer system (SBC) (such as, for example, a computer-on-module (COM) or system-on-module (SOM)), a desktop computer system, a laptop or notebook computer system, an interactive kiosk, a mainframe, a mesh of computer systems, a mobile telephone, a personal digital assistant (PDA), a wearable computer device, a server, or a combination of two or more of these systems or devices. Where appropriate, the computer system  400  may include one or more computer systems  400 ; be unitary or distributed; span multiple locations; span multiple machines; or reside in a cloud, which may include one or more cloud components in one or more networks. Where appropriate, one or more computer systems  400  may perform, without substantial spatial or temporal limitation, one or more steps of one or more methods described or illustrated herein. As an example and not by way of limitation, one or more computer systems  400  may perform in real time or in batch mode one or more operations of one or more methods described or illustrated herein. One or more computer systems  400  may perform at different times or at different locations one or more operations of one or more methods described or illustrated herein, where appropriate. 
     The processor  302  may be, for example, a conventional microprocessor such as an Intel™ Pentium™ microprocessor or Motorola™ Power IDC™ microprocessor. One of skill in the relevant art may recognize that the terms “machine-readable (storage) medium” or “computer-readable (storage) medium” include any type of device that can store data or instructions for the processor. The processor  302  may include computer-executable instructions  304 . 
     The main memory  306  may be coupled to the processor  302  by, for example, a bus  330 . The main memory  306  may include, by way of example but not limitation, random access memory (RAM), such as dynamic RAM (DRAM) and static RAM (SRAM). The main memory  306  may be local, remote, or distributed. The main memory  306  may include computer-executable instructions  308 . 
     The bus  330  may also couple the processor  302  to the non-volatile memory  310  and drive unit  322 . The non-volatile memory  310  may often be a magnetic floppy or hard disk, a magnetic-optical disk, an optical disk, a read-only memory (ROM), such as a CD-ROM, EPROM, or EEPROM, a magnetic or optical card, or another form of storage for large amounts of data. Some of this data may often be written, by a direct memory access process, into memory during execution of software in the computer system  400 . The non-volatile storage may be local, remote, or distributed. The non-volatile memory  310  is optional because systems may be created with all applicable data available in memory. A typical computer system may usually include at least a processor  302 , a memory  306 , and a device (e.g., a bus  330 ) coupling the memory  306  to the processor  302 . 
     Software may typically be stored in the non-volatile memory  310  and/or the drive unit  322 . The drive unit  322  may include a machine-readable (storage) medium  324 . The machine-readable (storage) medium  324  may include instructions  326 . Indeed, for large programs, it may not even be possible to store the entire program in the memory  306 . Nevertheless, it should be understood that for software to run, if necessary, it is moved to a computer-readable location appropriate for processing, and for illustrative purposes, that location is referred to as the memory  306 . Even when software is moved to the memory for execution, the processor  302  may typically make use of hardware registers to store values associated with the software, and local cache that, ideally, serves to speed up execution. As used herein, a software program is assumed to be stored at any known or convenient location (from non-volatile storage to hardware registers) when the software program is referred to as “implemented in a computer-readable medium.” A processor  302  is considered to be “configured to execute a program” when at least one value associated with the program is stored in a register readable by the processor  302 . 
     The bus  330  may also couple the processor  302  to the network interface device  312  to communicate via one or more networks  314 . The network interface device  312  may include one or more of a modem or network interface. It will be appreciated that a modem or network interface may be considered to be part of the computer system  400 . The interface may include an analog modem, an integrated services digital network (ISDN) modem, a cable modem, a token ring interface, a satellite transmission interface (e.g., “direct IDC”), or other interfaces for coupling a computer system to other computer systems. The interface may include one or more input and/or output (I/O) devices (e.g., video display  316 , alpha-numeric input device  318 , cursor control device  320 , etc.). The I/O devices may include, by way of example but not limitation, a keyboard, a mouse or other pointing device, a gesture control and/or detection device, an eye movement control and/or detection device, disk drives, printers, a scanner, and other input and/or output devices, including a video display device  316 . The video display device  316  may include, by way of example but not limitation, a cathode ray tube (CRT), a liquid crystal display (LCD), or some other applicable known or convenient display device. For simplicity, it is assumed that controllers of any devices not depicted in the example of  FIG. 4  reside in the interface. 
     In operation, the computer system  400  may be controlled by operating system software that includes a file management system, such as a disk operating system. The file management system may typically be stored in the non-volatile memory and/or drive unit and causes the processor to execute the various acts required by the operating system to input and output data and to store data in the memory, including storing files on the non-volatile memory and/or drive unit. 
     Some portions of the detailed description may be presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated (e.g., by signal generation device  328 ). It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. 
