Patent Publication Number: US-11663584-B2

Title: System and method for indicating entry of personal identification number

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/540,666, filed Aug. 14, 2019, entitled SYSTEM AND METHOD FOR INDICATING ENTRY OF PERSONAL IDENTIFICATION NUMBER, which is a continuation-in-part of Patent Cooperation Treaty Application No. PCT/CN2019/086235 to Tsai et al., filed May 9, 2019 and entitled SYSTEM AND METHOD FOR CONFIGURATION OF TERMINAL HARDWARE, which claims the benefit of U.S. Provisional Patent Application No. 62/668,866 to Tsai et al., filed May 15, 2018, entitled SYSTEM AND METHOD FOR CONFIGURATION OF TERMINAL HARDWARE, the specifications of which are incorporated herein by reference in their entirety. This application also is a continuation-in-part of U.S. patent application Ser. No. 16/166,353 to Tsai et al., filed Oct. 22, 2018 entitled SYSTEM AND METHOD FOR A KEYPAD ON A TOUCH SCREEN DEVICE, which claims the benefit of U.S. Provisional Patent Application No. 62/576,401, to Tsai et al, filed Oct. 24, 2017, entitled SYSTEM AND METHOD FOR A KEYPAD ON A TOUCH SCREEN DEVICE, the specifications of which are incorporated herein by reference in their entirety. This application also claims the benefit of U.S. Provisional Patent Application No. 62/721,795 to Tsai et al, filed Aug. 23, 2018, entitled SYSTEM AND METHOD FOR INDICATING ENTRY OF PERSONAL IDENTIFICATION NUMBER, the specification of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to software-based personal identification number (PIN) entry on commercial off-the-shelf (COTS) devices. 
     BACKGROUND 
     In payment processes which utilize payment cards, usually the identification of the cardholder has to be verified. The following Cardholder Verification (CV) methods are usually used:
         Signature verification, that is, where the cardholder signs his or her name on a piece of paper (on a receipt or an invoice), or   Personal Identification Number (PIN) verification, that is, where the cardholder enters his or her PIN on a secure PIN pad.       

     Typically an authentication process is based on the following 3 factors, or answering the following questions:
         What I know, or the knowledge factor;   What I have, or the possession factor; and   What I am, or the inherence factor.       

     In a transaction which utilizes a PIN, the payment involves submitting
         the payment card, which is an example of a possession factor; and   the PIN, which is an example of a knowledge factor.       

     These two factors form what is called a two-factor authentication which is a measure to protect against card fraud. 
     Because the PIN is a very sensitive piece of information, typically the pad used to enter PINs is a specialized hardware device which is highly secured against tampering or attempts to steal the PIN from its legitimate owner. 
     Initially, payment cards only had magnetic stripes. These could be read easily making it easy to counterfeit. This increased the attractiveness of PIN-based payment cards. Because of this, the importance of protection on PIN has become of paramount importance. 
     In recent years, the introduction of chip-based payment cards has greatly improved the security of payment cards. In particular, the Europay Mastercard Visa (EMV) chip card standard has become the international standard. 
     The migration from magnetic stripe cards to EMV payment cards has been a long process having varying progress in different countries. It is likely that in the near future, all payment cards will be moving to the EMV standards. 
     Recently, the Payment Card Industries Security Standards Council (PCI SSC) announced a new PCI Security Standard for software-based PIN entry on commercial off-the-shelf (COTS) devices. This standard is known as the Software-based PIN entry on Commercial Off The Shelf (SPoC) standard. The SPoC standard provides guidelines for PIN entry on a touch screen of a mobile phone or tablet without needing a physical secure PIN pad. It is also loosely referred to as PIN on Mobile (PoM) or PIN on Glass (PoG). 
     Typically in a system that would utilize PoM or PoG, the user can see the following:
         a special card reader that he/she feels to be secure, as he/she know it is a special device that he/she seen in many stores/merchants and he/she cannot buy elsewhere; and   a COTS device that he/she is very familiar with, as it is a device he/she can buy anywhere, which may make him/her not that confident that the device is really capable of being used for the card transaction purpose.       

