System and method for a secure display module

Abstract

A system for a secure display module includes a display element array, a driver controller, a communication interface, a host controller and a cryptographic engine. The display element array includes one or more segments, and the driver outputs are configured to drive the one or more segments, respectively. The host controller is configured to send commands and data to the driver controller via the communication interface and the cryptographic engine is configured to encrypt communication data between the display element array and the host controller.

What is claimed is: 
     
       1. A display module comprising:
 a control interface configured to receive encrypted commands and encrypted data for display;   a cryptographic engine coupled to the control interface,
 the encrypted commands and 
 data received by the control interface being decrypted by the cryptographic engine to produce decrypted commands and decrypted data, the decrypted commands being executed by the control interface to control a plurality of display driver outputs; 
   the plurality of driver outputs coupled to the control interface, the plurality of display driver outputs using the decrypted data to update the display array element with a randomized number grid; and   a PIN pad for entering positional information corresponding to the randomized number grid.   
     
     
       2. The display module of  claim 1  further comprising a display memory, the display memory storing the status of a portion of the display array element. 
     
     
       3. The display module of  claim 1  wherein the status of a portion of the display array element is stored within a state of the display array element. 
     
     
       4. The display module of  claim 1  wherein the cryptographic engine stores a key used for data encryption of the encrypted commands and data. 
     
     
       5. A method for operating a display module comprising:
 establishing, by a cryptographic engine, a key for data encryption between a control interface and an external device;   receiving encrypted commands and encrypted data by the control interface;   decrypting the encrypted commands using the key, by the cryptographic engine, to produce decrypted commands and decrypted data;   executing the decrypted commands, by the control interface, to control a plurality of driver outputs to update a display array element using the decrypted data, the decrypted commands defining a randomized number grid; and   receiving positional information input on a PIN pad corresponding to the randomized number grid.   
     
     
       6. The method of  claim 5  further comprising storing in a display memory a status of a portion of the display array element. 
     
     
       7. The method of  claim 5  further comprising storing within a state of the display array element a status of a portion of the display array element. 
     
     
       8. The method of  claim 5  further comprising storing the key used for data encryption of the encrypted commands and data within the cryptographic engine. 
     
     
       9. A method for a display module comprising:
 providing a control interface to receive encrypted commands and encrypted data for display;   providing a cryptographic engine;   performing one of:
 enabling the provided cryptographic engine to decrypt the encrypted commands and data received by the control interface to produce decrypted commands and decrypted data, or 
 configuring the provided cryptographic engine to decrypt the encrypted commands and data received by the control interface to produce decrypted commands and decrypted data; 
   performing one of:
 enabling the provided control interface to control a plurality of display driver outputs based on the decrypted commands, or 
 configuring the provided control interface to control the plurality of display driver outputs based on the decrypted commands; 
   enabling a display array element to display a randomized number grid based on the plurality of display driver outputs using the decrypted data;   enabling positional information corresponding to the randomized number grid to be input using a personal identification number (PIN) pad;   enabling the positional information to be received and decoded into PIN digits;   enabling generation of an encrypted PIN based on the PIN digits; and   enabling transmission of the encrypted PIN to the PIN pad.   
     
     
       10. A system comprising:
 a display module comprising:
 a control interface to receive encrypted commands and encrypted data for display, and 
 a cryptographic engine coupled to the control interface, 
 the encrypted commands and data received by the control interface being decrypted by the cryptographic engine to produce decrypted commands and decrypted data, 
 the control interface controls a plurality of display driver outputs based on the decrypted commands; 
 the plurality of display driver outputs coupled to the control interface, the plurality of display driver outputs using the decrypted data to update a display array element with a randomized number grid; and 
 the display module receives positional information corresponding to the randomized number grid entered at a personal identification number (PIN) pad,
 the display module decodes the received positional information into PIN digits, 
 the cryptographic engine generates an encrypted PIN based on the PIN digits, and 
 the display module transmits the encrypted PIN to the PIN pad. 
 
   
     
     
       11. The display module of claim 10 further comprising a display memory, the display memory storing a status of a portion of the display array element. 
     
     
       12. The display module of claim 10 wherein a status of a portion of the display array element is stored within a state of the display array element. 
     
     
       13. The display module of claim 10 wherein the cryptographic engine stores a key for data encryption of the encrypted commands and data. 
     
     
       14. A method for operating a display module comprising:
 establishing, by a cryptographic engine, a key for data encryption between a control interface and a host controller;   receiving, by the control interface, encrypted commands and encrypted data sent by the host controller;   decrypting, by the cryptographic engine, the encrypted commands and encrypted data using the key to produce decrypted commands and decrypted data;   controlling, by the control interface, a plurality of driver outputs to update a display array element using the decrypted data, wherein:
 the controlling is based on the decrypted commands, and 
 the decrypted commands defining a randomized number grid; 
   receiving positional information input on a PIN pad corresponding to the randomized number grid;   decoding the received positional information into PIN digits;   generating an encrypted PIN based on the PIN digits; and   transmitting the encrypted PIN to the PIN pad.   
     
     
       15. The method of claim 14 further comprising storing in a display memory a status of a portion of the display array element. 
     
     
       16. The method of claim 14 further comprising storing within a state of the display array element a status of a portion of the display array element. 
     
     
       17. The method of claim 14 further comprising storing the key for data encryption of the encrypted commands and data within the cryptographic engine.