     Example Architecture for Client Device 
       FIG. 5  is a flow diagram of a method  500  for operating a client device on a secure POS platform. Method  500  can begin with step  501  in which secure data is received from a user via an input device. An example of step  501  could be a user  110  entering sensitive payment information on the touch screen of a point of sale terminal. This data, which could be in the form of coordinates that describe a touch interaction with a touch display, would be received by a touch controller such as input device controller  102 . As another example of step  501 , a user  110  could enter similar information via other means such as a voice activated interface or standard key pad. Method  500  continues with step  502 , in which the secure data is routed to a secure processor using a hardware multiplexer, and step  503 , in which the secure data is processed by the secure processor. As an example based on  FIG. 1 , the payment information received in step  501  could be routed to SP  106  by MUX  104 , and then processed by SP  106 . The mode in which client device  120  operates while routing data to SP  106  can be referred to as the secure mode. 
     Method  500  also includes steps that describe how the device operates in the normal or non-secure mode. In step  504 , non-secure data is received from a user via an input device. An example of step  504  could be a user  110  entering a quantity of items to purchase using client device  120 . In step  505 , this data is routed to a second processor using the hardware multiplexer. The second processor could be AP  108 . In step  506 , the non-secure data is processed using the second processor. 
     The non-secure mode and secure mode differ in terms of which processor data is routed to for processing. With reference to the system in  FIG. 1 , the routing state of MUX  104  sets which processor the data is routed to. In turn, the routing state of MUX  104  can only be controlled by SP  106 . As such, when client device  120  is switched to operate in either mode, SP  106  can conduct either of steps  507  and  508  in which the routing state of the hardware multiplexer is altered. SP  106  will generally alter the routing state prior to the receipt of information from the user input device in order to match the mode of operation to the type of information being received. 
       FIGS. 6 and 7  illustrate a particular implementation of client device  120  described in  FIG. 1  and include communication lines that have been annotated to illustrate the effect of the routing state of MUX  104  on the routing of data through the architecture. The particular implementation can be referred to separately as device  600 . In the state illustrated by  FIG. 6 , device  600  is operating in non-secure mode. In the state illustrated by  FIG. 7 , device  600  is operating in secure mode. Active data lines in each figure have been annotated with white arrows to show the direction of data flow. Active control lines in each figure have been annotated with white circles. 
     Device  600  is capable of receiving user data from at least one input device. IDC  102  includes an input device user data connection to receive that data from an input device. As illustrated, IDC  102  is a touch screen controller which receives touch data from touch display  109 . Device  600  also includes a set of additional input devices with additional input device user data connections. Any input device that handles secure data can be substituted in place of these additional devices. However, an exemplary set includes a chip reader  604 , a near field communication (NFC) device  606 , a magnetic swipe reader (MSR)  608 , and a tamper sensor  610 . The chip readers  604  may be configured to check one or more embedded microchips in a credit card or debit card or any other card that may contain readable information. The NFC device  606  may be configured to activate the client device  120  by touch or by proximity through a touch sensitive handle on the client device  120  or by detecting an NFC device within certain proximity of client device  120 . 
     Device  600  also includes computing device  630  which includes multiplexer  104 , SP  106 , and a second processor. In the illustrated example, the second processor is AP  108 . The multiplexer  104  includes a multiplexer control input port communicatively coupled to a control output port on SP  106 , a multiplexer data input port communicatively coupled to IDC  102 , a first data output port communicatively coupled to a secure processor data input port on SP  106 , and a second data output port communicatively coupled to a second processor data input port on AP  108 . SP  106  and AP  108  are connected by bus  640 . The elements of computing device  630  and the other components in device  600  are communicatively coupled in that information can be transmitted from one component and coherently received by the other component without intermittent alteration of that information. For the avoidance of doubt, information is not altered by standard signal conditioning or the application of CODECs that preserve the actual informational content of the signal. The term port is used here as it is used by those of skill in the art in the field of electronic communication and can encompass the pins of an integrated circuit, a via within an integrated circuit, a connection on a printed circuit board, or any other node in a circuit schematic. 
     The data lines that connect IDC  102  to MUX  104 , MUX  104  to SP  106 , and MUX  104  to AP  108  can comprise any communication interface such as I 2 C, SPI, USB, or equivalents along with any interrupts required by the peripheral controlled by IDC  102 . Bus  640  between SP  106  and AP  108  can include any communication interface such as I2C, SPI, USB, UART, or equivalents. The number of interrupts required on bus  640  will vary depending upon the application as will be apparent to those of ordinary skill upon obtaining an understanding of the following disclosure. 