     As a consequence it may be difficult for the user to know whether the COTS device is genuine, and whether the user is safe in entering his/her confidential PIN. 
     There is therefore a need for a solution to give the user some degree of comfort and security before entering his or her PIN. 
     SUMMARY 
     A system to indicate to a user to enter a personal identification number (PIN) on a commercial off the shelf (COTS) device, said system comprising: a secure card reader coupled to the COTS device via a connection, and wherein the secure card reader receives a payment card; a payment application installed on the COTS device; and one or more devices other than the COTS device, wherein the payment application installed on the COTS device transmits one or more prompts to the one or more devices other than the COTS device based on a set of signals received from the secure card reader, further wherein the secure card reader transmits the set of signals after the payment card is received at the secure card reader, and wherein said one or more prompts comprise at least one indication to the user to enter the PIN on a display of the COTS device. 
     A method to indicate to a user to enter a personal identification number (PIN) on a commercial off the shelf (COTS) device, said method comprising: receiving a payment card on a secure card reader coupled to the COTS device; and transmitting, by a payment application running on the COTS device, one or more prompts to one or more devices other than the COTS device after said receiving, wherein said one or more prompts comprise at least one indication to the user to enter the PIN on a display of the COTS device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which: 
         FIG.  1    illustrates an example of a system to enable seamless transition for PIN entry in accordance with various embodiments of this disclosure; 
         FIG.  2 A  illustrates an example of a COTS device in accordance with various embodiments of this disclosure; 
         FIG.  2 B  illustrates an example of downloading and installing a payment application on a COTS device using a secure process for application installation and updating in accordance with various embodiments of this disclosure; 
         FIG.  2 C  illustrates an example of a COTS device incorporating an application installation controller in accordance with various embodiments of this disclosure; 
         FIG.  2 D  illustrates an example of a process for vendor distribution of applications in accordance with various embodiments of this disclosure; 
         FIG.  2 E  illustrates an example of a security measure to prevent a sensitive portion of an application from running on one or more unauthorized devices in accordance with various embodiments of this disclosure; 
         FIG.  2 F  illustrates an example of segregation of an application into different classes and utilization of application level sandboxes in accordance with various embodiments of this disclosure; 
         FIG.  2 G  illustrates an example of a method for vendor upload of applications incorporating classification of applications for different sandboxes in accordance with various embodiments of this disclosure; 
         FIG.  3    illustrates an example of a process for prompt transmission by a payment application in accordance with various embodiments of this disclosure; 
         FIG.  4    illustrates an example of a payment screen in accordance with various embodiments of this disclosure; 
         FIG.  5    illustrates an example of a display of an alert in accordance with various embodiments of this disclosure; 
         FIG.  6    illustrates an example of a verification screen in accordance with various embodiments of this disclosure; 
         FIG.  7 A  illustrates an example of a COTS device which incorporates a randomization subsystem in accordance with various embodiments of this disclosure; 
         FIG.  7 B  illustrates an example of a keypad displayed on a touchscreen in accordance with various embodiments of this disclosure; 
         FIG.  7 C  illustrates a detailed example of a keypad in accordance with various embodiments of this disclosure; 
         FIG.  7 D  illustrates an example of a process to randomly select the width of a button in accordance with various embodiments of this disclosure; 
         FIG.  7 E  illustrates an example of a process to randomly select the height of a button in accordance with various embodiments of this disclosure; 
         FIG.  7 F  illustrates an example of a process to select row heights and column widths in series in accordance with various embodiments of this disclosure; 
         FIG.  7 G  illustrates an example of a process to select row heights and column widths in parallel in accordance with various embodiments of this disclosure; 
         FIG.  7 H  illustrates a starting position for a keypad in accordance with various embodiments of this disclosure; 
         FIG.  7 I  illustrates an example of rolling up rows on a keypad in accordance with various embodiments of this disclosure; 
         FIG.  7 J  illustrates an example of flipping columns on a keypad in accordance with various embodiments of this disclosure; 
         FIG.  7 K  illustrates an example of a left to right mirrored keypad in accordance with various embodiments of this disclosure; 
         FIG.  7 L  illustrates an example of a vertically mirrored keypad in accordance with various embodiments of this disclosure; 
         FIG.  7 M  illustrates an example of random selection of two or more display parameters in combination in accordance with various embodiments of this disclosure; and 
         FIG.  7 N  illustrates an example of a sequence for a random selection of combinations of display parameters in accordance with various embodiments of this disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of a system and method for indicating entry of personal identification number are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments. 
     A system and method to reduce discontinuities and present a seamless transition from a payment application or “app” to the CV application is detailed below. 
       FIG.  1    illustrates an example of a system to enable seamless transition for PIN entry in accordance with various embodiments of this disclosure. User  101  interfaces with commercial off the shelf (COTS) device  102  to, for example, make payments. COTS device  102  is, for example, a smartwatch, smartphone, tablet, laptop, or any appropriate computing and network-enabled device. 
     An example of COTS device  102  is shown in  FIG.  2 A . Processor  102 - 1  performs processing functions and operations necessary for the operation of COTS device  102 , using data and programs stored in storage  102 - 2 . An example of such a program is payment application  102 - 4 . Display  102 - 3  performs the function of displaying data and information for user  101 . Input devices  102 - 5  allow user  101  to enter information. This includes, for example, devices such as a touch screen, mouse, keypad, keyboard, microphone, camera, video camera and so on. In some embodiments, display  102 - 3  is a touchscreen which means it is also part of input devices  102 - 5 . Communications module  102 - 6  allows COTS device  102  to communicate with devices and networks external to COTS device  102 . This includes, for example, communications via BLUETOOTH®, Wi-Fi, Near Field Communications (NFC), Radio Frequency Identification (RFID), 3G, Long Term Evolution (LTE), Universal Serial Bus (USB) and other protocols known to those of skill in the art. Sensors  102 - 7  perform functions to sense or detect environmental or locational parameters. Sensors  102 - 7  include, for example, accelerometers, gyroscopes, magnetometers, barometers, Global Positioning System (GPS), proximity sensors and ambient light sensors. The components of COTS device  102  are coupled to each other as shown in  FIG.  2 A . 
     Returning to  FIG.  1   , secure card reader  103  is communicatively coupled to COTS device  102  via either connection  107  or networks  105 . In certain embodiments, secure card reader  103  is coupled to server  106  via networks  105 . Secure card reader  103  is functional to read payment cards such as payment card  104 . Payment card  104  is, for example, a credit card or a debit card. In some embodiments, payment card  104  has a chip, such as an EMV chip. In yet other embodiments, payment card  104  has a magnetic stripe. In yet other embodiments, payment card  104  is enabled for near field communications (NFC). 
     In some embodiments, secure card reader  103  is able to read payment cards having magnetic stripes, chips, and NFC capabilities. 
     Networks  105  can be implemented using a variety of networking and communications technologies. In some embodiments, networks  105  are implemented using wired technologies such as Firewire, Universal Serial Bus (USB), Ethernet and optical networks. In some embodiments, networks  105  are implemented using wireless technologies such as WiFi, BLUETOOTH®, NFC, 3G and LTE. In some embodiments, networks  105  are implemented using satellite communications links. In some embodiments, the communication technologies stated above include, for example, technologies related to a local area network (LAN), a campus area network (CAN) or a metropolitan area network (MAN). In yet other embodiments, networks  105  are implemented using terrestrial communications links. In some embodiments, networks  105  comprise at least one public network. In some embodiments, networks  105  comprise at least one private network. In some embodiments, networks  105  comprise one or more subnetworks. In some of these embodiments, some of the subnetworks are private. In some of these embodiments, some of the subnetworks are public. In some embodiments, communications within networks  105  are encrypted. 
     As explained above, COTS device  102  is coupled to secure card reader  103  via, for example, connection  107  or networks  105 . Connection  107  is implemented using technologies which enable communicative coupling between COTS device  102  and secure card reader  103 . Examples of connection  107  include:
         A connection via an audio jack on COTS device  102 ,   A connection via a Universal Serial Bus (USB) or Firewire connection on COTS device  102 ,   BLUETOOTH® connection,   NFC connection, and   Wi-Fi connection.       

