634 research outputs found
Internet-Wide Scanners Classification using Gaussian Mixture and Hidden Markov Models
International audienceInternet-wide scanners are heavily used for malicious activities. This work models, from the scanned system point of view, spatial and temporal movements of network scanning activities, related to the difference of successive scanned IP addresses and timestamps, respectively. Based on real logs of incoming IP packets collected from a darknet, Hidden Markov Models (HMMs) are used to assess what scanning technique is operating. The proposed methodology, using only one of the aforementioned features of the scanning technique, is able to fingerprint what network scanner originated the perceived darknet traffic
Voice signature based Speaker Recognition
Magister Scientiae - MSc (Computer Science)Personal identification and the protection of data are important issues because of the ubiquitousness of computing and these havethus become interesting areas of research in the field of computer science. Previously people have used a variety of ways to identify an individual and protect themselves, their property and their information
Multibiometric security in wireless communication systems
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 05/08/2010.This thesis has aimed to explore an application of Multibiometrics to secured wireless communications. The medium of study for this purpose included Wi-Fi, 3G, and
WiMAX, over which simulations and experimental studies were carried out to assess the performance. In specific, restriction of access to authorized users only is provided by a technique referred to hereafter as multibiometric cryptosystem. In brief, the system is built upon a complete challenge/response methodology in order to obtain a high level of security on the basis of user identification by fingerprint and further confirmation by verification of the user through text-dependent speaker recognition.
First is the enrolment phase by which the database of watermarked fingerprints with
memorable texts along with the voice features, based on the same texts, is created by sending them to the server through wireless channel.
Later is the verification stage at which claimed users, ones who claim are genuine, are verified against the database, and it consists of five steps. Initially faced by the identification level, one is asked to first present oneâs fingerprint and a memorable word, former is watermarked into latter, in order for system to authenticate the fingerprint and verify the validity of it by retrieving the challenge for accepted user.
The following three steps then involve speaker recognition including the user
responding to the challenge by text-dependent voice, server authenticating the response, and finally server accepting/rejecting the user.
In order to implement fingerprint watermarking, i.e. incorporating the memorable word as a watermark message into the fingerprint image, an algorithm of five steps has been developed. The first three novel steps having to do with the fingerprint
image enhancement (CLAHE with 'Clip Limit', standard deviation analysis and
sliding neighborhood) have been followed with further two steps for embedding, and
extracting the watermark into the enhanced fingerprint image utilising Discrete
Wavelet Transform (DWT).
In the speaker recognition stage, the limitations of this technique in wireless
communication have been addressed by sending voice feature (cepstral coefficients)
instead of raw sample. This scheme is to reap the advantages of reducing the
transmission time and dependency of the data on communication channel, together
with no loss of packet. Finally, the obtained results have verified the claims
Voice-signature-based Speaker Recognition
Magister Scientiae - MSc (Computer Science)Personal
identification
and
the
protection
of
data
are
important
issues
because
of
the
ubiquitousness
of
computing
and
these
have
thus
become
interesting
areas
of
research
in
the
field
of
computer
science.
Previously
people
have
used
a
variety
of
ways
to
identify
an
individual
and
protect
themselves,
their
property
and
their
information.
This
they
did
mostly
by
means
of
locks,
passwords,
smartcards
and
biometrics.
Verifying
individuals
by
using
their
physical
or
behavioural
features
is
more
secure
than
using
other
data
such
as
passwords
or
smartcards,
because
everyone
has
unique
features
which
distinguish
him
or
her
from
others.
Furthermore
the
biometrics
of
a
person
are
difficult
to
imitate
or
steal.
Biometric
technologies
represent
a
significant
component
of
a
comprehensive
digital
identity
solution
and
play
an
important
role
in
security.
The
technologies
that
support
identification
and
authentication
of
individuals
is
based
on
either
their
physiological
or
their
behavioural
characteristics.
Live-Ââdata,
in
this
instance
the
human
voice,
is
the
topic
of
this
research.
The
aim
is
to
recognize
a
personâs
voice
and
to
identify
the
user
by
verifying
that
his/her
voice
is
the
same
as
a
record
of
his
/
her
voice-Ââsignature
in
a
systems
database.
To
address
the
main
research
question:
âWhat
is
the
best
way
to
identify
a
person
by
his
/
her
voice
signature?â,
design
science
research,
was
employed.
This
methodology
is
used
to
develop
an
artefact
for
solving
a
problem.
Initially
a
pilot
study
was
conducted
using
visual
representation
of
voice
signatures,
to
check
if
it
is
possible
to
identify
speakers
without
using
feature
extraction
or
matching
methods.
Subsequently,
experiments
were
conducted
with
6300
data
sets
derived
from
Texas
Instruments
and
the
Massachusetts
Institute
of
Technology
audio
database.
Two
methods
of
feature
extraction
and
classification
were
consideredâmel
frequency
cepstrum
coefficient
and
linear
prediction
cepstral
coefficient
feature
extractionâand
for
classification,
the
Support
Vector
Machines
method
was
used.
The
three
methods
were
compared
in
terms
of
their
effectiveness
and
it
was
found
that
the
system
using
the
mel
frequency
cepstrum
coefficient,
for
feature
extraction,
gave
the
marginally
better
results
for
speaker
recognition
Automatic human trajectory destination prediction from video
This paper presents an intelligent human trajectory destination detection system from video. The system assumes a passive collection of video from a wide scene used by humans in their daily motion activities such as walking towards a door. The proposed system includes three main modules, namely human blob detection, star skeleton detection and destination area prediction, and it works directly with raw video, producing motion features for destination prediction system, such as position, velocity and acceleration from detected human skeletons, resulting in several input features that are used to train a machine learning classifier. We adopted a university campus exterior scene for the experimental study, which includes 348 pedestrian trajectories from 171 videos and five destination areas: A, B, C, D and E. A total of six data processing combinations and four machine learning classifiers were compared, under a realistic growing window evaluation. Overall, high quality results were achieved by the best model, which uses 37 skeleton motion inputs, undersampling on training data and a random forest. The global discrimination, in terms of area of the receiver operating characteristic curve is around 87%. Furthermore, the best model can predict in advance the five destination classes, obtaining a very good ahead discrimination for classes A, B, C and D, and a reasonable ahead discrimination for class E. (C) 2018 Elsevier Ltd. All rights reserved.This work is funded by the Portuguese Foundation for Science and Technology (FCT - Fundação para a CiĂȘncia e a Tecnologia) under research grant SFRH/BD/84939/2012
A Review on Featuresâ Robustness in High Diversity Mobile Traffic Classifications
Mobile traffics are becoming more dominant due to growing usage of mobile devices and proliferation of IoT. The influx of mobile traffics introduce some new challenges in traffic classifications; namely the diversity complexity and behavioral dynamism complexity. Existing traffic classifications methods are designed for classifying standard protocols and user applications with more deterministic behaviors in small diversity. Currently, flow statistics, payload signature and heuristic traffic attributes are some of the most effective features used to discriminate traffic classes. In this paper, we investigate the correlations of these features to the less-deterministic user application traffic classes based on corresponding classification accuracy. Then, we evaluate the impact of large-scale classification on feature's robustness based on sign of diminishing accuracy. Our experimental results consolidate the needs for unsupervised feature learning to address the dynamism of mobile application behavioral traits for accurate classification on rapidly growing mobile traffics
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