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v
ar
io
u
s
n
o
d
e
s
in
th
e
n
et
w
o
r
k
,
f
ac
in
g
th
e
d
if
f
er
en
t
co
n
s
tr
ain
ts
an
d
ad
ap
tin
g
to
t
h
e
to
p
o
lo
g
y
ch
a
n
g
es.
Se
v
er
a
l
s
ec
u
r
e
s
ch
e
m
e
s
o
f
d
ata
ag
g
r
e
g
atio
n
f
o
r
w
ir
ele
s
s
s
e
n
s
o
r
n
et
w
o
r
k
s
h
a
v
e
b
ee
n
p
r
o
p
o
s
ed
an
d
it p
r
o
v
id
es b
etter
s
ec
u
r
it
y
co
m
p
ar
ed
w
it
h
tr
ad
itio
n
al
ag
g
r
eg
atio
n
.
T
h
e
p
ap
er
is
o
r
g
an
ized
a
s
f
o
llo
w
s
:
Sec
tio
n
t
w
o
d
ea
ls
w
it
h
t
h
e
u
s
e
o
f
s
ec
u
r
it
y
m
ec
h
a
n
is
m
i
n
t
h
e
n
et
w
o
r
k
,
i
n
s
ec
tio
n
t
h
r
ee
w
e
d
ef
i
n
e
s
o
m
e
d
i
f
f
er
en
t
attac
k
s
i
n
w
ir
ele
s
s
s
e
n
s
o
r
n
e
t
w
o
r
k
s
,
s
ec
tio
n
f
o
u
r
w
it
h
g
iv
in
g
a
b
r
ief
s
tate
m
e
n
t
o
f
t
h
e
v
ar
io
u
s
ap
p
r
o
ac
h
es
u
s
ed
f
o
r
s
ec
u
r
e
d
ata
ag
g
r
eg
atio
n
in
w
ir
eles
s
s
e
n
s
o
r
n
et
w
o
r
k
s
an
d
f
i
n
all
y
w
e
co
n
cl
u
d
e
in
s
ec
t
io
n
f
iv
e.
2.
SE
CUR
I
T
Y
I
N
W
SN
T
o
d
esig
n
a
lo
w
p
o
w
er
w
ir
el
ess
s
en
s
o
r
n
e
t
w
o
r
k
s
,
en
er
g
y
o
p
tim
izatio
n
is
a
cr
it
ical
i
s
s
u
e,
w
ith
o
u
t
f
o
r
g
etti
n
g
th
e
u
s
e
o
f
a
s
ec
u
r
e
m
ec
h
a
n
i
s
m
to
p
r
o
tect
o
u
r
n
et
w
o
r
k
.
T
h
e
en
er
g
y
co
n
s
u
m
p
tio
n
m
a
y
n
o
t
b
e
n
eg
l
ig
ib
le
co
m
p
ar
ed
to
th
e
ac
tu
al
tr
an
s
m
it
p
o
w
er
,
to
p
er
f
o
r
m
th
e
s
en
s
i
n
g
p
h
a
s
es,
t
h
e
r
es
ea
r
ch
w
ill
b
e
ai
m
ed
at
th
e
d
ev
elo
p
m
en
t
o
f
ef
f
ic
ien
t
s
y
s
te
m
s
ab
le
to
d
ir
ec
tl
y
u
s
e
th
e
an
ten
n
a.
T
h
e
an
te
n
n
a
p
la
y
s
a
s
i
g
n
i
f
ica
n
t
r
o
le
in
t
h
e
o
v
er
all
r
eliab
ilit
y
o
f
t
h
e
n
et
w
o
r
k
,
s
in
ce
it
m
u
s
t
g
u
ar
an
tee
t
h
e
co
m
m
u
n
icat
io
n
d
esp
ite
t
h
e
d
if
f
ic
u
l
t
en
v
ir
o
n
m
e
n
t
i
n
w
h
ic
h
it
h
as
t
o
o
p
er
ate
[
4
-
6
]
,
also
th
e
ch
o
ic
e
o
f
th
e
a
n
te
n
n
a
s
to
b
e
ex
p
lo
i
ted
f
o
r
th
e
w
ir
ele
s
s
s
en
s
o
r
n
et
w
o
r
k
r
ea
lizatio
n
ca
n
s
a
v
e
o
u
r
n
e
t
w
o
r
k
f
r
o
m
th
e
d
if
f
er
en
t
attac
k
s
,
b
ec
au
s
e
t
h
e
s
ec
u
r
it
y
b
ec
o
m
es
cr
itical
in
w
i
r
eles
s
s
en
s
o
r
n
et
w
o
r
k
s
in
v
ie
w
o
f
a
lar
g
e
n
u
m
b
er
o
f
n
o
d
es.
T
h
e
s
ec
u
r
it
y
r
eq
u
ir
e
m
e
n
t
f
o
r
w
ir
eles
s
s
en
s
o
r
n
et
w
o
r
k
s
ar
e
s
i
m
i
lar
to
th
e
o
t
h
er
s
n
et
w
o
r
k
s
,
a
m
u
l
ti
-
h
o
p
co
m
m
u
n
icatio
n
is
p
r
ef
er
r
ed
,
an
d
th
e
d
ata
ca
n
b
e
s
en
t b
y
an
y
n
o
d
e
d
ep
en
d
in
g
o
n
t
h
e
to
p
o
lo
g
y
o
f
t
h
e
n
et
w
o
r
k
.
2
.
1
.
Aut
hentic
a
t
io
n
T
h
e
au
th
en
ticatio
n
i
s
a
m
ea
s
u
r
e
o
f
s
ec
u
r
it
y
[
7
]
,
ea
ch
m
e
m
b
er
o
f
th
e
n
et
w
o
r
k
is
au
t
h
e
n
tic
ated
b
ef
o
r
e
r
ev
ea
lin
g
in
f
o
r
m
a
tio
n
,
it
’
s
a
f
u
n
d
a
m
e
n
tal
m
ec
h
a
n
is
m
f
o
r
ac
ce
s
s
co
n
tr
o
l
in
th
e
n
et
wo
r
k
.
Gen
er
all
y
,
th
e
au
th
e
n
tica
tio
n
i
s
t
h
e
p
r
o
ce
s
s
o
f
v
er
i
f
y
in
g
t
h
e
id
e
n
tit
y
o
f
s
o
m
eo
n
e
o
r
s
o
m
et
h
i
n
g
.