     Server  106  performs back-end processing as necessary. This back-end processing is performed to facilitate, for example, payment flows and cardholder verification. As previously stated, in some embodiments server  106  is coupled to secure card reader  103  via networks  105 . In some embodiments, server  106  is coupled to COTS device  102  via networks  105 . Server  106  can be implemented in a variety of ways. In some embodiments, server  106  is implemented using a single server. In other embodiments, server  106  is implemented using a plurality of devices. In some embodiments, server  106  is implemented using some combination of hardware and software. In yet other embodiments, server  106  is implemented in a distributed fashion, whereby the components of server  106  are situated at one or more locations. 
     Additionally, the user has one or more user devices  110  associated with the user. These include, for example, smartwatches, smartphones, tablets, laptops, desktops or any appropriate computing and network-enabled device. In some embodiments, these one or more user devices  110  are communicatively coupled to networks  105  so as to transmit communications to, and receive communications from networks  105 . 
     Payment application  102 - 4  of  FIG.  2 A  will now be discussed in more detail. Payment application  102 - 4  is functional to implement a payment process for a vendor. It serves to accept price inputs, calculate price totals and so on. In some embodiments, it also performs functions such as displaying a PIN pad for the user to enter a PIN. It also interacts with secure card reader  103  as necessary and transmits prompts to other devices and to other components of  FIG.  1    such as server  106  as necessary. 
     In some embodiments, the payment application  102 - 4  is downloaded and installed on COTS device  102  using a secure process for application installation and updating as described in Patent Cooperation Treaty Application No. PCT/CN2019/086235 to Tsai et al, filed May 9, 2019. 
     An example of such a process is described below with reference to  FIGS.  2 B to  2 G . In  FIG.  2 B , COTS device  2 B- 01  is similar to COTS device  102  and includes an additional application installation controller. A detailed example of COTS device  2 B- 01  is shown in  FIG.  2 C . Components  2 C- 01  to  2 C- 07  are similar to components  102 - 1  to  102 - 7  of COTS device  102  respectively. Additionally, COTS device  2 B- 01  comprises application or “app” installation controller  2 C- 08  for installation of payment application  2 C- 04  which is similar to payment application  102 - 4 . This will be described in further detail below. 
     COTS device  2 B- 01  is also coupled to terminal management server (TMS)  2 B- 02  via network  2 B- 05 , which is similar to networks  105 . TMS  2 B- 02  performs the functions of acquiring and processing payment transactions from COTS device  2 B- 01 , and communicating with COTS device  2 B- 01  to perform identification, verification, authorization and authentication functions. TMS  2 B- 02  receives and transmits information and also performs encryption and decryption as necessary. In some embodiments, communications between TMS  2 B- 02  and COTS device  2 B- 01  are performed using encrypted channels. 
     Application or “app” store  2 B- 03  stores one or more apps and allows apps to be uploaded from vendors  2 B- 04 . Apps are distributed from app store  2 B- 03  to COTS device  2 B- 01 . 
     All of these components are communicatively coupled to each other by networks  2 B- 05 , which as explained previously is similar to networks  105 . 
     As explained above, in some embodiments, TMS  2 B- 02  and COTS device  2 B- 01  communicate with each other over networks  2 B- 05  using encrypted channels. Examples of encryption techniques used include:
         symmetric encryption techniques, such as those based on shared secrets, and   asymmetric encryption techniques.       

     In some embodiments, COTS device  2 B- 01  communicates with TMS  2 B- 02  to indicate to TMS  2 B- 02  that it wants to install and run an app. The TMS  2 B- 02  then performs the following functions:
         Granting of authorization for COTS device  2 B- 01  to install and run the app, and   Vendor-based authentication for COTS device  2 B- 01  to install and run the app. The communications necessary to perform these functions are, as explained previously, encrypted.       

     Therefore, since only authorized devices would be able to communicate with the TMS  2 B- 02  using an encrypted channel, this alleviates the concern of payment apps running on unauthorized devices such as generic smart devices. This also removes the need for extra authorization mechanisms such as out-of-band license keys. 
     An example of a process for vendor distribution of apps including the TMS  2 B- 02  providing authentication for COTS device  2 B- 01  before installation and running of the app is illustrated in  FIG.  2 D . 
     In step  2 D- 01  the payment app  2 C- 04  is uploaded into the app store  2 B- 03 . In step  2 D- 02  the user requests download of the app via COTS device  2 B- 01  from the app store  2 B- 03 . In step  2 D- 03  the app image is hashed using a hash function on the app store  2 B- 03  to create a hash value. The resulting hash value is then signed with the app store private key. In step  2 D- 04  the app image is bundled with the signed application hash and transmitted to the COTS device  2 B- 01 . In step  2 D- 05 , the COTS device  2 B- 01  authenticates the downloaded app  2 C- 04 , to determine whether it is from the app store  2 B- 03 . The encrypted application hash is decrypted using the app store public key, and the downloaded app image is hashed on the COTS device  2 B- 01  using the same hash function which is on the app store  2 B- 03 . The decrypted hash and the hash corresponding to the downloaded app image are compared to verify that the app image has
         authenticity, that is, the app image is real, and   integrity, that is, the app image is good.       

     In step  2 D- 06  the authentication process is carried out. If the downloaded app does not pass the authentication process in step  2 D- 06 , then in step  2 D- 08 , the app  2 C- 04  is deleted from COTS device  2 B- 01 . 
     In step  2 D- 11  of  FIG.  2 D , the app installation controller  2 C- 08  on COTS device  2 B- 01  calculates the hash value of the app image. This is performed using, for example, a hash function stored in storage  2 C- 03  of COTS device  2 B- 01 . 
     In step  2 D- 12 , the COTS device  2 B- 01  then signs the app image prior to transmission to the TMS  2 B- 02 . This step comprises encrypting the resultant hash by a unique-per-device key and submitting the signature together with the app image to TMS  2 B- 02 . In some embodiments, a symmetric key arrangement is used, that is, where TMS  2 B- 02  uses the same key as COTS device  2 B- 01  for decryption. In some embodiments, the signing then utilizes a symmetric key or some means based on a shared secret for TMS  2 B- 02  to derive such a symmetric key. An example is where TMS  2 B- 02  derives a symmetric key from a base-key and a unique number from COTS device  2 B- 01 . 
     In some embodiments, an asymmetric key arrangement is used, that is, where TMS  2 B- 02  uses a different key to COTS device  2 B- 01  for decryption. An example would be where COTS device  2 B- 01  has a private key and sends the signature with a certification of its public key, so the TMS  2 B- 02  can verify and extract the terminal public key and using it for verifying the signature. 
     Steps  2 D- 13  to  2 D- 17  concern the authorization and authentication steps performed by TMS  2 B- 02 . In step  2 D- 13 , TMS  2 B- 02  receives the signed app image, and decrypts the received encrypted hash. In step  2 D- 14 , TMS  2 B- 02  calculates a hash for the received app image using a stored hash function. In step  2 D- 15 , TMS  2 B- 02  compares the two hash values. If the two hash values match each other, then in step  2 D- 16  TMS  2 B- 02  authenticates the app and authorizes the COTS device  2 B- 01  to install and run the app. If the two hash values do not match each other, then in step  2 D- 17 , TMS  2 B- 02  instructs COTS device  2 B- 01  that the app is not valid. 
     While the above describes a situation where the key is unique per device, there are other possibilities. For example, the keys can be unique per account, unique per session or unique per download. This offers more security compared to the prior art where the keys are limited to being unique per app image. 
     Since the signature for vendor app authentication no longer needs to be bundled with the app download package, the app is transparent to the standard app store. This is because the process of downloading the app is then similar to the process of downloading other non-payment apps. This makes it easier to use an app store for the purposes of distribution and managing of payment apps for terminals. 
     As the apps for the COTS device  2 B- 01  are intended to be distributed in normal smart device platform app stores, such as the Google® Play store, devices other than those intended for payment may download and run the apps. This is not desirable. As explained above, one security measure is the requirement for a device to communicate with TMS  2 B- 02  over an encrypted channel.  FIG.  2 E  shows an example of a further security measure to prevent the sensitive part of the app from running on unauthorized devices. In  FIG.  2 E :
         The vendor  2 B- 04  encrypts the one or more portions of the app code which handle sensitive operations prior to uploading the app to the app store, as shown in step  2 E- 01 , and   Once the app is authenticated and authorized by the TMS  2 B- 02  for installation and running on COTS device  2 B- 01  following the process of  FIG.  2 D , the COTS device  2 B- 01  obtains a decryption key from the TMS  2 B- 02  to decrypt the encrypted one or more portions of the app image in step  2 E- 02 .
 
