Int
ern
at
i
onal
Journ
al of Ele
ctrical
an
d
Co
mput
er
En
gin
eeri
ng
(IJ
E
C
E)
Vo
l.
9
, No
.
5
,
Octo
ber
201
9
, pp.
4154
~
41
62
IS
S
N:
20
88
-
8708
,
DOI: 10
.11
591/
ijece
.
v
9
i
5
.
pp415
4
-
41
62
4154
Journ
al h
om
e
page
:
http:
//
ia
es
core
.c
om/
journa
ls
/i
ndex.
ph
p/IJECE
Securin
g
v
ehicula
r
cloud n
etworks
Dj
il
ali
Mouss
aoui
1
, Mo
ha
m
ed Feh
am
2
,
Bou
ci
f
A
m
ar
B
ensa
be
r
3
,
Be
n
am
ar
K
ad
ri
4
1,2,4
STIC
La
b
.
,
Depa
rtment
of
T
e
l
ec
om
m
unic
at
ion
s,
Univer
sit
y
of Tle
m
ce
n
,
Alg
eria
3
La
bora
toi
re
de
Mathé
m
at
iqu
es
et
Inform
atique
Appliqué
es
LAMIA
,
Univer
sit
é
du
Québ
ec
à Tr
ois
-
Rivi
èr
es
,
C
a
nada
Art
ic
le
In
f
o
ABSTR
A
CT
Art
ic
le
history:
Re
cei
ved
J
a
n
24
, 2
01
9
Re
vised
A
pr
15
, 2
01
9
Accepte
d
Apr
22
, 201
9
Vehic
ul
ar
Cloud
Networks
(VC
N)
is
the
net
wor
k
tha
t
ensure
s
m
obil
ity
and
ava
i
la
bi
li
t
y
of
re
source
s
allowing
new
servi
ce
s
an
d
appl
i
cations
l
i
ke
Network
as
a
Service
(Na
aS),
STorage
as
a
Service
(STaaS
),
Com
puta
ti
on
as
a
Service
(Com
paa
S)
and
Coopera
t
ion
as
a
Service
(C
aa
S).
In
th
is
pap
er,
we
propose
a
soluti
on
to
sec
ur
e
the
Veh
ic
ul
ar Cloud
Network
(VCN
).
Our c
hal
l
enge
in
th
is
work
is
to
adapt
th
e
PK
I
ar
c
hit
e
ct
ure
,
whi
ch
is
m
ai
nl
y
use
d
in
wir
ed
net
works
to
be
used
in
VCN
.
T
o
propose
a
sec
urity
solu
ti
on
fo
r
Vehic
ula
r
Cloud
Networks
(VC
N),
our
wo
rk
is
base
d
on
thre
e
steps;
th
e
fir
st
one
is
to
m
ake
net
work
arc
hi
te
c
ture
stu
d
y
,
where
we
t
rie
d
to
h
ighl
igh
t
the
m
ain
net
work
components.
The
sec
o
nd
step
is
to
pr
opose
the
sec
urity
solut
ion
arc
hi
te
c
ture.
Fi
nal
l
y
,
the
la
st
step
is
to
progr
am
a
te
s
t
and
val
id
at
e
the
soluti
on
using
a
sim
ula
ti
on.
Ke
yw
or
d
s
:
Cl
oud
c
om
pu
ti
ng
Van
et
VCN
p
rivacy
VCN
s
ecu
rity
Veh
ic
ular
c
l
oud
n
et
w
orks
(V
C
N)
Copyright
©
201
9
Instit
ut
e
o
f Ad
vanc
ed
Engi
n
ee
r
ing
and
S
cienc
e
.
Al
l
rights re
serv
ed
.
Corres
pond
in
g
Aut
h
or
:
Dj
il
al
i M
oussa
ou
i,
STIC La
b.,
De
par
tm
ent o
f
T
e
le
com
m
un
ic
at
i
on
s
,
Un
i
ver
sit
y o
f Tl
e
m
cen,
Tlem
cen,
Al
ge
ria.
Em
a
il
: dj
_m
oussao
ui@yah
oo.
fr
1.
INTROD
U
CTION
Mod
e
rn
netw
orks
a
re
de
vel
oped
al
ong
tw
o
axes.
T
he
fi
r
st
on
e
is
m
ob
il
it
y
,
this
is
to
ensure
the
netw
ork
a
vaila
bili
ty
to
the
connecte
d
entit
ie
s
in
m
otion
.
Unde
r
this
axi
s,
we
ca
n
fi
nd
diff
e
re
nt
ty
pes
of
netw
orks
su
c
h
as
M
AN
E
T
(
Mob
il
e
Ad
ho
c
NE
Tw
ork),
VANET
(
Ve
hicular
A
d
ho
c
NET
wor
k)
a
nd
WSN
(
W
irel
ess
Se
nsor
Netw
ork
).
The
sec
ond
axis
is
the
res
ources
a
vaila
bi
l
ity
in
ty
pes
(co
m
pu
ti
ng,
st
or
a
ge,
so
ft
war
e
)
a
nd
vo
l
um
e. Th
e m
os
t
us
ed
n
et
work
s
are
p
a
rall
el
co
m
pu
ti
ng, gri
d
c
om
pu
ti
ng
a
nd
cl
oud com
pu
ti
ng.
Veh
ic
ular
Cl
oud
Netw
ork
(
VCN
)
is
the
netw
ork
that
ens
ur
es
the
m
ob
il
it
y
and
av
ai
la
bili
ty
of
resou
rces
al
lo
wing
ne
w
se
r
vi
ces
and
a
pp
li
c
at
ion
s,
li
ke
Ne
twork
as
a
Se
r
vice
(N
aa
S),
S
Tor
a
ge
as
a
S
erv
ic
e
(S
TaaS
),
C
ompu
ta
ti
on
as
a
S
erv
ic
e
(C
om
paaS)
an
d
Co
ope
rati
on
as
a
Se
r
vice
(CaaS)
.
T
he
VC
N
are
th
e
resu
lt
of
m
erg
ing
of
two
m
ai
n
net
works,
t
he
V
A
NET
an
d
Cl
oud
netw
orks
.
