CONTACTLESS BIOMETRIC AUTHENTICATION SYSTEM-based ...

CONTACTLESS BIOMETRIC AUTHENTICATION
SYSTEM-based on human odour
Participant name: P.ASHIKA,
P.KARTHIGA,
II YEAR I.T,
College name: IFET college of
engineering
ABSTRACT-
Biometrics is the current buzzword in
user authentication domain. Finger print
and retinal scan, that are examples of
biometric systems that are in use
today,have the drawback that, they are
not fool proof. Recent surveys have
revealed the uniqueness of human odour.
Human odour will join the Elite list in
the near future. The advantage lies in the
fact that it is impossible to replicate
human odor. This paper deals with the
feasiblity of creating a model system that
authenticates people based on their body
odour. The challenge is in designing a
sensor that identifies every human by his
scent. An abstract model of a system that
implements this sensing and
identification has been proposed here.
This authentication system is very useful
in safeguarding bank vaults and
documents of International
repercurssions from potentially smart
anti-social crooks.
KEYWORD:
biometrics, body odour, sensor,
authentication, foolproof
INTRODUCTION
Every huge technological advancement
derives its inspiration from Nature and
so has biometrics. Especially the concept
of human odour.
The ability of canines to identify
large number of people by solely
sniffing is what got us into thinking.
Detector dogs are used by law
enforcement agents for the detection of
drugs, explosives, flammable and
ignitable liquid residue, and human
scent. Research has recently begun to
identify some of the volatile organic
compounds present in human scent, but
there is still limited knowledge
concerning the identity of target-vapor
signature and the transport and detection
mechanisms associated with a canine
alert. There is also limited understanding
of how the body produces human scent.
The superiority of this technique can be
well apperciated by visualising and
analysing the simple scenario. Bank
vaults are restricted areas which has
restricted access. It has been long time
since keys have lost their significance.
Even hi-tech banks which boast of
biometric fingerprint and retinal scan are
not entirely safe. Science and
Technology have enabled anti-social
enthusiasts to replicate fingerprint and
retinal copy in a fairly inexpensive way.
Also the authenticated person may be
threatened at gun-point and be puppeted
to make a forced entry. If the fingerprint
system is replaced by odour recognition
system, which monitors the vault to
check for any unauthenticated user. The
presence of an alien person leads to a
siren going off and doors getting auto
locked. Even in the absence of an alien
user, this sequence of operations take
place if the user presses the help button
twice.
EXISTING BIOMETRICS
Fingerprint Verification
This is one of the oldest forms of
biometric techniques which involves
mapping of the pattern of the fingerprint
of the individual and then comparing the

idges, furrows, within the template. The
fingerprint given to the device is first
searched at the coarse level in the
database and then finer comparisons are
made to get the result.
Iris Recognition
In Iris and Retinal scanning, the iris and
the retina are scanned by a low intensity
light source and the image is compared
with the stored patterns in the database
template. This is one of the fastest forms
of biometry.
Facial Scanning
Facial scanning involves scanning of the
entire face and checking of critical
points and areas in the face with the
template. This method is not completely
reliable and so it is used in association
with another biometric technique.
Hand and Finger geometry
This method uses the data such as
length, shape, distance between the
fingers, overall dimensions of the hand
and also the relative angle between the
fingers. Modern systems use this
technique in association with the
Fingerprint scanning technique.
Voice Biometry
It is proved that the frequency, stress and
accent of speech differ from person to
person. Voice biometry uses this concept
to solve the problem of illegal user. This
system has been implemented in the
latest laptops as well.
Signature Verification
This technology uses the dynamic
analysis of a signature to authenticate a
person. This technology is based on
measuring speed, pressure and angle
used by the person when a signature is
produced.
Keystroke dynamic
In this technique, the system analyses
the rhythm of typing the password.
UNIQUENESS OF HUMAN ODOUR
Human scent is the most abundant of the
volatile organic compounds determined
to be in the headspace above scent
samples; however, other substances may
contribute to human odor. The individual
body odors of humans are determined by
several factors that are either stable over
time (genetic factors) or vary with
environmental or internal conditions. For
this manuscript, the following
distinguishing terminology for these
factors will be used:
The primary odor of a person
contains constituents that are stable over
time regardless of diet or environmental
factors.
Secondary odor contains
constituents that are present due to diet
and environmental factors.
Tertiary odor contains
constituents that are present because of
the influence of outside sources (i.e.,
lotions, soaps, perfumes). For an
individual identification by human scent,
the primary odor must have constituents
that are stable over time and diverse
across people. Compounds present in
male and female axillary secretion
extracts that contained the characteristic
odors present in the axillary region have
been isolated and identified. These
analysis showed the presence of several
C6-C10 straight chains, branched, and
unsaturated acids, and the major odorcausing
compound was determined to be
(E)-3-methyl-2-hexenoic acid. Other
important odor contributors were
terminally unsaturated acids, 2-methyl
C6- C10 acids, and 4-ethyl C5-C11
acids. Short-chain fatty acids have also