Steps  2 E- 01  and  2 E- 02  work to prevent the protected code segment from being exposed outside a trusted execution environment, and the protected code segment prevents the app from performing critical/sensitive operations in devices or platforms other than intended devices with intended Electronic Funds Transfer Point of Sale (EFTPOS) platforms.
       

     In some embodiments, app class sandboxes are employed to protect system resources and applications from being accessed by unauthorized apps. In some embodiments, the apps are divided into 3 classes, each having a corresponding app class sandbox, so as to achieve segregation of applications based on level of authorization and type of application. In some embodiments, these app class sandboxes are employed in addition to, for example, existing Linux/Android sandboxes. 
     An example of this segregation into different classes followed by utilization of app level sandboxes is shown in  FIG.  2 F .  FIG.  2 F  shows the properties of each class in table  2 F- 00 . Row  2 F- 01  of  FIG.  2 F  corresponds to class A, row  2 F- 02  of  FIG.  2 F  corresponds to class B, and row  2 F- 03  corresponds to class C. Column  2 F- 04  describes the types of app covered in each class, column  2 F- 05  describes the security objective of each class, and column  2 F- 06  describes the control means. For the remainder of this description each cell of the table  2 F- 00  is denoted by (row, column). For example, the cell which indicates the type of app covered in class A is in the cell within row  2 F- 01  and column  2 F- 04 , and will be denoted as ( 2 F- 01 ,  2 F- 04 ). 
     Class A covers authorized payment apps, as shown in cell ( 2 F- 01 ,  2 F- 04 ). Class B covers authorized non-payment apps as shown in cell ( 2 F- 02 ,  2 F- 04 ). Class C covers unauthorized apps as shown in cell ( 2 F- 03 ,  2 F- 04 ). 
     The security objectives for each class are different. For class A apps: As shown in cell ( 2 F- 01 ,  2 F- 05 ), since these are authorized payment apps the OS does not restrict the access of these apps to sensitive data and functions. These apps are then placed in a relatively loose app class sandbox, with restrictions similar to, for example, the application sandbox in Security-Enhanced Linux (SE Linux), as shown in cell ( 2 F- 01 ,  2 F- 06 ). 
     For class B apps, as shown in cell ( 2 F- 02 ,  2 F- 05 ), the OS restricts the access of these apps to sensitive data and functions, such as the functions for reading finance card data, and certain related functions for cryptographic operations. Therefore, these apps will not be able to impact such sensitive assets. It significantly reduces the effort of app approval processes. The app class sandbox for class B apps therefore has restrictions on access to sensitive data and functions in addition to the restrictions of the app class sandbox for class A apps, as shown in cell ( 2 F- 02 ,  2 F- 06 ). 
     For class C apps, as shown in cell ( 2 F- 03 ,  2 F- 05 ), as the apps are not authorized by the vendor, in addition to the security objective for class B apps of restricting access to sensitive functions and data, the OS prevents these apps from requesting data from consumers and merchants, which may lead to security issues. Specifically, for EFTPOS, the risk with an unknown app is that the app can ask user to enter authentication information such as Personal-Identification-Number (PIN) or card account number. In some embodiments, a combination of one or more techniques is used to warn the user not to enter such information when running a class C app. These warning techniques operate independently of the app and have the following effect: If there is an unauthorized app displaying misleading messages requesting sensitive information such as payment data to be entered into the app, then since the app cannot control the operation of these techniques, the user will then be warned not to enter sensitive information into the app. These methods include, for example:
         Screen watermarking,   Screen flying stamp,   Screen status bar,   Screen border,   Screen overlay,   Dedicated light indicator,   Warning sound, and   Warning vibration.
 
The app class sandbox for class C apps therefore has extra restrictions when compared to the app class sandbox restrictions for class B apps.
       

     It would be known to one of skill in the art that the approach described above and in  FIG.  2 F  is generalizable to more than 3 classes. 
     In some embodiments, the COTS device determines the class of the app being installed. The determination is based on, for example:
         attribute field from the app,   the signing key of the app, or   the information from TMS  2 B- 02  when the app is being authenticated.       

     An example of a method for vendor upload of apps incorporating classification of apps so as to determine the relevant app class sandbox is illustrated in  FIG.  2 G . Steps  2 G- 01  to  2 G- 06  and  2 G- 08  are identical to steps  2 D- 01  to  2 D- 06  and  2 D- 08  of  FIG.  2 D . If in step  2 G- 06  the downloaded app passes the authentication process, then in step  2 G- 07  a determination is made as to whether the app is an EFTPOS vendor app. If no, then in step  2 G- 21  the app is installed as a class C app. If yes, then step  2 G- 11  is executed. Steps  2 G- 11  to  2 G- 17  are identical to steps  2 D- 11  to  2 D- 17  of  FIG.  2 D . In step  2 G- 18  a determination is made as to whether the app is a payment app. If it is a payment app in step  2 G- 19  the app is installed as a class A app. If not, then in step  2 G- 20  the app is installed as a class B app. 
     Typically, apps may require patches for bugs and vulnerabilities, upgrades and introductions of new features. For EFTPOS vendors, traditionally these updates were distributed by terminal vendors, acquirers, or other third parties certified by electronic payment industrial standards. However, as the size of the new updates and patches are significantly larger in size than ordinary EFTPOS firmware and software, it implies a heavy loading to the traditional terminal-management-system or other traditional distribution channels, which is very undesirable. 
     In some embodiments, the process outlined above in  FIGS.  2 D and  2 G  can be generalized to these other processes. This makes maintenance and updating of such apps easier as well, as most app stores are better equipped for maintenance and updating of apps. Furthermore, this makes it easier to improve Quality of Service (QoS), as app stores have established procedures to improve QoS. Then, the authenticity, authority, integrity and sensitive code privacy can be assured by such methods. 
     As part of the payment process, the payment application  102 - 4  transmits one or more prompts to one or more user devices  110  to indicate to the user to enter a card and a PIN.  FIG.  3    demonstrates a process for prompt transmission by the payment application  102 - 4 . 
     In step  301 , the payment application presents a payment screen on display  102 - 3  of COTS device  102  to user  101 . An example of a payment screen  400  is presented in  FIG.  4   . Screen  400  displays items for purchase  401 , payment totals  402  and “pay” button  403 . 
     In step  302 , user  101  activates pay button  403 . The payment application receives the input, and prompts the user to enter payment card  104  into the secure card reader. 
     In step  303 , the user is prompted to enter the payment card into the secure card reader  103 . The secure card reader  103  is able to read information stored on the payment card and retrieve, for example, an email address associated with the user. 
     In step  304 , the payment application  102 - 4  running on COTS device  102  receives a set of signals from secure card reader  103  over connection  107  indicating that the payment card  104  has been entered into secure card reader  103 , and requesting a PIN number for verification. In some embodiments, the set of signals also comprises one or more addresses necessary to transmit one or more prompts to the user. 
     In step  305 , the payment application  102 - 4  transmits one or more signals to one or more devices other than COTS device  102 , wherein the one or more signals comprise one or more prompts to indicate to the user to enter a PIN. In some embodiments, this comprises a prompt transmitted to the secure card reader. In some embodiments, this comprises a prompt transmitted to one or one or more devices  110  over a messaging medium such as Short Message Service (SMS), email, instant messaging. 
     In step  306 , the device other than COTS device  102  receives the transmitted prompt and based on the transmitted prompt, indicates to the user to enter a PIN. In some embodiments, this comprises displaying an alert on a screen of the device other than the COTS device  102 . An example is shown in  FIG.  5   . Alert  502  is displayed on, for example, screen  500  of secure card reader  103 . 
     As would be known to one of skill in the art, other forms of indication can also be used, for example:
         Visual indication, such as a flashing light/LED on the device other than the COTS device.   Audio indication, such as a beep sound from buzzer on the device other than the COTS device.   Motion indication, including vibration or movement on the device other than the COTS device.       

