WO1999008234A2

WO1999008234A2 - A method and apparatus for printing marks

Info

Publication number: WO1999008234A2
Application number: PCT/EP1998/004900
Authority: WO
Inventors: Daniele Pittori
Original assignee: Elettronica Meccanica Sistemi S.R.L.
Priority date: 1997-08-08
Filing date: 1998-08-06
Publication date: 1999-02-18
Also published as: WO1999008234A3; AU9159698A; IT1293961B1; ITTO970731A1

Abstract

Method and apparatus for printing marks (23) on documents include means for printing specific information (22) on the document in association with the mark. The apparatus is characterised in that it uses a dot matrix printing technique and includes the printing of an additional field (31) with the aforesaid specific information containing the franking data that is encrypted according to an electronic algorithm key that cannot be copied and which is provided exclusively by the aforesaid authorising body. The apparatus is particularly usable in post offices for franking.

Description

A METHOD AND APPARATUS FOR PRINTING MARKS

The present invention concerns a method and apparatus for printing validation marks on documents .

More specifically, the object of the invention is apparatus for printing validation marks on documents, for example, for franking machines, comprising means for printing information specific to the document in association with the aforesaid mark and/or a method for performing this printing.

In public offices, in particular post offices, the operations are usually performed on documents by printing a State and/or Government mark, together with characters and alphanumeric symbols and/or graphics representing the operation. The mark is formed from the impression of a stamp provided exclusively by the State, by law.

Printing by stamps cannot be reproduced using printing presses in general use, and is easily identifiable because of the impressions formed on the surface of the document. In addition, forging State stamps or the related marks is prohibited by the provisions of the Penal Code. This represents a serious deterrent to the falsification of validation marks, even those reproduced using means other than stamp printers.

On the other hand, the use of State stamps obliges the manufacturers of franking machines and the like to use rather complex impact printing techniques, which limit the possibilities for composing printable information.

Franking using dot matrix printing technology would introduce a vast programmability into the composition of the stamp, but it is not compatible with the use of the State stamp, in particular due to the different inking requirements of the two systems. Furthermore, printing validation marks using the same dot matrix printer would not be acceptable. In fact, a mark printed in this way would be easily reproducible for illegal purposes and be difficult to prosecute due to the wide commercialisation of printers using technology of this kind.

The object of the present invention is to produce apparatus and a method for printing marks that can utilise different techniques from stamping, but which can remain under the control of an authorising body and in which the mark is difficult to forge, maintaining the possibility of legal prosecution in the event of possible forgery.

This object is achieved according to the invention with apparatus for printing documents of the type indicated above, characterised in that it provides for the printing of an additional field containing the aforesaid specific information in a form encrypted according to an algorithm which uses an electronic key, this key not being reproducible and being provided exclusively by the authorising body. Similarly, the related printing method is characterised by the following steps : providing apparatus with an electronic coding key, which is not reproducible and provided exclusively by an authorising body; encrypting the information specific to the document according to an algorithm that uses the aforesaid electronic key; and printing an additional field containing the aforesaid encrypted specific information, for the verification, after decoding, of the unencrypted printed information.

In this way, the mark and the document information can benefit from the wide range of compositional possibilities offered by the dot matrix printing technique. The validity of the franking will be easily verifiable, as it is sufficient to read the additional field and decrypt the information contained therein. The decrypted information will match with the unencrypted printed information only if the franking has been performed using a legally authorised franking machine, while the absence of a match will be an indication of forgery.

Because of the difficulties of reproduction and the ability to control the production and distribution, the electronic key and the printable additional field on the document both have the characteristics of being protected in a way similar to that applicable to the current State press stamp and its impressions . Further characteristics and advantages of the apparatus for printing marks and the related method according to the invention will become clear from the following detailed description, with reference to the accompanying drawings, given purely by way of non-limitative example, in which:

Figure 1 is a block diagram showing apparatus for printing validation marks on documents, of known type;

Figure 2 is an example of a print, of known type, of a validation mark and other information specific to the document;

Figure 3 is a block diagram showing apparatus for printing validation marks on documents according to the invention;

Figure 4 is an example of a print of a validation mark and other information, made by the use of the apparatus of Figure 3 ;

Figure 5 is a block diagram showing some details of the apparatus of Figure 3 ;

Figure 6 is a block diagram of a control device associated with the apparatus of Figure 3 ;

Figure 7 is a flow diagram showing schematically the method for printing marks according to the invention; and

Figure 8 is a flow diagram showing schematically a method for verifying the marks printed according to the invention.

According to the regulations in force in Italy, the marks of public offices and, in particular, those used in post offices, are constituted by the impressions of stamps manufactured exclusively by the Mint section of the State Printing Works, Stationery Office and Mint, which thus supplies Government departments and franking machine manufacturers .

By way of example and in block diagram form, Figure 1 illustrates a franking machine 11, of known type, which prints specific information 14 on a zone 12 of a document 13 , which information indicates the kind of operation performed, and a validation mark 15 which represents the particular Government and/or State department .