I
f
t
h
e
a
u
th
e
n
tica
tio
n
f
ailed
,
an
attac
k
er
ca
n
j
o
in
t
h
e
n
et
wo
r
k
an
d
i
n
j
ec
t
th
e
w
r
o
n
g
d
ata
.
W
e
h
av
e
t
h
r
ee
t
y
p
e
s
o
f
cr
y
p
to
g
r
ap
h
ic
f
u
n
ctio
n
s
u
s
ed
f
o
r
au
t
h
e
n
ticatio
n
:
t
h
e
h
ash
f
u
n
c
tio
n
,
s
ec
r
et
k
e
y
f
u
n
ct
io
n
,
an
d
p
u
b
lic
k
e
y
f
u
n
ct
io
n
.
B
u
t
th
e
tr
ad
itio
n
al
au
th
e
n
tica
tio
n
b
ased
o
n
p
u
b
li
c
k
e
y
cr
y
p
to
g
r
ap
h
y
i
s
n
o
t
s
u
it
ab
le
f
o
r
w
ir
eless
s
en
s
o
r
n
et
wo
r
k
s
,
d
u
e
to
li
m
ited
b
an
d
w
id
t
h
a
n
d
co
m
m
u
n
icat
i
o
n
b
ein
g
m
o
s
t
e
x
p
en
s
iv
e
in
ter
m
s
o
f
e
n
er
g
y
.
T
h
e
m
e
s
s
ag
e
s
h
o
u
ld
n
o
t
b
e
ex
ten
d
ed
s
i
g
n
i
f
ican
t
l
y
i
n
le
n
g
t
h
w
h
e
n
w
e
ap
p
l
y
t
h
e
s
ec
u
r
it
y
s
er
v
ice.
Fo
r
th
at,
i
n
w
ir
eles
s
s
en
s
o
r
n
et
w
o
r
k
s
,
w
e
u
s
e
t
w
o
t
y
p
e
s
o
f
a
u
th
e
n
ticat
io
n
:
t
h
e
d
e
v
ice
le
v
el
a
u
t
h
e
n
ticat
io
n
m
ea
n
s
a
m
e
s
s
a
g
e
i
s
p
r
o
v
e
d
to
o
r
ig
in
ate
f
r
o
m
a
s
p
ec
if
ic
d
ev
ice,
a
n
d
th
e
g
r
o
u
p
lev
el
au
t
h
en
ticatio
n
m
es
s
a
g
e
is
p
r
o
v
ed
f
r
o
m
a
g
r
o
u
p
o
f
d
ev
ices.
2
.
2
.
Co
nfident
ia
lity
T
h
e
co
n
f
id
en
tia
lit
y
is
t
h
e
p
r
o
p
er
ty
t
h
at
i
n
f
o
r
m
atio
n
is
n
o
t
m
ad
e
av
ailab
le
to
u
n
au
t
h
o
r
ize
d
p
r
o
ce
s
s
es
[
8
]
.
I
t
p
r
o
v
id
es
p
r
iv
ac
y
in
t
h
e
n
et
w
o
r
k
,
al
l
i
n
f
o
r
m
atio
n
s
h
o
u
l
d
b
e
k
ep
t
s
ec
r
et,
th
a
t’
s
m
ea
n
,
w
e
h
a
v
e
to
en
cr
y
p
t
th
e
d
ata
w
ith
a
s
ec
r
et
k
e
y
.
2
.
3
.
F
re
s
hn
ess
T
h
e
f
r
esh
n
ess
i
s
an
i
m
p
o
r
ta
n
t
m
ea
s
u
r
e
r
eq
u
ir
ed
b
y
t
h
e
s
en
s
o
r
b
ec
au
s
e
th
is
s
er
v
ice
m
ak
e
s
ce
r
tain
th
at
th
e
tr
an
s
f
er
r
ed
d
ata
o
n
th
e
n
et
w
o
r
k
ar
e
r
ec
en
t.
Ho
w
is
t
h
at
d
o
n
e?
I
t’
s
s
i
m
p
le,
t
h
e
m
aj
o
r
co
n
ce
p
t
is
to
m
ai
n
tai
n
Evaluation Warning : The document was created with Spire.PDF for Python.
IJ
-
I
C
T
I
SS
N:
2252
-
8776
S
ec
u
r
ity
in
w
ir
eles
s
s
en
s
o
r
n
et
w
o
r
ks
(
B
a
h
a
e
A
b
id
i
)
15
a
tab
le
w
h
ich
co
n
tai
n
s
t
h
e
l
ast
v
alu
e
r
ec
eiv
ed
f
r
o
m
ev
er
y
s
e
n
d
er
,
t
h
at’
s
m
ea
n
,
w
e
h
av
e
to
i
n
cl
u
d
e
a
n
in
cr
ea
s
i
n
g
co
u
n
ter
w
i
th
e
v
er
y
m
es
s
ag
e
a
n
d
r
ej
ec
t m
es
s
a
g
e
with
o
ld
v
al
u
es.
2
.
4
.
Av
a
ila
bil
it
y
Fo
r
th
i
s
co
n
ce
p
t,
in
w
ir
eles
s
s
e
n
s
o
r
n
e
t
w
o
r
k
s
,
it
m
ea
n
s
,
t
h
at
o
u
r
n
e
t
w
o
r
k
m
u
s
t
f
ac
e
t
h
e
v
ar
io
u
s
co
n
s
tr
ain
ts
r
elate
d
to
th
e
to
p
o
lo
g
y
w
it
h
th
e
li
m
i
ted
r
eso
u
r
ce
s
,
an
d
b
e
av
ailab
le
to
p
r
o
v
id
e
s
er
v
ices
a
n
d
au
th
o
r
ize
t
h
e
co
m
m
u
n
icat
io
n
.
2
.
5
.
I
nte
g
rit
y
Fo
r
ex
a
m
p
le,
a
m
alic
io
u
s
n
o
d
e
m
a
y
ad
d
s
o
m
e
m
a
n
ip
u
lated
d
ata
w
i
th
i
n
a
p
ac
k
et.
