Abstract: In a method for improving the security of postage meter machines in credit transfers, having at least two modes, the presence of a security flag is necessary for operation of the machine. The security flag is erased in a step of the system routine if an unauthorized action occurs in an attempt to operate the postage meter machine, and the postage meter machine is switched into a first mode in order to effectively shut it down. Otherwise, a special mode for negative remote crediting is entered by setting a special flag when a predetermined operating action for lateral entry into the special mode is undertaken upon machine turn-on. The communication with the data center sequences under time and status (flag) monitoring by the control unit of the postage meter machine until the transaction is completed. The data center monitors the behavior of the postage meter machine user on the basis of data communicated during the transaction.

Abstract: A method for securing data and program code of an electronic postage meter machine against manipulation, having a microprocessor in a control unit of the postage meter machine for implementing steps for a start and initialization routine and following system routine with a possibility of entering into a communication mode with a remote data central, as well as further input steps in order to enter into a franking mode from which a branch is made back into the system routine after the implementation of an accounting and printing routine, includes conducting a start security check within the framework of a start and initialization routine which runs before a secure printing data call routine and the following system routine for determining the validity of a program code and/or of data in the predetermined memory location and of an appertaining MAC (message authentification code) that is present in the same storage medium.

Abstract: In a method and apparatus for paying for recrediting of an electronic postage meter machine, switchable into a reloading mode, and communicating with a data central, data is entered into the postage meter machine and the postage meter machine is switched into a communication mode or into a credit inquiry mode. Communication is established with the data central and a plausibility check of the entered data and register values is undertaken in the data central, and a credit inquiry process is begun by the data central if a credit card number has been entered via the postage meter machine. The data central contacts a credit card processing center for verifying the credit card status of the customer and, upon receiving an authorization indicating an acceptable credit card status of the customer, the data center processes the reloading event. If the credit card processing center indicates an unacceptable credit card status, the preceding steps are repeated. A list of successful credit inquiries can be produced.

Abstract: In a method for improving the security of postage meter machines, the intent to conduct an authorized opening of the machine, such as for inspection or maintenance purposes, is first reported to a central data station, after the postage meter machine to be opened has established communication between the machine and the central data station. The postage meter machine has a code word stored therein, the presence of this code word being necessary for authorized operation of the machine. Following the request to open, the central data station transmits a new code word to the postage meter machine, which is also stored therein. Upon any opening of the postage meter machine, the current code word is automatically erased. If the opening is authorized, and thus a new code word is stored in the machine, this new code word is automatically substituted for the erased code word, so that operation of the machine can proceed in a normal fashion.