Efforts to make travelers’ journeys across borders more efficient are nothing new. When global governments met in 1944 and established the core principles permitting international transportation by air that continue to apply today, they required the contracting states to sign the Chicago Convention “to prevent unnecessary delays to aircraft, crews, passengers and cargo, especially in the administration of the laws relating to immigration, quarantine, customs and clearance”.
Since that time, the contracting states have worked toward this goal with much success. Several factors have ensured that the traveler journey has incrementally become easier, smoother and more consistent and predictable. These include collaboration between governmental authorities, international partners and aviation and transportation stakeholders on regulatory requirements; harmonization of global processes and capabilities; specification of formats and requirements for travel documents; and implementation of supporting infrastructure.
Accommodating passenger growth
Since 1944, the number of passengers flying internationally has grown from a mere handful into the billions. This growth would simply not have been possible without the aforesaid efforts of the international air transportation industry. The wide-scale collapse of international connectivity that came about when borders closed due to the Covid-19 pandemic highlighted how today’s civil aviation system depends on the ease with which passengers cross international borders.
With growth anticipated to persist for decades to come, traveler journeys must continue to be facilitated if delays are not to grow and hinder connectivity by air. Given the economic and social benefits of aviation for all, it is unsurprising that many parties are willing to invest in improved traveler processing. Governments take note of the 88 million jobs supported worldwide in aviation and related tourism and the generation of US$961.3bn of GDP per year, while also recognizing the importance of global connectivity for promoting cooperation between nations and peoples and fostering global peace. Airlines appreciate the business benefits of rapid and predictable passenger processing, including shorter transit times and improved customer experience. Airport operators seek – among other things – increased passenger dwell time in airport facilities and enhanced competitiveness in regional, national and international transportation ecosystems.
“Trust in the reference facial image biometric is obviously key”
Global use cases
Fortunately, technological development provides opportunities for further enhanced facilitation of travel. For example, US Customs and Border Protection (CBP) trialled the use of facial recognition as part of the airplane boarding process as early as 2014. Other trials and projects – such as the initiatives undertaken at Nanyang Jiangying Airport in China and Changi Airport in Singapore – sought to use the facial image as a single token across multiple touchpoints in the airport.
The basis of these initiatives was the inclusion of high-quality digital images of the travelers’ faces in the chips of electronic passports (e-passports), as defined by ICAO. The e-passport enables automated document bearer verification by matching the facial image in the document with one taken live. The value of this use case has been evidenced for many years in successful automated border control (ABC) systems that have been implemented around the world.
The aforementioned initiatives in China and Singapore confirmed that the e-passport could facilitate even more than previously expected. These projects highlighted that by matching the e-passport with live-capture facial images, it was possible to establish a link to the passport and complete all checks at the very beginning of the process. This meant that facial image matching could be implemented at some or all subsequent touchpoints – bag drop, security screening, immigration and boarding. By confirming identities in this seamless and paperless manner, operators could improve passenger throughput and travelers could keep their passports in their pockets and simply walk through the entire airport.
Similar trusted facial image biometric initiatives have been rolled out across the globe in the ensuing years. Hong Kong Airport launched the facial biometric as a ‘flight token’, enabling the use of the passenger’s facial image as a single token at bag drop, security checks, immigration, departure and boarding. Airports Company South Africa (ACSA) is rolling out a similar process at several of its airports.
Recent work seeks to extend biometric processes beyond the airport and across facilities. The Star Alliance group of airlines has implemented its own biometric program that involves enrollment and storage of the facial image on the consenting passenger’s mobile device. This is to support its transmission and use at different airports and at different times. In July 2024, the Caribbean island of Curaçao launched its Express Pass initiative that lets passengers enroll and submit a live facial image with their e-passport facial image off-site, using a dedicated smartphone application.
Seamless cross-border processing
Trust in the reference facial image biometric is obviously key in all the examples given. The fact that the e-passport is a government-issued document is an important foundation of such trust. The verifiability of the image through the process of passive authentication (PA), as defined in ICAO Doc 9303, is also vital. Full and proper execution of PA – a protocol based on the principles of public key cryptography and leveraging the public key infrastructure (PKI) defined by ICAO – provides for the electronic verification of the authenticity and integrity of all data on the e-passport chip, including the facial image. The ICAO Public Key Directory (PKD) is an important component of the overall international infrastructure for establishing trust in e-passports. It facilitates sharing of the public keys needed for the execution of PA between issuers and verifiers globally by acting as a central broker between state parties.