T
h
is
n
e
w
p
ac
k
et
ca
n
t
h
en
b
e
s
en
t
to
t
h
e
o
r
ig
i
n
a
l
r
ec
eiv
er
.
So
t
h
e
i
n
teg
r
it
y
,
e
n
s
u
r
i
n
g
th
at
th
e
m
e
s
s
a
g
e
b
ei
n
g
tr
an
s
f
er
r
ed
is
n
ev
er
m
o
d
i
f
ied
b
y
a
n
y
ad
v
er
s
ar
y
w
it
h
o
u
t b
ein
g
d
etec
ted
.
3.
AT
T
ACK
S I
N
WI
R
E
L
E
S
S SE
NSO
R
NE
T
WO
RK
S
Sen
s
o
r
n
et
w
o
r
k
s
ar
e
p
ar
ticu
lar
l
y
s
u
itab
le
to
s
ev
er
al
t
y
p
es
o
f
attac
k
s
,
ea
c
h
o
n
e
w
it
h
h
er
o
wn
g
o
als.
I
n
th
is
s
ec
tio
n
,
w
e
w
il
l p
r
esen
t so
m
e
f
a
m
o
u
s
attac
k
s
i
n
w
ir
eles
s
s
en
s
o
r
n
et
w
o
r
k
s
.
3
.
1
.
S
y
bil
a
t
t
a
ck
A
r
e
m
aj
o
r
r
o
u
tin
g
attac
k
s
a
n
d
a
h
ar
m
f
u
l
th
r
ea
t
to
s
e
n
s
o
r
n
et
w
o
r
k
s
,
a
m
alicio
u
s
n
o
d
e
t
r
y
to
h
av
e
m
o
r
e
ad
v
a
n
ta
g
e
th
a
n
th
e
leg
i
t
i
m
e
n
o
d
es
[
9
]
,
[
10
]
.
A
n
ad
v
er
s
ar
y
ca
n
b
e
in
m
o
r
e
th
an
o
n
e
p
lace
at
o
n
ce
,
h
o
w
th
at?
A
m
alicio
u
s
n
o
d
e
ca
n
c
lai
m
d
if
f
er
en
t
id
en
t
ities
to
o
t
h
er
n
o
d
es
in
t
h
e
n
et
w
o
r
k
w
h
i
ch
ca
n
s
ig
n
i
f
ica
n
tl
y
r
ed
u
ce
th
e
e
f
f
ec
t
iv
e
n
es
s
o
f
f
a
u
lt
to
ler
an
t
s
c
h
e
m
es
s
u
c
h
as
d
is
tr
ib
u
ted
s
to
r
ag
e,
d
is
p
er
s
it
y
,
m
u
ltip
at
h
.
Ne
w
s
o
m
e
an
d
al.
p
r
o
p
o
s
e
to
class
if
y
t
h
e
S
y
b
il a
ttac
k
s
i
n
t
h
r
ee
d
i
m
en
s
i
o
n
s
:
T
h
e
f
ir
s
t o
n
e
co
n
s
is
t o
f
d
ir
ec
t
co
m
m
u
n
icatio
n
to
i
n
d
ir
ec
t c
o
m
m
u
n
icatio
n
:
-
Dir
ec
t: th
e
m
alicio
u
s
n
o
d
es c
o
m
m
u
n
icate
d
ir
ec
tl
y
w
it
h
th
e
le
g
iti
m
e
o
n
e.
-
I
n
d
ir
ec
t:
th
e
m
a
licio
u
s
n
o
d
es
co
m
m
u
n
icate
t
h
r
o
u
g
h
o
th
er
m
alicio
u
s
n
o
d
es
p
r
o
clai
m
i
n
g
ab
le
to
ac
h
ie
v
e
th
e
m
.
T
h
e
s
ec
o
n
d
o
n
e
co
n
s
is
t o
f
f
ab
r
icate
d
id
en
tit
y
,
s
to
len
id
en
tit
y
:
-
A
S
y
b
il
n
o
d
e
ca
n
cr
ea
te
an
id
en
tit
y
.
-
A
S
y
b
il
n
o
d
e
ca
n
s
to
l
th
e
id
e
n
tit
y
o
f
le
g
it
i
m
e
n
o
d
es.
T
h
e
th
ir
d
o
n
e
co
n
s
is
t o
f
s
i
m
u
lt
an
eit
y
:
-
T
h
e
attac
k
er
s
ca
n
i
n
v
o
l
v
e
all
i
ts
id
en
tit
y
i
n
th
e
n
et
w
o
r
k
i
n
a
s
i
m
u
lta
n
eo
u
s
w
a
y
.
-
T
h
e
attac
k
er
ca
n
p
r
esen
t j
u
s
t a
p
ar
ts
o
f
its
id
en
tit
y
o
v
er
a
g
iv
en
ti
m
e
p
er
io
d
.
3
.
2
.
Wo
rm
ho
le
a
t
t
a
cks
T
h
e
w
o
r
m
h
o
le
attac
k
s
ca
n
d
estab
ilize
o
r
d
is
ab
le
w
ir
eles
s
s
e
n
s
o
r
n
et
w
o
r
k
s
.
T
h
e
attac
k
er
r
ec
eiv
es
t
h
e
p
ac
k
ets
at
o
n
e
p
o
in
t
in
th
e
n
e
t
w
o
r
k
,
f
o
r
w
ar
d
s
t
h
e
m
th
r
o
u
g
h
a
w
ir
eles
s
lin
k
w
it
h
m
u
c
h
le
s
s
la
ten
c
y
t
h
a
n
t
h
e
n
et
w
o
r
k
li
n
k
s
,
an
d
r
ela
y
s
th
e
m
to
an
o
th
er
p
o
in
t
i
n
t
h
e
n
et
w
o
r
k
.
F
i
g
u
r
e
2
s
h
o
w
s
a
n
ex
a
m
p
le
o
f
a
w
o
r
m
h
o
l
e
attac
k
.
(
a)
(
b
)
Fig
u
r
e
2
: W
o
r
m
h
o
le
attac
k
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
2
5
2
-
8776
IJ
-
I
C
T
Vo
l.
8
,
No
.
1
,
A
p
r
il
20
1
9
:
13
–
18
16
3
.
3
.
