Method for conducting a transaction between a chip card and an information system

A method of conducting a transaction between first and second chip cards, the first and second chip card being linked by a transaction management device, the method comprising the steps of

• A. sending transaction information which describes the transaction the transaction information being sent from the transaction management device to the first and second chip cards;
• then
• B. temporarily recording the transaction in the first and second chip cards, including the step of performing an update of information previously stored information in the first and second chip cards, the update being performed based on the transaction information, and the update having a temporary character;
• then
• C. verifying that the temporarily recording step has been correctly performed in both the first and second chip cards;
• and
• D. in response to the verifying step, definitively recording the transaction in the first and second chip cards, including the step of changing the character of the previously performed temporary update from temporary to definitive.

A method of conducting a transaction between a chip card and an information system, the chip card and the information system being linked by a transaction management device, the transaction relating to a transferring of units between the chip card and the information system, the method comprising the steps of

• A. temporarily recording the transaction in the chip card, including the steps of
• 1. sending a transaction count of units from the transaction management device to the chip card, then
• 2. altering an original count of units so as to form an altered count of units, the original count of units being stored in a first memory zone of the chip card, and the original count of units being altered by the transaction count of units, and then
• 3. storing the altered count of units in a second memory zone of the chip card, the altered count of units being stored so as to have a temporary character;
• B. temporarily recording the transaction in the information system;
• C. verifying that the temporarily recording step (B) has been correctly performed in the information system;
• D. in response to the verifying step (C), definitively recording the transaction in the chip card by changing the character of the altered count of units from temporary to definitive, the definitively recording step including the step of copying the altered count of units stored in the second memory zone to a third memory zone of the chip card, the chip card then referencing the third memory zone in order to determine a number of available units.