GB2080203A

GB2080203A - A postage meter

Info

Publication number: GB2080203A
Application number: GB8121636A
Authority: GB
Original assignee: Pitney Bowes Inc
Current assignee: Pitney Bowes Inc
Priority date: 1980-07-14
Filing date: 1981-07-14
Publication date: 1982-02-03
Also published as: DE3126786C2; JPH087805B2; GB2080203B; FR2486689A1; CA1175568A; DE3126786A1; FR2486689B1; DE3126786C3; JPS5750090A

Abstract

A postage meter for use in a remote meter resetting system includes: means for entering a selected, variable amount of postage in preparation for funding the postage meter with that amount, means 24 to internally generate a unique combination which varies as a function of signals generated within the postage meter and of the selected, variable postage amount entered into the postage meter, means 14 for entering an externally generated combination into the postage meter, a comparator 28 to compare the internally generated and externally generated combinations, and a means 30 to fund the postage meter with the selected, variable postage amount when the comparison indicates the existence of a predetermined relationship between the internally generated combination and the externally generated combination also includes means 20 are provided for establishing a new unique authorization code for accessing the next externally generated combination from a data center. <IMAGE>

Description

SPECIFICATION A postage meter The present invention relates to a postage meter specially designed for use with a remote recharging system.

Postage meters are devices for dispensing value in the form of postage printed on a mail piece such as an envelope. The term postage meter as used herein also includes other meters which dispense a value imprint such as parcel post meters. Meters of this type print and account for postage stored within the meter. Since representations of postage available for printing are stored in the meter, the postage meter must be provided with safeguards against tampering.

Within the above requirement, systems have been developed to enable postage meters to be recharged or reset with additional postage for printing by the meter without the need to physically carry the postage meter to the postal authorities for resetting. This avoids the inconvenience to the users of the postage metered mailing system by avoiding the necessity to bring the meters to the postal service for recharging. The remote recharging systems have met the requirement for security for the postage meters and have been developed for both fixed increment resetting for mechanical meters and variable increment resetting for electronic meters.

In the mechanical resetting meters, the system is equipped with a combination lock whose combination changes in a predetermined random sequence (often referred to as psuedo-random sequence) each time it is actuated. The combination lock operates on the resetting mechanism of the postage meter such that, when unlocked, the mechanism may be manipulated to recharge the meter with a postage increment. As the meter is recharged, the combination lock automatically locks itself to prevent subsequent recharging of the meter unless and until the correct new and different combination is entered. Combination locks of this type, suitable for use in postage meters are disclosed in U.S. Patent Nos. 3,034,329 entitled Combination Lock Device and 3,664,231 entitled Locking Device.

The remote meter resetting system may also be incorporated in electronic postage meters such as described in U.S. Patent No.

4,097,923 for REMOTE POSTAGE RE CHARGING SYSTEM USING AN ADVANCED MICROCOMPUTERIZED POSTAGE METER.

The resetting system involves a data center which may be equipped with a voice answer back unit. The data center processes telephone calls from the postage meter users, requiring the transmission by the user of information unique to the particular meter being reset. The information is used to verify the authenticity of the caller and to update the record of the user stored at the data center.

The postage meter user informs the data center of the postage which is desired to be funded into the meter. The postage amount requested for resetting may be varied according to the requirement of the user. The computer at the data center formulates a combination based on the identifying information and the amount of postage requested for resetting.

This combination is then transmitted back to the user. The user enters both the amount and the combination into the postage meter.

The postage meters contains circuitry for comparing the entered combination with an internally generated combination based upon the amount of postage requested for resetting and the identifying information. If the entered combination matches the internally generated combination, the funding registers of the meter are increased by the new postage amount.

A system disclosed in European published Patent Application No. 18081 employs encryptors at both a printing station and an accounting station interconnected through an insecure communcations link. Each time the meter is tripped, a number generator at the printing station is activated to generate a number signal which is encrypted to provide an unpredictable result. The number signal is also transmitted to the accounting station. At the accounting station, the postage to be printed is accounted for and the number signal is encrypted to provide a reply signal. The reply signal is transmitted to the printing station where a comparator compares it with the encryption results generated at the printing station. An equality of the encryption result and the reply signal indicates that the postage to be printed has been accounted for and the printer is activated.

