US 5,293,577 AGranted

Method and apparatus for preventing inadmissible deviations from the runtime protocol of an application in a data exchange system

AssigneeSiemens Nixdorf Informationssysteme Aktiengesellschaft

InventorsThomas Hueske, Hildegard Jost, Klaus Mueller, Axel Pfau

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Abstract

Method and apparatus for preventing inadmissible deviations from the runtime protocol of an application in a data exchange system. The data exchange system has, for example, a terminal T and a chip card K. For various applications (for example, automatic teller unit, computer access), basic functions B stored in the chip card K are processed in a sequence respectively defined in a protocol. Since the basic functions B are called in proceeding from the terminal T, the data integrity could be deteriorated by intentional modifications of the protocol sequence at the terminal T. By storing the allowable protocols in a control list STL and establishing a status memory area ZS on the chip card K, it becomes possible to monitor the protocol execution on the chip card K independently of the terminal T. The respective status Z of an application is fixed in the status memory area ZS. All basic function designations Bn permitted for a status Z are deposited in the control list STL.

Claims32

Dependent claims

A method for preventing inadmissible deviations from a runtime protocol of an application in a data exchange system having at least one terminal and at least one portable data carrier, the portable data carrier having at least one processor and at least one memory for executing at least one application, comprising the steps of:

for data exchange, with the data carrier being connected to the terminal, placing a status memory area present in the memory of the data carrier into a basic status;
transmitting an application command from the terminal to the data carrier, said application command specifying an application allocated to the terminal;
transmitting a function command from the terminal to the data carrier, the function command containing at least one basic function designation of a basic function that is to be executed next;
comparing in the data carrier the basic function designation to basic function designations stored in the memory of the data carrier with reference to the previously specified application and with reference to an existing protocol status, said existing protocol status being fixed by an entry in the status memory area;
executing in the data carrier the basic function allocated to the basic function designation communicated to the data carrier, only for a positive comparison;
after a successful execution of the basic function, adapting the data deposited in the status memory area to a new protocol status, and transmitting an acknowledge signal from the data carrier to the terminal;
and
if the application has not terminated by one of ending after execution of the basic function and being aborted during execution of the basic function transmitting a further function command from the terminal to the data carrier.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/731,257Filed 17 Jul 1991
Priority: EP 90113990.720 Jul 1990
Granted: 8 Mar 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G07F 7/1008
Together with a coded signal , e.g. in the form of personal identification information, like personal identification number [PIN] or biometric…
G06Q 20/341
Using cards, e.g. integrated circuit [IC] cards or magnetic cards: active cards, i.e. cards including their own processing means, e.g. including…
G06Q 20/3576
Cards having a plurality of specified features: multiple memory zones on card
G06Q 20/367
Using electronic wallets or electronic money safes: involving electronic purses or money safes