Patent ID: 7222236

Claim:
A method for dispensing and evidencing postage indicia by a postage generating device (PGD) in a system having a plurality of PGDs that have been divided into n groups identified by a group designation G i , i=1, . . . n, the method performed by the PGD comprising: (a) receiving by the PGD a master secret key K and a secret key K i from a distribution center over a network after manufacture of the PGD, and storing the master secret key K and the secret key K i in the PGD; (b) in response to receiving a request to generate an indicium for a mail piece destined for a particular postal destination Dest, generating the indicium; (c) computing by the PGD a verification key V i Dest as a function of the secret key K i and the postal destination; (d) computing a key ID I i Dest as a function of the master secret key K and the postal destination; (e) using by the PGD the computed verification key V i Dest to create a digital signature for the indicia; and (f) digitally signing by the PGD the indicia by including the digital signature and the computed key ID I i Dest on the indicia.