Denia
l o
f
Serv
ice
a
t
t
a
ck
s
T
h
e
d
en
ial
o
f
s
er
v
ice
a
ttack
ca
n
r
ed
u
ce
th
e
w
ir
ele
s
s
s
e
n
s
o
r
n
et
w
o
r
k
s
a
v
ailab
ilit
y
[
1
1
]
.
I
t
is
a
n
y
o
cc
u
r
r
en
ce
t
h
at
d
i
m
in
is
h
es
o
r
eli
m
in
ate
s
a
n
et
w
o
r
k
’
s
ca
p
ac
it
y
,
it
’
s
a
s
i
m
p
le
e
v
e
n
t
t
h
at
p
r
ev
en
t
s
t
h
e
n
o
r
m
al
f
u
n
ctio
n
i
n
g
o
f
its
s
er
v
ices.
De
n
ial
o
f
s
er
v
ice
is
to
p
r
ev
e
n
t
t
h
e
n
o
r
m
al
o
p
er
atio
n
o
f
s
e
n
s
o
r
v
icti
m
b
y
s
en
d
i
n
g
a
lo
t o
f
u
n
i
m
p
o
r
tan
t
m
e
s
s
a
g
es a
n
d
d
en
y
i
n
g
ac
ce
s
s
to
o
th
er
u
s
e
r
s
.
3
.
4
.
P
hy
s
ica
l a
t
t
a
ck
s
T
h
e
w
ir
ele
s
s
s
en
s
o
r
n
et
w
o
r
k
s
ar
e
d
ep
lo
y
ed
in
h
o
s
tile
en
v
ir
o
n
m
e
n
ts
,
th
e
y
ar
e
s
u
s
ce
p
tib
le
to
m
a
n
y
t
y
p
es
o
f
p
h
y
s
ical
attac
k
s
d
u
e
t
o
th
e
u
n
s
a
f
e
a
n
d
u
n
p
r
o
tecte
d
co
m
m
u
n
icatio
n
n
et
w
o
r
k
.
T
h
e
p
h
y
s
ical
attac
k
i
s
an
u
n
at
ten
d
ed
o
p
er
atio
n
,
o
n
e
o
f
t
h
e
m
o
s
t
m
alic
io
u
s
attac
k
s
a
n
d
h
ar
m
f
u
l
at
tack
s
o
n
w
ir
eles
s
s
en
s
o
r
n
e
t
w
o
r
k
s
.
All
p
h
y
s
ical
attac
k
s
h
av
e
t
h
e
ab
i
lit
y
to
d
ea
l
e
x
tr
a
d
a
m
ag
e,
a
n
attac
k
er
w
ill
ai
m
to
r
ec
o
v
er
th
e
k
e
y
u
s
ed
f
o
r
en
cr
y
p
tio
n
.
An
a
ttack
er
ca
n
al
s
o
r
ep
r
o
g
r
am
th
e
s
e
n
s
o
r
to
d
i
s
r
u
p
t
t
h
e
n
et
w
o
r
k
a
n
d
t
h
e
ap
p
licatio
n
v
o
lu
n
tar
il
y
ca
u
s
i
n
g
th
e
ab
n
o
r
m
al
b
eh
a
v
io
r
o
f
th
e
n
o
d
e.
3
.
5
.
Da
t
a
c
o
rr
up
t
io
n a
t
t
a
ck
s
Data
co
r
r
u
p
tio
n
at
tack
is
a
t
y
p
e
o
f
at
tack
o
n
tr
an
s
it.
Data
co
r
r
u
p
tio
n
i
s
ca
u
s
ed
b
y
a
n
attac
k
o
n
d
ata
i
n
th
e
n
e
t
w
o
r
k
la
y
er
.
T
h
ese
t
y
p
e
s
o
f
attac
k
s
ar
e
a
m
o
n
g
o
th
er
s
t
o
cr
ea
te
lo
o
p
s
o
r
d
r
aw
h
i
m
a
wa
y
f
r
o
m
th
e
tr
af
f
ic,
g
en
er
ate
f
al
s
e
er
r
o
r
s
.
Ho
w
t
h
i
s
?
T
h
e
attac
k
er
ca
n
r
e
p
ea
t,
d
ela
y
o
r
m
o
d
i
f
y
t
h
e
co
n
te
n
t
o
f
m
es
s
ag
e
s
d
u
r
i
n
g
t
h
e
tr
an
s
it.
4.
DATA A
G
G
R
E
G
AT
I
O
N
SE
CURI
T
Y
4
.
1
.
L
it
er
a
t
ure
Sche
m
es
Ozd
e
m
ir
[
1
2
]
p
r
o
p
o
s
ed
Secu
r
e
R
eliab
le
Data
Ag
g
r
e
g
ati
o
n
.
T
h
e
au
th
o
r
s
in
d
icate
t
h
a
t
th
e
o
n
l
y
cr
y
p
to
g
r
ap
h
y
ca
n
n
o
t
g
u
ar
an
t
ee
s
u
f
f
icie
n
t
s
ec
u
r
it
y
f
o
r
w
i
r
eless
s
en
s
o
r
n
et
w
o
r
k
s
a
n
d
p
r
o
p
o
s
e
a
tr
u
s
ted
n
et
w
o
r
k
.
T
h
e
m
aj
o
r
id
ea
is
th
at
ea
ch
s
e
n
s
o
r
n
o
d
e
o
b
s
er
v
es
th
e
b
eh
a
v
io
r
o
f
its
n
ei
g
h
b
o
r
s
to
d
ev
elo
p
a
tr
u
s
t
lev
el.
Fo
r
th
is
,
m
o
n
ito
r
i
n
g
m
e
ch
an
i
s
m
s
ar
e
u
s
ed
to
d
etec
t
th
e
av
ail
ab
ilit
y
o
f
th
e
n
o
d
e
an
d
th
e
b
ad
b
eh
av
io
r
o
f
n
eig
h
b
o
r
s
.
Secu
r
e
R
eliab
le
D
ata
Ag
g
r
eg
atio
n
ca
n
d
etec
t
i
f
an
ag
g
r
eg
a
to
r
is
th
e
s
u
b
j
ec
t
o
f
a
d
en
ial
o
f
s
er
v
ice
attac
k
.
