Smart card system having asynchronous communication with the smart card operating either as master or slave
AssigneeAxalto SA
InventorsMichael A. Montgomery, Scott B. Guthery, Bertrand du Castel
Life of this patent
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Abstract
A smart card comprises a microcontroller, a memory unit, a storage unit, and a communications unit. The smart card may be connected to a terminal, which is in turn may be connected to a host computer and/or a network. The smart card is configured to initiate communications with the terminal, which enables the smart card to control the terminal, host computer, or network and to access the resources connected to the terminal, host computer, or network. A communications protocol defines the commands that the smart card can send and allows the smart card to communicate using asynchronous or logical asynchronous communication.
Claims18
A method of operating a smart card and smart card terminal to simulate asynchronous communication between the smart card and smart card terminal such that either the smart card or the smart card terminal may operate as master and the other operating as slave wherein the smart card and smart card terminal communicate in a half-duplex protocol, comprising:
- sending a first message from the smart card terminal to the smart card, wherein if the smart card terminal has no data to send the smart card, the first message is a polling packet;
- receiving the first message at the smart card;
- upon receipt of the first message, if the smart card has data to send, sending a second message from the smart card to the terminal containing a length of data indication;
- upon receipt of the second message from the smart card, sending a third message from the terminal to the smart card as an indication from the terminal to the smart card to commence sending the data;
- and
- sending a message containing the data from the smart card to the terminal.
A smart card comprising:
- means configured to simulate the initiation of communications to a smart card terminal having:
- means operable to receive a polling packet from the terminal on a synchronous communications channel;
- and
- means, in response to receiving a polling packet, operable to transmit an indication that the smart card desires to transmit data to the terminal over the synchronous communications channel;
- means operable to use the means configured to simulate the initiation of communications to request resources selected from the set including terminal resources, host resources, and network resources.
A computer system comprising:
- a terminal for communicating with smart cards over a synchronous communications channel;
- the terminal having means for simulating allowing the smart card to initiate communication with the terminal and means for transmitting, over the synchronous communications channel, a polling packet to the smart card requesting an indication of whether the smart card desires to transmit data to the terminal.
Dependencies are inferred from the claim text.