The term Biometrics derives from the Greek words “bios” (life) and “metros” (measure), and the scope of this study is the research and measuring of the physiological and behavioural components of live organisms, through the use of methodologies of mathematical and/or statistical calculations.
Essentially, the process of biometric authentication, according to the informatics meaning, refers to the automatic identification and/or to the verification of the identity of persons examined, in function of their own physical and/or behavioural characteristics.
The study of Biometrics is divided in two parts:
- Physical Biometrics is based on the analysis of the data deriving from the measurements effected on the physical parameters of a human being (conformation of the retina or of the irises, fingerprints, analysis of the geometry of the face or hands);
- Behavioural Biometrics is based on the analysis of data deriving from the measurements of the behavioural parameters (timbre and tonality of the voice, typology of gait, analysis of the signature).

During recent years, mainly, thanks to the constant evolution of the informatics technologies, scientists, all over the world, have concentrated their efforts on the study of the different variables, which can permit the identification of an individual with a near zero percentage of error. Precisely in function of the difficulty of the alteration of the physiological characteristics of a human being, it is believed that Biometrics can constitute the real and only turning point for the certain identification of a human being.
The applications that utilize biometric techniques are many and they can be used for a variety of scopes: from the control of access to locations or sectors, authentication and access to information, recognition of people etc.
Each biometric process is based on a series of phases (or processes), which aim at the registration, verification and authentication of the individual object of the action of identification. In a first phase (enrolment), the subject furnished the biometric system (by means of special sensors) with their own physical and/or behavioural characteristics, which are then analyzed according to a mathematic model or template. In addition, models of mathematic computation (algorithms) are used, which allow the optimizing of the operations of comparison of the data that has been stored in the learning phase.

The modalities, at operative level, of the Biometrics are:
- Model 1:1 (one-to-one). In this model the data produced by the biometric sensors are compared with a single mathematic model, making possible the process of authentication;
- Model 1:N (one-to-many). The data is compared with a nucleus of mathematic models grouped together in a special archive, thus, proceeding to the successive phase of authentication. Another important concept for the study of the applications that are based on the Biometrics, concerns the distinction between physical access and logical access.

Physical access – is verified when the identification of the individual is made at the entrance of premises (building or area).

Logical access – is verified when the identification of the individual is made to permit the subject the use of informative resources or of data (computer access).
To better clarify these concepts, let us make an example. Mr. Mario Rossi, employee of the company, Security World Spa, must enter the building where his office is located. To enter the structure (physical access), he must identify himself through a specific biometric control which is based on the recognition of a physical characteristic (e.g. a fingerprint). The print is memorized within a smart-card which will allow verification of the correspondence of the physical characteristic utilized (process 1:1). After having obtained access to his office, he must be authenticated by his own computer (logical access). To do this, he utilizes the same smart-card (containing the digitalized image of his fingerprint), which will be compared with all those present within the database containing the fingerprints of personnel authorized to use the information systems (process 1:N).



The phases of the biometric process

As we have understood, all the systems of biometric authentication are based on a series of activities of comparison of physical or behavioural characteristics ascribable to a human being. These activities of verification are based on a series of phases (figure 1), which permit the verification of the correspondence of the characteristics of the individual, with data (samples) previously registered:
- Enrollment. Represents the phase of registration in which the individual furnishes the biometric system with one or more physical or behavioural characteristics, through a device of acquisition and data memorization (e.g. a special camera or scanner prepared to acquire a visual imprint, or a device to acquire a fingerprint). This phase is also defined as sampling, in function of the fact that the characteristic collected is subsequently stored within a centralized database (or also on a single smart-card), which will be interrogated each time that the authentication of a person is required. The sample is represented by a sequence of digital data (bit) which represents l’the digitalized image of the individual..

Figure 1 - The phases of biometric process

- Verification. The phase of the verification allows the comparison of the physical characteristic of the individual with the sample previously memorized. It is important to underline that in function of the results of this phase, two actions, linked together, are activated: the authentication and the recognition of the person.
- Authentication. In the case in which the authentication of the person is successful (verifying whether the subject is actually who he says he is), a username or a code number could be requested which, through an algorithm of comparison, would allow the authentication of the individual.
- Identification. It is the conclusive phase that supplies the answer (positive or negative) to the request of verification of the identity of an individual. Also in this case, it is important to emphasize that the process of identification is based on the answer of the elaboration of a mathematic algorithm, which establishes (in function of the attribution of a score defined with the term of ‘threshold’) the correspondence between the supplied data and those memorized. The authentication is essentially an integrated and explicit process whereas the identification can also be, for the interested party, both explicit and reserved.
In the explicit processes, the individual asks voluntarily and in a manifest manner, the identification of his own identity (usually for physical access) or to use a special service (in this case, it concerns logical accesses). In the reserved processes, the physical and/or behavioural characteristics are verified – without the knowledge of the individual – with those memorized in the database, with operations of verification, which are also defined ‘of surveillance’ (special camera).