     MUX  104  is configurable between a first state and a second state. The first state corresponds to the secure mode of operation for device  600  and is illustrated in  FIG. 7 . The second state corresponds to the non-secure mode of operation for device  600  and is illustrated in  FIG. 6 . Examples of a secure operation may include entering a PIN used for cardholder verification, or entering a payment card number or verification code. Examples of non-secure transactions may include entering orders, entering a ZIP code, etc. When the current state of the multiplexer is the second state, the multiplexer data input port is communicatively coupled to the second data output port through the multiplexer. As seen in  FIG. 6 , this causes data to flow from IDC  102  through MUX  104  to AP  108 . When the current state of the multiplexer is in the first state, the multiplexer data input port is communicatively coupled to the first data output port. As seen in  FIG. 7 , this will cause data to flow from IDC  102  through MUX  104  to SP  106 . In both figures, the line connecting the control output port of SP  106  to the control input port of MUX  104  is emphasized using a white circle to note that the current state of MUX  104  is set by SP  106 . 
     SP  106  has a direct connection to the set of second input devices in addition to that through IDC  102  and MUX  104 . As illustrated, this set includes reader  604 , NFC  606 , MSR  608 , and tamper sensor  610 . SP  106  is communicatively coupled with a second input device in this set of second input devices via a second input device user data connection and a second data input port on SP  106 . The connection is direct in that the devices are communicatively coupled with the secure processor  106  via the second input device user data connection and second data input port and not via MUX  104 . In approaches in which SP  106  and MUX  104  are implemented on a single IC, the second data input port could be a second input pin on the IC in addition to the first data input pin that leads to the data input of MUX  104 . 
     The current state of MUX  104  is exclusively controlled by SP  106  via the control output port of SP  106 . In this regard, and with reference to  FIG. 3 , SP  106  can implement the functionality of security module  224 . AP  108  can communicate with SP  106  along an inter-processor line which forms part of bus  640 . AP  108  can utilize this line to indirectly affect the current state of MUX  104 . For example, AP  108  can inform SP  106  that a user has requested a screen on display  109  for the entry of secure information. In response, SP  106  can choose to alter the routing state of MUX  104  and put device  600  into the secure mode of operation. In this example, AP  108  is only providing a request to transfer the state of MUX  104  and it does not control the state of MUX  104  directly. Also, once SP  106  takes control of MUX  104 , SP  106  can be placed into a state in which it will not respond to any interrupts from AP  108  or other devices and will only relinquish control of the device and change the state of MUX  104  back when its own internal logic determines that such a change is necessary. This architecture thereby provides a high degree of control to SP  106  at the expense of AP  108 . As a result, less secure programs can be installed on the device and run on AP  108  while a high level of security is still provided by SP  106 . 
     The architecture illustrated in  FIGS. 6 and 7  provides an additional benefit besides security in that IDC  102  can operate without regard to the state of computing device  630 . In other words, a state machine that describes IDC  102  does not require information regarding whether or not device  600  is operating in the secure mode or the non-secure mode or information regarding the routing state of MUX  104 . As shown in  FIG. 6 , when the device is operating in the non-secure mode, data will be passed through MUX  104  to AP  108 . As shown in  FIG. 7 , when the device is operating in the secure mode, data will be passed through MUX  104  to SP  106 . As long as SP  106  is configured to respond to data from IDC  102  in the same way that AP  108  does, IDC  102  will not need to know which processor is actually receiving the data it sends to computing device  630 . As a result, steps  502  and  505  can both be preceded by identical pre-processing steps in which the data is pre-processed using IDC  102  in the same manner regardless of the state of MUX  104 . Also, since AP  108  can be a standard applications processor, IDC  102  can also be an off the shelf user input device controller such as a standard touch display controller. 
       FIG. 6  and  FIG. 7  include emphasized data lines that continue through the processors to display  109 . In the secure mode of  FIG. 7 , data travels from SP  106  through inter-processor communication line  640  to AP  108  and then on through a display signal connection line to display  109 . In the non-secure mode of  FIG. 6 , data travels from AP  108  through the display connection line to display  109 . As a result, in either mode of operation AP  108  is the sole processor that display  109  needs to interact with. However, in the secure mode, SP  106  is controlling display  109  via a channel that comprises the inter-processor communication line  640  and display signal connection line. 
     SP  106  may apply one or more security algorithms (e.g., encryption) to protect subsequent outputs from the SP  106 . Indeed, this may be one of the main components of the processing steps conducted by SP  106 . Conducting encryption using SP  106  can provide device  600  with certain advantageous characteristics in that the crypto keys used to encrypt the information can be solely accessible to SP  106  and therefore isolated from AP  108 . 
