With increasing global travel and the advancing sophistication of organised crime and counterfeiters, passports must become ever more sophisticated in order to offer protection against the growing threat of identity fraud. As advancing digital technologies make it easier for counterfeiters to copy and reproduce passports, it is vital to take a multilevel approach to designing and implementing identity security technologies. A wide range of solutions are currently available that have been designed to address the challenges faced by governments and official organisations. Simon Jarvis discusses recent overlay innovations and their usability for passport security, in the fight against passport fraud.

The physical nature of passports has changed significantly over recent years. From the introduction of digitally printed images to biometric data being included on an integrated chip, specifications have been under constant review to ensure the integrity, authenticity and confidentiality of the personal data included on passports.

ICAO requirements
2002 saw the International Civil Aviation Organisation (ICAO) mandate that passports should feature an optically variable device (OVD) such as a hologram to combat counterfeiters. The importance of OVDs was further reinforced in 2004 when the European Council Regulation 2252/2004 specified the standards for security features and biometrics in passports and travel documents issued by member States to protect against falsification. This regulation required a metalised or transparent OVD to be used on the biographical data page, in the form of diffractive structures which vary when viewed from different angles. These structures have to be incorporated into the heat-sealed laminate, or an equivalent, or applied as an OVD overlay.

These requirements have necessitated the introduction of new overlay materials and techniques to preserve the security of passports, with state-of-the-art computer systems and software being used to incorporate sophisticated features which are difficult for forgers to replicate. These, combined with OVDs, enable passports to be validated quickly and easily. Additionally, covert techniques, such as infrared (IR) and ultraviolet (UV) pigments, security printing techniques and unique synthetic tagging, also raise the level of protection.

Holography: a long-trusted technique
Holography has long been used on passports as a security feature in passport data page overlays. Easily identifiable, holograms are primarily used as first level identification devices and are designed to enable successful authentication at point of inspection. Although several different holographic technologies have been extensively used, the ability of holograms to provide effective protection against passport counterfeiters depends on the continuous evolution of holographic techniques.

HRI holograms
Most recently, high refractive index (HRI) holograms emerged, offering a higher level of protection. HRI holograms are transparent, allowing them to be placed directly over personal data and are seen as more difficult to reproduce than conventional holograms.

Combining solutions for superior overlay security
The level of security achieved by using holograms can be increased further by combining complex holographic designs with intricate high-security print. Sophisticated overt and covert security design features can be built into each design, thus helping to protect documents from counterfeiting.

Microtext print
Additional specific features, such as microtext print, fine line designs and hidden images, can be used in extremely tight register with holograms. Microprint creates text characters which cannot be seen with the naked eye and can therefore be hidden within larger overt images, such as text and pictures. Of course, microtext can also be printed with UV security inks, meaning that the finished image is only visible under UV light, thus adding to the complexity. The invisibility of this printing technology enables it to be used without affecting other design elements.

Infrared inks
IR inks can also be an extremely secure addition, especially if they are completely invisible to the naked eye under normal lighting conditions or outside of typical wavelengths, as this makes them easy to overlook during forgery attempts. These inks require a bespoke reader with a specialist camera and lens technology to detect and view the prints, as they do not emit light in the visible spectrum. As supply of very specialist inks is highly restricted, this enhances security of the passport or carrier document even further.

Resin systems
Security can be improved further by the use of functional resin systems offering a range of tamper-evident features, including selective heat transfer, solvent sensitivity and water sensitivity. For example heat transfer inks transfer from the overlay directly onto the paper and printed personalised data and clearly show tampering if attempts are made to change the photograph or other credentials, particularly when used as invisible (often UV fluorescent) over personalisation areas. Currently, the most secure overlays are produced by combining the best holographic effects with high-security print in register to the holographic design, using tamper-evident functional inks that utilise a range of security inks to achieve optimum overt and covert authentication.

figure 1.

Technological innovations
Latest technological advancements have seen the development of secure and complex passport data page overlays using a multi-layered approach combining security printing, holography and functional inks.

