A process for managing an electronic transaction with a trader by use of a
microprocessor chip card and of a reading terminal able to interact with
the card. The card performs a first comparison where it compares a
transaction amount with a first threshold value and instigates a bearer
authentication procedure when this amount is above the first threshold.
When the amount of the transaction is below the first threshold, the chip
card performs a second comparison where it compares with a second
threshold value an incremented value of a first counter. The first
counter being an aggregate of small amounts counter and being
successively incremented by values of amounts of transaction in cases
where the amounts are below the first threshold. A procedure for
authenticating the bearer of the card is instigated by the card depending
on the result of this second comparison.