Although the above systems operate quite satisfactorily for their intended purpose, it has been a constant desire to enhance the security of postage meter remote recharging systems and to provide improved performance. This is particularly so with variable increment recharging which requires a more secure and more complex environment than fixed increment recharging systems. The reasons for this are that the amounts which may be involved in a reset (recharge) can be substantially larger than with fixed systems where the amount is established in advance.

The variable amount of the resetting makes it more difficult to reconstruct previous information stored in the meter should that be needed. With fixed increment recharging the amount of the recharge is established in advance. Consequently, the change in the accounting registers in the meter can more easily be reconstructed. This is not the case for variable recharging.

For example, if the control sum in the postage meter's registers is employed in the recharging system, the user would communicate this information to the data center. The control sum is the sum of the postage meter descending register (which is the amount of the postage remaining to be printed) and the postage meter ascending register (which is the total of postage printed by the meter). This sum remains constant until the meter is recharged. At that time, the control sum increases by the amount of the reset. However, where the recharging amount is variable, the effect on the control sum change is not a defined progression for each recharge operation.

The problem is further complicated in those systems where user identification is accomplished by the utilization of information such as the control sum, the ascending register amount, the descending register amount, the meter serial number, the account number and other similar types of information. On such systems, many reset amounts can be requested by a user but not necessarily entered into the meter.

The present invention provides a postage meter capable of operating an improved remote meter recharging system having validation capability of the customer or user entered data. The invention as particularly disclosed herein inhibits a user from obtaining a series of reset amounts which are not entered into the meter and could cause the information stored at data center and the information stored in the meter to be inconsistent. Moreover, the present system enables a level of protection against inaccurate information either accidently or intentionally entered by a user, as the system establishes valid conditions for a recharge based on whether or not the previous recharge has been successfully entered.

The present invention involves the use of means to provide enhanced protection by providing within the postage meter a means for generating a variable authorization code which is employed by the user when communications are established with a remotely located data center in the funding operation. The authorization code may be varied by the postage meter after each resetting.

A postage meter embodying the present invention includes means for entering a selected amount of postage into the meter in preparation for funding the postage meter with that amount. Means internally generate a unique combination which varies as a function of signals generated within the postage meter and of the selected postage amount entered into the postage meter. Means are provided for entering an externally generated combination into the postage meter. Means within the postage meter compare the internally generated and the externally generated combinations.Means fund the postage meter with the selected postage amount when the comparison indicates the existence of a predetermined relationship between the internally generated combination and the externally generated combination and means generate a new unique authorization code for accessing the next externally generated combination from a data center. The authorization code is displayable to the user on the postage meter display.

A better understanding of the present inven-" tion will be obtained by reference to the following detailed description and to the draw- ings, wherein like reference numerals are used for similar components in the various figures and in which Figure 1 is a block diagram of one example of a postage meter embodying present invention; Figure 2 is a block diagram of a postage meter similar to that shown in Fig. 1 but modified to include a second encryptor and mixer to enhance the security of the system; Figure 3 is a block diagram of a data center suitable for use in cooperation with the postage meter shown in Fig. 1; Figure 4 is a block diagram of a data center suitable for use in cooperation with the postage meter shown in Fig. 2.

A postage meter 1 2 (Fig. 1) includes a user data entry means 14 such as a keyboard for entering postage to be printed by a postage printing mechanism 16. The postage meter 12 may be of the type disclosed in U.S.

Patent 3 978 457 entitlted MICROCOMPU TERIZED ELECTRONIC POSTAGE METER or in published U.K. Patent Application Serial No. 2 062 312. The postage meter 12 includes a register 1 8 to account for postage stored in the meter and for storing other postage accounting information. Such information may include, the total amount of postage printed by the meter (an ascending register) the total amount of postage remaining in the meter for printing (a descending register) and the sum of the ascending register and the descending register (a control sum register).

The control sum register amount remains fixed for a particular postage meter unless and until the descending register is charged with additional postage.

Register 1 8 is coupled to an encoder and cyclical redundancy character (CRC) generator 20 as is a reset counter 23. The encoder and cyclical redundancy character generator oper- ates upon the information from register 1 8 and from the reset counter 23 to generate an authorization code. The authorization code may be displayed on the postage meter display 24. The authorization code is utilized in conjunction with the remote meter resetting of postage meter 1 2 in communications with a data center (not shown in Fig. 1); the data center may be accessed by a postage meter user over an insecure communications link such as a telephone line.

