A method and system for a virtual stamp dispensing metering system is
provided wherein indicia of varying values are calculated at a data
center and downloaded to a mailing machine on a periodic basis. The
mailing machine securely stores the indicia and dispenses the indicia as
needed. At the end of the period, any unused indicia are returned to the
data center, the user's account is credited, and a new set of indicia are
downloaded to the mailing machine. Accordingly, the processing
requirements of the meter are reduced, as there is no longer any need to
generate digital signatures, an attacker is prevented from generating
indicia indefinitely if the security of the meter is compromised, as the
cryptographic key is not resident at the meter, and tracking requirements
of the meter are reduced, as the meter alone can not be used to generate
postage funds.