Automated Fingerprint Identification System
Encyclopedia
Automated fingerprint identification is the process of automatically matching one or many unknown fingerprint
s against a database
of known and unknown prints. Automated fingerprint identification systems are primarily used by law enforcement agencies for criminal identification initiatives, the most important of which include identifying a person suspected of committing a crime
or linking a suspect to other unsolved crimes.
Automated fingerprint verification is a closely related technique used in applications such as attendance and access control systems. On a technical level, verification systems verify a claimed identity (a user might claim to be John by presenting his PIN or ID card and verify his identity using his fingerprint), whereas identification systems determine identity based solely on fingerprints.
With greater frequency in recent years, automated fingerprint identification systems have been used in large scale civil identification projects. The chief purpose of a civil fingerprint identifications system is to prevent multiple enrollments in an electoral, welfare, driver licensing, or similar system. Another benefit of a civil fingerprint identifications system is its use in background checks for job applicants for highly sensitive posts and educational personnel who have close contact with children.
holds all fingerprint sets collected in the country, and is managed by the FBI. Many states also have their own AFIS. AFISes have capabilities such as latent searching, electronic image storage, and electronic exchange of fingerprints and responses.
Many other entities, including Canada
, the European Union
, the United Kingdom
, Israel
, Pakistan
, Argentina
, Turkey
, Morocco
, Italy
, Chile
, Venezuela
, Australia
, Denmark
, the International Criminal Police Organization
, and various states, provinces, and local administrative regions have their own systems, which are used for a variety of purposes, including criminal identification, applicant background checks, receipt of benefits, and receipt of credentials (such as passports).
European police agencies are now required by a European council act to open their AFISes to each other to improve the war on terror and the investigation of cross-border crime. The act followed the Pruem treaty, an initiative between the countries Belgium, Germany, Spain, France, Luxembourg, the Netherlands and Austria. While technically not being an AFIS itself, the Pruem treaty's decentral infrastructure allowes AFIS queries on all European criminal AFIS'es within a reasonable timeframe.
Fingerprint matching has an enormous computational burden. Some larger AFIS vendors deploy custom hardware while others use software to attain matching speed and throughput. In general, it is desirable to have, at the least, a two stage search. The first stage will generally make use of global fingerprint characteristics while the second stage is the minutia matcher.
In any case, the search systems return results with some numerical measure of the probability of a match (a "score"). In tenprint searching, using a "search threshold" parameter to increase accuracy, there should seldom be more than a single candidate unless there are multiple records from the same candidate in the database. Many systems use a broader search in order to reduce the number of missed identifications, and these searches can return from one to ten possible matches. Latent to tenprint searching will frequently return many (often fifty or more) candidates because of limited and poor quality input data. The confirmation of system suggested candidates is usually performed by a technician in forensic systems. In recent years, though, "lights-out" or "auto-confirm" algorithms produce "identified" or "non-identified" responses without a human operator looking at the prints, provided the matching score is high enough.
"Lights-out" or "auto-confirm" is often used in civil identification systems, and is increasingly used in criminal identification systems as well.
Fingerprint
A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger. In a wider use of the term, fingerprints are the traces of an impression from the friction ridges of any part of a human hand. A print from the foot can also leave an impression of friction ridges...
s against a database
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
of known and unknown prints. Automated fingerprint identification systems are primarily used by law enforcement agencies for criminal identification initiatives, the most important of which include identifying a person suspected of committing a crime
Crime
Crime is the breach of rules or laws for which some governing authority can ultimately prescribe a conviction...
or linking a suspect to other unsolved crimes.
Automated fingerprint verification is a closely related technique used in applications such as attendance and access control systems. On a technical level, verification systems verify a claimed identity (a user might claim to be John by presenting his PIN or ID card and verify his identity using his fingerprint), whereas identification systems determine identity based solely on fingerprints.
With greater frequency in recent years, automated fingerprint identification systems have been used in large scale civil identification projects. The chief purpose of a civil fingerprint identifications system is to prevent multiple enrollments in an electoral, welfare, driver licensing, or similar system. Another benefit of a civil fingerprint identifications system is its use in background checks for job applicants for highly sensitive posts and educational personnel who have close contact with children.