S
o,
it
s
a
rc
hitec
ture
co
ntains
both
th
e
cl
oud
c
om
pu
ti
ng and
V
ANE
T en
ti
ti
es.
Secu
rity
in
VCN
is
a
big
chall
eng
e
,
w
here
secur
it
y
requirem
ents
m
us
t
be
gu
a
ran
te
e
d.
T
he
m
os
t
i
m
po
rtant
sec
ur
it
y
requirem
ents
are
a
uthe
ntica
ti
on
,
int
egr
it
y,
pri
vac
y,
confide
ntial
it
y
and
trac
eabil
it
y.
In
li
te
ratu
re,
t
he
s
olu
ti
on
th
at
sat
isfie
s
these
requirem
ents
f
or
wire
d
netw
orks
is
th
e
PKI
(Pu
blic
Key
Infr
ast
ru
ct
ur
e
)
enh
a
nce
d
wit
h
secu
rity
m
ec
han
ism
s
to
en
su
re
pr
i
vacy.
Fo
r
t
his
reas
on,
our
s
olu
ti
on
cal
le
d
VCPKI
(
Ve
hicular
Cl
oud
Publi
c
Key
I
nfra
structu
re)
is
ba
sed
on
P
K
I,
and
a
s
it
is
prov
e
n
in
sect
io
n
7
our
so
luti
on
sec
ur
es
the
netw
ork
with
a
ne
gligible
im
pact
on
netw
ork
perform
ance.
The
rest
of
this
pa
per
is
orga
nized
a
s
f
a
ll
ow
s.
W
e
pres
ent
ne
tw
orks
a
rch
it
ect
ure
in
s
ect
ion
2,
f
ollo
wed
by
th
e
sec
ur
it
y
re
quirem
ent
f
or
the
VCN
in
Se
ct
ion
3.
We
de
scribe
the
arc
hi
te
ct
ur
e
of
sec
ur
it
y
so
luti
on
in
Sect
ion
4.
T
he
Sect
ion
5
presents
how
t
he
s
olu
ti
on
w
orks
un
de
r
VCPKI
proto
col.
T
he
s
ol
ution
analy
sis
(se
cur
it
y
an
d
pe
rfor
m
ance
analy
sis)
is
pr
ese
nted
in S
e
ct
ion
s
6
a
nd
VII.
Fi
nally
, a
c
oncl
us
i
on is g
i
ve
n
in
Secti
on
8.
Evaluation Warning : The document was created with Spire.PDF for Python.
In
t J
Elec
&
C
om
p
En
g
IS
S
N:
20
88
-
8708
Securi
ng
ve
hicular cl
oud net
works (Dji
lali
Mo
us
sao
ui)
4155
2.
NETWO
RKS
ARCHITE
CT
UR
E
In
the
f
ollow
i
ng
we
present
the
a
rch
it
ect
ure
of
VANET
,
C
loud
C
om
pu
ti
ng
,
al
so
the
VC
N
ta
xonom
y
and
arc
hitec
tur
e.
A
fter
stu
dying
the
V
A
NE
T
[
1]
an
d
Cl
ou
d
C
om
pu
ti
ng
ne
tworks
[
2
,
3],
the
F
ig
ur
e
1
de
fine
s
the V
e
hicula
r C
loud
Netw
ork
a
rch
it
ect
ure
.
Figure
1.
VCN Ar
c
hitec
ture
The
en
d
us
e
r
is
the
veh
ic
le
,
the
RSU
is
the
gateway
to
ach
ie
ve
the
cl
oud
par
t.
I
n
the
cl
oud
we
fi
nd
the
Cl
oud
P
rovide
r
a
nd
Cl
oud
Se
rv
e
rs.
V
ehicular
cl
ou
d
is
di
vid
e
d
i
nto
t
hr
ee
m
ajo
r
arch
it
ect
ures
nam
el
y
Veh
ic
ular
Cl
ouds
(
VC)
,
Vehi
cl
es
us
in
g
Cl
ouds
(
V
uC),
an
d
Hybr
i
d
Cl
ou
ds
(H
C
).
The
Veh
ic
ular
Cl
ouds
(
VC)
is a net
work f
orm
ed
on
ly
by vehicl
es an
d r
e
ga
rd
i
ng the
ve
hicle
as sho
wn in
Fig
ur
e
2
(a)
.
(a)
(b)
(c)
Figure
2
.
Ve
hi
cular Clo
ud
Ne
twork
(VCN
)
Also
,
t
he
VC
N
can
be
f
or
m
ed
Ve
hicle
s
an
d
these
veh
ic
l
es
are
co
nnect
ed
to
the
tra
diti
on
al
cl
ouds
wh
e
r
e cl
oud
se
rv
ic
es a
re a
vaila
ble as s
how
n
i
n
Fi
gure
2
(b
)
.
The
t
hi
rd case
is cal
le
d
Hy
br
i
d
Cl
oud as s
ho
wn in
Figure
2
(c
),
wh
e
re
ve
hicul
ar
cl
ou
ds
will
interact
wit
h
the
tra
diti
on
al
cl
oud
f
or
ser
vices
e
xc
hange.
The ve
hicle
s an
d R
SUs wil
l s
erv
e
as
gatewa
ys on the
V
ANET p
a
rt the
reby
com
m
un
ic
at
i
ng w
it
h t
h
e
gat
eways
of traditi
onal
c
louds.
3.
SECURIT
Y R
EQUI
REME
NTS
The
m
os
t
i
m
p
or
ta
nt
secu
rity
requirem
ents
in
the
Ve
hic
ular
Cl
oud
N
et
work
a
re
au
thentic
at
ion,
integrity
, pri
va
cy
, conf
i
den
ti
a
li
ty
and
tracea
bili
ty
.
-
The
a
uth
e
ntica
ti
on
e
ns
ures
th
at
the
m
essage
is
gen
e
r
at
ed
by
the
le
gitim
at
e
us
er
.
It p
r
otect
s
the
el
em
ents
of
com
m
un
ic
at
ion
(m
essages and
e
ntit
ie
s)
[4
,
5]
.
