The United States essentially relies on a two-step process to prevent inadmissible people from entering the country. The Bureau of Consular Affairs in the State Department is responsible for issuing international travel documents, such as passports to United States citizens and visas to citizens of other countries. On March 1, 2003, the Bureau of Customs and Border Protection in the Department of Homeland Security assumed responsibility for inspecting travelers at and between ports of entry. Inspectors from the Immigration and Naturalization Service (INS), the U.S. Customs Service, and the Animal and Plant Health Inspection Service (APHIS) were brought together in this new bureau. In fiscal year 2002, there were about 440 million border crossings into the United States at over 300 designated ports of entry (see table 1). Of the more than 358 million border crossers who entered through land ports of entry, almost 50 million entered as pedestrians. The rest entered in more than 131 million vehicles, including cars, trucks, buses, and trains. Further, the State Department processed about 8.4 million nonimmigrant visa applications and issued about 7 million passports. The term biometrics covers a wide range of technologies that can be used to verify a person’s identity by measuring and analyzing his or her physiological characteristics, based on data derived from measuring a part of the body directly. For example, technologies have been developed to measure a person’s finger, hand, face, retina, and iris. Biometric systems are essentially pattern recognition systems. They use electronic or optical sensors such as cameras and scanning devices to capture images, recordings, or measurements of a person’s characteristics and computer hardware and software to extract, encode, store, and compare these characteristics. Using biometrics as identifiers for border security purposes appears to be appealing because they can help tightly bind a traveler to his or her identity by using physiological characteristics. Unlike other identification methods, such as identification cards or passwords, biometrics are less easily lost, stolen, or guessed. The binding is dependent on the quality of the identification document presented by the traveler to enroll in the biometric system. If the identification document does not specify the traveler’s true identity, the biometric data will be linked to a false identity. In our work last year, we examined several different biometric technologies and found four to be suitable for border control systems: fingerprint recognition, facial recognition, iris recognition, and hand geometry. Other biometric technologies were determined to be impractical in a border control application because of accuracy or user acceptance issues. For example, speaker recognition systems do not perform well in noisy environments and do not appear to be sufficiently distinctive to permit identification of an individual within a large database of identities. We defined four different scenarios in which biometric technologies could be used to support border control operations. Two scenarios use a biometric watch list to identify travelers who are inadmissible to the United States (1) before issuing travel documents and (2) before travelers enter the country. The other two scenarios help bind the claimed identity of travelers to their travel documents by incorporating biometrics into (1) U.S. visas or (2) U.S. passports. Linking an individual’s identity to a U.S. travel document could help reduce the use of counterfeit documents and imposters’ fraudulent use of legitimate documents. Biometrics have been used in border control environments for several years. For example, the INS Passenger Accelerated Service System (INSPASS), a hand geometry system first installed in 1993, has been used in seven U.S. and two Canadian airports to reduce inspection time for trusted travelers. Since April 1998, border crossing cards, also called laser visas, have been issued to Mexican citizens that include their photograph and prints of the two index fingers. The Automated Biometric Fingerprint Identification System (IDENT) is used by DHS to identify aliens who are repeatedly apprehended trying to enter the United States illegally. IDENT is also being used as a part of the National Security Entry-Exit Registration System (NSEERS) that was implemented last year. Laws passed in the last 2 years require a more extensive use of biometrics for border control. The Attorney General and the Secretary of State jointly, through the National Institute of Standards and Technology (NIST) are to develop a technology standard, including biometric identifier standards. When developed, this standard is to be used to verify the identity of persons applying for a U.S. visa for the purpose of conducting a background check, confirming identity, and ensuring that a person has not received a visa under a different name. By October 26, 2004, the Departments of State and Justice are to issue to aliens only machine- readable, tamper-resistant visas and other travel and entry documents that use biometric identifiers. At the same time, Justice is to install at all ports of entry equipment and software that allow the biometric comparison and authentication of all U.S. visas and other travel and entry documents issued to aliens and machine-readable passports. While biometric technology is currently available and used in a variety of applications, questions remain regarding the technical and operational effectiveness of biometric technologies in applications as large as border control. In addition, before implementing any biometric border control system, a number of other issues would have to be considered including: The system’s effect on existing border control procedures and people. Technology is only part of an overall security solution and only as effective as the procedures within which it operates. The costs and benefits of the system, including secondary costs resulting from changes in processes or personnel to accommodate the biometrics. The system’s effect on privacy, convenience, and the economy. The successful implementation of any technology depends not only on the performance of the technology but also on the operational processes that employ the technology and the people who execute them. The implementation of biometrics in border security is no exception. Further, the use of technology alone is not a panacea for the border security problem. Instead, biometric technology is just a piece of the overall decision support system that helps determine whether to allow a person into the United States. The first decision is whether to issue travelers a U.S. travel document. The second decision, made at the ports of entry, is whether to admit travelers into the country. Biometrics can play a role in both decisions. Sorting the admissible travelers from the inadmissible ones is currently conducted by using information systems for checking names against watch lists and by using manual human recognition capabilities to see if the photograph on a travel document matches the person who seeks entry to the United States. When enabled with biometrics, automated systems can verify the identity of the traveler and assist inspectors in their decision making. However, a key factor that must be considered is the performance of the biometric technology. For example, if the biometric technology that is used to perform watch list checks before visas are issued has a high rate of false matches, the visa processing workload could increase at the embassies and consulates. If the same biometric solution were used at the ports of entry, it could lead to increased delays in the inspection process and an increase in the number of secondary inspections. Exception processing will also have to be carefully considered. Exceptions would include people who fail to enroll in the biometric visa system or are not correctly matched by it. Exception processing that is not as good as biometric-based primary processing could be exploited as a security hole. Failure of equipment must also be considered and planned for. Further, to issue visas with biometrics, an appropriate transition strategy must be devised to simultaneously handle both visas with biometrics and the current visa that could remain valid without biometrics for up to the next 10 years. Before any significant project investment is made, the benefit and cost information of the project alternatives should be analyzed and assessed in detail. A clear statement of the high-level system goals should drive the overall concept of a U.S. border control system. System goals address the system’s expected outcomes and are usually based on business or public policy needs, which for a border control system could include items such as binding a biometric feature to a person’s identity on a travel document, identifying undesirable persons on a watch list, checking for duplicate enrollments in the system, verifying identities at the borders, ensuring the security of the biometric data, and ensuring the adequacy of privacy protections. The benefits gained from a biometric border control system should be based on how well the system achieves the high-level goals. A concept of operations should be developed that embodies the people, process, and technologies required to achieve the goals. To put together the concept of operations, a number of inputs have to be considered, including legal requirements, existing processes and infrastructure used, and known technology limitations. Performance requirements should also be included in the concept of operations, such as processing times. Business process reengineering, such as new processes to conduct inspections of passengers in vehicles or to maintain a database of biometric data, would also be addressed in the concept of operations. As we have noted, the desired benefit is the prevention of the entry of travelers who are inadmissible to the United States. More specifically, the use of a biometric watch list can provide an additional check to name- based checks and can help detect travelers who have successfully established separate names and identities and are trying to evade detection. The use of visas with biometrics can help positively identify travelers as they enter the United States and can limit the use of fraudulent documents, including counterfeit and modified documents, and impostors’ use of legitimate documents. However, the benefits gained by using biometric have several limitations. First, the benefit achieved is directly related to the performance of the biometric technology. The performance of facial, fingerprint, and iris recognition is unknown for systems as large as a biometric visa system that would require storage and comparison against 100 million to 240 million records.