     The encryption can be conducted by an encryption module instantiated by SP  106  and a memory to which SP  106  has access. The encryption module can encrypt a quantum of data received from IDC  120  to create an encrypted quantum of data that is stored in that memory. The encryption module can also encrypt a quantum of data received from another input to the device such as MSR  608  or other input devices. The secure data entered on device  600  can be encrypted in real time as it is received or in bulk when the data is ready for transmission. SP  106  will have access to a network connection in order to send off secure data for verification. For example, SP  106  will be able to encrypt credit card information in order to receive an authorization for a charge against a credit card account. 
     The transferred data can be sent through AP  108  and then on to a network connection. In these situations, the encrypted quanta of data can be sent along an inter-processor line on bus  640 . Since the data is in encrypted form, it is safe to be handled by AP  108 , and the actual network connection does not need to interface with SP  106 . However, in certain approaches SP  106  will have an isolated network connection to send out authorization information and receive confirmation of authorization. 
     In a POS application, SP  106  can conduct numerous additional secure features in addition to handling secure data and controlling when the state of MUX  104  should be altered. For example, SP  106  can run tamper sensors, such as tamper sensor  610 , to determine when a physical attack has taken place on a device and destroy any sensitive information upon detection of an attack. SP  106  can also run code to conduct contact and contactless payments, and perform crypto operations required by the kernels of such payments, and protect private keys used in the payment processing infrastructure. 
     The actual hardware implementation of SP  106  and AP  108  can vary in terms of the isolation between the devices. As will be described below, SP  106  and AP  108  can be implemented on the same physical processor. However, in certain embodiments, SP  106  and AP  108  can be independent microcontrollers. SP  106  and AP  108  can also be independently associated with first and second memories that are distinct and separate hardware components. The first memory can be associated with the operation of SP  106  and the second memory can be associated with the operation of AP  108 . To ensure the security of SP  106 , AP  108  may be incapable of addressing the first memory. As such, attacks that attempt to illicitly enter instructions for execution by SP  106  or access data utilized by SP  106  using AP  108  will not be physically possible. The independent microcontrollers may include multiple processing cores but the overall device will still be referred to herein as a processor. 
     One or more of the components in computing device  630  may exist on the same chip or a combination of the components may be on the chip, examples of which can be discussed with reference to  FIGS. 8A-8D . For example, MUX  104  and SP  106  could be implemented on a single integrated circuit while AP  108  and IDC  102  were left as stand-alone devices. In that IC, MUX  104  could be a block of circuitry on the IC, and SP  106  could include an encryption circuit configured to conduct the encryption operations for SP  106 . In these approaches, the control output port of SP  106  and the control input of MUX  104  would be connected via interconnects in that single integrated circuit. In addition, the multiplexer data input port would be communicatively coupled to an input pin on the IC and the second multiplexer data output port (i.e., the one that is communicatively coupled to AP  108 ) would be communicatively coupled to an output pin on the IC. The pins on the IC could be solder bumps, copper posts, or any other IC packaging connection technology. As another example, and referring to  FIGS. 8A-8D , SP  106  and AP  108  may coexist on one multi-core processor, while MUX  104  may be a standalone device. One or more devices such IDC  102 , chip reader  604 , NFC  606 , MSR  608  and tamper sensor  610  may be accessible from the TrustZone™ of one of the cores of the multi-core processor. In order to access one or more of these devices, an application may need to go through the TrustZone™ of the dedicate core. 
     In another embodiment, one core of a multi-core processor may be designated to function as SP  106  and another core to function as AP  108 , while both of these cores may be connected directly to the MUX  104 . Further, the IDC  102  may be connected to MUX  104 . In that scenario, the IDC  102  may be isolated from both SP  106  and the AP  108 . In one embodiment the TrustZone™ portion of the SP  106  core may determine whether the data passing through MUX  104  may go through SP  106  core or AP  108 . 
     In another embodiment, a multi-core processor may not contain the TrustZone™ technology but instead rely on the physical security on the chip, such as, a secure mesh that protects the cores from tampering. It is understood that a multi-core processor may include any number of cores and not limited by the examples of  FIGS. 8A-8D . 
     In one embodiment, the IDC  102  may be connected directly to a TrustZone™ area of a processor or a core of a multi-core processor. In this scenario, the core that includes the TrustZone™ may be always dedicated as a secure core that handles secure and normal (non-secure) transactions. 
     In one embodiment, it may not be necessary to have a MUX  104  included in the computing device  630 . For example, in scenarios where a core of a multi-core processor is dedicated to be a secure microcontroller with a TrustZone™, and a IDC  102  may be connected through the TrustZone™, the TrustZone™ may decide whether to switch between secure and non-secure transactions based on the touches received from user  110  on client device  120 . 