een extracted from sweat samples
obtained from feet. Olfactory evaluation
by humans of 1000 ppm solutions of
shortchain acids (C2-C9) showed that
each short-chain fatty acid resembled
either foot or axillary odor. Short-chain
acids that resembled axillary odor tended
to be higher in carbon number than those
that resembled foot odor. Investigations
into the compounds emitted by humans
that attract the yellow-fever mosquito
have provided insight into the
compounds present in human odor.
Samples were collected using glass
beads that were rolled between fingers.
The beads were then loaded into a gas
chromatograph and cryofocused by
liquid nitrogen at the head of the column
before analysis with gas
chromatography-mass spectrometry. The
results showed more than 300
observable compounds. In a later study,
346 compound peaks were observed and
of the compounds detected, 43 were
unidentifiable, whereas 303 were
identified by standard or identified
tentatively by library and spectral
interpretation. Of the 303 compounds
identified, 26 were confirmed to be of
background origin, leaving 277
compounds identified as components of
human skin emanations. Through this
method, comparisons of the compounds
found in different people showed
qualitative similarities among the
people; however, quantitative
differences were observed. Laundry
soiled with human sweat and then
washed with a laundry detergent has
been analyzed for the residual presence
of human odor. Esters, ketones, and
aldehydes were identified as primary
odorants in the swatch's postwashing.
However, organic acids, which are
considered to be the dominant
characteristic odorants in human axillary
sweat, were not present in the extracts of
residual odor. Solid phase
microextraction in conjunction with gas
chromatography-mass spectrometry has
been used previously to identify volatile
components that are responsible for odor
produced from human skin. The
sampling was done using a 6 cm glass
tube with a septum at one end that was
placed over the skin and secured.
Several different classes of compounds,
including shorter and longer chain
hydrocarbons, short-chain aldehydes,
and a branched ketone, were identified
from human skin in the headspace.
Eighty-eight percent of the subjects
showed the presence of short-chain
aldehydes, such as octanal, nonanal, and
decanal. Hydrocarbons of longer chain
lengths were found in 96 percent of the
subjects, such as tetradecane,
pentadecane, and hexadecane. The
abundances of these compounds varied
among people, and some subjects
exhibited specific volatile compounds,
such as 6-methyl-5-hepten-2-one, and
hydrocarbons of shorter chain lengths
including decane. In this study,
headspace solid phase microextraction
was combined with gas chromatographymass
spectrometry to identify the
signature odors that law enforcementcertified
detector dogs alert to when
searching for humans and distinguishing
among people. Solid phase
microextraction gas chromatographymass
spectrometry has demonstrated
unique capabilities for extracting
volatiles from the headspace of forensic
specimens and shows great potential to
aid in the investigation and
understanding of the complicated
process of canine odor detection.
Surveys are underway to identify the
ideal composition of human scent and
trace patterns influenced by genetic

heridity, long term stress factors and the
living environment. Some organic
components present in human odour are
listed here below:
DATA PROCESSING METHODS
The signals generated by an array of
odour sensors need to be processed in a
sophisticated manner. Odour can be
sensed using an electronic nose(e-nose)
which is analogous to the human nose.
The functioning of e-nose is similar to
the human nose. An odor is composed of
molecules, each of which has a specific
size and shape. Each of these molecules
has a correspondingly sized.
DATA PROCESSING METHODS
The signals generated by an array of
odour sensors need to be processed in a
sophisticated manner. Odour can be
sensed using an electronic nose(e-nose)
which is analogous to the human nose.
The functioning of e-nose is similar to
the human nose. An odor is composed of
molecules, each of which has a specific
size and shape. Each of these molecules
has a correspondingly sized andshaped
receptor in the human nose. When a
specific receptor receives a molecule, it
sends a signal to the brain and the brain
identifies the smell associated with that
particular molecule. Electronic noses
based on the biological model work in a
similar manner, albeit substituting
sensors for the receptors, and
transmitting the signal to a program for
processing, rather than to the brain.
Electronic noses are one example of a
growing research area called
biomimetics, or biomimicry, which
involves humanmade applications
patterned on natural phenomena.
WORKING MODEL
Studies conducted at the National
Institute for Medical Research in
London have shown that there is a
current of warm air that surrounds the
human body due to the natural body
temperature. The current of warm air is
approximately one-third to one half-inch
thick, and it travels up and over the body
at a rate of 125 feet each minute.
Analysis of the air current indicates that
it contains four to five times as many
germs asthe air in the rest of the
sampling room. The germs come from
the bacteria that are shed with dead skin
cells. Larger flakes of skin fall to the
ground, but smaller ones are drawn up
into the current. These currents can also
be visualized through clothing. The
warm air currents carry the rafts from
the body into the surrounding area
allowing for the deposit of human scent
in the environment. The idea that human
scent is produced through bacterial
action on dead skin cells and secretions
is the most common depiction of the
creation of human odor. Other studies
have suggested that odor is formed very
quickly, supporting the idea that odor
production is due to simple bond
cleavage as opposed to a complex
bacterial action.
The main task of the working model is to
perform the following tasks:
1. Sniffing
2. Delivery
3. Reception
4. Computation
5. Authentication
Fig i)blocking diagram