T
h
e
au
t
h
o
r
s
clai
m
t
h
at
th
is
ap
p
r
o
ac
h
i
n
v
o
l
v
es
a
c
h
ar
g
e
o
f
to
ler
ab
le
co
m
m
u
n
icatio
n
w
h
ile
s
ig
n
i
f
ica
n
tl
y
in
cr
ea
s
i
n
g
s
af
e
t
y
i
n
t
h
e
ag
g
r
eg
atio
n
p
r
o
ce
s
s
.
P
r
zy
d
atek
a
n
d
al.
[
1
3
]
p
r
o
p
o
s
e
d
a
s
ec
u
r
e
d
ata
ag
g
r
e
g
atio
n
,
t
h
is
i
s
o
n
e
o
f
th
e
f
ir
s
t
s
o
lu
t
io
n
p
r
o
p
o
s
ed
b
y
t
h
e
s
c
ien
t
if
ic
co
m
m
u
n
it
y
.
T
h
is
s
o
lu
tio
n
is
d
esi
g
n
ed
to
ca
lcu
late
w
it
h
t
h
e
s
ec
u
r
e
m
a
n
n
er
th
e
ag
g
r
eg
atio
n
f
u
n
ctio
n
.
So
w
ith
t
h
at,
t
h
e
u
s
e
r
ca
n
n
o
t
o
n
l
y
ac
ce
p
t
d
ata
w
it
h
h
i
g
h
p
r
o
b
ab
ilit
y
i
f
th
e
a
g
g
r
eg
ate
r
esu
lt
is
a
g
o
o
d
ap
p
r
o
x
im
a
tio
n
o
f
t
h
e
ac
tu
a
l
r
esu
lt,
al
s
o
th
e
u
s
er
ca
n
d
etec
t
th
e
attac
k
w
i
th
h
i
g
h
p
r
o
b
ab
ilit
y
a
n
d
r
ej
ec
t
th
e
r
esu
lt
i
f
it
is
o
u
ts
id
e
o
f
th
e
li
m
it.
T
h
e
au
th
o
r
s
p
r
o
p
o
s
ed
th
e
a
p
p
r
o
ac
h
’
Ag
g
r
e
g
ate
C
o
m
m
i
t
P
r
o
v
e’
in
w
h
ic
h
th
e
ag
g
r
e
g
ato
r
n
o
t
o
n
l
y
a
g
g
r
eg
ate
s
d
ata
b
u
t a
l
s
o
p
r
o
v
es t
h
at
p
er
f
o
r
m
s
t
h
i
s
ta
s
k
co
r
r
ec
tl
y
.
T
h
e
f
ir
s
t
s
tep
co
n
s
i
s
t
s
o
f
co
llectin
g
d
ata
f
r
o
m
s
e
n
s
o
r
n
o
d
e
b
y
th
e
a
g
g
r
e
g
ato
r
an
d
th
en
lo
ca
ll
y
co
m
p
u
te
s
th
e
co
r
r
esp
o
n
d
in
g
ag
g
r
eg
at
e
d
ata.
C
o
n
ce
r
n
i
n
g
t
h
e
s
ec
o
n
d
s
tep
,
t
h
e
a
g
g
r
e
g
ato
r
is
co
m
m
itted
to
p
r
o
v
id
i
n
g
a
p
r
o
o
f
en
s
u
r
in
g
t
h
at
th
e
ag
g
r
e
g
ate
i
s
w
e
ll
g
i
v
en
co
llec
ted
.
T
h
e
s
er
v
er
w
il
l
b
e
v
er
if
ie
d
th
is
e
v
id
en
ce
.
T
h
e
f
r
es
h
n
e
s
s
o
f
d
ata
is
e
n
s
u
r
ed
w
it
h
th
e
c
h
an
g
e
o
f
d
y
n
a
m
ic
k
e
y
s
,
a
f
ter
ea
ch
d
ef
i
n
ed
ti
m
e
in
ter
v
al.
An
d
t
h
e
a
u
t
h
en
ticatio
n
w
it
h
d
ata
i
n
te
g
r
it
y
,
th
e
y
ar
e
e
n
s
u
r
ed
b
y
u
s
i
n
g
th
e
m
es
s
ag
e
a
u
t
h
en
t
icatio
n
co
d
e.
T
o
p
r
o
v
id
e
ef
f
icien
c
y
a
n
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w
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C
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tell
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cia
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n
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al
[
1
4
]
p
r
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p
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ed
an
e
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f
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r
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p
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d
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t
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ld
m
e
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a
to
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o
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.
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w
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h
ea
ch
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w
m
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.
Yan
g
an
d
al
[
1
5
]
p
r
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p
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ed
a
s
ec
u
r
it
y
p
r
o
to
co
l
f
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d
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ag
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g
atio
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,
’
Sec
u
r
e
h
o
p
b
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p
Data
Ag
g
r
eg
atio
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P
r
o
to
co
l’
.
Ho
w
ca
n
t
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b
ase
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a
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t
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Evaluation Warning : The document was created with Spire.PDF for Python.
IJ
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B
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[
1
6
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p
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p
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cr
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g
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t
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m
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ter
k
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y
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f
t
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b
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s
tatio
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w
it
h
t
h
eir
r
esp
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tiv
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id
en
ti
f
ier
s
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Mo
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to
th
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c
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n
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d
e
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w
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k
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ild
r
en
w
h
ic
h
is
u
s
ed
f
o
r
en
cr
y
p
tio
n
.
4
.
2
.
L
i
m
it
s
o
f
L
it
er
a
t
ure
Sc
he
m
es
E
ac
h
s
y
s
te
m
ac
co
r
d
in
g
to
t
h
er
e
s
p
ec
if
ic
c
h
ar
ac
ter
is
tic
s
h
a
v
e
s
o
m
e
ad
v
a
n
tag
e
s
an
d
d
is
ad
v
a
n
tag
e
s
.
I
n
th
is
p
ar
ag
r
ap
h
,
w
e
w
il
l
tr
y
t
o
d
is
cu
s
s
t
h
e
li
m
it
s
o
f
t
h
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d
i
f
f
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t
s
ch
e
m
e
s
th
a
t
w
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h
av
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m
e
n
tio
n
ed
i
n
t
h
e
p
r
ev
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u
s
p
ar
ag
r
ap
h
.