     In step  307 , based on the indication, the user enters a PIN on a PIN pad displayed by payment application  102 - 4  on a verification screen presented on the display of the COTS device  102 . An example of the verification screen is presented in  FIG.  6   . In  FIG.  6   , verification screen  500  comprises background  601 , and a software PIN pad region  602  where the PIN pad is displayed. 
     In some embodiments, the display parameters of the PIN pad are randomized. Systems and methods for randomization were described in U.S. patent application Ser. No. 16/166,353, to Tsai et al, filed Oct. 22, 2018. 
     Examples are shown below in  FIGS.  7 A- 7 N .  FIG.  7 A  illustrates an example of a COTS device. In  FIG.  7 A , components  7 A- 01  to  7 A- 07  of COTS device  701  are similar to components  102 - 1  to  102 - 7  of COTS device  102 . COTS device  701  also incorporates the functionalities of an additional randomization subsystem similar to randomization subsystem  7 A- 08  of FIG. 1 of U.S. patent application Ser. No. 16/166,353. In some embodiments, as shown in  FIG.  7 A , COTS device  701  comprises a separate randomization subsystem  7 A- 08  component. While in  FIG.  7 A  additional randomization subsystem  7 A- 08  is shown as a separate component, one of skill in the art would know there are other ways to incorporate additional randomization subsystem  7 A- 08  into COTS device  701 . For example, in some embodiments, payment application  7 A- 04  comprises an additional randomization subsystem. In some embodiments, processor  102 - 1  performs the functionalities of additional randomization subsystem  7 A- 08 . 
     Randomization subsystem  7 A- 08  performs the function of randomly selecting values for one or more variables related to at least one of said one or more display parameters. Randomization subsystem  7 A- 08  can be implemented in a variety of ways. In some embodiments, randomization subsystem  7 A- 08  is implemented in hardware. In some embodiments, randomization subsystem  7 A- 08  is implemented in software. In some embodiments, randomization subsystem  7 A- 08  is implemented using a combination of hardware and software. Randomization subsystem  7 A- 08  performs the random selections detailed below using one or more probability distributions. Examples of probability distributions which are used are, for example, the uniform distribution and the Gaussian distribution. 
     A detailed example of a keypad on a touchscreen is shown in  FIG.  7 B . As explained previously, in some embodiments, display  7 A- 03  of COTS device  701  is a touchscreen. In the following explanations, this touchscreen will be referred to as touchscreen  7 A- 09 , and it is also part of input devices  7 A- 05 . In  FIG.  7 B , keypad  7 B- 03  is displayed within touchscreen  7 A- 09 . Touchscreen  7 A- 09  has a width  7 B- 07  in the horizontal or x-direction; and a height  7 B- 05  in the vertical or y-direction. Keypad  7 B- 03  has a width  7 B- 14  in the x-direction and a height  7 B- 09  in the y-direction. There is an x-direction gap  7 B- 12  between the vertical edge of the touchscreen and the vertical edge of the keypad, such that keypad width  7 B- 14  is less than touchscreen width  7 B- 07 . Similarly, there is a y-direction gap  7 B- 08  between the horizontal edge of the touchscreen and the horizontal edge of the keypad, such that keypad height  7 B- 09  is less than touchscreen height  7 B- 05 . 
     In some embodiments, randomization subsystem  7 A- 08  randomly selects only the location of the keypad relative to a corner of the touchscreen. Examples are shown below. In these embodiments, keypad width  7 B- 14  and keypad height  7 B- 09  are fixed. 
     The location of the bottom left corner of the keypad relative to the bottom left corner of touchscreen  7 A- 09  is given by the variables of (x, y) co-ordinates ( 7 B- 13 ,  7 B- 11 ). The range of possible values of the location x-co-ordinate  7 B- 13  is calculated based on the touchscreen width  7 B- 07  and the keypad width  7 B- 14 . Similarly, the range of possible values of the location y-co-ordinate  7 B- 11  is calculated based on the touchscreen height  7 B- 05  and the keypad height  7 B- 09 . 
     In some embodiments, these calculations take into account the need for gaps between the vertical edges of the touchscreen  7 A- 09  and keypad  7 B- 03 ; and between the horizontal edges of the touchscreen  7 A- 09  and keypad  7 B- 03 . Examples are demonstrated below: 
     The maximum value of the location x-co-ordinate  7 B- 13  is calculated based on the touchscreen width  7 B- 07  and the keypad width  7 B- 14 . In some embodiments, this takes into account any x-direction gaps. For example, in some embodiments, the maximum value of the location x-co-ordinate  7 B- 13  given by the difference between touchscreen width  7 B- 07  and keypad width  7 B- 14  and an x-direction gap  7 B- 12  between the right edge of the touchscreen  7 A- 09  and keypad  7 B- 03 . That is:
 
Maximum value of location  x -co-ordinate 7 B -13=(touchscreen width 7 B -07)−(keypad width 7 B -14+ x -direction gap 7 B -12)
 
