Counterfeiting is a worldwide epidemic. It threatens the global economy and public health through the production of inferior products that circumvent consumer protection regulatory channels. Spending by the public and corporations is increased to counter the illegal trade, and prices of legitimate products increase as companies seek to recover their financial losses. The International Chamber of Commerce estimated that in 2015, the value of counterfeit goods globally exceeded $1.7 trillion. That represents more than two percent of the world’s current total economic output. With profits, corporate liability and brand reputations at stake, companies are fighting back to protect their brands. Decades of experience and information derived from reputable global sources clearly demonstrate that no single anticounterfeit technology works best for all products and situations. Multiple approaches and solutions are needed, i.e., a layered approach works best. This article examines “overt” and “covert” security authentication solutions.
Anticounterfeiting Technology Classifications
Anticounterfeiting technologies can be classified and explained in different ways. In this article, technology classifications are shown on the basis of usage.
Authentication
Authentication is the act of establishing or confirming something as genuine. ISO 12931:2012 specifies performance criteria and evaluation methodology for authentication solutions used to establish material good authenticity throughout the entire product life cycle. However, it does not specify how technical solutions achieve these performance criteria. Authentication generally is done through the overt or covert features in the product. Depending upon the importance and value of the product, combining overt and covert features provides layered protection solutions.
Anti-counterfeit Technologies – Overt and Covert
Overt and covert security authentication is examined in this article. The main difference between the two is that overt technologies can be verified by users (typically visually) who are familiar with the overt technology and have a reference genuine sample of the feature with which to compare the suspect feature on the suspect product. Overt and covert solutions are designed to be applied in such a way that they cannot be reused or removed without being defaced or causing damage to the pack. For this reason, an overt device might be incorporated within a tamper-evident feature for added security.
Overt techniques are clearly visible and do not require detection devices because they are based upon the sensorial capability of the human being. Note: overt technologies also can be used as covert technologies and vice versa, depending on the complexity of the design. Most of the recent developments in overt and covert technologies have embedded hidden features to make them more difficult to be illegally replicated.
Overt technologies include the following:
- 2D/3D holography (morphing, flip image, gradient, pseudo color, grayscale image, linear/circular kinetic)
- Optical variable devices
- Watermark
- Security graphics (micro/nano text, security patterns, multicolor designs, deliberately integrated errors)
- Security threads
- Security foils
- Color shifting inks
- Intaglio printing
- Laser marking
- Fluorescence artifacts
- Colored interlayers
- 2D codes (QR, data matrix)
- Sequential product numbering, serialization
- Contact microchip
- Photograph
- Magnetic strip
Covert technologies typically require specific equipment to be verified, as the details of the technology are not disclosed. Some covert technologies – such as infrared (IR) and ultraviolet (UV) inks, microtext and microscopic tagging – are invisible and difficult to detect and replicate without special detection equipment. Images printed with UV inks are only visible under a UV lamp. UV inks are available in different frequencies, thus ? depending on the formulation of the ink – the investigators will need to use either a long-wave or short-wave UV lamp for the printed images or text to become visible. UV inks may fluoresce in a variety of colors, adding to the complexity of this covert feature.
Covert technologies include the following:
- Micro/nano printing
- Hidden imagery
- Polarization imagery
- Taggants and chemicals, up-converting phosphors
- Security inks
- Nanoparticles
In addition, covert technologies, such as taggants, also can be placed onto packaging, with the most effective being completely invisible and only detectable with a special reading device. As with other covert technologies, taggants only can be identified by the brand owner or people they equip with the appropriate knowledge and technology to provide conclusive verification.
Featured Technology: Innovations in Optically Variable Devices
Optical Variable Devices (OVDs) are a relatively new form of security technology. Complex images exhibit various optical effects depending on the amount of light striking the OVD and the angle in which the OVD is viewed. Sometimes an illuminating light source is used as an additional security benefit. OVDs cannot be photocopied or scanned and cannot be accurately replicated or reproduced. Figure 2 demonstrates optically variable inks with color shifting effects when viewed under reflected and transmitted light conditions.
Another example of OVD security, as shown in Figure 3, demonstrates optically variable inks with polarizing effects.
Properties of Optical Variable Devices
OVDs, similar to holograms, generally involve image flips or transitions, color transformations and monochromatic contrasts. OVDs typically are composed of a transparent film (as the image carrier) and a reflective backing layer, which usually is a very thin layer of aluminum or copper that produces a feature characteristic hue. Additional security features may be added by the process of partial de-metallization, whereby some of the reflective layer is chemically removed to give an intricate outline to the image, as seen on banknotes. The reflective layer can be so thin as to be transparent, resulting in a clear film with more of a ghost reflective image visible under certain angles of viewing and illumination.
Ultra high-resolution micro/nano images (10-micron and smaller, 62,000 characters per cm2) are one of the important breakthroughs in optical security, using beam-steered lasers. This detail exceeds the resolution available via any other copying, printing or scanning device in industry. Features can be visible to the naked eye, while fine detail only can be viewed using hand-held magnification. The risk of counterfeiting has been greatly reduced by recent advances in the production of micro/nano images and security patterns, which now can be resolved at more than double the previous level.
- OVDs can be placed on the surface of products (typically by stamping or rolled laminator process) or under the surface of products (by laminating or injection molding).
- OVDs can be metallized (shiny) or transparent (HRI – High Refractive Index).
- Some OVDs are a combination of metallized and transparent (like the US Passport Card).
- When laser marking is done on HRI type OVD, the laser passes through the transparent OVD.
- When laser marking is done on a metallized OVD, the laser ablates the metallization, creating a unique or personalized OVD.
- OVDs can be manufactured to fracture when attempts are made to remove them from the product. This is a tamper-evident feature that helps keep counterfeiters from removing or reusing OVDs.
Conclusion
In today’s global economy when products are under attack in forms of counterfeiting and tampering, authentication technologies play a vital role in protecting brand reputation and the public. With the use of increasingly sophisticated counterfeit methods, criminals continue to advance and profit at the cost of public safety and company revenue. It is essential to implement overt, covert and forensic technologies to ensure that criminals are unable to reuse, copy or misappropriate products.
Scott R. Sabreen is founder and president of The Sabreen Group, Inc., an engineering company specializing in secondary plastics manufacturing processes ? laser marking, surface pretreatments, bonding, decorating and finishing, and product security. Sabreen has been developing pioneering technologies and solving manufacturing problems for over 30 years. He can be contacted at 972.820.6777 or by visiting www.sabreen.com or www.plasticslasermarking.com.