C
o
n
ce
r
n
i
n
g
th
e
f
ir
s
t
ap
p
r
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ac
h
o
f
Ozd
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m
ir
,
it
p
r
o
v
id
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h
i
g
h
d
ata
c
o
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f
id
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n
tialit
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a
n
d
au
th
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n
tica
tio
n
,
b
u
t i
t’
s
v
u
ln
er
a
b
le
to
attac
k
s
a
n
d
t
h
is
is
d
u
e
t
o
th
e
k
e
y
s
ize.
T
h
e
s
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o
n
d
ap
p
r
o
ac
h
o
f
P
r
z
y
d
atek
an
d
al.
g
u
ar
an
tees
p
er
f
ec
t
r
esi
lien
ce
,
b
ec
au
s
e
t
h
e
i
n
f
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r
m
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is
n
o
t
d
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s
p
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s
ed
o
n
t
h
e
s
h
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k
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et
w
ee
n
t
w
o
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o
n
co
m
p
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m
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s
ed
n
o
d
es.
B
u
t
if
a
s
in
g
le
n
o
d
e
is
co
m
p
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m
is
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,
th
e
s
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r
it
y
o
f
th
e
w
h
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le
n
et
w
o
r
k
i
s
co
m
p
r
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m
is
ed
.
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h
e
attac
k
er
ca
n
p
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t
m
a
n
y
m
o
r
e
n
o
d
es
in
a
cr
itical
s
itu
at
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n
,
in
o
r
d
er
to
d
am
a
g
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th
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co
m
m
u
n
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n
li
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k
s
a
n
d
t
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a
m
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n
t
o
f
m
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m
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s
e
x
tr
e
m
el
y
li
m
i
ted
.
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h
e
ap
p
r
o
ac
h
o
f
C
astell
u
cia
an
d
al.
p
r
o
v
id
es
h
ig
h
s
ec
u
r
it
y
an
d
t
h
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s
is
d
u
e
to
t
h
e
u
s
e
o
f
t
h
e
ellip
t
ic
cu
r
v
e
cr
y
p
to
g
r
ap
h
y
b
u
t
it
h
as
li
m
ited
ab
ilit
y
to
p
r
o
tect
p
r
iv
ate
k
e
y
,
w
it
h
o
u
t
f
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r
g
etti
n
g
th
at
th
e
in
te
g
r
it
y
i
s
n
o
t
ch
ec
k
ed
.
I
n
Ya
n
g
an
d
al.
ap
p
r
o
ac
h
,
T
h
e
d
ata
to
b
e
en
cr
y
p
ted
is
d
iv
id
ed
i
n
to
s
ev
er
al
te
x
t
s
b
u
t
it
’
s
in
e
f
f
icie
n
t
b
ec
au
s
e
n
o
t
r
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b
u
s
t
o
p
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s
ar
e
ap
p
lied
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en
cr
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p
tio
n
,
w
h
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w
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k
e
n
s
t
h
e
alg
o
r
it
h
m
an
d
th
e
d
ata
s
ec
u
r
it
y
.
T
h
e
ad
v
an
ta
g
e
o
f
th
e
ap
p
r
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ac
h
o
f
B
o
u
d
ia
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d
al.
en
s
u
r
ed
a
d
etec
tio
n
o
f
a
n
o
m
al
y
n
o
d
es b
u
t
o
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l
y
t
h
e
f
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al
ag
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g
ate
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s
v
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f
ied
,
s
o
i
f
t
h
e
v
er
if
ica
tio
n
f
ai
ls
,
a
n
i
m
p
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tan
t
n
u
m
b
er
o
f
en
cr
y
p
te
d
p
ac
k
ets
w
ill b
e
lo
s
t.
4
.
3
.
Securit
y
An
a
ly
s
is
I
n
th
i
s
p
ar
t
o
f
o
u
r
w
o
r
k
,
w
e
w
i
ll
co
m
p
ar
e
t
h
e
d
if
f
er
en
t
s
c
h
e
m
es
i
n
ter
m
s
o
f
th
e
s
ec
u
r
it
y
p
er
f
o
r
m
a
n
ce
s
,
w
h
ic
h
m
ea
n
s
t
h
e
d
if
f
er
en
t
attr
ib
u
tes
t
h
at
we
s
tu
d
ied
in
s
ec
t
io
n
2
.
T
h
er
e
ar
e
s
o
m
e
s
c
h
e
m
e
s
w
h
ic
h
p
r
o
v
id
e
m
o
r
e
th
a
n
o
n
e
s
er
v
ice
li
k
e
t
h
e
s
c
h
e
m
e
o
f
B
o
u
d
ia
an
d
al.
w
it
h
th
at
o
f
Ozd
e
m
ir
w
h
ich
e
n
s
u
r
e:
C
o
n
f
id
en
tia
lit
y
,
I
n
te
g
r
it
y
,
A
u
th
en
ticatio
n
,
a
n
d
Av
ailab
ilit
y
.
C
o
n
ce
r
n
i
n
g
t
h
e
s
c
h
e
m
e
o
f
Yan
g
a
n
d
al.
,
h
e
p
r
o
v
id
es
C
o
n
f
id
en
tia
lit
y
,
I
n
te
g
r
it
y
,
a
n
d
A
u
th
e
n
ticatio
n
,
b
u
t
th
at
o
f
C
as
tellu
c
ia
an
d
al.
C
o
n
f
id
en
tia
lit
y
an
d
Fre
s
h
n
es
s
.
Fi
n
all
y
t
h
e
s
c
h
e
m
e
o
f
P
r
z
y
d
atek
a
n
d
al.
en
s
u
r
e
b
o
th
,
I
n
te
g
r
it
y
an
d
Au
t
h
en
ticat
io
n
.
W
e
n
o
tice
t
h
at
ea
ch
s
o
l
u
tio
n
p
r
o
v
id
es
v
ar
io
u
s
s
ec
u
r
it
y
s
er
v
ices
to
r
esi
s
t
a
g
ain
s
t
a
n
attac
k
er
;
f
o
r
e
x
a
m
p
le
th
e
s
c
h
e
m
es
o
f
P
r
zy
d
atek
a
n
d
al.