It is noteworthy that in all initiatives mentioned above, the process is confined to one airport facility, one group of airlines or one state. Mechanisms for seamless cross-border processing have been lacking. How can this challenge be addressed? The e-passport is a useful reference to answer this question. It is globally interoperable and can be used to attest trusted identity at touchpoints across the world. This is because it can be read and understood using infrastructure available internationally, while trust can be established in the document and its data based on the various security mechanisms defined. It contains the data that authorities worldwide have agreed is needed for processing travelers through air transportation, and as such it can often be used as the only document required for travel. Could the e-passport’s beneficial features be maintained in the development of a new format that meets evolving processes and needs, in particular the need to share relevant, necessary and trusted traveler data?
ICAO, through its various expert groups, has been working on developments beyond the e-passport for several years. The ICAO Digital Travel Credential (DTC) is the outcome of this work. The DTC encodes the same data as the e-passport in a digitally signed credential that is verifiable using PA as already defined for the e-passport. It is intended to temporarily or permanently substitute a conventional passport with a digital representation of the traveler’s identity. The virtual component of the DTC can be stored on various media, including mobile and smartphone devices. It can also be shared across networks in a format that is globally standardized and agreed upon. In other words, it is globally interoperable as it can be read, understood and trusted internationally. If the necessary trusted public keys are available to the verifier, and assuming that both issuance and implementation are in line with ICAO specifications, a DTC can be authenticated using infrastructure that is already in place in the international aviation industry today.
“In Finland, 90% of the participants … would continue to use the DTC to travel”
It should be evident that by progressing toward DTC issuance, enhancing issuance and verification infrastructure globally and developing tools such as the ICAO Public Key Directory (PKD), seamless crossborder processing can become a reality. Based on specifications already available, an entity can use a fixed reader and tools or a smartphone/tablet with an NFC sensor and camera to enroll data from an e-passport, execute PA to confirm authenticity and integrity, verify the holder by matching a live facial image taken with the device against the verified e-passport image, and create and then share the virtual component of an ICAO DTC. Recipients involved in processing at different touchpoints can then use that verifiable data, including the facial image obtained, for easy processing.
In recent months, several pilot projects have been completed internationally, seeking to go beyond initiatives already undertaken. These projects use the ICAO DTC as a means to obtain, share and use the trusted facial image as a seamless travel token in their processes. Trials were undertaken in Finland and Croatia with the support of the European Commission, enabling passengers to submit a DTC in advance of travel and then transit through border controls by matching the live facial image against that enrolled from the DTC. Meanwhile, a trial between Canada and the Netherlands demonstrated a true cross-border use of the DTC, with passengers departing Canada sharing their DTCs with Dutch authorities pre-departure and moving through the arrival airport using the facial image from the shared DTC. The trials demonstrated a notably quicker throughput compared with the use of the e-passport at the same touchpoints. In Finland, 90% of the participants indicated that they would continue to use the DTC to travel, indicating the improvement in the passenger experience.
Future plans
The variety of trials mentioned above indicates a global readiness to explore increased implementation of seamless travel processes across the sector, as well as the readiness of the facial matching technologies necessary to support such processes. The basic infrastructure and tools needed are in place in many locations. The foundations seem set and the time seems right for building on the findings of the trials already completed and working toward the future implementation of new developments in airports’ operational processes.
ICAO has launched its own pilot project on PKD use that can contribute to the operationalization of DTC-based seamless travel. Seamless travel requires multistakeholder cooperation. This is made clear by the fact that most of the initiatives mentioned previously relied on contributions from various entities, both public and private, to achieve any success. Although the public keys needed to verify DTCs are included in the ICAO PKD, private-sector entities are not currently permitted to use data from the PKD in their products or services. While non-governmental entities can revert to physical document checks on e-passports, this becomes cumbersome and difficult when DTCs are used. The PKD pilot, launched in 2022, permits authorized private-sector entities to use trustworthy data from the ICAO PKD to verify electronic and digital documents, including e-passports and DTCs. This should provide operational flexibility in the execution of PA as part of seamless travel implementation, including the involvement of the private sector when this is deemed appropriate and prudent as part of a collaborative process. The pilot project remains open for free-of-charge participation.
Efforts to move people through aviation facilities more efficiently and make the overall traveler journey more seamless have been ongoing for generations. Different parties contribute. We all benefit as we are all passengers in the international aviation system. Progress is typically made in small increments as innovations are launched, processes are remodeled and technologies bring benefits. We are currently at a point where technological possibilities are converging with the completion of an international effort to agree upon the foundations for more seamless operations across borders. The time seems ripe for the next big step in traveler facilitation. We’ll be taking that step together.
This article originally appeared in the 2025 Annual Showcase issue of Passenger Terminal World. To view the magazine in full, click here.