The authorization code provides a level of assurance that the postage meter user calling the data center has physical access to the meter being reset and also that the information has been accurately transferred between the meter and the data center. The encoder and CRC generator 20 are of the type which process input information to provide a detection scheme for errors which may occur in transferring information.

When the postage meter 1 2 is to be recharged with postage, a reset amount is entered by the postage meter user at the data entry station 14. The reset amount is applied to an encryptor 24. Additionally, applied to the encryptor 24 is information from the control sum register 19, and a prestored seed number signal from seed storage 26. The seed number signal is stored in the meter 1 2 in an unencrypted form. Encryptor 24 can be any one of a large number of encrypting devices including those devices which use the Data Encryption Standards described in FIPS pUB 46, dated January 15, 1977 and published by the U.S. Department of Commerce, National Bureau of Standards.Encryptor 24 generates an encrypted signal based upon the user entered reset amount, the information from the control sum register 1 8 and the seed number signal from seed storage register 26.

Output signal from encryptor 24 is applied to a comparator 28. Comparator 28 compares the signal generated by the encryptor 24 with a user entered signal or combination.

If the comparator 28 determines that a user entered combination coincides with the combination generated by encryptor 24, the reset amount signal is applied, with the current descending register amount signal from register 1 8 to an adder 30. The reset amount is applied to increment the descending register and the control sum register.

It should be noted that in accordance with the embodiment shown in Fig. 2 the reset amount and the control sum may be first applied to a mixer circuit 33 before being applied to the encryptor 24. The mixer 33 provides additional security for the postage meter. The mixer provides a mixed input signal to the encryptor 24 such that the determination of the output signal from the encryptor 32 is more difficult to determine.

Referring again to Fig. 1, a successful comparison of a user entered combination and a combination generated in encyrptor 24 results in a new clear text seed number signal being stored in the seed storage register 26 for the next reset activity.

Additionally, the reset counter 23 is incremented. The reset counter 23 may be one of many types including a modulo 2 or modulo 1 6 counter. The counter 23 provides an input signal to the encoder and CRC generator 20 such that the authorization code signal contains information as to whether the postage meter 1 2 has been successfully reset. The reset counter 23 is incremented by an output signal from the comparator 28 only when a successful comparison of the user entered reset combination signal and the internally meter generated reset combination signal occurs.

The output signal from the comparator 28 is applied to a signal splitter 32. The splitter 32 extracts a new seed number signal from the generated cypher-text. The new seed number is stored in the seed register 26 and the reset amount is applied to the adder 30.

Reference is now made to Fig. 3 which is a block diagram of a remote data center operable in conjunction with the remote settable meter 1 2 shown in Fig. 1. The data center 40 receives the authorization code generated by postage meter 1 2 and transmitted by the user such as by use of a tone generator type telephone. The authorization code is applied via a receiver 42 to a decoder and verifier 44.

The decoder and verifier 44 decodes the authorization code to generate the rest count and, for example, the descending register amount for postage meter 1 2. The decoder further verifies the CRC to ensure that the data has been accurately transmitted and additionally to provide a level of verification that the user has had physical access to the meter being reset. This is because a user who determines the reset count and the descending register amount for a particular meter would not have sufficient information to access the data center; still needing to determine the signal processing in the encoder and CRC generator.

It should be noted that further security can be provided by applying the authorization code to an encryptor 21 (Fig. 2) prior to display on the postage meter display 22 and thus, prior transmission by the postage meter user. If this occurs, the encrypted authorization code, as is shown in Fig. 4, would be decrypted in a decryption circuit 45.

Referring again to Fig. 3, if the decoder and verifier 44 verifies the accuracy of the transmission (the CRC is correct), the reset count signal is generated and applied to a comparator 46 wherein the decoded reset count signal is compared to the reset count signal stored at the data center. The decoded descending register amount signal is applied to an adder 48 with the reset amount signal from receiver 42 which is also provided to the data center by the user. If the sum of the descending register and reset amount exceeds the amount of postage capable of being stored in the postage meter, the reset operation is inhibited.

This information may be communicated back to the user via a voice generating means 51.

If the stored reset count signal and the decoded reset count signal compare correctly, the comparator 46 enables an adder circuit 49 coupled to the control sum storage register 50 to provide the current control sum associated with postage meter 1 2 to a physically sealed unit 52 and to add the reset amount to the control sum storage register. The physically sealed unit 52 is sealed in a manner to prevent access to the circuitry by data center personnel. The sealed unit, which will be described in greater detail hereinafter, results in an enhanced security for the remote meter resetting system because the data center personnel do not have access to the encryption circuit and certain unencrypted data associated with the resetting of the meter 1 2.