,
Yan
g
an
d
al.
ar
e
m
o
r
e
r
o
b
u
s
t
b
ec
au
s
e
t
h
e
y
ca
n
r
esi
s
t
to
th
r
ee
d
i
f
f
er
e
n
t
attac
k
s
f
r
o
m
t
h
e
attac
k
s
in
s
ec
tio
n
3
:
De
n
ial
o
f
Ser
v
ice,
S
y
b
il
at
tack
,
a
n
d
P
h
y
s
ical
attac
k
s
.
C
o
n
tr
ar
y
to
t
h
e
s
ch
e
m
e
o
f
Ozd
e
m
i
r
ca
n
r
esis
t
to
j
u
s
t
S
y
b
il
attac
k
.
B
u
t
th
at
o
f
B
o
u
d
ia
an
d
al.
w
it
h
C
aste
l
lu
c
ia
an
d
al.
ca
n
p
r
o
v
id
e
s
ec
u
r
it
y
in
f
r
o
n
t
o
f
Den
ial
o
f
Ser
v
ice
a
n
d
S
y
b
il
attac
k
.
5.
CO
NCLU
SI
O
N
Secu
r
it
y
i
n
w
ir
eles
s
s
en
s
o
r
n
et
w
o
r
k
s
is
th
e
m
o
r
e
i
m
p
o
r
tan
t
th
in
g
s
to
en
s
u
r
e
th
e
r
o
u
ti
n
g
o
f
d
ata
f
r
o
m
th
e
s
o
u
r
ce
to
th
e
d
esti
n
atio
n
,
t
h
e
n
ee
d
f
o
r
s
ec
u
r
it
y
i
n
W
SN
s
b
ec
o
m
e
s
m
o
r
e
ap
p
ar
en
t.
E
s
p
e
ciall
y
in
t
h
e
r
ec
e
n
t
y
ea
r
s
,
it
h
as
a
ttra
cted
a
lo
t
o
f
atten
tio
n
b
ec
au
s
e
it
’
s
v
er
y
c
h
allen
g
in
g
to
d
esi
g
n
s
tr
o
n
g
s
ec
u
r
it
y
a
lg
o
r
it
h
m
s
.
I
n
th
is
p
ap
er
,
w
e
h
av
e
d
escr
ib
ed
s
o
m
e
r
eq
u
ir
e
m
e
n
t
o
f
w
ir
eles
s
s
en
s
o
r
n
et
w
o
r
k
s
an
d
s
ec
u
r
it
y
p
r
o
b
lem
s
,
w
e
h
a
v
e
also
s
u
r
v
e
y
ed
s
o
m
e
p
r
o
p
o
s
ed
s
ch
e
m
es
f
o
r
s
ec
u
r
i
n
g
d
at
a
ag
g
r
e
g
atio
n
.
Fin
a
ll
y
,
w
e
h
av
e
d
i
s
cu
s
s
ed
t
h
e
li
m
ita
tio
n
a
n
d
s
ec
u
r
it
y
an
a
l
y
s
i
s
o
f
th
e
s
e
s
c
h
e
m
e
s
.
RE
F
E
R
E
NC
E
S
[1
]
S
a
m
a
y
v
e
e
r
S
in
g
h
,
A
K
Ch
a
u
h
a
n
,
S
a
n
jee
v
Ra
g
h
a
v
,
V
ik
a
s
Ty
a
g
i,
S
h
e
rish
Jo
h
ri,
He
ter
o
g
e
n
e
o
u
s
p
ro
t
o
c
o
ls
f
o
r
in
c
re
a
sin
g
t
h
e
li
fetime
o
f
wire
les
s
se
n
so
r
n
e
two
rk
s
,
Jo
u
rn
a
l
o
f
G
l
o
b
a
l
Re
se
a
rc
h
in
Co
m
p
u
ter
S
c
ie
n
c
e
,
v
o
l.
2
,
n
o
.
4
,
A
p
ril
(2
0
1
1
),
1
7
2
-
1
7
6
.
[2
]
W
e
s
a
m
A
l
m
o
b
a
id
e
e
n
,
Kh
a
led
Hu
sh
a
id
a
n
,
A
z
z
a
m
S
leit,
M
o
h
a
m
m
a
d
Qa
ta
w
n
e
h
,
A
Clu
ste
r
-
Ba
se
d
A
p
p
ro
a
c
h
f
o
r
S
u
p
p
o
rt
in
g
Qo
s
in
M
o
b
il
e
A
d
Ho
c
Ne
tw
o
rk
s,
In
tern
a
ti
o
n
a
l
Jo
u
r
n
a
l
o
f
Dig
it
a
l
Co
n
ten
t
T
e
c
h
n
o
lo
g
y
a
n
d
it
s
A
p
p
li
c
a
ti
o
n
,
Vo
l.
5
,
N
o
.
1
,
(
2
0
1
1
)
,
1
-
9.
[3
]
Ed
u
a
rd
o
F
.
Na
k
a
m
u
ra
,
A
l
e
jan
d
ro
C.
F
re
ry
,
A
N
T
O
NIO
A
.
,
In
f
o
rm
a
ti
o
n
F
u
si
o
n
f
o
r
W
irele
ss
S
e
n
so
r
Ne
tw
o
rk
s:
M
e
th
o
d
s,
M
o
d
e
ls,
a
n
d
C
las
sif
ica
t
io
n
s,
A
CM
Co
m
p
u
ti
n
g
S
u
rv
e
y
s,
V
o
l
.
3
9
,
N
o
.
3
,
A
rti
c
le 9
,
A
u
g
u
st
2
0
0
7
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
2
5
2
-
8776
IJ
-
I
C
T
Vo
l.
8
,
No
.
1
,
A
p
r
il
20
1
9
:
13
–
18
18
[4
]
S
.
K.
Ja
y
a
w
e
e
ra
,
"
V
irt
u
a
l
M
I
M
O
-
b
a
se
d
c
o
o
p
e
ra
ti
v
e
c
o
m
m
u
n
ica
ti
o
n
f
o
r
e
n
e
rg
y
-
c
o
n
stra
in
e
d
w
irele
ss
se
n
so
r
n
e
tw
o
rk
s,"
IEE
E
T
ra
n
sa
c
ti
o
n
s o
n
W
irele
ss
Co
m
m
u
n
ica
ti
o
n
s,
v
o
l
.
5
,
n
.
5
,
p
p
.
9
8
4
-
9
8
9
,
2
0
0
6
;
[5
]
P
.