Biometric techniques


The biometric sciences, for the analysis and recognition of the characteristics of an individual, focus their attention on those particular physical elements which are more distinctive of the human being, and are summarized as follows:
- in the finger prints;
- in the geometry of the hands;
- in the eye, more specifically in the retina and in the irises;
- in the somatic traits
- in the voice;
- in the methodology of appending a signature.
The taking of fingerprints The taking of fingerprints is certainly the most “dated” technique in the sector of biometric recognition. Essentially, the process of recognition is expressed through the placing of the finger of the person to be identified, on an optical or capacitive scansion device (1) .The recognition of the fingerprint is verified through three modalities:
- Complete image. The entire image of the fingerprint is scanned and memorized;
- Minute detail. The particulars of the fingerprint (the epidermal lines, small scars, skin imperfections) are scanned and memorized;
Particularly used for the physical and logical access, the taking of finger prints represents, still today, a methodology of authentication of the highest level, the success of which is tied to the fact that, over time, the finger prints of the human being do not suffer particular mutation, unless factors of burning or abrasion intervene.
Nevertheless, the reluctance or diffidence of the person in granting this particular authorization still remains. It suffices to cite the example of the Identity Card that all Italian citizens possess: even though there is a special space in the lower left-hand corner of the page that bears our photograph (with specific indication “imprint of the left index finger), probably, almost no-one has ever dreamed of registering their own fingerprint on this extremely important document of identification.
The technique of the geometry of the hands is based on the acquisition of a digitalized image, at a three-dimensional level of the hand. The tactile organ of the person is placed on a special reader, which acquires all the parameters (width of the hand, length of the fingers) which allow the unequivocal identification of the registered individual. Also this technology, in terms of reliability, guarantees a minimal margin of error and, furthermore, consents the modification of the memorized imprint, in function of the biological evolutions that can concern the human body and, therefore, also the limbs, over the course of time. Also this technology lends itself well to applications ascribable to the control of the presence of individuals in places and buildings. Above all in the United States, for example, the recognition of the hand is utilized in numerous government and military structures that require an extremely high level of privacy and control of the accesses. Also the Israelis utilize this methodology, principally, for the control of accesses into the airports.
The human eye represents the element of greatest distinction among human beings and the technique of recognition of the iris or the retina is based on this organ. Before, however, proceeding to the explanation of the functioning of the methodology of authentication and recognition, it is opportune to clarify certain basic concepts of the structure of the eye. The iris is a membrane placed behind the cornea and in front of the crystalline and represents the coloured portion of the eye. This element divides the inside of the eye into the anterior chamber and the posterior chamber. Its function is to regulate the quantity of light that enters our eyes. The retina is that nerve stratum which delimits the posterior part of the ocular bulb. Its function is to perceive the light, transforming it in nerve impulses which, through the optical nerve, are transmitted to the brain.
As far as the methodologies of recognition are concerned, that of the retina is based on the analysis of the structure of the blood vessels present at the back of the eye, the only characteristic that distinguishes, in an exclusive way, each individual human being. The acquisition is performed by directing a beam of light, at low intensity, into the pupil of the subject, who must put his eye close to the device for a time which varies from 6 to 10 seconds. Among all the methods of Biometrics, it represents the one of greatest reliability and accuracy, and in virtue of this, is utilized for accesses to areas of the highest security (among the various user are the CIA and the NSA). The iris, in function of its structure, possesses an enormous quantity of unique characteristics which makes it, as in the case of the retina,a unique element of association to each single human being (among its various characters is that of the position and frequency of the different chromatic streaking of the respective eyes). As is easily deductable, the analysis of the eye represents the surest technique that exists at the moment. Principally because it presents a margin of error equal to zero in the identification of the human being. Even between homozygous twins, each iris differs one from the other.