     While only one x-direction gap between the right edges of the touchscreen  7 A- 09  and keypad  7 B- 03  is shown in  FIG.  7 B , one of skill in the art would know that this is one example. In some embodiments, there is a second x-direction gap between the left edges of the touchscreen  7 A- 09  and keypad  7 B- 03 . 
     Similarly, the maximum value of the location y-co-ordinate  7 B- 11  is calculated based on the touchscreen height  7 B- 05  and the keypad height  7 B- 09 . In some embodiments, this takes into account any y-direction gaps. For example, in some embodiments, the maximum value of the location y-co-ordinate  7 B- 11  given by the difference between touchscreen height  7 B- 05  and keypad height  7 B- 09  and a y-direction gap  7 B- 08  between the upper edges of the touchscreen  7 A- 09  and keypad  7 B- 03 . That is:
 
Maximum value of location  y -co-ordinate 7 B -11=(touchscreen height 7 B -05)−(keypad height 7 B -09+ y -direction gap 7 B -08)
 
     While only one y-direction gap between the upper edges of the touchscreen  7 A- 09  and keypad  7 B- 03  is shown in  FIG.  7 B , one of skill in the art would know that this is one example. In some embodiments, there is a second y-direction gap between the bottom edges of the touchscreen  7 A- 09  and keypad  7 B- 03 . 
     Then, in the example corresponding to a single x-direction gap, the location x-co-ordinate  7 B- 13  is selected randomly from the range [0, (touchscreen width  7 B- 07 )−(keypad width  7 B- 14 +x-direction gap  7 B- 12 )]. Similarly, in the example corresponding to a single y-direction gap, location y-co-ordinate  7 B- 11  is selected randomly from the range [0, (touchscreen height  7 B- 05 ) −(keypad height  7 B- 09 +y-direction gap  7 B- 08 )]. 
     In the example corresponding to two x-direction gaps, the location x-co-ordinate  7 B- 13  is selected randomly from the range [x-direction gap  7 B- 12 , (touchscreen width  7 B- 07 )−(keypad width  7 B- 14 +x-direction gap  7 B- 12 )]. Similarly, in the example corresponding to two y-direction gaps, location y-co-ordinate  7 B- 11  is selected randomly from the range [y-direction gap  7 B- 08 , (touchscreen height  7 B- 05 )−(keypad height  7 B- 09 +y-direction gap  7 B- 08 )]. 
     These variables are randomly selected by randomization subsystem  7 A- 08  based on one or more probability distributions such as the uniform distribution or the Gaussian distribution as explained above. 
     In this way, the location of the keypad ( 7 B- 13 ,  7 B- 11 ) is randomly distributed. Therefore, the locations of each of the buttons are not fixed in time as well. This makes it difficult for an attacker to guess the coordinates of user interactions with keypad  7 B- 03  on touchscreen  7 A- 09 . 
     In some embodiments, randomization subsystem  7 A- 08  only randomly selects the size of the keypad, that is, only the variables of keypad width  7 B- 14  and keypad height  7 B- 09  are randomly selected. In some embodiments, the ranges of available keypad widths and keypad heights take into account any requirements for gaps between the keypad and touchscreen edges. Examples are demonstrated below for a case where there are two x-direction gaps and two y-direction gaps. 
     With reference to  FIG.  7 B , in some embodiments, the keypad width  7 B- 14  is randomly selected from the range [Xkeymin, (touchscreen width  7 B- 07 )−2×(x-direction gap  7 B- 12 )], where Xkeymin is the minimum length of the keyboard in the x-direction. The keypad height  7 B- 09  is randomly selected from the range [Ykeymin, touchscreen height  7 B- 05 −2×(y-direction gap  7 B- 08 )], where Ykeymin is the minimum height of the keyboard in the y-direction. Then the location co-ordinates ( 7 B- 13 ,  7 B- 11 ) are calculated taking into account the randomly selected touchscreen width and height.
 