Ro
c
c
a
a
n
d
A
.
F
.
M
o
ra
b
it
o
,
“
Op
ti
m
a
l
s
y
n
th
e
sis
o
f
re
c
o
n
f
i
g
u
ra
b
le
p
lan
a
r
a
rra
y
s
w
it
h
sim
p
li
f
ied
a
rc
h
it
e
c
tu
re
s
f
o
r
m
o
n
o
p
u
lse
ra
d
a
r
a
p
p
li
c
a
ti
o
n
s,”
I
EE
E
T
ra
n
s.
A
n
ten
n
a
s
P
ro
p
a
g
.
,
v
o
l.
6
3
,
n
.
3
,
p
p
.
1
0
4
8
-
1
0
5
8
,
2
0
1
5
.
[6
]
C.
M
.
Kru
e
si,
R.
J.
V
y
a
s,
a
n
d
M
.
M
.
T
e
n
tze
ris,
"
De
sig
n
a
n
d
De
v
e
lo
p
m
e
n
t
o
f
a
No
v
e
l
3
-
D
C
u
b
ic
A
n
ten
n
a
f
o
r
W
irele
ss
S
e
n
so
r
Ne
t
w
o
rk
s
(
W
S
Ns
)
a
n
d
RF
ID
A
p
p
li
c
a
ti
o
n
s,"
in
:
IEE
E
T
ra
n
sa
c
ti
o
n
s
o
n
A
n
ten
n
a
s
a
n
d
P
r
o
p
a
g
a
ti
o
n
,
v
o
l.
5
7
,
n
.
1
0
,
p
p
.
3
2
9
3
-
3
2
9
9
,
2
0
0
9
.
[7
]
S
h
a
n
tala
P
a
ti
l,
Dr
V
i
j
a
y
a
Ku
m
a
r
B
P
,
S
o
n
a
li
S
i
n
g
h
a
,
Ra
sh
iq
u
e
Ja
m
il
,
A
S
u
rv
e
y
o
n
A
u
th
e
n
ti
c
a
ti
o
n
T
e
c
h
n
iq
u
e
s
f
o
r
W
irele
ss
S
e
n
so
r
Ne
t
w
o
rk
s,
In
tern
a
ti
o
n
a
l
Jo
u
rn
a
l
o
f
A
p
p
li
e
d
E
n
g
in
e
e
rin
g
Re
se
a
rc
h
,
V
o
l
.
7
,
No
.
1
1
,
2
0
1
2
.
[8
]
B.
V
e
e
ra
m
a
ll
u
,
S
.
S
a
h
it
y
a
,
Ch
.
Lav
a
n
y
a
S
u
sa
n
n
a
,
Co
n
f
id
e
n
ti
a
li
ty
in
W
i
re
les
s
S
e
n
so
r
Ne
t
w
o
rk
s,
In
ter
n
a
ti
o
n
a
l
Jo
u
rn
a
l
o
f
S
o
f
t
Co
m
p
u
ti
n
g
a
n
d
En
g
in
e
e
ri
n
g
,
Vo
l.
2
,
Iss
u
e
-
6
,
Ja
n
u
a
ry
2
0
1
3
.
[9
]
Ne
w
so
m
e
,
J.,
S
h
i,
E.
,
S
o
n
g
,
D,
a
n
d
P
e
rrig
,
A
,
T
h
e
S
y
b
il
A
tt
a
c
k
in
S
e
n
so
r
Ne
tw
o
rk
s:
A
n
a
l
y
sis a
n
d
De
f
e
n
se
s,
P
ro
c
.
o
f
th
e
th
ir
d
i
n
tern
a
ti
o
n
a
l
sy
m
p
o
s
iu
m
o
n
In
f
o
rm
a
ti
o
n
p
r
o
c
e
ss
in
g
in
se
n
so
r
n
e
tw
o
rk
s,
2
0
0
4
,
2
5
9
-
2
6
8
.
[1
0
]
Do
u
c
e
u
r,
J.T
h
e
S
y
b
il
A
tt
a
c
k
,
1
st I
n
tern
a
ti
o
n
a
l
W
o
rk
sh
o
p
o
n
P
e
e
r
-
to
-
P
e
e
r
S
y
ste
m
s 2
0
0
2
.
[1
1
]
Al
-
S
a
k
ib
Kh
a
n
P
a
th
a
n
,
Hy
u
n
g
-
W
o
o
L
e
e
,
Ch
o
o
n
g
S
e
o
n
Ho
n
g
,
S
e
c
u
rit
y
in
W
irele
s
s
S
e
n
so
r
Ne
t
w
o
rk
s:
Iss
u
e
s
a
n
d
Ch
a
ll
e
n
g
e
s,
ICA
C
T
2
0
0
6
,
F
e
b
2
0
0
6
,
2
0
-
2
2
.
[1
2
]
S
.
Oz
d
e
m
ir,
H.Ich
a
k
a
wa
e
t
a
l.
S
e
c
u
re
a
n
d
Re
li
a
b
le
Da
ta
A
g
g
re
g
a
ti
o
n
f
o
r
W
irele
ss
S
e
n
so
r
Ne
tw
o
rk
s,
(Ed
s.),
L
NCS
4
8
3
6
,
2
0
0
7
,
1
0
2
–
1
0
9
.
[1
3
]
B.
P
rz
y
d
a
te
k
,
D.X
.
S
o
n
g
,
A
.
P
e
rrig
,
S
e
c
u
re
In
f
o
rm
a
ti
o
n
A
g
g
re
g
a
ti
o
n
in
S
e
n
so
r
Ne
tw
o
rk
s,
Co
n
f
e
re
n
c
e
On
Em
b
e
d
d
e
d
Ne
tw
o
rk
e
d
S
e
n
so
r
S
y
ste
m
s,
2
0
0
3
,
2
5
5
-
2
6
5
.
[1
4
]
C.
Ca
ste
ll
u
c
c
ia,
E.
M
y
k
letu
n
,
G
.
Tsu
d
ik
,
Ef
f
icie
n
t
Ag
g
re
g
a
ti
o
n
o
f
En
c
ry
p
ted
Da
ta
in
W
irele
ss
S
e
n
so
r
Ne
tw
o
rk
s,
M
o
b
iQ
u
it
o
u
s,
2
0
0
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