The procedure of acquisition is based on the use of a special camera, which identifies and registers a multiplicity of information (position of the eye, the conformation of the irises, the nerve ramifications, etc.). For reliability, it also results one of the most frequently used systems for the identification and control of individuals (among its different users are the English banks, the CIA and the FBI). It should be remembered that also in the presence of an ocular surgical operation, the system of recognition of the irises can still be valid, provided that a surface of, at least, 60% of the eye is preserved intact. Even contact lenses do not interfere, in a minimally way, with the ocular biometric recognition.
The system of recognition through the somatic traits, is based on the recognition of the physical characteristics of the face of the individual.
The process of enrolment of this system of identification is effected in the shortest time, and it is based on the memorization of multiple images (often made from different angles) of the face of the person to be identified, to obtain a tridimensional image of the face. Being extremely rapid and not invasive, this methodology is utilized with a certain frequency by different organizations (above all, operating in the sector of airport security) and is accepted, without particular difficulty, by persons submitted to this process of identification. Even though it is easily practicable, this methodology presents, nevertheless, a series of disadvantages. The first among all, the low reliability of facial recognition, which implies the drawback of the changeability of the human face over the passage of time. Apart from the aging process, which inevitably affects the lineaments and the form of the face, also chance events like accidents and injuries can render the identification system practically useless. Added to this is the cost of the devices, which can be high if a particularly accuracy level of detail of the physiognomy of the face analyzed is required.
The system of recognition of the voice is based on the recognition of the human voice by means of a process of sampling which is constructed with the use of simple microphones. Naturally, the accuracy and reliability of the methodology varies in function of the typology and sensitivity of the system of vocal registration utilized (a particularly sophisticated and sensitive device will permit the analyzing of all the aspects more characteristic of the registered voice, increasing significantly the level of reliability). As in the cases of the other human characteristics, also in this case the distinctive elements of the voice can vary enormously, from person to person, and this methodology represents a species of “mixed method”, between a system of physical recognition and a behavioural one, given that the human voice is usually influenced by both physical conformation (throat and larynx structure) and by behavioural aspects (fatigue, joy, cold etc.). Easy to use and inexpensive to implement, this system is spreading rapidly and also it is utilized for entrance to structures with controlled accesses. Nevertheless, it should be remembered that the methodology, being based on the sampling of the voice registered in a determinate historical period, can be affected by all the alterations or modifications that can happen over the course of time (background noise, a state of influenza that can influence the voice, a mouth complaint, swollen gums etc.).
The last physical parameter analyzed is the methodology of the appending a signature, which, among the typologies examined until now, represents the technique of greater vulnerability and scarce reliability. Although based on the analysis of the characteristics tied to the action of the signature of one’s own name, (such as pressure, speed, angle of inclination of the pen, the overall time employed for the signing etc.). Given that the methodology of the handwriting of each single individual can change, also very much, in the course of a life time, the memorized sample cannot be considered a stable and reliable element. In function of this, the system is very little used, above all, with regard to the applications of identification which require a substantial stability in time.