     Example Mode Transitions and Transaction Processing 
     Client device  120  can alternate between secure mode and the non-secure mode in various ways. After transitioning into secure mode, secure transactions can be conducted by SP  106  including reading data from display  109 , reader  604 , NFC  606 , or MSR  608 , encrypting that data, transmitting the data for authorization at a remote server, instantiating a virtual keypad on display  109 , and other secure actions. After the secure transactions have been conducted, SP  106  will then relinquish control of client device  120  and then alter the state of client device  120  back to the non-secure mode. 
     SP  106  alters the state of MUX  104  to alternate the device between a secure mode and a non-secure mode. As mentioned previously, SP  106  has exclusive control over the state of MUX  104 . However, given the particular architecture of the client device as described herein, there is no need for an additional interrupt line or special secure firmware on IDC  102  or AP  108  in order to enforce the secure mode of operation. Bus  640  will include a data line on which AP  108  can indicate that user inputs on IDC  102  are requesting a secure mode, and SP  106  can react to this information, but the manner in which access to the data from IDC  102  is provided is not burned into device  120 . Instead, a dynamic runtime decision is made to decide which processor gets access to the input device. The decision is made entirely by SP  106 , but can accommodate requests from any application running on AP  108  in a flexible manner. In addition, SP  106  can react directly to data received on a second input device without immediately interfering with the operation of AP  108 . In specific approaches, this will also cause an interrupt to be sent on bus  640 , but in these cases the interrupt will transfer from SP  106  to AP  108 . 
     A set of methods in which a transition is made from the non-secure mode to the secure mode in response to a message sent by AP  108  can be described with reference to  FIGS. 9-11 .  FIG. 9  illustrates a set of methods  900  that can be conducted by a client device  120  in the form of a POS terminal having the architecture of device  600 . In these examples, device  600  can be a POS terminal with a touch display in place of display  109 , and IDC  102  may be a touch screen controller configured to receive touch input from user  110  (e.g., a merchant or customer) operating client device  600 . 
     In step  901 , a start transaction (“TX”) message is sent from AP  108  to SP  106  using an inter-processor line on bus  640 . The start transaction message can be provided by the AP  108  in response to receiving an input from a user. The input could indicate that the user wants to initiate a payment transaction, in which case SP  106  would administrate the entire payment transaction. However, the input could also indicate that the user would like to enter a secure piece of information, in which case SP  106  would only administrate the entry of that secure piece of information. In the context of a secure piece of information being entered as part of an overall payment flow, AP  108  could then retain control of the device for the other steps in the payment flow besides the receipt of the secure information. In this sense the term “transaction” is referring to a secure transaction between the user of the device and the device itself, not a payment transaction that is being conducted using the device. In keeping with this later case, the input can be the selection of a button on the screen that indicates the user would like to enter a credit card number manually, enter a PIN number, enter a CVV number, or any other secure information. The specific example of a manual credit card number entry button  902  is provided in  FIG. 9 . 
     In step  903 , the touch display is used to instantiate a secure interface. Prior to step  903 , but after receiving the start transaction message, the routing state of MUX  104  can be altered as in step  507  of  FIG. 5  under the control of SP  106 . The secure interface will provide the user with the ability to view or enter secure information. For example, the secure interface could be a virtual keypad  904 , an account selection interface, or an account information interface. Step  903  can be a sub-part of a larger process in which the SP  106  controls display  109  via the channel that includes the inter-processor processor line and the display drive line mentioned above. This channel can also include AP  108 . As SP  106  controls display  109  in this step, and the data received in the secure mode is sent to SP  106 , no programs associated with AP  108  will have access to the touch data entered on the keypad  904 . In specific approaches, SP  106  will retain control of display  109  as the secure information is being entered so that it can display wild card characters while the user is entering the secure information. 
       FIG. 10  provides a ladder diagram showing the communication between SP  106  and AP  108  during the execution of step  903  in approaches where the control channel includes AP  108 . In one embodiment, while a user  110  is entering secure information on display  109 , SP  106  may send a message to AP  108  instructing it to display a virtual keypad. The AP  108  may carry out the instruction by communicating with display  109  of client device  120  and may respond (acknowledgement “Ack”) to the SP  106  when the action is completed. SP  106  may receive one or more button touches on the touch screen and may convert one or more of the button touches to wild card characters (e.g., #, *, etc.). The AP  108  may respond to the SP  106  when the instructions are completed and the user  110  is presented with the characters (e.g., #, *, etc.). This process continues until user  110  presses a completion button, such as, “enter,” “OK,” etc. 