-
In
ou
r
co
ntext
(V
ehic
ular
Cl
oud
Net
work),
the
authen
ti
c
at
ion
is
ver
y
im
po
rtant
secu
rity
req
uirem
ent,
because
it
is
fr
equ
e
ntly
so
li
ci
te
d,
to
us
e
cl
oud
se
rv
ic
es
[6]
.
So
,
our
s
olu
ti
on
pro
vid
es
pri
vacy
-
preser
vi
ng
authe
ntica
ti
on
.
R
S
U
O
B
U
/
A
U
C
l
o
u
d
S
e
r
v
i
c
e
P
r
o
v
i
d
e
r
C
l
o
u
d
S
e
r
v
e
r
s
N
e
t
w
o
r
k
C
l
o
u
d
N
e
t
w
o
r
k
C
l
o
u
d
G
P
R
S
/
3
G
/
W
i
-
F
i
G
P
R
S
/
3
G
/
W
i
-
F
i
G
P
R
S
/
3
G
/
W
i
-
F
i
Evaluation Warning : The document was created with Spire.PDF for Python.
IS
S
N
:
2088
-
8708
In
t J
Elec
&
C
om
p
En
g,
V
ol.
9
, N
o.
5
,
Oct
ober
201
9
:
4
1
5
4
-
4
1
6
2
4156
-
The
integ
rity
ens
ur
es
that
the
data
is
pr
ot
ect
ed
fr
om
delet
ion
,
m
od
ific
at
ion
,
an
d
pr
oductio
n
with
out
per
m
issi
on
[
7]
.
The
prop
os
e
d solutio
n
s
houl
d g
uar
a
ntee the
integ
rity
.
-
The
Pr
i
vacy
i
s
necessary
to
pr
otect
the
pro
file
and
dri
ve
r’
s
in
form
at
i
on
a
nd
the
ve
hicle
local
iz
at
i
on
against
un
a
uthorize
d
acce
ss
[8]
.
T
he
pri
va
cy
pr
otect
io
n
m
echan
ism
s
a
re
em
bed
de
d
in
our
sec
ur
it
y
so
luti
on.
-
The
ai
m
of
con
fi
den
ti
al
it
y
is
to
protect
the
com
m
un
ic
at
ion
of
a
set
of
ve
hicle
s
from
an
exter
nal
intr
ud
e
r
.
The
e
ncr
ypti
on
is
the
m
ai
n
t
oo
l
to
e
nsure
t
his
secu
rity
req
ui
rem
ent
and
the
enc
ryptio
n
m
echan
ism
s
are
def
i
ned
to
be
su
re
that
th
e
encr
ypte
d
inf
or
m
at
ion
is
decr
ypte
d
only
by
the
gr
ou
p
of
m
e
m
ber
s
(
ve
hicle
s
)
[6]
ECC
.
-
The
tracea
bili
ty
identifie
s
ve
hicle
s
an
d
thei
r
com
m
un
ic
at
ion
s
an
d
pr
e
ser
ves
thei
r
pr
iva
cy
and
inf
orm
a
ti
on
confide
ntial
it
y
[9]
.
T
o
protect
us
er
i
nfor
m
at
i
on,
the
i
den
ti
ty
m
us
t
be
hi
dd
e
n
an
d
al
s
o
it
is
i
m
po
rtant
to
us
e
a syst
e
m
co
m
p
on
e
nt
(trace m
anag
e
r) to
obta
in the real
ide
nt
it
y wh
ere it
is
need
e
d
[
10
]
.
4.
PROP
OSE
D ARCHITE
CT
UR
E
FO
R
SE
CURI
NG VE
HICULA
R C
LOUD WIT
H
PKI (
VC
P
KI
)
4.1.
Prop
os
ed
m
odel
f
or
VCPK
I
The VCN
is c
om
po
sed of
t
hr
e
e lay
ers
-
The net
w
ork
la
ye
r
(
VANET
)
-
Mob
il
e in
fr
ast
r
uctu
re lay
er
-
Cl
oud
c
om
pu
ti
ng lay
er
The
F
ig
ur
e
3
s
hows
ou
r
pro
pose
d
m
od
el
f
or Secur
e
d
VC
N
and
it
s co
m
po
ne
nts.
The go
al
of
the
VCN
secur
it
y arc
hitec
ture
is t
o be i
n harm
on
y
with th
ree m
ai
n
ar
chite
ct
ur
es
(V
AN
E
T, Cl
oud
,
PK
I
).
Figure
3. P
rop
os
e
d
Mo
del
for
Secure
d VCN
4.2.
Co
m
ponen
ts
4.2.1.
RCA (R
oot
Cer
tifica
te
Au
t
ho
ri
t
y)
The
RC
A
is
th
e
trust
a
nc
hor
i
n
the
syst
em
wh
ere
t
he
tr
us
t
i
s
assum
ed
an
d
no
t
de
rive
d,
it
s
certi
ficat
e
is
sel
f
-
sig
ned.
Its
m
a
in
ro
le
is
to
issue
a
nd
sign
certi
ficat
e
on
ly
f
or
s
ub
ordinate
a
utho
riti
es
of
the
V
CPKI
secur
it
y sy
ste
m
(
LTCA, V
C
SP)
.
4.2.2.
LT
CA
(Long
-
Te
rm Cer
tific
at
e
A
u
thori
t
y)
LTCA
iss
ue
a
nd
sig
n
l
ong
-
t
erm
certi
ficat
e
for
t
he
syst
e
m
end
us
e
rs
(
Veh
ic
le
s)
.
Eac
h
e
ntit
y
m
us
t
sen
d
it
s
req
ues
t
direct
ly
to
L
TCA
to
obta
in
a
lon
g
-
te
rm
c
erti
ficat
e.
Also,
the
LTCA
is
responsi
ble
to
issue
tok
e
ns
f
or
vehi
cl
es
(o
r
ot
her
entit
ie
s),
these
tok
en
s
are
use
d
to
re
qu
est
ps
e
udonym
s
(sh
ort
-
te
rm
certif
ic
at
e)
from
the P
CA.
4.2.3.