The future of Biometrics



Last year, the Swiss Federal Council, in agreement with the Parliament, announced the introduction, starting from March, 2010, of the biometric passport. In function of the adhesion of Switzerland to the Treaty of Schengen, which provides for the adoption of the new document of digital recognition by all the State Members, the Helvetian Government, during the course of 2010, will issue to all its citizens exclusively, passports in which are electronically memorized, the image of the face and two fingerprints. In consideration of the proverbial attention and efficiency of the Helvetian Country, it is already thinking towards the future and to the utilization of another fundamental element of identification of the human being: the DNA. Not by coincidence, in the last months of 2009, Berne announced that it could accede to the Treaty of Prüm (2) which provides for the exchange of DNA data of the citizens of the adherent Countries, as well as other measures of cooperation attributable to the exchange of information on all persons identified as belonging to the criminal world (organized and not) and of the international terrorism. The Treaty provides for the access to the famous “Prüm Database”, a gigantic (and in some ways, almost mysterious) above-national database which contains the DNA, the fingerprints and all the data ascribable to all the well-known criminals, identified by the Police Forces of various European Countries.
As was easily predictable, following the diffusion of this news reported by the media and, above all, by the Internet, a planetary offensive has been triggered off by political, philosophical and sociological groups, over the fear of the birth of a system that would feed the ‘bugaboo’ of a phantom “Big Brother”, destined to control and monitor the entire planet. It is worth remembering that the database of the Treaty originated in 2005, on behalf of a good 14 EU Member Countries (among which, also Italy) and one of the fundamental nuclei of the agreement is based on the exchange of the data of the DNA of criminals, but also of biological elements (ascribable to sample takings gathered on the scene of the crime or on elements pertinent to the crime) of persons not entered in the register of suspects, of missing persons or non-identified corpses. Furthermore, it is necessary to consider that the taking of biological samples in the EU Countries is obligatory and the judicial authorities can impose a forced sample taking also from persons who are not suspects, if the Judicial Authorities consider that these elements are indispensable for a better evaluation of the elements collected for the inquiry. Moreover, it is equally true that the elimination of the DNA profile from the bank is authorized only if the inquiry concludes with the acquittal of the individual of whom the biometric data is memorized, or if the fact, object of the attention of the investigating authorities, does not constitute a crime. In all other cases, the conservation of the DNA is foreseen for 40 years. The sample taking is not allowed for certain typologies of crime, like those of tax, companies and banking.
Beyond the alarmism and considerations on the birth of a “system of global control” or of a digital “Big Brother”, the problem of the identification and registration of individuals connected to the world of organized crime and international terrorism, represents an unavoidable need at world level.
The dramatic events of the last decade have amply demonstrated to us that geographic borders and/or limits no longer exist – or at least, of the kind that can slow down or impede the growth of the spiral of violence generated by organized crime and, in particular, the growing phenomenon of international terrorism. A terrorism that has assumed the form of an endemic sickness, which strikes, above all, the more modern industrialized societies.
The modern technologies, also in this case, can furnish a very great contribution as far as the control and identification of “suspect” persons are concerned – thanks to the recent and more innovated applications connected to the Biometrics. In this sense, the most important news was released in September of 2009, and concerns the announcement of a research, financed by the European Commission, which is developing a particularly innovative technique able to make the scanning of the cerebral activities of the human being. The project was baptized with the acronym of Humabio (Human Monitoring and Authentication using Biodynamic Indicators and Behaviourial Analysis – http://www.humabio-eu.org/).
The research, prevalently developed in Greece, has as its objective the creation of a scanner able to analyze the schemes of the cerebral activities of man, realizing a duplicity of intentions: the identification of the individual (with a reliability value close to 100%), controlled without any kind of invasive control, and the levels of certain parameters referable to the cerebral functions (fear, excitement, fatigue etc.). The first experiment was made in Germany, at the Lab Innovation Centre (LIC) of the Fraunhofer IAO and Fraunhofer IGB in Stuttgart, and has interested 15 volunteers, who submitted themselves to various types of tests, which measured, thanks to particular instruments, all the functions and the alterations of the physical elements of the subjects, such as the heart rate (electrocardiogramme – ECG), the electric activities of the brain (electroencephalogramme – EEG), information, anthropometric profiles (recognition of the face, length of the limbs) to the analysis of the word and the gait of the examined individual
All the biometric data of each single person, have been memorized within a RFID tag – Radio Frequency IDentification – (microprocessors which were previously incorporated by the volunteers), transforming each single experimenter into a sort of autonomous digital database. The research, prevalently developed in Greece, has as its objective the creation of a scanner able to analyze the schemes of the cerebral activities of man, realizing a duplicity of intentions: the identification of the individual (with a reliability value close to 100%), controlled without any kind of invasive control, and the levels of certain parameters referable to the cerebral functions (fear, excitement, fatigue etc.). The first experiment was made in Germany, at the Lab Innovation Centre (LIC) of the Fraunhofer IAO and Fraunhofer IGB in Stuttgart, and has interested 15 volunteers, who submitted themselves to various types of tests, which measured, thanks to particular instruments, all the functions and the alterations of the physical elements of the subjects, such as the heart rate (electrocardiogramme – ECG), the electric activities of the brain (electroencephalogramme – EEG), information, anthropometric profiles (recognition of the face, length of the limbs) to the analysis of the word and the gait of the examined individual
All the biometric data of each single person, have been memorized within a RFID tag – Radio Frequency IDentification – (microprocessors which were previously incorporated by the volunteers), transforming each single experimenter into a sort of the Guardian,reported that the IARPA have declared they were extremely interested in the project for the very reason of the use of non-invasive biometric technologies. Also the English are very interested in the Humabio, so much so that the Foreign Ministry of Her Majesty has decided to allocate a good 15 million sterling to implement the technologies of the project on its control devices in use in the major airports of Great Britain. According to government sources, it seems that the use of these devices will be limited, at least, in the initial phase, to the airports of Heathrow, Gatwick, Stansted, Manchester and Birmingham, where they will remain active for at least, five years.
Assuredly, this long period of experimentation will guarantee the Home Office (a sort of principaldirection of the government for the immigration and passports, policies on drugs, terrorism and the police), the cataloguing and the memorizing of the biometric data of, at least, a million people. The English Government, to favour the availability of all those who submit themselves to the enrolment phase, has assured that the registration will permit them to benefit from a series of facilitations, principally, as far as the entry into Britain is concerned, thanks to the utilization of special corridors dedicated to those who have reduced enormously the waiting time for the controls effected in the air stations.

