Patent ID: 6868407

Claim:
A postage security device, including a cryptographic key, for generating a digital token with a level of security, wherein the digital token is generated as proof of postage payment requested by a user who provides mailing parameters to the postage security device, and wherein the digital token is generated based on the provided mailing parameters in order to allow the user to produce an indicia on a mailpiece based on the digital token, said postage security device comprising: storage means for storing replacement keys; means for determining whether unused storage means for replacement keys is available and for reporting an error condition if unused storage means is not available; first means, responsive to a command for a key change, for providing a further cryptographic key to replace the cryptographic key; and second means, operatively connected to the first means, for generating a further digital token, based on the provided mailing parameters and the further cryptographic key, wherein the cryptographic key has a first key length and the further cryptographic key has a second key length, which is greater than the first key length, so as to improve the level of security associated with said postage security device.