     After the secure data is entered, SP  106  can retain control of display  109  for a period of time while the secure data is processed. For example, SP  106  could retain control of the display while a PIN entered by the user is encrypted and transferred off of client device  120  for authorization as in step  905 , when control is relinquished. The display could show a transaction processing screen to a user, and allow the user to exit secure mode by pressing a cancel button on the screen. 
     Alternative or additional secure transactions can be conducted in place of step  903  in  FIG. 9 . For example, the display of the virtual keypad could be combined with encryption of the received data and transmission of that data for authorization from a remote server. One of the secure transactions could be the activation and communication with one of the input devices in  FIG. 6  besides display  109 . This communication could be conducted independent of AP  108 . 
       FIGS. 11 and 12  include ladder diagrams that show exemplary additional secure transactions that can be conducted along with step  903 . The ladder diagrams show the exchange of information between the AP  108 , SP  106 , MUX  104 , and other devices during the execution of these secure transactions. Both  FIGS. 11 and 12  involve transactions where AP  108  initiates a request for the secure mode by sending a start transaction message to SP  106 . However, the ladder diagrams differ in terms of what additional secure transactions are illustrated along with the receipt of secure data in secure mode. 
     In  FIG. 11 , the secure mode is activated and SP  106  takes control of display  109 . However, SP  106  also activates reader  604 ,  606 , or  608  (Readers “ON”) in order to receive additional secure data via a second input device besides display  109 . The additional secure data can be provided directly from readers  604 ,  606 , or  608  to SP  106  such that it is not routed through MUX  104 . The data can be received via a second data input port on SP  106  that is communicatively coupled with a user data connection providing data from the reader. SP  106  can then process the additional secure data by, for example, encrypting the secure data. The encrypted secure data can then be sent on to a remote server for authorization. As mentioned previously, SP  106  can send off the information via AP  108  as the data is in encrypted format. In  FIG. 12 , the secure mode is activated and SP  106  instructs AP  108  to display an account selection screen and PIN entry screen to receive secure information from a user in the form of a PIN and account. As illustrated in  FIG. 12 , the SP  106  can then instruct  108  to establish a network connection with a server  1200  in order to authorize the transaction by providing server  1200  with the secure data in encrypted form. 
     Device  600  will exit the secure mode under the control of SP  106  when SP  106  relinquishes control of display  109  as in step  806 . Control can be relinquished before or after additional secure transactions are conducted. For example, as in the ladder diagram in  FIG. 11 , control can be relinquished prior to encrypting the data for transmission. As long as display  109  is not being used to input secure information, SP  106  can relinquish control of the display to AP  108 . Once control is relinquished, SP  106  will alter the routing state of MUX  104  as in step  508 . 
     In some approaches, SP  106  will force the device into the secure mode without receiving a prompt from AP  108 . As illustrated in flow chart  1300  of  FIG. 13 , SP  106  could receive a direct communication from a second input device such as reader  604 , NFC  606 , MSR  608 , or tamper sensor  610  as in step  1301 . In step  1301 , a user of client device  120  may initiate a secure transaction without first prompting the device using IDC  120  and instead using a second user input device. For example, if a secure transaction and/or operation is performed by a merchant (e.g., user  110 ), such as, card swipe, insertion of a payment card, etc., the appropriate system (e.g., chip reader  604 , or NFC  606 , or MSR  608 , or tamper sensor  610 ) may be triggered. With specific reference to a POS terminal with a touch display and NFC reader, this kind of secure transaction could be initiated via the unprompted introduction of an NFC device into close proximity with the POS terminal. 
     In step  1302 , SP  106  could issue a hardware interrupt to AP  108  to initiate a secure transaction and put the device into secure mode. Continuing the above example, depending on the token used to provide the direct input (e.g., debit card, credit card, or chip card) the SP  106  may be able to determine whether to instantiate a virtual keypad, account selection, or account information screen on the display of the device. If SP  106  determines that the entry of secure information is required, the routing state of MUX  104  could be altered to protect the secure information. As another example, SP  106  could receive a tamper indication in step  1301  and transfer the device into secure mode in  1302  to lock out the device. At that point, SP  106  could continue a secure transaction such as erasing any crypto keys stored on the device. After the secure transaction or transactions were complete, SP  106  could relinquish control in step  1303  and the device could return to non-secure mode. 
     Exemplary Encryption Methods 
       FIG. 14  illustrates another flow diagram of an example method for operating a secure POS platform in accordance with one or more example embodiments. The description is provided with reference to AP  108  conducting the transaction; however, in certain approaches SP  106  will be able to conduct these operations directly. In one embodiment, the AP  108  may send secure information to the server. The secure information may be a result of the secure transaction conducted using SP  106 . A certificate may need to be exchanged before the AP  108  may communicate with the server. The certificate may need to be signed by an authority associated with First Data Corporation of Atlanta Ga., such as root certification authority (e.g., Clover™). The certificate may be captured in one or more secure areas of the AP  108 . For example, if the AP  108  contains a secure area, such as, TrustZone (TZ™), the TZ™ may contain an encrypted key (or private key) that may be unique for the AP  108  processor. In other approaches, the certificate will be stored in a memory that is only accessible to SP  106 . 