CLA
(
Cloud
Au
t
ho
ri
ty)
The
CL
A
is
re
sp
onsi
ble
o
f
m
anag
i
ng
us
e
rs
cl
oud
acco
unts
,
an
d
to
iss
ue
tok
e
ns
for
veh
i
cl
es
(or
ot
her
entit
ie
s),
these
tok
e
ns
a
re
us
e
d
to
r
e
quest
clo
ud servic
e
fro
m
the V
CS
P.
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Securi
ng
ve
hicular cl
oud net
works (Dji
lali
Mo
us
sao
ui)
4157
4.2.4.
VCSP
(
Ve
hicul
ar Clou
d S
e
rvice Pr
ov
ider
)
It
m
akes
the
cl
oud
ser
vice
av
ai
la
ble
to
the
connecte
d
ve
hicle
s.
Fo
r
t
his,
it
acqu
ire
s
an
d
m
anag
es
th
e
com
pu
ti
ng
in
frast
ru
ct
ure’
s
inf
or
m
at
ion
.
I
n
V
ehicular
Cl
ou
d,
there
are
tw
o
ty
pes
of
res
ources
,
the
Ve
hi
cl
es
resou
rces
(O
B
U)
,
a
nd co
m
pute
rs
res
ources
(Dat
ac
enter
).
4.2.5.
PCA
(
Pseud
onym
Cer
tifica
te
Au
t
ho
ri
ty)
The
us
e
of
pse
udonym
s
is
i
mp
ort
ant
t
o
protect
the
pri
vacy
of
use
rs
i
n
th
e
netw
ork
.
T
his
auth
ori
ty
has
t
wo m
ai
n
ro
le
s:
-
Issu
i
ng
ps
e
udonyms
(
short
-
te
rm
cert
if
ic
ate
)
:
Each
veh
ic
le
s
ends
a
request
to
the
cl
os
est
PC
A
to
achieve
a
set
of
ps
e
udonym
ou
s
certi
fi
cat
es.
Usi
ng
pse
udonym
s,
each
veh
ic
le
ca
n
com
m
un
ic
at
e
in
the
netw
ork
anonym
ou
sly
.
-
Pseu
dony
m
re
so
luti
on:
T
he
PCA
is
en
dow
ed
with
the
functi
on
of
res
olv
in
g
ps
e
udony
m
s
identit
y.
T
his
op
e
rati
on
is
use
d
w
he
n
it
is
ne
ces
sary,
it
co
ns
ist
s
of
fi
nd
i
ng
out
the r
el
at
ed
to
ken
t
o
a
s
pe
ci
fic
ps
e
udon
ym
,
after
that
it
queries
the
LTC
A
to
ide
ntify
and
rev
eal
the
r
eal
identit
y
fo
r
that
tok
e
n.
I
f
the
ps
e
udonym
is
identifie
d as m
al
ic
iou
s,
t
he
P
CA ca
n
re
voke
all
r
el
at
ed pse
udonym
s.
4.2.6.
VC
-
R
SU (L
oc
al V
e
hicul
ar Clou
d S
er
vice
Provider
)
It
is
a
n
RS
U
as
us
e
d
in
VANET
eq
ui
pp
e
d
with
the
com
pu
ta
ti
on
a
l
un
it
us
e
d
t
o
offe
r
m
or
e
functi
onal
it
ie
s
and
se
rv
ic
es
f
or
veh
ic
le
s.
S
o
the
VC
-
RS
U
ens
ur
e
tw
o
m
ai
n
fu
nctio
ns,
the
first
is
the
RSU
m
anag
in
g
the
VANE
T
,
the
s
econd
is
cl
ou
d
m
anag
em
ent
fu
nctio
n.
As
t
he
first
f
unct
ion
is
known
a
nd
al
read
y
us
e
d
in
VANE
T,
the
sec
ond
on
e
c
onsist
s
of
offer
i
ng
l
ocal
cl
oud
ser
vices
for
ve
hicle
s,
w
it
ho
ut
requesti
ng
t
he
serv
ic
e
from
V
CSP.
4.3.
Prop
os
ed
Mo
del Archi
tectur
e
The pr
opose
d
arch
it
ect
ure
ca
n be
div
ide
d
i
nt
o
f
our La
ye
rs.
4.3.1.
The end
users
La
yer
This lay
er c
onta
ins the
v
e
hicle
s con
nected t
o
the
closest
V
C
-
RSU
.
4.3.2.
Gatew
ay la
ye
r
This
la
ye
r
can
be
com
po
un
de
d
by
a
set
of
VC
-
RS
U
an
d
ano
t
her
netw
ork
com
ponen
t
(
ex:
routers
)
tha
t al
lows t
he direct
access
to
the
oth
e
r
syst
e
m
co
m
po
nen
ts
.
4.3.3.
Service L
ay
er
In
this
la
ye
r
,
we
fin
d
t
he
c
om
po
ne
nts
tha
t
al
low
t
he
se
rv
ic
es:
pr
i
vac
y
(P
CA
)
a
nd
the
Cl
ou
d
Ser
vice (
VCSP
)
.
4.3.4.
Au
t
ho
ri
ties
Thr
ee
el
em
ents
are
the
essen
ti
al
co
m
po
ne
nts
in
this
la
ye
r:
The
RC
A
(
iss
ue
the
certi
fic
at
e
fo
r
this
la
ye
r
com
po
ne
nts), the
LTCA
and CL
A.
4.4.
Functi
onal Vi
ew
In
t
his
sect
io
n,
we
pr
ese
nt
f
unct
ions
or
se
rvi
ces,
this
arc
hitec
ture
al
lo
ws
t
wo
m
ai
n
ser
vices:
secur
it
y
and clo
ud.
4.4.1.
Securi
t
y
ser
vice:
This
se
rv
ic
e
r
egro
up
s
al
l
se
cur
it
y
operati
ons
in
the
netw
ork
with
sec
uri
ty
entit
ie
s
(LTCA,
PCA
).
These
operati
ons c
oncer
n
LT
Cs an
d pse
udonym
s.
4.4.2.
Cloud Ser
vice
This
se
rv
ic
e
c
on
ce
r
ns
the
cl
oud
a
uthoriti
es
(CLA
,
VCSP
)
an
d
the
pe
rform
ed
operati
on
s
to
ob
ta
in
a
cl
oud
ser
vice.
