Postage printing system including prevention of tampering with print data sent from a postage meter to a printer

摘要

A postage printing system includes a printer and a postage meter. The postage meter includes a controller for generating print information having a plurality of print data blocks necessary to print a postal indicia. The printer is located remotely from the postage meter and includes a controller and a printer for printing the postal indicia. The printer controller is in operative communication with the postage meter controller for receiving the plurality of print data blocks. The postage meter controller encrypts the plurality of print data blocks into a plurality of encrypted print data blocks, respectively, using a cypher block chaining encryption algorithm prior to transmitting the plurality of encrypted print data blocks to the printer controller where they are decrypted by the printer controller. Check numbers for each print data block and validation of the check numbers may be employed at the printer controller. Also, the printer controller may compare the validation rates of print data blocks containing significant data and those containing insignificant data for evidence of tampering.