The information 14 (see Figure 2) comprises alphanumeric characters, graphic symbols and images, while the mark 15 is generally constituted by an outline frame and the symbol of the State and/or Government department in question.

The machine 11 has a print unit with a section 16 provided with a composition stamp 17 for printing the information 14, and a section 18 with a State stamp 19 for printing the mark 15.

The use of a State stamp enables the machine 11 to produce a mark that is difficult to forge and which falls under the provisions of several articles (467, 468 and 469) of the Italian Penal Code which provides sanctions in the form of imprisonment for forgery. This deterrent would without doubt be worthless in the event that the printed information did not have the endorsement of the impressed mark. Figure 3 shows in the form of a block diagram, apparatus 21 according to the invention for printing information 22 and marks 23 on documents 24. This apparatus provides for the use of a dot matrix print technique achieved, for example, by way of inkjet heads, needles, thermal transfer etc. or using lasers .

The information 22 relating to the operation can comprise a franking amount 25 (see Figure 4) , the date of the operation 26, the name or number of the office 27, a sequential number 28, the specialisation 29 etc.

The validation mark 23 can have the same appearance as the mark 15 printed using the State stamp but, if appropriate, the mark 23 may have an entirely different form.

In accordance with the invention, the apparatus 21 prints, together with the information 22 and the validation mark 23, an additional field 31 containing the same information that is printed in unencrypted format, but encrypted using an inaccessible key.

The field 31 is of graphic type, of high redundancy and with the possibility of identifying and self-correction of errors, and is generated, using a twin key algorithm, from the information 22 containing the details of the operation performed and described above. The apparatus 21 comprises an electronic control unit 32, a keyboard 33, a printer 34 and a visual display 35.

The electronic control unit 32 (Figure 5) comprises a central unit 36, a ROM memory 37 and a RAM memory 38, and controls the printer 34 in known way on the basis of data introduced from the keyboard 33 and a program resident in the ROM 37.

According to the invention, the electronic control unit 32 further includes a microprocessor circuit 39 having sections that are not addressable from the outside, which stores a coding algorithm 40 and a primary electronic key 41.

The circuit 39 is adapted to convert the characters of the information 22 to be printed on the document 24 into intermediate information. This information is encrypted using the algorithm 40 and a twin key system, including the primary key 41 and a public secondary key generated by an algorithm that forms part of the program resident in the ROM 37.

The program of the ROM 37 then converts the intermediate information into punctiform information for printing a two- dimensional graphic image according to a standard code.

Conveniently, this standard code is formed by utilising a known bar code such as PDF417, an acronym for Portable Data File, comprising 4 bars and 4 spaces to give a total of 17 modules for each unit of elementary data. The PDF417 code has been proposed for printing a great number of information in a very small space on paper, and implements algorithms for recovering information in the event that the print is damaged. Specifically, in the present application, the encrypted information derived from the information 22 and the public key can be represented on a rectangular area of 2- 6 cm .

The method for validating the printed information, represented schematically in Figure 7, includes by way of example an initialisation step 43 in which the initial and semi-permanent information in the form of the date 26, the name 27 and the sequential number 28 is introduced. Data relating to the information 25 to be franked, the specialisation 29 etc. relating to the document 24 are introduced from the keyboard 33 in a step 44. This data is verified on the visual display unit 35 and is added to the semi-permanent information and processed for printing in a step 45.

The data that has been introduced and stored is then encoded by the circuit 39 in a step 46 to give encrypted intermediate information containing information relating to franking, the date, the office number, a sequential number and the specialisation, encrypted using the primary key 41 and the secondary key generated at the time.

Then, in a step 47, the encrypted intermediate information, together with the secondary key, is encoded for a graphic transposition using the bar code PDF417, and is then printed in the additional field 31 in a step 48.

The use of a standard algorithm PDF417 for the graphic transposition of the encrypted data is also advantageous because it enables the use of a commercially available reading device 50 for connection, for example, to a personal computer 51 (Figure 6) provided with a cryptographic module 52, this also having the circuit 39 with the algorithm 40 and the primary key 41.

By way of example, the reading device 50 is an optical reader with a laser scanner, which is able to read the additional field 31 in a way that is compatible with the specifications of the code PDF417.

The device 50 operates on the basis of a program associated therewith which converts the graphic information into the encrypted intermediate information and then activates the circuit 39 for decryption using the algorithm 40, the primary key 41 and the secondary key contained in the information itself.

As illustrated schematically in Figure 4, the recognition method thus involves reading the field 31 in a step 54 and, in a step 55, decoding the graphic information in the encrypted intermediate information using the code PDF417. In a step 56, the intermediate information is decrypted using the algorithm 40 and the two keys and, in a step 57, all the information is displayed unencrypted on the PC 51. Finally, in a step 58, the displayed information can be compared visually with that read on the document 24.

If the information displayed is consistent with the unencrypted printed information, franking has been performed using a legally authorised franking machine. On the other hand, if there is a discrepancy in the information displayed, this will be an indication of forgery.

The circuit 39 is such as to simplify the operation for replacing it in the apparatus 21 and the PC 51 so as to enable the primary keys 41 to be changed periodically, with a consequent increase in the security of the system.

