Dr. sc. Vilko Žiljak ,
profesor, Grafički fakultet, Zagreb
Security Systems Based on Graphic Technologies
Graphic methods have always been used in security jobs: in making documents, securities, receipts, shares of the widest application. On the other hand, efforts have been made to produce the same graphic products as copies, counterfeits. The printing business has been offering constant novelties in the security and protection area, and these efforts are continuing in trying to discover original, contemporary and specific solutions. This paper gives a report on some of our novelties in this area. We have developed individual rastering, application of micro-lenses as a unique three-dimensional image and have entered the field of radio-frequency identification. A contemporary document integrates simultaneous presence of all these techniques in order to enable a wide range of control such as control by visual and tactile contact and instrumental control using computer technology.
2. Progress in Document Counterfeiting
Owing to mass accessibility to digital printing, color printers, photocopying machines and digital cameras, this is an era of cheap and successful counterfeiting on the level of evaluations being made based on eye sight. There is fineness in imitating color, fine thin security lines, paper type and even some holographic designs in modern examples of imitating original products made by applying graphic, printing techniques. Instrumental procedures for determining product authenticity have been improved greatly and there is no mistake here in accepting documents and securities, even in cases when an old print is tested that has been produced by already abandoned methods. Semi-automatic control by units that determine the presence of security colors, for instance, is not a very good technology because such colors already exist in the free market. The situation is favorable for counterfeiting also due to the fact that people, in general, are not informed about issues such as: what security details should be checked, what they look like, how should they look like and which counterfeit methods are the current trend.
New areas in finding more sophisticated security methods are being explored in both directions: recognizing authenticity by eye sight, and recognizing authenticity with the help of instruments. The second method depends on expensive instruments, and it is therefore, a procedure used only in vaults where other securities characteristics are determined, such as wear, damages, fading of certain colors. Inexpensive torches with UV detectors are only the first stage but this has ceased to be a significant method in printed matter protection. Instrumental authenticity control comprises checking such as infrared color state, holograph recognizable shine, yellow element coding, hidden bar codes, radio-frequency identifier state, incorporated thread and metal band condition.
The human eye can see a very narrow area of light, electromagnetic emission. (Picture 1). Because of this technologies are used in securing documents where material is applied that is either not visible to the eye or is black, i.e. it either reflects or absorbs light. These are materials that the human eye could see if it were sensitive in respect to the ultraviolet or infrared area. Only by applying planned sources of emission these materials become active in emitting light components that our eyes can see. This phenomenon is good for hiding marks that we applied on a document that may be detected only after special treatment. Some procedures include computer support translating signals into our visual range. Development has gone so far as to store such images into databases with a large quantity of data. This is why it is not necessary for us to see anything except digital information that enables automatic interpretation of the authentic product as well as the counterfeit one. The area of application spreads to very old documents, signature ink usage, paper composition, ageing analysis. For instance, our naked eye sees a blue ink signature, but a device for detecting counterfeits today „sees“ and selects precisely hundreds of different „blue signatures“, shows attempts at replacing parts of lines, translating parts of the signature into the red visual area and the other into the yellow area, for example. Our database has several scores of blue ballpoint pen inks that emit in the most various wavelengths under the influence of various radiations coming from the ultraviolet area.
The area that is becoming much more important is the area of elements for visual detection. In the past ten years holography has become obligatory on securities. Kinetic movement is interesting if it is the case of a three-dimensional graphic image with simply described graphics. Multiple colors are obligatory. Image changing in high resolution holograph technique is justified for printing runs amounting to over one million pieces. This is the reason for not applying this technique on unique items or on low run security graphics. The technology successfully applied is the technology of micro-lens coming from the area of lenticular graphics. In our laboratories we have developed systems for one-time-only application of a three-dimension image for a micro-lens resolution from 20 to 110 periods per inch. Effective are those examples that emit the image up to some ten centimeters above the document.
3. Development of the Database on Counterfeits
We have developed a web oriented system for recognizing the most different technologies in imitating securities, with many fine points and instructions on education in this field. The software processes almost all known methods that have been used so far, with links to the databases on general understanding as to how the original had been made, as well as the counterfeit product. The databases contain many examples of counterfeiting with notes – criticisms, comments, detail analysis. It is possible to enter one's own experience according to the explicit and broad questionnaire. The recording plan design allows the database to be expanded automatically with data on new findings. The database allows statistic scanning according to all program variables on counterfeiting such as: printing techniques, place of detection, applied inks, quality review, level of effectiveness, and many others.
4. Lenticular Micro-lens Technique for Making Portraits and Background Graphics
Portrait images on documents are individualized prints made on basis of several different technological procedures in the past fifteen years. We introduced non-dimensional color images for our passports and identity cards as first in the world to do so as far back as 1991. Because of being so expensive, this production procedure was used for special editions only, such as diplomatic passports and passports for those with a special status. A couple of years later a similar technology was then introduced all over the world, but with printers that entered commercially into graphic application as trial prints. In 1998 things were improved with the help of digital printing. Today this is a mass application with printers that are available everywhere so the production of such images is not considered as a means for security protection.