Even though, at the moment, to acquire the biometric information, the consent of the interested party is indispensable, everything suggests that in the not too distant future, the filing of all citizens will become “obligatory”. The principal reason remains that of national security, which every Country must guarantee its citizens.
And it is not merely coincidence that States which are particularly sensitive to this problem are equipping themselves, in a significant way, with biometric instruments to improve their systems of frontier control.
An example which can testify to the level of attention given to the identification of people comes to us from the United States. Thanks to research conducted by researchers of the Buffalo University, experts in behavioural sciences, experiments are being done in the laboratories on a biometric scanner which, through the scanning and analysis of the facial expression, tones of the voice and other biometric signs, are able to individuate potentially dangerous subjects, who could reach the airports and other places of transit of the United States’ borders. The project, which has obtained from the National Science Foundation, a financing of almost a million dollars, is based on the use of behavioral indicatorsable to verify the single ways of behaviour of the passengers who are compared with samples of “ways of acting”, typical of terrorists or of potentially dangerous individuals. The results deriving from the test phases of these samples, have confirmed the efficacy and the sensitivity of the parameters examined by the device, confirming the validity of the utilized methodology.
In a famous citation, the Prussian General, Karl von Clausewitz asserted “You cannot condemn a method unless you are able to indicate a better one”.
The methodologies and techniques of prevision and prevention, can really constitute an effective system of control and defence to guarantee the security of a Country. In a world that is intrinsically unstable like the present one, the situations of dangerousness and instability, apart from the different geographic contexts in which they are verified, can be triggered off with extreme facility, thanks also to the easy and always less expensive availability of advanced technology of communication and transmission data, which above all, thanks to Internet, permits the perpetration of criminal actions and activities of every species.
In function of this, the prevention and the control probably represens the only path to take, to attempt to reduce the new dangers of the third millennium. Nevertheless, one could object that the problem of indiscriminate control of the individual, presents a substantial level of problems deriving, mainly, from the protection of the privacy of the citizen.
Undeniably, in the future, this will be one of the disquieting problems which must be resolved by the next generation, which will be faced with a difficult quesito: a greater security, to the detriment of one’s privacy, or absolute protection of one’s privacy, to the detriment of less security?
Certainly, in the next decades, it is easy to predict that justified by the problems attributable to “public order” and to “National security”, the States, to guarantee this security, will increasingly rely on machines which are able to identify and monitor the movements of every single human being.
But if we think about it well, all this happens already today, almost unconsciously, before our very eyes. Let us make an example: the technological instruments we use with such ease, like the cell telephone, the telepass, the satellite navigator, the credit card; are they not, perhaps, devices that “identify” us daily, both at the level of geographical location and at the level of what we are doing? And the time passed on the Internet, frenetically using applications such as the social software or the electronic post. Do not these leave an indelible (and perennial) sign of our presence, and in what precise instance, in the Network?
The Orwellian dystopia is no longer a science fiction scenario, it is a new world that man (perhaps, involuntarily) has constructed around himself and which is demonstrating the contradictions and dangerousness derived from the distortions of the unhealthy utilization of the informatics technologies. From this derives that the level of security and the threats perceived by man, has suffered – especially in the course of recent years – a significant growth and the tragic daily incidents connected to attacks and criminal events testify to the validity.
In conclusion, the applications that biometric technologies currently utilize constitute the best answer, both with regards to the guarantee of the identity of the person (e.g. biometric passport) and for measures attributable to the prevention of criminal occurrences which can put the security of the Country at serious risk. We have arrived at a crossroads which forces us to make a choice between the global protection of our privacy and that of our security. Apart from any consideration over the wisest choice, the grossest error that could be made is that of seeing the present world with its gaze still turned towards the past. This is surely the greatest error that can be committed.