The control sum register 50 signal is applied to an encryptor 54 within sealed unit 52 as is the user entered reset amount signal from receive 42. Additionally applied to the encryptor 54 are unencrypted seed number signals. The encryptor 54 may be any one of a large number of encrypting devices such as those employing the data encryption standard previously identified. However, it should be noted that encryption device 54 is identical in its operation to the encryption device 24 in postage meter 12.

The seed number signal applied to the encryptor 54 is stored in the data center so that it may be accessible by data center personnel. However, the seed number signal is stored in an encrypted form in encrypted seed storage 56. This is the only form of the seed signal to which data center personnel have access.The encrypted seed signal from storage 56 is applied to a decryption device 58 which need not be similar to or compatible with the form of encryption provided by encroptor 54 and encryptor 24 in the postage meter 1 2. The decryption device 58 which may be any one of a large number of known devices functions to decrypt the encrypted seed number signal and to provide an unencrypted, clear seed number signal which is the same as the seed number signal stored in the seed storage 26 postage meter 1 2. The encryptor 54 generates an encrypted output signal which is applied to a signal splitter circuit 60. The splitter circuit 60 splits the encrypted output signal from encryptor 54 into a first part which is transmitted via the voice generator means 51 to the postage meter user.The voice transmitted combination is the combination which is entered by the user and applied to the comparator 28 in Fig.

1.

The splitter circuit 60 additionally applies the other part of the encrypted output signal from encryptor 54 to a second encryptor 62 to generate a new encrypted seed number signal. Encryptor 62 encrypts the seed number signal in a manner so that it is compatible with the decryptor 58. The new encrypted seed number signal for postage meter 1 2 is transmitted from within the sealed unit 12 to the encrypted seed stoage 56 which is accessible to the data center personnel.

Reference is now made to Fig. 4 which shows the use of a mixer 64 located within the sealed unit 52. In this embodiment, the mixer 64 provides a further enhanced security, similar to mixer 30 provided in postage meter 1 2. If a mixer 30 is provided in the postage meter 12, a like mixer 64 must be provided at the data center.

Claims

1. A postage meter comprising: means for entering a selected, variable amount of postage into the meter in preparation for funding the postage meter with that amount; means for internally generating a unique combination which varies as a function of signals generated within the postage meter and of said selected, variable postage amount entered into the postage meter; means for entering an externally generated combination into the postage meter; means for comparing the internally generated and externally generated combinations; means for funding the postage meter with said selected, variable postage amount when the comparison indicates the existance of a predetermined relationship between the internally generated combination and the externally generated combination; and means for establishing a new unique authorization code for accessing the next externally generated combination from a data center.

2. A postage meter as defined in claim 1 wherein the authorization code establishing means includes an encoder and a CRC generator.

3. A postage meter suitable to be recharged with postage by a user, comprising: means for entering data into said postage meter; an encryptor coupled to the data entry means; means coupled to said encryptor for entering into said encryptor signals which are stored internally of the postage meter in a signal storage means; comparator means coupled to said encryptor and to the data entry means for comparing output signals from the encryptor and signals entered via said data entry means; splitter means coupled to said comparator means for separating the output signal from said comparator means into a first part and a second part, the splitter means being coupled to the signal storage means for updating the signal storage means with said first part of said signal; register means for storing postage meter accounting information; adder means coupled to said splitter means and to said register means for adding said second part of said signal to the contents of said postage meter register to provide a new signal for storage in the register means; and means coupled to the register means and for generating an authorization code.

4. A postage meter as defined in claim 3 in which the signal storage means includes a control sum register and a seed storage regis ter, and wherein the said internally stored signal includes a signal from the control sum register and a signal from the seed storage register.

5. A postage meter as defined in claim 1 further including a reset counter, said reset counter being coupled to said authorization code establishing means so that in use said authorization code includes information from said reset counter.

6. A postage meter as defined in any preceding claim wherein said data entry means include means for causing an authori zation code to be displayed on a postage meter display.

7. A postage meter as defined in claim 1, 5 or 6 further including a second encryptor coupled to said authorization code generating means and for encrypting the authorization code.

8. A postage meter as defined in claim 3 further including a mixer means coupled to said data entry means, said signal storage means and said encryptor for mixing signals from said data entry means and said signal storage means prior to application to said encryptor.