Deployed automated fingerprint identification systems
The U.S. Integrated Automated Fingerprint Identification SystemIntegrated Automated Fingerprint Identification System
The Integrated Automated Fingerprint Identification System is a national automated fingerprint identification and criminal history system maintained by the Federal Bureau of Investigation . IAFIS provides automated fingerprint search capabilities, latent searching capability, electronic image...
holds all fingerprint sets collected in the country, and is managed by the FBI. Many states also have their own AFIS. AFISes have capabilities such as latent searching, electronic image storage, and electronic exchange of fingerprints and responses.
Many other entities, including Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
, the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
, Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
, Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
, Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, the International Criminal Police Organization
Interpol
Interpol, whose full name is the International Criminal Police Organization – INTERPOL, is an organization facilitating international police cooperation...
, and various states, provinces, and local administrative regions have their own systems, which are used for a variety of purposes, including criminal identification, applicant background checks, receipt of benefits, and receipt of credentials (such as passports).
European police agencies are now required by a European council act to open their AFISes to each other to improve the war on terror and the investigation of cross-border crime. The act followed the Pruem treaty, an initiative between the countries Belgium, Germany, Spain, France, Luxembourg, the Netherlands and Austria. While technically not being an AFIS itself, the Pruem treaty's decentral infrastructure allowes AFIS queries on all European criminal AFIS'es within a reasonable timeframe.
Fingerprint matching algorithms
Fingerprint matching algorithms vary greatly in terms of Type I (false positive) and Type II (false negative) error rates. They also vary in terms of features such as image rotation invariance and independence from a reference point (usually, the "core", or center of the fingerprint pattern). The accuracy of the algorithm, print matching speed, robustness to poor image quality, and the characteristics noted above are critical elements of system performance.Fingerprint matching has an enormous computational burden. Some larger AFIS vendors deploy custom hardware while others use software to attain matching speed and throughput. In general, it is desirable to have, at the least, a two stage search. The first stage will generally make use of global fingerprint characteristics while the second stage is the minutia matcher.
In any case, the search systems return results with some numerical measure of the probability of a match (a "score"). In tenprint searching, using a "search threshold" parameter to increase accuracy, there should seldom be more than a single candidate unless there are multiple records from the same candidate in the database. Many systems use a broader search in order to reduce the number of missed identifications, and these searches can return from one to ten possible matches. Latent to tenprint searching will frequently return many (often fifty or more) candidates because of limited and poor quality input data. The confirmation of system suggested candidates is usually performed by a technician in forensic systems. In recent years, though, "lights-out" or "auto-confirm" algorithms produce "identified" or "non-identified" responses without a human operator looking at the prints, provided the matching score is high enough.
"Lights-out" or "auto-confirm" is often used in civil identification systems, and is increasingly used in criminal identification systems as well.
See also
- EURODACEURODACEURODAC is a European Union automated fingerprint identification system for recording and comparing the fingerprints of asylum seekers and illegal immigrants. It is intended to enforce the Dublin Regulation, and is used in all EU member states as well as Iceland and Norway which are also covered by...
, an EU-wide system for storing and matching fingerprints of asylum seekers - Fingerprint recognition
- Fingerprint Verification CompetitionFingerprint Verification CompetitionFingerprint Verification Competition is an international competition focused on fingerprint verification software assessment. A subset of fingerprint impressions acquired with various sensors was provided to registered participants, to allow them to adjust the parameters of their algorithms...
- Pattern recognitionPattern recognitionIn machine learning, pattern recognition is the assignment of some sort of output value to a given input value , according to some specific algorithm. An example of pattern recognition is classification, which attempts to assign each input value to one of a given set of classes...
External links
- Screen shot of AFIS system used in Peru, as of Jan 2007. From the article Peru now uses AFIS fingerprint system .... Retrieved 2010-05-10.
- Automated Fingerprint Identification System (AFIS) Dacto 2000, Belarus
- Online Fingerprint Identification sdk, Saurabh
- SourceAFIS
