WO2015075680A1

WO2015075680A1 - Method of taking fingerprints

Info

Publication number: WO2015075680A1
Application number: PCT/IB2014/066227
Authority: WO
Inventors: Marius COETZEE
Original assignee: IDECO BOIMETRIC SECURITY SOLUTIONS Pty Ltd
Current assignee: IDECO BOIMETRIC SECURITY SOLUTIONS Pty Ltd
Priority date: 2013-11-21
Filing date: 2014-11-21
Publication date: 2015-05-28
Anticipated expiration: 2016-05-21
Also published as: ZA201406383B

Abstract

This invention concerns a method of taking a person's fingerprints in accordance with the 4-4-2 protocol. The method includes scanning the fingerprints of a first pair of fingers (16) from a person's left hand and a first pair of fingers (18) from the person's right hand simultaneously. Next, the fingerprints of a second pair of fingers (22) from the person's left hand and a second pair of fingers (24) from the person's right hand are scanned simultaneously. In the last step the fingerprints of the person's thumbs (28) are scanned simultaneously. The method preferably also includes the step of providing two separate scanners (14.1, 14.2) so that in each step the fingers on the person's left and right hands are scanned on separate scanners.

Description

METHOD OF TAKING FINGERPRINTS

BACKGROUND TO THE INVENTION

This invention relates to a method of taking biometric data. In particular, but not exclusively, this invention relates to a method of taking fingerprints in accordance with the 4-4-2 protocol.

Biometrics is playing an ever-increasing rote in identity management with the advancement in technology in the digital age. Identity management is part of all aspects of a person's life. For example, employment, health, marital and criminal data are all linked to one's Identity. Identity management is however not limited to personal records as it is also crucial in securing physical facilities, computers and networks. From the above examples it should be dear that identity control is a significant part of Identity management, and is applied in a wide range of applications, including national identification, licensing, health care, travel security, finance and access control in both the private and corporate sectors. Identity management relies on solutions that can accurately and consistently recognise and confirm the identity of an individual. It commences by creating a unique link between an individual and his/her unique identifier, such as a blometric characteristic. One example of a bfometric characteristic that is widely used in identity management is the fingerprint The uniqueness and permanence of a person's fingerprints allow for the un-repudiable electronic identification of an individual, which is the key principle in identity management.

The positions where the raised ridges on a fingerprint either split or end are unique. Advanced fingerprint scanners are able to recognise these points consistently and accurately, and assign a reference point to them. These reference points are referred to as mlnutia points. The information on the reference points is recorded by the fingerprint scanner and stored as an algorithm or a piece of mathematical code known as the template.

One problem encountered with fingerprint scanners is commonly referred to as false acceptance, which is when a person gets identified in error. This typically occurs when the fingerprint scanner fails only to work with true minutia and adds multiple false mlnutia to the template as a result of noise in the fingerprint image, wrinkles or cuts, for example. False rejection, which is when a person gets rejected (i.e. not identified) when they should have been identified, is another problem that is encountered with fingerprint scanners. This typically occurs when the required number of matching minutia points is set too high or the blometric scanner simply fails.

In order to reduce the occurrence of the above problems it is important that both the method of taking fingerprints and the underlying algorithms of the authentication process comply with the highest international standards. The Federal Bureau of Investigation (FBI) has set various internationally accepted standards dealing with both the collection of fingerprint data, which is also referred to as enrolment, and the method of authentication. Looking briefly at authentication, there are generally two methods namely verification and identification. Verification, which is also known as 1:1 or One to One, is where the sample is matched against one specific preselected template. In other words, the person needs to provide his/her ID number or member number, swipe a card or enter a user code to select a biometric template to match against. Identification, which is also known as 1:N or One to Many, on the other hand is where a sample is effectively matched against all templates in the database. In specialised high end systems, such as law enforcement Automated Fingerprint Identification Systems (AFIS) solutions, a sample can be matched against millions of templates. Simply put, a person does not have to provide any input other than their biometric.