The apparatus and method of the invention enable the problem of the easy forgery of marks when the State stamp is no longer used to be overcome .

The microprocessor circuit 39 can be constituted by an integrated circuit (chip) mountable in the apparatus 21 and which self-destructs in the event of tampering, or which has other known security systems .

The manufacture of the chip having the primary key, together with its distribution, can be controlled by the same organisation, the State Mint, which currently controls the stamps with the validation marks . The microprocessor circuit 39 with its electronic key represents a kind of "electronic State stamp". In fact, as the result of its characteristics of controllability and difficulty to forge, the chip can be seen as a tool intended for public authentication or certification, protectable in a way similar to the current State stamp. Similarly, the additional field 31 is comparable to the impression of the State seal, and is protectable in a way similar thereto.

Naturally, the principle of the invention remaining the same, the embodiments and the details of production can be widely varied with respect to that described and illustrated purely by way of non-limitative example, without by this departing from the scope of the present invention.

By way of example, in order to read the field 31, the reading device 50 may be connected to the same apparatus 21 used for the printing, using the same circuit 39 already provided in the apparatus and having a suitable program for controlling the device 50.

Alternatively, the apparatus of the invention can use a transcoding system of specific type which can form the State mark from graphic elements in dot matrix form with a density or form coded on the basis of the information 22.

Advantageously, the mark 23, the information 22 and the additional field 31 can be printed on a label or on a strip to be stuck to the document to be validated, using a known technique.

Alternatively, the additional graphic field can also include a purely alphanumeric code or a mixed graphic and alphanumeric type code.

The module 51 can also include an optical reader for identifying the unencrypted written information, and a recognition program for the automatic comparison of the unencrypted-printed and decrypted information.

Claims

1. Apparatus (21) for printing validation marks (15, 23) on documents (13, 24), including means for printing (34) information (14, 22) specific to the document (13, 24) in association with the aforesaid mark, characterised in that it includes means for the printing of an additional field (31) containing the aforesaid specific information (22) in an encrypted form according to an algorithm that uses an electronic key (41) that cannot be copied and which is provided exclusively by an authorising body.

2. Apparatus for printing marks according to Claim 1 , characterised in that a code (PDF417) of high redundancy and with characteristics of error detection and self-correction is used in the said field (31) .

3. Apparatus for printing marks according to Claim 1 or 2 , characterised in that the said additional field (31) is of graphic type .

4. Apparatus for printing marks according to Claim 2 or 3 , characterised in that the said additional field (31) is two- dimensional and of the PDF417 bar type.

5. Apparatus for printing identification marks according to any preceding claim, characterised in that it is adapted to be used in post office franking machines .

6. Apparatus for printing marks according to Claim 5 , characterised in that the said information includes one or more items of information relating to the franking (25) and its related value, the date of the operation (26) , the name or number of the office of origin (27) , a sequential number (28) and the specialisation (29) .

7. Apparatus for printing marks according to any preceding claim, characterised in that it uses a dot matrix printing technique, for example, achieved using inkjet heads, needles, thermal transfer, or laser printers.

8. Apparatus for printing marks according to any preceding claim, characterised in that it includes an electronic control unit (32) for the printing, including a microprocessor circuit (39) in which a coding algorithm (40) and the said electronic key (41) are stored, the said microprocessor circuit (39) being adapted to convert the specific information (22) on the document (24) into the encrypted information of the aforesaid additional field (31) .

9. Apparatus for printing marks according to Claim 8, characterised in that the said microprocessor circuit (39) is adapted to convert the aforesaid specific information into intermediate information encrypted using the aforesaid key (41) and a public key.

10. Apparatus for printing marks according to any of Claims 3, 4, 7 and 9, characterised in that the said microprocessor circuit (39) is adapted to convert the aforesaid intermediate information for the graphic printing in the aforesaid additional field (31) .

11. A method for printing identification marks (15, 23) on documents (24) , including the use of print means (34) for printing on the document specific information (22) associated with the mark, characterised by the following steps: providing apparatus with an electronic coding key (41) that cannot be copied and which is provided exclusively by an authorising body; encoding the information specific to the document by encrypting it using an algorithm (40) which uses the said electronic key (41) ; and printing an additional field (31) containing the said specific information (22) in an encrypted manner, for the verification, after decryption, of the unencrypted printed information.

12. A method for the verification of marks (15, 23) on documents (24) printed using the method of Claim 11, characterised by the following steps : reading the said specific information (22) in the said additional field (31) ; decrypting the data that has been read, according to an algorithm that uses the said electronic key (41) ; and comparing the decrypted data with the unencrypted written information.

13. An identification mark (15, 23) on documents (24), associated with information (22) specific to the said document, characterised in that it includes: an additional field (31) containing the aforesaid specific information (22) in encrypted form according to an electronic code key (41) that cannot be copied, and which is provided exclusively by an authorising body for the verification of the printed information after decryption.

14. An identification mark (15, 23) according to Claim 13, characterised in that the said additional field (31) is two- dimensional and of the PDF417 bar type.