Polyester overlays
Sophisticated security overlays use high-clarity base films in combination with a variety of complex copolymer heat-activated adhesive coatings to support and protect the passport’s biographical data page (figure 1). The overlays are available in a range of polyester and heat seal adhesive combinations, dependent upon the format required for the final application. The most important benefits offered by this technology are enhanced durability and superior protection of the data page, achieved with the highly durable and stable polyester film and the high bond strength permanent heat-activated adhesive.

Tamper-evident features on this style of laminate overlay are achieved by either the use of functional inks or holographic inset labels. Tamper evidence can be enhanced further by combining tamper-evident print and a holographic inset label.

Polyester overlays can also be used to create a separate RFID inlay page for countries not wishing to include a chip in the passport cover. The inlay can be stitched, folded and glued to be permanently fixed between the booklet cover and paper end page. The antenna and chip module are fully encapsulated within the laminated layers of the inlay, giving them utmost protection through the lifespan of the passport and providing authorities with an easy way of identifying whether the chip has been attacked.

Lacquer overlays
Ultrathin, crystal clear high-security lacquer overlays with supportive carriers have been developed specifically for use in passports and other travel documents. They provide the opportunity to combine different security elements depending upon the requirements of each document. They can be specified as clear laminates or with wallpaper HRI holography, which uses a HRI holographic design across the whole film for high security and as a forgery deterrent.

figure 2.

The new lacquer overlays are also available with a registered HRI holographic design with features that are registered to printing on the document. A further enhancement to this is to utilise precision print registration techniques to accurately register the overlay security print to the holographic effects, thus making it extremely difficult to counterfeit. The construction of the overlay makes it highly tamper-evident, as any attempt to remove it from the carrier document will cause the lacquer to break up. Further protection can be achieved by the use of tamper-evident functional inks. This will make it extremely difficult for even the most advanced counterfeiters to tamper with the personalisation data.

Pressure-sensitive films
Pressure-sensitive, self-adhesive films are ideal for use in local or emergency issuance situations and short-run document production (figure 2). The films have a permanent, highly aggressive adhesive that forms a strong tamper-evident bond to security papers and can be further enhanced by the use of bespoke selective release messages to clearly identify where adulteration of the document has been attempted. Permanent thermochromic ink can be applied to indicate where heat has been used to lift the laminate to try to alter the details on the document. The new films are available in multiple sheet formats (single, two or three images per sheet) and with or without perforations, to suit particular application method requirements and machinery. In addition, they are available in a range of filmic types and thicknesses, including polyester, PVC and polypropylene.

Polycarbonate
Polycarbonate passport data pages have been used in a number of passports. Generally, these consist of multiple layers of polycarbonate fused together, incorporating security features, such as holography and security print into the body of the laminate. These are usually personalised by laser personalisation and/or engraving techniques, to generate a greyscale photograph and personalisation. A combination of security print and holographic effects is necessary to achieve the best polycarbonate passport data pages that can then be personalised through the laser personalisation systems.

Conclusion
Due to the ever-growing number of criminals attempting to produce counterfeit passports and the sophistication of their methods, the development of more sophisticated technologies is essential. The discussed multilayered process, which aids the provision of high security for passports, consists of a combination of covert and overt techniques, such as microtext and -print, film overlays and UV and heat transfer inks. The development and implementation of these protective innovations will make it increasingly difficult for counterfeiters to make further progressions in their efforts to forge passports successfully, aiding in protecting public safety on a global level.

Simon Jarvis
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Simon Jarvis is Sales Director for Document and Identity Solutions at Payne Security. In this position he focuses on driving global sales of products and services for use in governmental and high security document and identity applications, enabling customers to beat counterfeiters and prove personal identity. Simon has over 16 years of experience in security solutions and risk management, having previously worked for Courtenays Limited as Director of Security Solutions. Prior to this, Jarvis spent 10 years at De La Rue in various roles, including Managing Director of their security paper manufacturing business.

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