Location  x -coordinate 7 B -13=touchscreen width 7 B -07−keypad width 7 B -14
 
Location  y -coordinate 7 B -11=touchscreen height 7 B -05−keypad height 7 B -09
 
     In some embodiments, randomization subsystem  7 A- 08  only randomly selects the size of the buttons in the keypad. That is, keypad width  7 B- 14 , keypad height  7 B- 09 , the location x-co-ordinate  7 B- 13  and y-co-ordinate  7 B- 11  are all fixed. At least one of the heights and widths of the buttons within the keypad are randomly selected. 
     This is demonstrated further below.  FIG.  7 C  illustrates a further detailed description of keypad  7 B- 03 . Keypad  7 B- 03  comprises columns  7 C- 14 - 1 ,  7 C- 14 - 2  and  7 C- 14 - 3 ; and rows  309 - 1 ,  309 - 2 ,  309 - 3  and  309 - 4 . In this example, each button within keypad  7 B- 03  is referenced by [row, column] notation. For example, the button containing the number “1” is button [ 309 - 4 ,  7 C- 14 - 1 ]. 
     The width of columns  7 C- 14 - 1 ,  7 C- 14 - 2  and  7 C- 14 - 3  are given by  7 C- 24 - 1 ,  7 C- 24 - 2  and  7 C- 24 - 3  respectively. The height of rows  7 C- 09 - 1 ,  7 C- 09 - 2 ,  7 C- 09 - 3  and  7 C- 09 - 4  are given by  7 C- 19 - 1 ,  7 C- 19 - 2 ,  7 C- 19 - 3  and  7 C- 19 - 4  respectively. Then the width of button [ 7 C- 09 - 4 ,  7 C- 14 - 1 ] is  7 C- 24 - 1  and the height of button [ 7 C- 09 - 4 ,  7 C- 14 - 1 ] is given by  7 C- 19 - 4 . 
     Examples to randomly select at least one of button widths and button heights of keypad  7 B- 03  are then presented below. 
     In some embodiments, the row heights  7 C- 19 - 1 ,  7 C- 19 - 2 ,  7 C- 19 - 3  and  7 C- 19 - 4  are fixed, and the width of each column is randomly selected. With reference to  FIG.  7 D , in step  7 D- 01  randomization subsystem  7 A- 08  randomly selects column width  7 C- 24 - 1  from the range [XBmin, (keypad width  7 B- 14 )−2×XBmin], where XBmin is the minimum width of the button in the horizontal (x) direction. 
     In step  7 D- 02 , column width  7 C- 24 - 2  is randomly selected by randomization subsystem  7 A- 08  from the range [XBmin, (keypad width  7 B- 14 )−( 7 C- 24 - 1 +XBmin)]. 
     In step  7 D- 03 , column width  7 C- 24 - 3  is then set to [keypad width  7 B- 14 −(column width  7 C- 24 - 1 +column width  7 C- 24 - 2 )]. 
     In some embodiments, the column widths are fixed, and the heights of each row are randomly selected. With reference to  FIG.  7 E , in step  7 E- 01 , row height  7 C- 19 - 1  is randomly selected by randomization subsystem  7 A- 08  from the range [YBmin, keypad height  7 B- 09 −3×YBmin], where YBmin is the minimum height of the button in the vertical (y) direction. 
     In step  7 E- 02 , row height  7 C- 19 - 2  is randomly selected by randomization subsystem  7 A- 08  from the range [YBmin, keypad height  7 B- 09 −(row height  7 C- 19 - 1 +2×YBmin)]. 
     In step  7 E- 03 , row height  7 C- 19 - 3  is randomly selected by randomization subsystem  7 A- 08  from the range [YBmin, keypad height  7 B- 09 −(row height  7 C- 19 - 1 +row height  7 C- 19 - 2 +YBmin)]. 
     In step  7 E- 04 , row height  7 C- 19 - 4  is then set to keypad height  7 B- 09 −(row height  7 C- 19 - 1 +row height  7 C- 19 - 2 +row height  7 C- 19 - 3 ). 
     In some embodiments, both row heights and column widths are randomly selected. This is a combination of the steps in  FIGS.  7 D and  7 E . 
     In some embodiments, this is performed in series.  FIG.  7 F  illustrates a detailed example for performance in series. With reference to  FIG.  7 F , steps  7 F- 01  to  7 F- 03  are identical to steps  7 D- 01  to  7 D- 03  of  FIG.  7 D . Steps  7 F- 04  to  7 F- 07  are identical to steps  7 E- 01  to  7 E- 04  of  FIG.  7 E . 
     In some embodiments, this is performed in parallel as shown in  FIG.  7 G . In  FIG.  7 G  branch  7 G- 08  comprises steps  7 G- 01  to  7 G- 03 , which are identical to steps  7 F- 01  to  7 F- 03  of  FIG.  7 F . Branch  7 G- 09  comprises the steps  7 G- 04  to  7 G- 07 , which are identical to steps  7 F- 04  to  7 F- 07  of  FIG.  7 F . The steps of branches  7 G- 08  and  7 G- 09  are performed in parallel by randomization subsystem  7 A- 08  to improve processing speed. 
     In some embodiments, one or more positions of groups of buttons are randomly selected by randomization subsystem  7 A- 08 . Examples of such groups are the rows and columns on the keypad. By random selecting the positions of groups of buttons, at least some of the positional relationships within the group are still maintained. For example, when the position of a row of buttons is changed, the horizontal relationships among the buttons within the row are still maintained. This is likely to reduce the difficulty faced by the user when compared to the case of complete randomization of button layout, where both horizontal and vertical relationships may be completely changed. 
     As would be appreciated by one of skill in the art, in a keypad such as that shown in  FIG.  7 B , there are 4!=24 possible row arrangements and 3!=6 possible column arrangements. In some embodiments, one of these row arrangements or column arrangement are randomly selected. By doing so, it is possible to increase the difficulty faced by an attacker in determining the coordinates of touchscreen interactions by a user. 
     Another possibility is “rolling” up the rows by rollup parameter RP, which is an integer greater than or equal to 1. This involves moving each row up RP times and “wrapping around” when it reaches the top. An example is demonstrated below: 
       FIG.  7 H  shows the starting position for the keypad. The notation for the row references in  FIG.  7 H  are  7 H- 01 -(row position). For example, the reference for row position 0 is denoted as  7 H- 01 - 0 ; the reference for row position  1  is denoted as  7 H- 01 - 1  and so on. The notation for the column references in  FIG.  4    are  7 H- 11 -(column position). For example, the reference for column position  0  is denoted as  7 H- 11 - 0 , the reference for column position  1  is denoted as  7 H- 11 - 1  and so on. 
     Initially
         row  7 C- 09 - 1  is in row position  0 , referenced as  7 H- 01 - 0 ;   row  7 C- 09 - 2  is in row position  1 , referenced as  7 H- 01 - 1 ;   row  7 C- 09 - 3  is in row position  2 , referenced as  7 H- 01 - 2 ;   row  7 C- 09 - 4  is in row position  3 , referenced as  7 H- 01 - 3 ;   column  7 C- 14 - 1  is in column position  0 , referenced as  7 H- 11 - 0 ;   column  7 C- 14 - 2  is in column position  1 , referenced as  7 H- 11 - 1 ; and   column  7 C- 14 - 3  is in column position  2 , referenced as  7 H- 11 - 2 .       

     Then RP is randomly selected from a range [1, 3]. The new row position is determined by
 
New row position=(Starting row position+ RP )(mod 4),
 
where mod denotes the integer modulo operation.
 
       FIG.  7 I  shows an example where RP=1. In  FIG.  7 I ,
 
New row position of 7 C -09-1=(0+1)(mod 4)=1, referenced by 7 H -01-1;
 
New row position of 7 C -09-2=(1+1)(mod 4)=2, referenced by 7 H -01-2;
 
New row position of 7 C -09-3=(2+1)(mod 4)=3, referenced by 7 H -01-3; and
 
New row position of 7 C -09-4=(3+1)(mod 4)=0, referenced by 7 H -01-0.
 
     A similar operation can be carried out for columns. This is denoted as “flipping” columns by flip parameter (FP) which is an integer greater than or equal to 1. Each column is moved rightwards FP times and “wrapped around” when it reaches the right edge. 
       FIG.  7 H  above shows the starting position for the keypad. FP is randomly selected from a range [1, 2]. The new column position is determined by:
 
New column position=(Starting column position+ FP )(mod 3)
 
       FIG.  7 J  shows an example where FP=1.
 
New column position of 7 C -14-1=(0+1)(mod 3)=1, referenced by 7 H -11-1;
 
New column position of 7 C -14-2=(1+1)(mod 3)=2, referenced by 7 H -11-2; and
 
New column position of 7 C -14-3=(2+1)(mod 3)=0, referenced by 7 H -11-0;
 
