Smart card which operates with the USB protocol

Abstract

A smart card that is compatible with the USB protocol and may be compatible with multiple different protocols includes a standard set of contacts that comply with the protocols of a published standard. Another contact, not designated by the standard, may be added and used to indicate whether the card is to operate in one of a number of protocol modes. When the card is to operate in the USB mode, a simple start-up procedure is employed which does not require strict timing constraints, enabling a less expensive interface device to be used. The interface device can be connected to any bus of a computer which operates in accordance with a desired protocol. Due to the flexibility and functionality offered by smart cards that have microprocessors incorporated therein, the multi-protocol smart card can be used to drive, or otherwise communicate with, any of a variety of peripheral devices, whether or not a personal computer is present in the system. The smart card can also be configured to function as a hub between a computer CPU and peripheral devices connected to the USB by being fitted with two USB ports to allow for simultaneous communication between the CPU and the peripheral devices.

1. A USB protocol smart card system, comprising:
 a user card containing a microprocessor and associated memory, and a plurality of contacts for transferring data to and from said microprocessor and memory, said contacts including a first set of contacts respectively associated with a set of signals that conform to an ISO protocol, said set of contacts including a first data contact;  
 a second data contact in addition to the contacts in said set of contacts; and  
 an interface device for connection to said user card, and having a set of mating contacts which correspond to the contacts in said user card, to transfer data between said user card and said interface device via said first and second contacts in accordance with the USB protocol.  
 
     
     
       2. The smart card system of  claim 1 , wherein said second data contact of the user card is not used when said user card operates in accordance with said ISO protocol. 
     
     
       3. The smart card system of  claim 1 , wherein said second data contact is normally maintained at a predetermined voltage level during operation in accordance with said ISO protocol, and said interface device switches said second data contact to a different voltage level when the user card is to operate in accordance with said USB protocol. 
     
     
       4. The smart card system of  claim 3 , wherein said USB protocol provides for two modes of operation, and said interface device places said first and second data contacts at first and second voltage levels, respectively, when one of said modes of operation is to be employed, and places said first and second data contacts at said second and first voltage levels, respectively, when the other of said modes of operation is to be employed. 
     
     
       5. A USB protocol smart card, having:
 a plurality of contacts for transferring data to and from said card, said contacts including a first set of contacts respectively associated with a set of signals that conform to an ISO protocol, said set of contacts including a first data contact;  
 a second data contact in addition to the contacts in said set of contacts; and  
 a microprocessor responsive to signals on said first and second data contacts for transferring data in accordance with said ISO protocol when a first pair of predetermined voltage levels are present at said first and second data contacts, and for transferring data in accordance with a USB protocol when a second pair of predetermined voltage levels are present at said first and second data contacts.  
 
     
     
       6. The smart card of  claim 5 , wherein said second data contact is not employed to transfer data when said microprocessor operates in accordance with said ISO protocol. 
     
     
       7. The smart card of  claim 5 , wherein said USB protocol provides for two modes of operation, and said microprocessor operates in one of said modes when said second pair of predetermined voltage levels are present at said first and second data contacts, and operates in the other of said modes when a third pair of predetermined voltage levels are present at said first and second data contacts. 
     
     
       8. The smart card of  claim 7 , wherein said third pair of voltage levels is the inverse of said second pair of voltage levels. 
     
     
       9. The smart card of  claim 7 , wherein said two modes of operation respectively pertain to different rates for transferring data. 
     
     
       10. A smart card system, comprising:
 a user card having a microprocessor, an associated memory storing at least one application program, and a plurality of contacts comprising a set of contacts, including a first data contact, which are respectively associated with a set of signals that conform to an ISO protocol, and a second data contact in addition to the contacts in said set of contacts for transferring data to and/or from said microprocessor and memory;  
 a peripheral device which is operable in accordance with said application program; and  
 a connector for connecting said peripheral device with said contacts to thereby enable said microprocessor to communicate with said peripheral device via said first and second data contacts, in conformance with the USB standard, to control the operation of said peripheral device in accordance with said application program.  
 
     
     
       11. The smart card system of  claim 10 , wherein said peripheral device does not contain a processor. 
     
     
       12. The smart card system of  claim 10 , wherein said peripheral device comprises one of a PIN pad, a display device or a modem. 
     
     
       13. A smart card that communicates over an I/O channel using the USB protocol, said smart card comprising:
   a microprocessor that performs smart card functions;        means for generating and receiving signals formatted in the USB protocol that correspond to smart card functions performed by the microprocessor; and        a set of contacts for transferring said signals between the smart card and the I/O channel.     
     
     
       14. The smart card of  claim 13 , wherein said microprocessor comprises the means for generating and receiving said signals. 
     
     
       15. The smart card of  claim 13 , wherein said smart card functions include security operations. 
     
     
       16. The smart card of  claim 15 , wherein said security operations comprise access control. 
     
     
       17. The smart card of  claim 15 , wherein said security operations comprise password authentication. 
     
     
       18. The smart card of  claim 13 , further comprising a body on which is located said microprocessor, said means for generating and receiving signals, and said set of contacts. 
     
     
       19. The smart card of  claim 18 , wherein said body has the form factor of a credit card. 
     
     
       20. The smart card of  claim 19 , further including additional contacts which, together with at least one of the contacts in said set of contacts, conform to ISO standards for smart cards, to thereby enable said smart card to communicate with an ISO- compliant reader.   
     
     
       21. A portable smart device for communicating over an I/O channel using the USB protocol, said device comprising:
   a microprocessor that performs smart card functions;        means for generating and receiving signals formatted in the USB protocol that correspond to smart card functions performed by the microprocessor; and        a set of contacts for transferring said signals between the portable smart device and the I/O channel.     
     
     
       22. The portable smart device of  claim 21 , wherein said microprocessor comprises the means for generating and receiving said signals. 
     
     
       23. The portable smart device of  claim 21 , wherein said smart card functions include security operations. 
     
     
       24. The portable smart device of  claim 23 , wherein said security operations comprise access control. 
     
     
       25. The portable smart device of  claim 23 , wherein said security operations comprise password authentication. 
     
     
       26. The portable smart device of  claim 21 , further comprising a body on which is located said microprocessor, said means for generating and receiving signals, and said set of contacts. 
     
     
       27. The portable smart device of  claim 26 , wherein said body has the form factor of a credit card. 
     
     
       28. A smart card apparatus for communicating over an I/O channel using the USB protocol, said apparatus comprising:
   processing means that perform smart card functions and that generate and receive signals formatted in the USB protocol that correspond to said smart card functions; and        a set of contacts for transferring said signals between the smart card apparatus and the I/O channel.     
     
     
       29. The smart card apparatus of  claim 28 , wherein said processing means comprises one and the same microprocessor that performs:
   said smart card functions, and        said signal generating and receiving functions.     
     
     
       30. The smart card apparatus of  claim 28 , wherein said smart card functions include security operations. 
     
     
       31. The smart card apparatus of  claim 30 , wherein said security operations comprise access control. 
     
     
       32. The smart card apparatus of  claim 30 , wherein said security operations comprise password authentication. 
     
     
       33. The smart card apparatus of  claim 28 , further comprising a body on which is located said processing means and said set of contacts. 
     
     
       34. The smart card apparatus of  claim 33 , wherein said body has the form factor of a credit card.