This service
is directl
y reli
ed
with
the sec
ur
i
ty
ser
vice b
eca
us
e w
e
wa
nt to
o
f
fer
a clo
ud s
erv
ic
e
in a
sec
ur
e
d
c
onte
xt.
5.
VC
P
KI
DE
SIGN
5.1.
Sec
urit
y
Ser
vice
5.1.1.
Requ
es
t
L
ong
-
Te
rm
Cert
ifi
cat
e
:
1: T
he vehicl
e
request
from
R
SU
’
s a
uthority
’s
ce
rtific
at
e.
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o.
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,
Oct
ober
201
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:
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1
5
4
-
4
1
6
2
4158
2: T
he
RS
U
se
nd
s
the
certi
fic
at
e to the
v
e
hic
le
s.
3: T
he vehicl
e
gen
e
rates El
li
pt
ic
Cur
ve
P
ub
li
c K
ey
Pai
r.
4: T
he vehicl
e
create
s a Ce
rtific
at
e Sign
i
ng
Re
qu
est
(CSR)
, en
c
rypte
d by
the pu
blic key
of the L
TCA.
5: T
he vehicl
e
sen
ds
it
onli
ne t
o
LTC
A.
6: LTC
A
iss
ue
s n
e
w
L
TC.
7: LTC
A
loa
d
i
ts pr
i
vate k
ey
, si
gn
s
LTC,
and
create a ce
rtific
at
e.
8: LTC
A
se
nds
it
b
ack
to
t
he
s
ub
s
cribe
r.
5.1.2.
Requ
es
t a
Pse
udonym
C
er
ti
ficat
e
:
To
e
nfo
rce
t
he
pri
vacy
i
n
t
his
protoc
ol,
we
div
id
e
the
operati
on
of
requesti
ng
ps
e
udonym
into
two
ste
ps.
The
fi
rst
one
is
toke
n
re
qu
e
st
wh
e
re
the
us
e
r
can u
se
his
real
ide
ntit
y
(Lo
ng
Te
rm
Ce
rtific
at
e)
fr
om
LTCA.
U
sin
g
this
tok
e
n,
the
us
er
ca
n
reque
st
a
ps
eudo
nym
fr
om
the
PCA
(step
2)
.
T
he
Figu
r
e
4
sho
w
us
a
n
Ov
e
r
view o
n m
essage ex
c
ha
ng
e
.
Figure
4
.
Req
uest
Pse
udony
m
Cert
ific
at
e
a.
Ob
ta
in
Sec
ur
it
y To
ken
1: P
rep
a
re T
ok
en
Re
qu
est
2: Se
nd the t
oken req
uest to
th
e LTCA
3: T
ok
e
n ge
nerat
ion
4: T
ok
e
n repla
y
5: Store t
he
to
ke
n
in
HSM
to
be use
d
in
the
nex
t
phase.
b.
Ob
ta
in
Pse
udonym
Certi
ficate
The
pse
ud
on
y
m
certi
ficat
e
req
ue
st
is
betw
een
the
PC
A
(P
se
udonym
Au
t
hority
)
an
d
the
ve
hicle
wh
e
re t
his lat
er
us
e the
to
ken
ob
ta
ine
d from
the step
b
e
fore.
1:
The Ve
hicle
pr
epar
es
the
Pse
udonym
Requ
est
.
2:
The
ve
hicle
send
s
th
e
Pseud
on
ym
Re
qu
est
to
the
PCA,
in
this
request
the
secur
it
y
tok
en
is
sent
as
a
par
am
et
er.
3:
The PC
A ve
rif
ie
s the r
e
quest
and the t
ok
e
n,
and g
e
ne
rates
a set o
f pse
udonym
s
.
4:
The PC
A sen
ds t
he ge
ner
at
e
d pse
udonym
s t
o
the
V
e
hicle
.
5.1.3.
Pseud
onym
R
esoluti
on
Pseudonym
reso
luti
on
is
a
pro
cess
us
e
d
t
o
id
entify
the
real
identit
y
of
a
pse
udonym
.
This
process
is
requested
by
the
poli
ce,
and
it
is
do
ne
in
two
phases
To
ken
R
es
olu
t
ion
,
ide
ntit
y
reso
luti
on
as
s
how
n
in
Fig
ure
5.
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Securi
ng
ve
hicular cl
oud net
works (Dji
lali
Mo
us
sao
ui)
4159
Figure
5
.
P
se
udonym
Resoluti
on
a.
Step
1: T
ok
e
n R
esolutio
n
1.
The
a
uthority
gets
the
m
al
ic
iou
s
node’
s
ps
e
udon
ym
fr
om
the
netw
ork
a
nd
prepa
res
th
e
To
ke
nRes
olu
ti
onReq
uest
.
2.
The
aut
hority
sen
ds
To
ke
nRe
so
luti
onRe
ques
t
to
the
PCA,
wh
e
re
the
pse
udonym
of
the
m
al
ic
iou
s
node
is
sent as a
p
a
ram
et
er
.
3.
The PC
A fin
ds t
he
c
orres
pondin
g
to
ke
n for
the pseu
donym
.
4.
The PC
A sen
d t
he
to
ken to
th
e autho
rity
b
y t
he
T
oke
nRes
olu
ti
onRepl
ay
.
b.
Step
2: Ide
ntit
y R
esolutio
n
1.
The
a
uthority
pr
e
par
e
s the
I
de
ntit
yR
esolutio
nReq
uest
.
2.
The
a
uthority
s
ends
I
de
ntit
yResolu
ti
onRe
qu
est
to the
LTC
A
.
3.
The
L
TCA
fin
ds
t
he
c
orrespo
nd
i
ng ide
ntit
y t
o
the
to
ken pre
par
e
the
rep
ly
m
essage.
4.
The
L
TCA
sen
ds
t
he
I
de
ntit
yR
esolutio
nRep
la
y
wh
e
re th
e
operati
on
res
ult i
s sen
t.
6.
SECURE
D C
LOUD SE
RVICE
The
cl
oud
se
r
vice
al
lows
th
e
us
er
to
acce
ss
to
the
cl
oud,
ou
r
pro
posit
ion
ens
ures
m
or
e
secur
it
y
and privacy
.
