This application claims priority to German Patent Application Ser. No. 10 2004 024 158.9, filed May 14, 2004, and which is incorporated herein by reference in its entirety.
The invention relates to a communications system having a chip card and at least one chip card communications partner.
This master/slave relationship is most pronounced in first-generation chip cards, memory cards. The latter are used, for example, in telephone cards or health insurance cards, the functionality being restricted to the storage and interchange of data. In order to keep the total costs of this communications system low, the memory cards (produced in large quantities) were designed as simply as possible, and the functionality required for communication was moved, as far as possible, to the few terminals. Further simplification was achieved by using a synchronous interface that prescribes the flow of communication in a relatively rigid manner, however.
The next generation of chip cards, the so-called microcontroller cards, also have a microcontroller and programmable software in addition to the memory. Chip cards of this type are, for example, bank cards having an encryption function or SIM (Subscriber Identity Module) modules in GSM mobile telephones. In order to interchange data, use is made of more flexible interfaces, as specified, for example, in the ISO-7816-3 standard. In spite of the greatly extended functionality of the chip cards, communication between a chip card and a terminal is still controlled by the terminal and is still based on the challenge/response method. If this was advantageous in the case of memory cards, it constitutes a restriction for microcontroller cards. If, for example, an error occurs in the chip card 2 and communication is disrupted as a result, the chip card 2 cannot itself inform the chip card communications partner 3 of the error. The chip card communications partner 3 will nevertheless attempt to continue to communicate by sending the data again. The chip card 2 can only inform the chip card communications partner 3 that the data have not been received correctly. However, it is not able to assume control of communication.
In the future, chip cards having an even greater range of functions, the so-called smart cards, will be manufactured and used. These will make it possible, for example, to control operations on a mobile phone using a smart card. To this end, however, the chip card must assume control of the communications system, i.e. must be able to assume the role of master. However, this is not provided for in today's communications systems 1; the chip card 2 can only react, as a slave, to commands from the chip card communications partner 3 and cannot itself start any actions. Without the possibility of initiating data interchange with a chip card communications partner 3, the possible field of use of chip cards 2 is greatly restricted.
Therefore, the invention is based on an object of specifying a communications system having a chip card and at least one chip card communications partner, in which the chip card can initiate data interchange.
The object is achieved, according to the invention, by virtue of the fact that the chip card has a module for initiating data interchange with the chip card communications partner, and that a method for interchanging data between a chip card and a chip card communications partner is specified.
In accordance with one development of the invention, the chip card has a standard interface for communication. This has the advantage that existing terminal infrastructures can be used.
One preferred embodiment variant of the inventive communications system provides an additional line which does not belong to the standard interface and is intended to transmit an initiation signal to the chip card communications partner. This additional line makes it possible for the initiation signal to be transmitted to the chip card communications partner even when no such possibility is provided for in the standard interface.
The communications system advantageously has a standard interface in accordance with the ISO-7816 standard. This ensures compatibility with the existing reader infrastructure.
The invention will be explained, by way of example, in more detail below with reference to the figures, in which:
In this exemplary embodiment, signaling for the purpose of initiating data interchange is effected via the existing standard interface 4. The module for initiating data interchange 5 is used by the chip card 2 to signal to the chip card communications partner 3 that it would like to communicate with the latter. This may be effected, for example, by a data line in the standard interface, which, when no data are presently being interchanged, signals a high state by default, being changed by the module for initiating data interchange 5 in order to signal a low state. The communications partner 3 then recognizes that the chip card would like to start data interchange and prepares for the latter. In this exemplary embodiment, no extra line or extra interface is used to signal the initiation of data interchange but rather an existing line, for example a data line, is manipulated. If the standard interface used is an interface in accordance with the ISO 7816-3 standard, signaling may also be effected via at least one of the three unused contacts C4, C6 and C8.
It is obvious that the invention is not restricted to the ISO 7816-3 interface. In principle, the invention functions with all other interfaces and protocols which are based on the master/slave system.
The fact that the chip card 2 is able to initiate data interchange results in a wealth of new options for use. It is thus conceivable, for example, for the chip card to independently use a mobile phone to make contact with a provider in order to request information and send information to the provider. The chip card 2 could thus inform the provider that it is, for example, a locked card or that an attempt was made to manipulate it. It is equally expedient if the chip card 2, without being requested to do so, can inform the chip card communications partner 3 that it has had a problem which is restricting its functionality or is even making its functionality impossible. A further conceivable use is signaling to the communications partner 3 if the communications system 1 is in a quiescent or standby state and the chip card 2 would now like to communicate that communication is to be continued.
In comparison with other solutions, the invention affords the advantage that the chip card 2 can signal to the chip card communications partner at any time that it would like to initiate data interchange.
The above description of the exemplary embodiments in accordance with the present invention serves only to illustrate and not to restrict the invention. Various changes and modifications are possible within the scope of the invention without departing from the scope of the invention and its equivalents.
Number | Date | Country | Kind |
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10 2004 024 158.9 | May 2004 | DE | national |