Turning now to enrolment, there are mainly two different types of processes followed when collecting fingerprint data. The first is known as the Type 4 process and involves taking rolled impressions of a person's fingerprints. Rolled impressions are the ten individually taken fingerprint images rolled from nail to nail. Plain impressions, which are the fingerprint images taken when a person's print is placed on a flat surface, are then used to verify the sequence and accuracy of the rolled impressions. For example, by taking the length and sequence of the fingerprints into account, the fingerprint associated with each individual finger can be identified. This verification process is typically performed automatically by an underlying algorithm.

The second type is known as Type 14 and involves the taking of fiat Impressions of multiple fingers simultaneously without rolling. The impressions taken using this process are also referred to as plain, slap or flat impressions. As a result, the fingerprint scanners used in this method is also referred to as slap scanners. During this process the impressions of four fingers of an Individual's right hand is taken first, followed by the Impressions of four fingers on the left hand and finally the impressions of the individual's two thumbs. This process is also often referred to as the 4- 4-2 method given the sequence in which the fingerprints are taken. Figures 1 to 3 of the accompanying drawings illustrate the 4-4-2 method. This fingerprint capture method is preferred over the Type 4 method as it is a lot quicker to carry out and ensures the highest level of fingerprint sequence accuracy. Again, underlying algorithms are used to Identify and verify the fingerprint associated with each finger.

One disadvantage of the Type 14 method is mat the slap scanners used in this method are generally bulky seeing that their screens must be large enough to scan four fingers simultaneously. Although this might not be a problem when using stationary scanners, it could be real problematic when travelling with slap scanners.

It is an object of this invention to alleviate at least some of the problems experienced with existing methods of taking fingerprints.

It is a further object of this invention to provide a method of taking fingerprints that will be a useful alternative to existing methods.

It is yet a further object of this invention to provide a method of taking fingerprints that will be a useful alternative to existing methods while stiH complying with the 4-4-2 protocol.

SUMMARY OF THE INVENTION

In accordance with the invention there is provided a method of taking a person's fingerprints including the following steps:

i) scanning the fingerprints of a first pair of fingers from a person's left hand and a first pair of fingers from the person's right hand simultaneously;

ii) scanning the fingerprints of a second pair of fingers from the person's left hand and a second pair of fingers from the person's right hand simultaneously; and

iii) scanning the fingerprints of the person's thumbs simultaneously. The method preferably includes the step of providing two separate scanners so that in each step the fingers on the person's left and right hands are scanned on separate scanners.

The first pair of fingers on the person's left and right hand respectively Is preferably the index and middle fingers.

The second pair of fingers on the person's left and right hand respectively is preferably the ring and pinkie fingers.

In accordance with a second aspect of the invention there is provided a system for taking a person's fingerprints in accordance with the 4-4-2 protocol, the system including two separate scanners so that the fingerprints on the person's left hand and the fingerprints on the person's right hand are taken on separate scanners. Preferably, each scanner is dimensioned to scan a pair of fingers at a time. The pair of fingers scanned simultaneously is preferably a pair of adjacent fingers.

In accordance with a third aspect of the invention there is provided a method of authenticating fingerprints using the 4-4-2 protocol including the following steps:

receiving fingerprints of a first pair of fingers from a person's left hand and a first pair of fingers from the person's right hand;

receiving fingerprints of a second pair of fingers from the person's left hand and a second pair of fingers from the person's right hand;

receiving fingerprints of the person's thumbs; and

identifying and/or verifying the individual fingerprints associated with the different fingers based on the length and sequence of the captured fingerprints. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 illustrates a first step of a prior art method of taking fingerprints using the 4-4-2 protocol;

Figure 2 illustrates a second step of the prior art method of taking fingerprints;

Figure 3 illustrates a third step of the prior art method of taking fingerprints;

Figure 4 illustrates a first step of a method of taking fingerprints in accordance with the invention using the 4-4-2 protocol;

Figure 5 illustrates a second step of a method of taking fingerprints in accordance with the invention; and

Figure 6 illustrates a third step in a method of taking fingerprints in accordance with the Invention.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Referring to the drawings, a non-limiting example of a method of taking fingerprints in accordance with the invention is illustrated in Figures 4 to 6.

Figure 4 illustrates a first step 12 of the method of taking fingerprints according to the invention using a scanning system or device 14. This step includes scanning the fingerprints of a first pair of fingers 16 from a person's left hand and a first pair of fingers 18 from the person's right-hand. From this figure it can be seen that the fingerprints from the first pair of fingers 16, 18 from both hands are taken simultaneously i.e. in one step.

