US 5,606,613 A · Method for identifying a metering accounting vault to digital printer

Abstract

The method for preventing monitoring of postage indicia data which is sent from a postage metering vault to a remotely located digital printer over a communication link between the meter vault and the digital printer. The meter is provided with an encryption engine for encrypting postage indicia data utilizing a encryption key. The digital printer includes a decryption engine for decrypting postage data received from said meter utilizing the same encryption key and then prints a postage indicia pursuant to the decrypted postage indicia data. The postage meter also includes a key manager for generating new encryption key pursuant to a token which is either randomly generated or generated pursuant to an algorithm by a similar encryption key manager located in the digital printer which token is also used to generate the decryption key for the decryption engine. As a result, the encryption keys are the same. Upon power-up of the system or at such other preselected times, the print controller module of the digital printer sends out an encrypted message to the meter. The message consist of a random number. The encryption/decryption engine of the vault decrypts the message. The vault then returns an encrypted new message to the print controller which includes an encoded representation of the relationship of the two messages. Upon receiving the new message from the vault, the print controller decrypts the new message and verifies the relationship. The print controller is then enabled to print a postage indicia.

Claims2

Dependent claims

A method for verifying a specific, operable combination of a postage metering controller and a remotely located digital printer over a communication link between the controller and the printer, comprising the steps of:

providing said meter with means for encrypting/decrypting data utilizing an encryption key;
providing said printer with means for encrypting/decrypting postage data utilizing said encryption key;
generating a random number and encrypting said random number at said printer;
transmitting said encrypted random number to said controller;
decrypting said random number and re-encrypting said random number at said controller in such a way to have a known relationship to said original random number and encrypting said known relationship in the same manner as the re-encryption of the random number;
transmitting said re-encrypted random number and said encrypted known relationship to said printer;
decrypting said re-encrypted random number and said known relationship and verifying said known relationship at said printer;
providing said printer with means of generating a token and with an encryption key manager for generating said encryption key pursuant to said token, said token corresponding to a key generation method based on at least one totally random variable;
generating a token by means of said printer;
communicating said token to said controller;
providing said controller with an encryption key manager for generating an encryption key pursuant to said token;
generating said encryption key by said encryption key manager in said controller pursuant to said token such that said encryption key of both of said encryption key managers are identical;
and
enabling said printer upon verification.

11 more elements

Dependencies are inferred from the claim text.

Method for identifying a metering accounting vault to digital printer

Life of this patent

Method for identifying a metering accounting vault to digital printer

Life of this patent

Abstract

Claims2