System and method of verifying cryptographic postage evidencing using a fixed key set
摘要
A method for controlling keys used in the verification of encoded information generated by a transaction evidencing device and printed on a document comprises the steps of generating a plurality of random verifier master keys to obtain a set of verifier master keys consisting of a fixed number of keys; generating at least one pointer by applying a psuedorandom algorithm to data unique to the transaction evidencing device; calculating a plurality of verifier token keys to obtain a verifier token key set corresponding to the set of verifier master keys; encrypting the verifier token key set with a privacy key; and distributing the set verifier token keys and the privacy key to verifiers. The token keys are a function of the verifier master keys and a code valid for a limited time. The pointer algorithm is an appropriate symmetric key cryptographic algorithm and the code is function of a date dependent parameter. The master keys are distributed to postal and vendor data centers.
申请公布号
US6058193(A)
申请公布日期
2000.05.02
申请号
US19990340592
申请日期
1999.06.28
申请人
PITNEY BOWES INC.
发明人
CORDERY, ROBERT A.;LEE, DAVID K.;PAULY, STEVEN J.;PINTSOV, LEON A.;RYAN, JR., FREDERICK W.;WEIANT, JR., MONROE A.