Fi
gure
6
giv
es
an o
verview
of th
e m
essage ex
c
hange.
Figure
6
.
Sec
ured Clo
ud Se
rv
i
ce
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o.
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,
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1
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6
2
4160
6.1.
Requ
es
t the
cl
ou
d s
ervice
6.1.1.
St
ep
1:
Cloud
Token Req
ues
t
a.
The ve
hicle
pr
epar
es
Cl
oud T
ok
e
n (r
e
quest
a
p
se
udonym
if it didn’t
befor
e
)
b.
The
ve
hicle
se
nd
s
the
Cl
oudT
okenRe
qu
e
st
to
the
CLA
w
he
re
the
cl
oud
a
ccount
ID
an
d
the
pse
ud
on
ym
are se
nt as
par
a
m
et
ers
(the
c
om
m
un
ic
at
ion
i
s p
e
rfor
m
ed
in
a
secu
red
cha
nnel
)
c.
The
Cl
ou
d Au
t
hority
(
CLA
) v
erify the cl
oud
account
ID an
d p
rep
a
re a
t
oke
n for the
use
r
c
loud acc
ount.
d.
The
Cl
ou
d Au
t
hority
(
CLA
)
s
end b
ac
k
t
he
C
loudT
ok
e
nRep
le
y t
hat conta
in the
Cl
oud To
ken.
6.1.2.
St
ep
2:
Cloud
Service
Requ
e
st
a.
The ve
hicle
se
nd
s
a
Cl
ou
dS
e
r
viceR
eq
uest
to
the
VCSP
u
si
ng the
clo
ud to
ke
n.
b.
The VCSP
se
nds a
Cl
oudAcc
ountStat
us
Re
q t
o
t
he
CL
A
t
ha
t i
nclud
e
s the
tok
e
n.
c.
The
CL
A repli
es w
it
h C
loud
Accou
ntStat
usR
ep
c
on
ta
ini
ng the clo
ud acc
ount i
nfor
m
at
ion
.
d.
The
VCSP
sto
res
the
cl
oud
a
ccount
sta
tus
with
the
co
rr
e
s
pondin
g
ps
e
udon
ym
to
offe
r
the
ap
pro
pr
ia
te
cl
oud
se
rv
ic
e.
e.
The
VCSP
se
nds
t
he
Cl
ou
dS
erv
ic
eR
eplay
,
if
the
ser
vice
is
grant
,
the
ve
hi
cl
e
can
us
e
his
ps
e
udonym
to
us
e it
s clo
ud se
rv
ic
e
.
6.2.
Renewi
ng th
e
cl
ou
d s
ervice
request
As
it
is
pr
ese
nted
a
bove,
th
e
veh
ic
le
re
quest
s
a
Cl
ou
d
Ser
vice
us
in
g
it
s
ps
eudo
nym
,
wh
e
re
the
ps
e
udonym
s
are
valid
f
or
a
pe
rio
d
a
nd
the
ve
hicle
can
us
e
a
no
t
her
the
ps
e
udonym
,
fo
r
t
ha
t
the
validit
y
of
the
cl
oud
se
r
vice
is
relat
ed
to
the
validit
y
of
t
he
ps
e
udonym
.
So
,
f
or
each
pse
udonym
chan
gi
ng
,
the
ve
hicle
m
us
t
update
the
cl
oud
ser
vice
re
quest
.
T
he
upda
ti
ng
re
quest
c
onta
ins
the
ol
d
ps
e
udonym
,
th
e
ne
w
pse
ud
onym
,
and
the clo
ud servi
ce tok
e
n.
7.
SECURIT
Y A
NA
L
YS
I
S
The
sec
uri
ty
analy
sis
is
ba
sed
on
ho
w
t
he
s
olu
ti
on
e
ns
ures
t
he
V
CN
sec
ur
it
y
r
equ
i
rem
ents
(Integ
rity
, P
riv
acy
and
Non
-
r
epudiat
ion).
7.1.
Int
e
grit
y
Our
syst
em
is
a
PK
I
base
d
so
luti
on,
s
o
the
exc
ha
ng
e
d
m
essages
m
u
st
con
ta
in
a
va
li
d
sende
r
sign
at
ur
e,
w
hich
is
easi
ly
veri
fiable
thr
ough
the
certi
ficat
e
auth
or
it
ie
s
(LT
CA,
PCA
).
T
he
refor
e
,
the
int
egr
it
y
in
ou
r
syst
em
i
s a
gu
a
ran
te
e.
7.2.
Pri
vacy
The
ps
e
udony
m
is
a
tem
po
rar
y
certi
ficat
e,
char
act
erize
d
by
the
anony
m
ity
and
a
short
pe
rio
d
of
validit
y.
This
ps
e
udonym
is
us
e
d
in
ste
ad
of
the
dig
it
al
certi
ficat
e
to
pro
vid
e
t
he
pr
i
vacy.
Pse
ud
on
ym
s
gu
a
ra
ntee
the
pr
i
vacy
in
us
i
ng
t
he
net
wor
k,
in
VCN
,
th
e
chall
eng
e
is
to
guara
ntee
the
pri
vacy
in
us
in
g
netw
ork
an
d
cl
oud
ser
vice.
F
or
this
ou
r
pro
po
sit
io
n
base
d
on
the
a
uthorit
y’s
separ
at
io
n
to
enfor
ce
the
pr
i
vacy
in the net
w
ork
and b
et
ween a
uthoriti
es whe
n usin
g
cl
oud
s
erv
ic
e
.
7.3.
Non
-
Repudi
at
ion
In
VCN
an
d
duri
ng
em
erg
e
nc
y
si
tuati
on
s
a
s
acci
den
ts
,
act
ion
s
or
cha
nge
s
m
us
t
be
asso
ci
at
ed
with
a
un
i
qu
e
veh
ic
le
(
dri
ve
r)
. Also, t
he
cl
oud
ser
vices are o
f
fer
e
d fo
r
m
ulti
ple te
nan
ts;
non
-
r
ep
ud
ia
ti
on is i
m
p
or
ta
nt
to
identify
the
te
nan
t
pa
rtic
ipati
on
i
n
any
argue
d
transac
ti
on
.