In our more recent testing of proposed new security procedures we have given a proposal for the space image. The image we feel is positioned outside the document, partly under and partly above the page on which the textual and numerical data is found. The same applies to security lines. They are designed to seem as moving, and their position depends on the angle of viewing. Such security lines may be shown to have a depth of as many as several centimeters. As the graphics seem to be swimming objects, it is impossible to scan them or interpret them by any fixed displays. The basis of this technology is a lenticular micro-lens system. Some countries have begun this type of application on personal documents two years ago in black-and-white portrait interpretation. In our country we have fully developed the multicolor technology of processing images shot with six digital cameras with the mutual viewing angle being from 1 to 4 degrees of mutual angle slant. A tool has been created with the goal to produce a 3D portrait in a small space of time. The first results dealt with the site height images. A much higher quality criteria rate is set for pictures taken from a short distance.
The final spatial image that partly falls in front and partly in back of the print consists of 6 internal images and does not allow repetition because of a great number of parameters that are included into the picture creating procedure. There are no existing scanner procedures that could replicate exactly these unique graphics.
5. Document Individualization with Graphic Techniques
The internal graphic structure in printing is worked out with the help of rastering, for which many methods have been developed. Raster element structures have been developed in our country that may be applied by printing with individualized markings. Software has been developed for this purpose that functions by using algorithms for generating pseudo chance numbers. This system is initiated by a piece of information on which a whole sequence of enumerated values depends and which is part of the antistochastic area group. The graphic rastering microstructure has been solved in this manner as a unique solution but with an imposture that depends on the entrance data, i.e. the seed necessary for generating a stochastic sequence. This piece of information may be: date of birth, eye color code, personal data from the document and a combination of such sources supplemented by some secret code.
We have been developing this technology from the time the first large digital machines were installed some ten years ago. Application was begun on tram tickets, and today such individualization may be found on all documents the original designs of which had been carried out in our laboratory. The databases initiating rastering are stored as an electronic record together with the algorithm software solutions and deciphering keys.
6. Radiofrequency Identifiers
Each product in the near future will be marked through a REID chip and its antenna. Securities and documents will have a system for remote identification. Now we are going through the experimental phase for such application on securities. The issues of durability, wear and tear are being solved rather than the very feature of identification signal emission. Packaging material as a typical graphic product includes this novelty in all individual products. Today everything is ready for this application. Products marked for remote identification come out of the printing press. The RFID information carrier is attached to the box, palette, container, fork vehicle and the very driver. When passing by a scanner everything is registered at once. Priorities: Chips with no charging of their own have an eternal life time.
Application, faults, agenda, priorities:
- Control of goods, animal and people circulation
- Individualized chip coding,
- Chip with simple passive data or
- Re-programmable chip for remote control
- Active transponders (with their own charging – limited life
- RFID technology functions through a net of scanners that are active data collectors on RFID chip transition – mobile data logging
- The scanners are usually at certain spots waiting for goods, vehicle and people transition
- Databases are sources for starting up programs aimed at target goals: warehouse storage management, speed of goods transition, instant registering of various goods transition, movement of vehicles in closed systems – motorways – where scanners are installed.
- Chips come in sizes as small as 0.15 mm, and the price is below 2 kunas
Application today covers thousands of articles; a list of some of them is given as a reminder:
- Document and securities flow:
- RFID implementation in passports is planned as early as this year by several countries.
- The next Euro bill editions will contain a RFID chip (the size of 0.15 mm)
- The World Soccer Championship in
- Movement of people in work premises
- Exotic application: animal transportation, movement of animals in zoos
- Protection and rescue: search for divers, lost mountain climbers, (swan observing)
This technology has the greatest application rate of growth in the security area. Nowadays millions of applications are installed daily. The mass application of bar codes will be abandoned, but parallel application will remain making identification and security more efficient and this also provides continuity in controlling supplies and databases on products and goods flow.
Problems linked with remote control of people and goods invade the area of privacy protection. There will be many organizations fighting against such control. However, events will take place regardless of such demonstrations. For what purposes could this enormous quantity of records be used? We should prepare an answer to this question. These technologies are not being introduced fast enough due to the lack of programmers, database designers, and the lack of definitions for using such information. We lack educated people for control of information that enable the processing of transition and private data. Legal systems have not even begun to be elaborated in this sense, and programming is still something to be done in the future. We have come to the point when we will import „grey cells“: expertly educated informatics experts with knowledge covering many other fields of specialization. The security area is constantly gaining in new issue quantity, new definitions and new application technologies.
Security in people, goods and services flow has required introduction of innovations in respect to graphic products too because they are the supporting elements at every transaction junction. The same graphic products that protect us may also lead us to undesired situations. The development of new designs is followed by the development of counterfeiting techniques. In this eternal struggle we have found reasons for elaborating the following themes: application of coloring products from the range of those that are invisible to the human eye; creating software for three-dimensional graphics produced by printing; innovations in the structure of individualizing raster forms; application of remote detection of goods or live beings. These subjects alter our behavior but also open the need to process information in a new manner. Soon we will have a deficit of educated experts with high qualifications – those who are necessary in order to design the tools and struggle with a new type of future in the area of security.