     In one embodiment, the AP  108  may look up the flash to determine whether a private key exists. If one exists, the key may be used with the TZ™. However, if a key is not found, the flash may report that a block location is empty and that a key needs to be created. The TZ™ may encrypt the key and send it to the AP  108  that sends a request to the flash memory to save the key at the block location. 
     In one embodiment, the AP  108  may have a persistent identity that may be presented to the server. The persistent identity may be due to maintaining the same private key over factory resets and/or power failures. 
     In order for the private key to service reset or power failures, the private key may be written to a non-volatile flash area that may survive resets and/or power failures. The private key may be saved in a TZ™ area during initial installation of a client device  120  at a user premises. It is understood that TZ™ is a system for securing peripherals such as memory, crypto blocks, keyboard and displays to ensure they can be protected from software attacks. 
     In one embodiment, the SP  106  and the AP  108  may have a persistent identity to present to a server that may provide services or data to the SP  106  or AP  108 . The persistent identity may be in the form of a digital public-key certificate (such as an X. 509  certificate). The SP  106  and AP  108  may authenticate themselves to a server using either transport-level security (e.g., SSL/TLS) or message-level security (e.g., RSA signature over a message). The private key component may be protected by the SP  106  secure cryptographic device such that tampering with the device may erase the private key, or a master symmetric key. This may provide strong, cryptographic, persistent device-to-server authentication in such a way that devices may not be cloned and communications remain private and authentic. 
     This persistent, cryptographic identity may be used by SP  106  to obtain financial encryption keys remotely from the server, for example a triple DES key for use with the derived unique key per transaction (DUKPT) key management scheme, which is a standard in the electronic transactions industry. The persistent identity of the SP  106  and the AP  108  may help prevent against security attacks where a component of the client device  120  may have been compromised or hacked because the persistent identity may be encrypted and communicated between components within the client device  120  and/or outside the client device  120 . In case of a malicious substitution of either the SP  106  or the AP  108  with other components, or a tamper event of the original components, the identity may not match which may render the client device  120  as compromised and may be inoperable. In one embodiment the SP  106  may implement a persistent identity by having a discrete battery for maintaining the private key or master symmetric key. 
     In one embodiment, the SP  106  and the AP  108  may have persistent identities that work as a pair. For example, each pair of SP  106  and AP  108  may be bonded by the pair of keys that define their persistent identity. In that sense, mixing various SP  106  and AP  108  that may not have been bonded together as a pair, may render the client device  120  inoperable. Therefore, only bonded pairs of SP  106  and AP  108  may function together in a client device  120 . 
     In one embodiment, a remote key injection may be implemented on the SP  106  and/or the AP  108 . For example, the SP  106  and/or the AP  108  may be placed in a secure room, containing a certificate authority. The certificate authority may sign a certificate signing request from the SP  106  or AP  108 , thus providing the device with its persistent identity. 
     In one embodiment, a key may be injected in the SP  106  and/or the AP  108 . During manufacturing of semiconductor components, a process for injecting keys is typically done inside of a key injection room with an injection device. A key may be generated by placing the SP  106  and/or the AP  108  in a secure room and injecting the key into the SP  106  and/or the AP  108  by a key injection device. 
     In one embodiment, bonding of the SP  106  and the AP  108  may be performed at the same time as signing the public key certificates. The purpose is to provide additional security against tampering and component swapping between devices. 
     Exemplary Physical Security Measures 
     As stated previously SP  106  may be in direct communication with a tamper sensor  610  that may be activated in case of a determination of tampering, such as unauthorized attempt to access the client device  120 . The tamper sensor can be connected to several tamper detection points including a detection point on a tamper resistant cover for client device  120 . The tamper resistant cover may be in keeping with the cover in  FIG. 15  which shows an upper view of an exemplary cover for client device  120 . 
     Cover  1502  may obscure or otherwise protect certain areas of an associated printed circuit board  1504  of a POS device or client device, such as client device  120 , which may be the target of third-party tampering. The cover  1502  can include any number of other physical security devices, techniques, and/or technologies to prevent, inhibit, or otherwise deter third-party tampering. 
     As shown in  FIG. 15 , the cover  1502  may be a relatively rigid structure with a predefined shape or configuration mounted to one or more areas of the printed circuit board  1504 . The cover  1502  may be mounted to the printed circuit board  1504  by way of any number of physical connectors, soldering, adhesives, etc. 
