Patent ID: 7370203

Claim:
A method of modifying the content of the non-volatile memory of a contactless microcircuit card, wherein the card is temporarily coupled to a terminal while a transaction is being executed, in particular a remote ticketing transaction, the transaction including the terminal applying to the card a plurality of modification commands, each command comprising at least one operation of recording in the card memory a respective data item designated by the command, the various data items recorded in this way being mutually interdependent, said method comprising the card executing the steps of: a) on receiving corresponding respective commands from the terminal, modifying the contents of the card memory by provisionally recording in the card memory each of said interdependent items of information without losing prior values corresponding to said items; and b) finalizing the modifications to the card memory by one of confirming all of the modifications and by discarding all of the modifications, wherein for subsequent operations, the commands executed in step a) will either all have been taken into account, or else all of them will be without effect.