I
n
VCPKI
pr
ot
oco
l,
ps
e
udonym
s
are
us
ed
to
exch
a
nge
m
es
sages.
T
he
m
e
ssage
ori
gi
nator
on
ly
knows
this
ps
eu
dony
m
and
there
fore,
the
se
nd
e
r
canno
t
repu
diate
.
8.
PERFO
R
MANC
E
A
NA
L
Y
SIS
To
eval
uate
the
i
m
pact
of
ou
r
s
olu
ti
on
on
the
networ
k
perform
ance,
we
ha
ve
im
pl
e
m
ented
ou
r
syst
e
m
VCPK
I
(V
e
hicula
r
Cl
oud
P
K
I)
on
OMNET
++
5.
0
sim
ulator
[
1
1
]
with
veins
4.4
[
1
2
]
an
d
S
UMO
-
0.25.0
sim
ulato
r
[
1
3
]
. I
n
T
ab
le
1,
w
e p
rese
nt
the
sim
ulatio
n
par
am
et
ers
In
this
sim
ulatio
n,
w
e
ha
ve
m
easur
e
d
the
delay
in
t
wo
sit
uations,
the
first
on
e
without
usi
ng
VCPKI
protoc
ol,
the
sec
ond
on
e
t
he
net
w
ork
us
e
VCPKI
as
a
s
ecur
it
y
protoc
ol.
As
seen
i
n
Figure
7
,
the
di
ff
ere
nce
is
ne
gligible,
it
is
be
tween
2,1.10
-
5
s
an
d
7,73.10
-
5
s.
Als
o,
we
ha
ve
m
e
asur
e
d
the
pac
ket
delivery
rat
io
(P
DR
),
as
s
how
n
in
Figur
e
8
,
an
d
it
is
the
sa
m
e
for
the
tw
o
s
it
uations
(
with
,
with
ou
t
VC
PK
I
).
So,
the
protoc
ol
VC
PK
I
ha
ve
no
i
m
pact
on
P
DR
in
the n
et
wor
k.
Evaluation Warning : The document was created with Spire.PDF for Python.
In
t J
Elec
&
C
om
p
En
g
IS
S
N:
20
88
-
8708
Securi
ng
ve
hicular cl
oud net
works (Dji
lali
Mo
us
sao
ui)
4161
Table
1.
Sim
ul
at
ion
par
am
et
e
rs
Ite
m
Valu
e
Map o
f
T
le
m
c
en
(
Alg
eria)
2
,5k
m
*
2
,5k
m
Si
m
u
latio
n
ti
m
e
1000s
Sp
eed
m
ax
1
4
m
/s
Pack
et size
1
0
2
4
bytes
Bit rate
6
Mps
Nu
m
b
e
r
o
f
RSU
4
Co
m
m
u
n
icatio
n
Rag
e of
veh
icle
8
0
0
m
Co
m
m
u
n
icatio
n
Rag
e of
RSU
8
0
0
m
Figure
7
.
Del
ay
in
VC
N
Figure
8
.
VCP
KI
im
pact on P
DR in
V
C
N
9.
CONCL
US
I
O
N
In
t
his
work,
we
hav
e
m
ade
a
tour
on
sec
uri
ty
in
Veh
ic
ular
Cl
oud
Net
work
s;
we
st
ud
ie
d
at
ta
cks
a
nd
their
im
pact
on
the
netw
ork
a
sp
ect
s
(Clo
ud
serv
ic
e
a
nd
se
c
ur
it
y
requirem
ent).
T
his
stu
dy
helps
us
two
def
i
ne
the
m
os
t
tou
c
he
d
sec
ur
it
y
re
quirem
ents
by
the
at
ta
cks
.
On
the
ba
se
on
thi
s
stu
dy,
we
ha
ve
pro
po
se
d
V
CPKI
as
a
protoc
ol
t
o
sec
ure
the
ne
twork
.
Af
te
r
th
e
im
ple
m
entat
i
on
a
nd
the
sim
ulati
on
of
t
he
VCPKI
prot
oc
ol,
we
con
cl
ud
e
t
hat
the
so
luti
on
e
nfor
ce
s
the
se
cur
it
y
of
the
netw
ork
with
a
neg
li
gi
ble
im
pact
on
the
netw
ork
perform
ance.
REFERE
NCE
S
[1]
S.
P.
Gods
e
and
P.
N.
Maha
lle,
“
A
Com
puta
ti
onal
Anal
y
sis
of
ECC
Based
Novel
Authent
i
ca
t
ion
Scheme
i
n
VA
NET,
”
In
te
rn
ati
onal Journal of
E
le
c
tric
al
and
Computer
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i
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C
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2018
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[2]
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Fran
ci
s,
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A
Com
par
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of
Cloud
Ex
ec
u
ti
on
M
ec
h
ani
s
m
s
Fog
,
Edge
,
and
Clon
e
Cl
oud
Com
puti
ng,
”
Inte
rnational
Jo
urnal
of El
e
ct
ri
c
al
and
Comput
er
Engi
n
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IJE
CE)
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[3]
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Hus
sain,
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l.
,
“
Ret
hinki
n
g
Vehic
ul
ar
Com
m
unic
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ions:
M
erg
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VA
NET
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oud
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puti
ng,
”
CloudC
om
201
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e
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N.
Maha
lle,
“
A
Com
puta
ti
onal
Anal
y
sis
of
ECC
Based
Novel
Authent
i
ca
t
ion
Scheme
i
n
VA
NET,
”
In
te
rn
ati
onal Journal of
E
le
c
tric
al
and
Computer
Eng
i
nee
ring (
IJ
EC
E)
,
vol
.
8
,
pp
.
5268
-
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2018
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[5]
R.
P.
Barnw
al
,
e
t
al.
,
“
Data
and
Applic
a
ti
on
Se
c
urity
in
Cloud,”
in
Intelli
g
ent
S
ystems
,
Springer
-
Verl
ag,
vol.
70,
pp.
479
-
495
,
20
14
.