     Another possibility is randomly “mirroring” the button layout. A left to right mirror image of the starting position keypad in  FIG.  7 H  is given in  FIG.  7 K . As can be seen in  FIG.  7 K , column  7 C- 14 - 1  changes position to column position  7 H- 11 - 2  and column position  7 C- 14 - 3  changes position to column position  7 H- 11 - 0 . Then randomization subsystem  7 A- 08  makes a random selection from either the starting position or the horizontal mirrored position. 
     In some embodiments, a vertical mirroring is used as shown in  FIG.  7 L . In the vertical mirror image, the row positions of  7 C- 09 - 1  and  7 C- 09 - 4  in the starting position are interchanged, as are the row positions of  7 C- 09 - 2  and  7 C- 09 - 3 . Then randomization subsystem  7 A- 08  makes a random selection from either the starting position or the vertical mirrored position. 
     It is possible to randomly select two or more display parameters in combination.  FIG.  7 M  illustrates one example of a random selection of a combination of location of the keypad relative to a corner; and size of the keypad. In step  7 M- 01 , keypad width  7 B- 14  is selected randomly by randomization subsystem  7 A- 08  from the range [Xkeymin, (touchscreen width  7 B- 07 −2×x-direction gap  7 B- 12 )]. Xkeymin represents a minimum width for the keypad. 
     In step  7 M- 02 , randomization subsystem  7 A- 08  randomly selects keypad height  7 B- 09  from the range [Ykeymin, (touchscreen height  7 B- 05 −2×y-direction gap  7 B- 08 )]. Ykeymin represents a minimum height for the keypad. 
     In step  7 M- 03 , randomization subsystem  7 A- 08  randomly selects x-coordinate  7 B- 13  from the range [0, (touchscreen width  7 B- 07 −keypad width  7 B- 14 )]. 
     In step  7 M- 04 , randomization subsystem  7 A- 08  randomly selects y-coordinate  7 B- 11  from the range [0, (touchscreen height  7 B- 05 −keypad height  7 B- 09 )]. 
     In some embodiments, sequences of random selections of combinations of display parameters are implemented. For example, a sequence for a combination of randomization of location of keypad, size of keypad, size of buttons and positions of groups of buttons is shown in  FIG.  7 N . In step  7 N- 01 , randomization subsystem  7 A- 08  randomly selects a size of the keypad  7 B- 03  as described above. In step  7 N- 02 , randomization subsystem  7 A- 08  randomly selects a location of the keypad  7 B- 03  using the process described above. In step  7 N- 03 , randomization subsystem  7 A- 08  randomly selects the size of the buttons of keypad  7 B- 03  as described above. In step  7 N- 04 , randomization subsystem  7 A- 08  randomly selects positions of groups of buttons as described above. 
     In some embodiments, the COTS device combines the features of the devices shown in  FIGS.  2 A,  2 C and  7 A . For example, in some embodiments, the COTS device implements the functionalities of randomization subsystem  7 A- 08  from  FIG.  7 A , and application installation controller  2 C- 08  shown in  FIG.  2 C . This enables implementation of the secure process for application installation and updating, and the randomization of the display parameters of the PIN pad for the same COTS device as described above. 
     One example of this disclosure includes a system to indicate to a user to enter a personal identification number (PIN) on a commercial off the shelf (COTS) device, said system comprising a secure card reader communicatively coupled to the COTS device via either a connection or a network, wherein the secure card reader receives a payment card, a payment application installed on the COTS device, and one or more devices other than the COTS device, wherein the one or more devices are communicatively coupled to the COTS device via the network; wherein the payment application installed on the COTS device transmits one or more prompts to the one or more devices other than the COTS device based on a set of signals received from the secure card reader, wherein the secure card reader transmits the set of signals after the payment card is received at the secure card reader, and wherein said one or more prompts comprise at least one indication to the user to enter the PIN on a display of the COTS device. 
     In one or more of the above examples, the at least one indication comprises at least one of a visual indication, an audio indication, and a motion indication. 
     In one or more of the above examples, the one or more devices other than the COTS device comprise the secure card reader. 
     In one or more of the above examples, the one or more devices other than the COTS device comprise a user device associated with the user. 
     In one or more of the above examples, the payment application transmits one or more prompts after a request is received from the secure card reader for the PIN. 
     In one or more of the above examples, the COTS device is coupled to an application store and a terminal management server (TMS) via a network, a vendor uploads the payment application to the application store, and said COTS device downloads said application via said network, and after said downloading by said terminal, said TMS authorizes said COTS device to install and run said downloaded application. 
     In one or more of the above examples, after said application is downloaded by said COTS device, said TMS authenticates said application. 
     In one or more of the above examples, prior to said upload, said vendor encrypts one or more portions of said application, and said the COTS device obtains a decryption key from said TMS to decrypt said encrypted one or more portions after said authentication and authorization. 
     In one or more of the above examples, said encryption is operative to either prevent exposure of said one or more portions of said application outside a trusted environment, or prevent the application from performing critical or sensitive operations in unauthorized platforms. 
     In one or more of the above examples, said payment application displays a PIN pad having one or more display parameters on a display of said COTS device, and said COTS device comprises a randomization subsystem to randomly select one or more variables related to at least one of one or more display parameters, wherein said one or more display parameters include a location of a keypad relative to an edge of a touchscreen, a size of said keypad, one or more sizes of one or more buttons within said keypad, and one or more positions of one or more groups of the one or more buttons within said keypad. 
     Another example of this disclosure includes a method to indicate to a user to enter a personal identification number (PIN) on a commercial off the shelf (COTS) device, said method comprising receiving a payment card on a secure card reader coupled to the COTS device, and transmitting, by a payment application running on the COTS device, one or more prompts to one or more devices other than the COTS device after said receiving, wherein said one or more prompts comprise at least one indication to the user to enter the PIN on a display of the COTS device. 
     In one or more of the above examples, the one or more devices other than the COTS device comprise either the secure card reader or a user device associated with the user. 
     In one or more of the above examples, the method further comprises receiving, by the COTS device, a request from the secure card reader for the PIN, wherein the transmitting of the one or more prompts occurs after the receiving of the request from the secure card reader. 
     In one or more of the above examples, the COTS device is coupled to an application store and a terminal management server (TMS) via a network, and the method further comprises uploading, by a vendor, the payment application to the application store, and downloading, by said COTS device, said application via said network, wherein said TMS authorizes said COTS device to install and run said downloaded application. 
     In one or more of the above examples, after said downloading, said TMS authenticates said application. 
     In one or more of the above examples, prior to said uploading, said vendor encrypts one or more portions of said application, and said COTS device obtains a decryption key from said TMS to decrypt said encrypted one or more portions after said authentication and authorization. 
     In one or more of the above examples, the method further comprises classifying said downloaded application into one of a plurality of classes, each of said plurality of classes corresponding to an app class sandbox, wherein said classifying is performed based on level of authorization and type of application. 
     In one or more of the above examples, the method further comprises uploading, by the vendor, either a patch or an upgrade to said payment application to said application store, wherein the COTS device downloads said patch or said upgrade via said network, and wherein after said downloading, said TMS authorizes said COTS device to install and run said patch or said upgrade. 
     In one or more of the above examples, the method further comprises displaying a PIN pad having one or more display parameters on a display of said COTS device, and randomly selecting one or more variables related to at least one of one or more display parameters, wherein said one or more display parameters comprise a location of a keypad relative to an edge of a touchscreen, a size of said keypad, one or more sizes of one or more buttons within said keypad, and one or more positions of one or more groups of the one or more buttons within said keypad. 
     In one or more of the above examples, said random selecting comprises either rolling up rows or flipping columns. 
     It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.