A second step 20 of the method of taking fingerprints according to the invention is illustrated in Figure 5. This step includes scanning the fingerprints of a second pair of fingers 22 from the person's left hand and a second pair of fingers 24 from the person's right hand. Again, the fingerprints from the second pair of fingers 22, 24 from both hands are taken simultaneously in a single step.

Figure 6, in turn, illustrates a third step 26 of the method of taking fingerprints according to the invention. In this step the fingerprints of the person's thumbs 28 are taken simultaneously.

From the above description of the method of taking fingerprints in accordance with the invention it must be clear that four fingerprints are taken in the first and second steps respectively, and two fingerprints are taken in the third step. This is an important aspect seeing that it ensures that the method according to the invention complies with the Type 14 or 4- 4-2 protocol as described above. The individual fingerprints associated with the different fingers are identified and/or verified by the underlying algorithm based on the length and sequence of the captured fingerprints.

Referring to Figures 4 to 6, it can be seen that the scanning device 14 Includes two separate scanners 14.1 and 14.2. It must be clear that in each of the above three steps the fingerprints of the person's left and right hands are taken by two separate scanners. In the accompanying drawings the fingerprints of the person's left hand are taken by the scanner 14.1 while the fingerprints of the person's right hand are taken by the scanner 14.2.

An advantage of using two separate scanners as opposed to a single scanner to capture fingerprints in accordance with the 4-4-2 protocol is that the size of each scanner can be reduced significantly. Instead of having to accommodate four fingers, each of the scanners 14.1 and 14.2 only needs to accommodate two fingers at a time. In other words, the scanners 14.2 and 14.2 are dimensioned to receive a single pair of fingers at a time, preferably a pair of adjacent fingers from the same hand. It follows naturally that the size of the individual scanners 14.1, 14.2 is reduced significantly when compared to conventional slap scanners. The reduction in size makes the scanners 14.1 , 14.2 more convenient to travel with, which could be of real interest during enrolment, for example, as it is often required to travel to different locations to collect biometric data. The method according to the invention therefore allows for a more convenient biometric data collection methods while still complying with the ISO standards of the 44-2 protocol as set out in the ISO/IEC 19794 series. Accordingly, by using the method of the invention as described above the same advantages of the traditional 4-4-2 method of taking fingerprints as illustrated in Figures 1 to 3 are achieved together with the additional benefits mentioned above, without the need to change the underlying algorithms of the Internationally accepted 4-4-2 method.

Claims

1. A method of taking a person's fingerprints including the following steps:

scanning the fingerprints of a first pair of fingers from a person's left hand and a first pair of fingers from the person's right hand simultaneously;

scanning the fingerprints of a second pair of fingers from the person's left hand and a second pair of fingers from the person's right hand simultaneously; and

scanning the fingerprints of the person's thumbs simultaneously.

2. A method according to claim 1, including the step of providing two separate scanners so that in each step the fingers on the person's left and right hands are scanned on separate scanners.

3. A method according to either claim 1 or 2, wherein the first pair of fingers on the person's left and right hand respectively is the index and middle fingers.

4. A method according to any one of claim 1 to 3, wherein the second pair of fingers on the person's left and right hand respectively Is the ring and pinkie fingers.

5. A system for taking a person's fingerprints in accordance with the 4- 4-2 protocol, the system including two separate scanners so that the fingerprints on the person's left hand and the fingerprints on the person's right hand are taken on separate scanners.

6. A system according to claim 5, wherein each scanner is dimensioned to scan a single pair of fingers at a time.

7. A system according to claim 6, wherein each scanner is dimensioned to scan a single pair of adjacent fingers at a time.

8. A method of authenticating fingerprints using the 4-4-2 protocol including the following steps:

receiving fingerprints of a first pair of fingers from a person's left hand and a first pair of fingers from the person's right hand; receiving fingerprints of a second pair of fingers from the person's left hand and a second pair of fingers from the person's right hand;

receiving fingerprints of the person's thumbs; and

identifying and/or verifying the Individual fingerprints associated with the different fingers based on the length and sequence of the captured fingerprints.