Patent ID: 7562050

Claim:
An electronic purse data carrier for performing monetary transactions, comprising a storage means for storing one or more payment units each having a respective monetary value, each of said payment units comprising an age information valuable for delimiting the use of the payment unit, and each of said payment units having a respective unique payment unit-ID, in which said age information reflects the extent of transactional use of the respective payment unit, and in which said age information represents a date information; a processor for read and/or write access to said storage means, and means for updating said age information whenever a transaction has been performed with a respective payment unit; means for splitting a parent payment having given non-minimum parent non-minimum monetary value into a plurality of child payment units each having a child monetary value smaller than the parent value, the sum of child monetary values being the same as the parent monetary value, and means for transferring a respective age information from said parent unit to the plurality of child payment units, means for joining a plurality of single payment units having a given total monetary value into a joined payment unit having a corresponding same monetary value, and means generating a resulting age information for said joined payment unit according to a predetermined rule, said means for transferring a respective age information further excluding said one or more payment units having a monetary value smaller than a predetermined value from inheriting age information, said means for transferring a respective age information further excluding said one or more payment units that have exceeded a predetermined change threshold age level from a split or join process.