[6]
R.
M.
Jab
ir,
et
a
l.
,
“
Anal
y
sis
of
cl
oud
computing
at
t
ac
ks
and
cou
nte
rm
ea
sures,
”
I
nt.
Co
nf
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Adv
.
C
omm
un.
Technol.
ICACT
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117
-
123
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Mar
2016.
[7]
C.
Kal
loni
a
ti
s,
et
al
.
,
“
Towa
rd
s
the
d
esign
of
sec
ure
and
pri
vacy
-
ori
ent
ed
in
form
at
ion
s
y
st
e
m
s
in
the
cl
ou
d:
Ide
nti
f
y
i
ng
th
e m
aj
or
concept
s,
”
Comput.
S
tand.
Inte
rfac
es
,
vo
l. 3
6,
p
p
.
759
-
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,
2014.
[8]
A.
Kert
esz
,
“
Chara
c
te
ri
zi
ng
C
l
oud
Feder
ation
Approac
hes,
”
in
Cloud
Comput
ing
Chall
enge
s,
Limitat
ions
an
d
Solut
ions
,
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1
-
26
,
2014
.
[9]
R.
G.
Engoul
ou
,
et
al.
,
“
VA
NET
sec
urity
surv
e
y
s
,
”
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mun.
,
vo
l. 44, pp
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-
13
,
2014
.
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Zha
ng
,
et
al.
,
“
Pr
iva
c
y
-
Preser
ving
Cloud
Establishm
ent
and
Data
Diss
eminat
io
n
Scheme
for
V
ehi
cu
la
r
Cloud,”
IEE
E
Tr
ans.
De
pendabl
e
Se
cur.
Comput
.
,
vo
l. 59
71,
pp
.
1
-
14
,
20
18.
[11]
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The
Discre
te Ev
ent
Sim
ulator
OM
NET+
+,
”
w
ww
.
om
net
pp.
org
.
[12]
“
Vehic
le
s in
Net
work Sim
ula
ti
on
VEINS
,
”
v
ei
ns.
ca
r2x.
org
.
[13]
“
Sim
ula
ti
on
of U
rba
n
MO
bil
ity
SU
MO
,
”
sum
o.
d
lr.
de
.
Evaluation Warning : The document was created with Spire.PDF for Python.
IS
S
N
:
2088
-
8708
In
t J
Elec
&
C
om
p
En
g,
V
ol.
9
, N
o.
5
,
Oct
ober
201
9
:
4
1
5
4
-
4
1
6
2
4162
BIOGR
AP
H
I
ES
OF
A
UTH
ORS
Djilal
i
Mouss
aoui
rec
ei
v
ed
his
engi
nee
r
degr
ee
s
in
compute
r
scie
nce
from
the
Univer
sit
y
of
Tl
emce
n
,
Alger
i
a
in
2004,
and
his
M.S.
degr
e
e
s
in
net
works
and
te
l
ec
om
m
unic
ation
s
y
st
em
s
withi
n
of
the
sa
m
e
Univer
sit
y
i
n
2007.
Mem
ber
of
STIC
l
abor
ator
y
in
th
e
Unive
rsit
y
of
T
le
m
cen
.
Now
he
is
an
assistant
prof
essor
in
facult
y
of
te
chnol
og
y
unive
rsit
y
of
T
le
m
ce
n,
Alger
ia.
His re
ce
n
t
work
is de
a
li
ng
wi
th
v
ehi
cu
la
r c
loud
c
om
puti
ng
net
wo
rks a
nd
their
se
c
urity
.
Mohamme
d
Feh
am
rec
ei
v
ed
hi
s
PhD
in
Engi
ne
eri
ng
in
optica
l
and
m
ic
rowave
comm
unic
at
ion
s
from
the
unive
r
sit
y
of
Li
m
oges,
Franc
e
in
1987
,
and
his
PhD
i
n
scie
n
ce
from
t
he
univ
ersity
o
f
Tl
emce
n
,
Alg
eria
in
1996
.
Sin
ce
1987
he
h
as
been
assistant
prof
e
ss
or
and
profe
ss
or
of
m
ic
rowave
and
comm
unic
ation
engi
ne
eri
ng
his
rese
arc
h
in
terest
is
in
te
l
ec
o
m
m
unic
at
ion
s
y
stems
and
m
obil
e
net
works
.
Bou
ci
f
Amar
Bensab
er
rec
eived
his
PhD
in
computer
scie
nce
from
the
unive
rsit
y
of
Re
ne
Desca
rte
s
(Paris
V),
Franc
e
in
1998.
In
1999,
he
worked
as
a
s
ci
en
ti
st
rese
ar
ch
associa
te
a
t
the
rese
arc
h
and
ev
al
ua
ti
on
c
enter
i
n
dia
gnosti
cs
(RECD),
CHU
S
S
her
brooke
(C
anada).
Sinc
e
2000
,
he
has
be
en
pro
fessor
at
th
e
un
ive
rsit
y
of
Queb
ec
(UQ
TR),
Ca
nada
.
His
rese
a
r
ch
intere
st
is
in
wire
le
ss
net
wor
ks,
m
ult
ic
ast
pro
toc
ols,
d
istri
but
e
d
arc
hi
tectur
es,
i
n
form
at
ion
and
comm
unic
at
ion
te
chno
logi
es
and
data
m
ini
ng
.
Benamar
Kadr
i
rec
e
ive
d
his
engi
nee
r
d
egr
ee
s
in
computer
scie
nce
from
t
he
Univer
sit
y
of
Tl
emce
n
,
Alger
i
a
in
2004,
and
his
M.S.
degr
e
e
s
in
net
works
and
te
l
ec
om
m
unic
ation
s
y
st
em
s
withi
n
of
the
sa
m
e
Univer
sit
y
i
n
2007.
Mem
ber
of
STIC
l
abor
ator
y
in
th
e
Unive
rsit
y
of
T
le
m
cen
.
Now
he
is
an
assistant
profe
ss
or
in
fac
ulty
of
t
ec
hnolog
y
univ
e
rsit
y
of
T
le
m
cen,
Alger
ia.
His
rec
en
t
work
is d
ea
l
ing
with
sec
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