Abstract: Disclosed is a time-accounting system with optimized management. It can be applied, in particular, to accounting for paid or regulated parking times. The aim is to provide a system that enables a protected replacement of card, a management of fractions of parking units and a management of the change returned by the system, for uses in one of more local authority areas. The disclosed system is of the type comprising a memory card, a box for the reception of the card comprising a memory, wherein the storage capacity of the management memory of the box is limited to a maximum number of pre-determined parking units, and wherein transfer means provide for the transfer of the balance of parking units contained in the card towards the management memory of the box when the arithmetical total of the number of added-up units of the card balance and of the current content of the management memory of the box is smaller than or equal to the capacity of the management memory.

Abstract: A device that can be used to check the authenticity of time-accounting systems and devices, and notably of time-accounting devices for reckoning periods of parking regulated by rules. The system is constituted by a plurality of boxes, each held by a distinct user, each box comprising computation means that determine at least two secret codes, the changing from one secret code to another being done substantially at one and the same instant for all of boxes and secret codes being identical for all of boxes substantially at the same instant to enable a checker to ascertain the authenticity of boxes, code-changing instant resulting from a secret computation.

Abstract: A snooper device that can be used to memorize data elements relating to the most recent instances of parking, notably for proof in the event of disputes, in time-accounting devices, and notably time-accounting devices for reckoning periods of parking regulated by rules. This snooper device comprises first means to memorize operation checking data elements in which there are written, at each fresh use of the time-accounting system, data elements corresponding to the time and to the date of commencement of at least each instance of parking and data elements corresponding to the time and to the date of the end of this instance of parking.