1) Sniffing:
This is done by using a pump which
sucks in air from the immediate
environment.
2) Delivery:
This block consists of a Metal Oxide
Semiconductor(MOS) which acts as the
sensor. When a voltage is applied across
a MOS structure, it modifies the
distribution of charges in the
semiconductor. Thus, when in contact
with volatile compounds, the sensor
reacts, as they experience a change of
electrical properties. Each sensor is
sensitive to all volatile molecules but
each in its own specific way. Most
electronic noses use sensor arrays that
react to volatile compounds on contact:
the adsorption of volatile compounds on
the sensor surface causes a physical
change of the sensor. A specific
response is recorded by the electronic
interface transforming the signal into a
digital value. Recorded data are then
computed based on statistical models.
3) Reception:
The computing system works to
combine the responses of all of the
sensors, which represents the input for
the data treatment. This part of the
instrument performs global signature
analysis and provides results and
representations that can be easily
interpreted. This can be performed by
using Gas chromatography-Mass
Spectrometry(GC-MS). Fig ii) Gas
Chromotagraphy-working chamber The
GC-MS is consists of two major
building blocks: the gas chromatograph
and the mass spectrometer. The gas
chromatograph utilizes a capillary
column which depends on the column's
dimensions (length, diameter, film
thickness) as well as the phase
properties. The difference in the
chemical properties between different
molecules in a mixture will separate the
molecules as the sample travels the
length of the column. The molecules
take different amounts of time (called
the retention time) to elute from the gas
chromatograph, and this allows the mass
spectrometer downstream to capture,
ionize, accelerate, deflect, and detect the
ionized molecules separately. The mass
spectrometer does this by breaking each
molecule into ionized fragments and
detecting these fragments using their
mass to charge ratio. The GC chamber is
enclosed in order to amplify the
properties of the volatile gases so that
they can be adsorbed easily.
4) Computation:
The composition of scent is identified
from the chromatogram obtained by
observing the time taken by the
substance to come out of the tube. This
composition is converted to digital form.
5) Authentication:
The digital equivalents of the body
odour of all authenticated people are
stored in a database. If the body odour
matches with any of the stored binary
code, the person is authenticated.
APPLICATIONS

i. It can used for secure admission into
bank vaults which permit only one
authenticated user at a time. Forceful
entry of unrecognised people will result
in an alarm beeping in the security
chamber, auto-dialling to the nearest
police station and auto-locking of the
cabin door.
ii. Its portable version can be used to
detect drugs. Also in airports and
harbours, smuggling of drugs can be
detected by using this system.
iii. Also, it can detect the presence of
any excess gas in laboratories or
factories or even in kitchens. The normal
composition of the gas that can be
present in the surroundings is fed into
the database. If the content increases, it
results in an alarm buzzing.
ADVANTAGES
A. Fool-Proof:
B. Even deodrants and perfumes cannot
mask the basic human odour. These
artificial scents do not eliminate the
organic compounds present in the odour.
As of now, it is not possible to replicate
human odour. Hence, intruders cannot
break in without alerting the system.
C. Reduce password administration
costs.
D. Replace hard-to-remember passwords
which may be shared or observed.
E. Reduces Human Labour:
F. This system is accomplished with an
automated system, which reduces the
amount of human work required to make
a positive match.
G. it's impossible to bribe or trick the
system to get in, as might be a possiblity
with a human.
H. It is particularly useful in routine
operations due to its ease of use and
rapid response rate.
In biometric domain, odour detection for
authentication is a novel idea. This,
when implemeted would result in
enhanced security systems. The added
advantage is that, it is a contactless
approach. A novice will never know that
he is being monitored. The development
of such a system may be a little
expensive but the benefits are
noteworthy.
REFERENCES
[1] Biometric technologies and
verification systems By John R. Vacca
[2] Curran, A. M. and Furton, K. G.
Optimization of Collection and Storage
Methods for Scent Evidence and the
Identification of the Volatile
Components Comprising an Individual
Human Odor Signature. Presented at the
American Academy of Forensic
Sciences, Dallas, Texas, 2004.
[3] Schoon, G. A. A. Scent identification
lineups by dogs (Canis familiaris):
Experimental design and forensic
application, Applied Animal Behavior
Science .
[4] Sommerville, B. A., McCormick, J.
P., and Broom, D. M. Analysis of human
sweat volatiles: An example of pattern
recognition in the analysis and
interpretation of gas chromatograms,
Pesticide Science.
[5] Curran, A. M., Rabin, S. I., Prada, P.
A., and Furton, K. G. Comparison of
volatile organic compounds present in
human odor using SPME-GC/MS,
Chemical Ecology .
CONCLUSION