     Further, the cover  1502  can include one or more physical security devices, techniques, and/or technologies. In one embodiment, the cover  1502  may include special traces that may be molded on or in the plastic. In one embodiment, the cover  1502  may contain one or more break channels embedded on the cover  1502  to deter tampering if the cover is attempted to be removed. For example, if an attempt was made to remove the cover  1502 , one or more break channels may disconnect the cover  1502  from the printed circuit board  1504  rendering the associated client device  120  or POS device inoperable by way of one or more signals generated by the client device  120  or POS device, and sent by the client device  120  or POS device to a remote server, such as a Clover™ server operated by First Data Corporation of Atlanta, Ga. In one embodiment, the cover  1502  may be a laser direct structuring (LDS) or other printed circuit with traces that may have certain predefined heat tolerance and/or resistance, flexibility, and/or strength characteristics. For example, the cover  1502  may have a predefined heat tolerance that may be relatively higher than the heat tolerance of one or more components of the client device  120  or POS device that are being obscured or otherwise protected by the cover  1502 . Having a relatively higher heat tolerance than one or more components of the client device  120  or POS device may provide additional security against third-party tampering since exposing the cover  1502  to a temperature above the heat tolerance of one or more components of the client device  120  or POS device may render the one or more components inoperable and ultimately cause failure of or otherwise render inoperable certain functionality or features of the client device  120  or POS device. Similarly, the cover  1502  may have a relatively low flexibility tolerance to prevent flexing the cover  1502  beyond a predefined point of breakage. That is, the cover  1502  may break rather than flex, when the cover  1502  is flexed beyond a certain point. Breaking the cover  1502  may render the client device  120  or POS device inoperable by way of the client device  120  or POS device generating one or more signals, and sending the signals to a remote server, such as a Clover™ server operated by First Data Corporation of Atlanta, Ga. 
     In another embodiment, the cover  1502  may include one or more zones that may each have one or more respective layers of physical security. In some embodiments, the cover  1502  may have a relatively high strength factor that prevents, inhibits, or deters drilling or applying other forces to the cover  1502  to attempt to access the one or more components of the client device  120  or POS device. 
     For example, the cover  1502  may be divided into two zones (e.g., zones  1520  and  1530 ). The division of the zones may be based on what components of the printed circuit board  1504  are covered by that zone. Further, the zones may contain various layers of physical security, again, based on what components of the printed circuit board  1504  are covered by that zone. For example, zone  1520  may cover the IDC  102 , the SP  106 , the NFC  606 , the MSR  608 , and the chip readers  604 . The IDC  102 , the SP  106 , the NFC  606 , the MSR  608 , and the chip readers  604  may be considered as sensitive components that may require additional security protection against tampering. A malicious access to one or more of these components may expose sensitive information and may provide access to secure data. Therefore, zone  1520  may contain one or more layers of security to prevent against malicious access. Zone  1530  may cover AP  108 , memory  306 , and the LCD device driver. Since these components may not contain sensitive data where a malicious access may not severely impact the client device  120 , the zone  1530  may contain less layers of security than the zone  1520 . It is understood that the above is only an example of division between two zones and that other divisions between one or more zones may be implemented based on the security need for the client device  120 . 
     CONCLUSION 
     The operations and processes described and shown above may be carried out or performed in any suitable order as desired in various implementations. Additionally, in certain implementations, at least a portion of the operations may be carried out in parallel. 
     These computer-executable program instructions may be loaded onto a special-purpose computer or other particular machine, a processor, or other programmable data processing apparatus to produce a particular machine, such that the instructions that execute on the computer, processor, or other programmable data processing apparatus create means for implementing one or more functions specified in the flow diagram block or blocks. These computer program instructions may also be stored in a computer-readable storage media or memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage media produce an article of manufacture including instruction means that implement one or more functions specified in the flow diagram block or blocks. As an example, certain implementations may provide for a computer program product, comprising a computer-readable storage medium having a computer-readable program code or program instructions implemented therein, said computer-readable program code adapted to be executed to implement one or more functions specified in the flow diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational elements or steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions that execute on the computer or other programmable apparatus provide elements or steps for implementing the functions specified in the flow diagram block or blocks. 
     Many modifications and other implementations of the disclosure set forth herein will be apparent having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. 
     While the specification has been described in detail with respect to specific embodiments of the invention, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. For example, although a majority of the application was directed specifically to devices with touch screens, the methods devices and systems disclosed above can be utilized on any terminal that receives secure information and non-secure information. These and other modifications and variations to the present invention may be practiced by those skilled in the art, without departing from the scope of the present invention, which is more particularly set forth in the appended claims.