2018-05-17 00:58:59 +00:00
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<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
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"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
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]>
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<chapter id="intro" xmlns:xi="http://www.w3.org/2003/XInclude">
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<title>Introduction</title>
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<para>
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libfprint is an open source library to provide access to fingerprint
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scanning devices. For more info, see the
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<ulink url="http://www.reactivated.net/fprint/Libfprint">libfprint project homepage</ulink>.
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</para>
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<para>
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This documentation is aimed at application developers who wish to integrate
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fingerprint-related functionality into their software. libfprint has been
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2018-05-18 03:51:58 +00:00
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designed so that you only have to do this once – by integrating your
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2018-05-17 00:58:59 +00:00
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software with libfprint, you'll be supporting all the fingerprint readers
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that we have got our hands on. As such, the API is rather general (and
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therefore hopefully easy to comprehend!), and does its best to hide the
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technical details that required to operate the hardware.
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</para>
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<para>
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This documentation is not aimed at developers wishing to develop and
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contribute fingerprint device drivers to libfprint.
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</para>
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<para>
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Feedback on this API and its associated documentation is appreciated. Was
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anything unclear? Does anything seem unreasonably complicated? Is anything
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missing? Let us know on the
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<ulink url="http://www.reactivated.net/fprint/Mailing_list">mailing list</ulink>.
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</para>
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<refsect2 id="enrollment">
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<title>Enrollment</title>
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<para>
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Before you dive into the API, it's worth introducing a couple of concepts.
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</para>
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<para>
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The process of enrolling a finger is where you effectively scan your
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finger for the purposes of teaching the system what your finger looks like.
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This means that you scan your fingerprint, then the system processes it and
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stores some data about your fingerprint to refer to later.
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</para>
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</refsect2>
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<refsect2 id="verification">
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<title>Verification</title>
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<para>
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Verification is what most people think of when they think about fingerprint
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scanning. The process of verification is effectively performing a fresh
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fingerprint scan, and then comparing that scan to a finger that was
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previously enrolled.
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</para>
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<para>
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As an example scenario, verification can be used to implement what people
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would picture as fingerprint login (i.e. fingerprint replaces password).
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For example:
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</para>
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<itemizedlist mark='dot'>
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<listitem>
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I enroll my fingerprint through some software that trusts I am who I say
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I am. This is a prerequisite before I can perform fingerprint-based
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login for my account.
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</listitem>
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<listitem>
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Some time later, I want to login to my computer. I enter my username,
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but instead of prompting me for a password, it asks me to scan my finger.
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I scan my finger.
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</listitem>
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<listitem>
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The system compares the finger I just scanned to the one that was
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enrolled earlier. If the system decides that the fingerprints match,
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I am successfully logged in. Otherwise, the system informs me that I am
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not authorised to login as that user.
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</listitem>
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</itemizedlist>
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</refsect2>
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<refsect2 id="identification">
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<title>Identification</title>
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<para>
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Identification is the process of comparing a freshly scanned fingerprint
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to a <emphasis>collection</emphasis> of previously enrolled fingerprints. For example,
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imagine there are 100 people in an organisation, and they all have enrolled
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their fingerprints. One user walks up to a fingerprint scanner and scans
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their finger. With <emphasis>no other knowledge</emphasis> of who that user might be,
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the system examines their fingerprint, looks in the database, and determines
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that the user is user number #61.
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</para>
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<para>
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In other words, verification might be seen as a one-to-one fingerprint
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comparison where you know the identity of the user that you wish to
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authenticate, whereas identification is a one-to-many comparison where you
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do not know the identity of the user that you wish to authenticate.
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</para>
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</refsect2>
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</chapter>
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