I
nte
rna
t
io
na
l J
o
urna
l o
f
E
lect
rica
l a
nd
Co
m
p
ute
r
E
ng
in
ee
ring
(
I
J
E
CE
)
Vo
l.
8
,
No
.
1
,
Feb
r
u
ar
y
201
8
,
p
p
.
6
0
5
~
6
1
0
I
SS
N:
2088
-
8708
,
DOI
: 1
0
.
1
1
5
9
1
/
i
j
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e
.
v
8
i
1
.
p
p
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0
5
-
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1
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605
J
o
ur
na
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ep
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e
:
h
ttp
:
//ia
e
s
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r
e
.
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m/
jo
u
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ls
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d
ex
.
p
h
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/
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JE
C
E
Cry
ptana
ly
sis
on
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cy
-
a
w
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re Tw
o
-
f
a
ctor
Authe
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ticatio
n
Protoco
l
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o
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Wire
less
Senso
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tw
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rk
s
Yo
un
s
u
ng
Cho
i
De
p
a
rtme
n
t
o
f
C
y
b
e
r
S
e
c
u
rit
y
,
H
o
w
o
n
Un
iv
e
rsity
,
6
4
,
3
-
g
il
,
G
u
n
sa
n
,
Je
o
ll
a
b
u
k
-
d
o
,
5
4
0
5
8
,
Re
p
u
b
l
ic o
f
Ko
re
a
Art
icle
I
nfo
AB
ST
RAC
T
A
r
ticle
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to
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y:
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ec
eiv
ed
J
u
n
28
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2
0
1
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R
ev
i
s
ed
No
v
17
,
2
0
1
7
A
cc
ep
ted
Dec
1
,
2
0
1
7
Da
s
f
irst
p
ro
p
o
se
d
tw
o
-
f
a
c
to
r
a
u
th
e
n
ti
c
a
ti
o
n
c
o
m
b
in
in
g
t
h
e
sm
a
rt
c
a
rd
a
n
d
p
a
ss
w
o
rd
to
re
so
lv
e
th
e
se
c
u
rit
y
p
ro
b
lem
s
o
f
w
ir
e
les
s
se
n
so
r
n
e
tw
o
rk
s
(W
S
Ns
).
Af
ter
th
a
t,
v
a
rio
u
s
re
se
a
rc
h
e
rs
stu
d
ied
tw
o
-
f
a
c
to
r
a
u
th
e
n
ti
c
a
ti
o
n
su
it
a
b
le
f
o
r
W
S
Ns
.
In
u
se
r
a
u
th
e
n
ti
c
a
t
io
n
p
ro
to
c
o
ls
b
a
se
d
o
n
t
h
e
s
y
m
m
e
tri
c
k
e
y
a
p
p
ro
a
c
h
,
a
n
u
m
b
e
r
o
f
e
ll
ip
ti
c
c
u
rv
e
c
ry
p
to
g
ra
p
h
y
(E
CC)
-
b
a
se
d
a
u
th
e
n
ti
c
a
ti
o
n
p
ro
t
o
c
o
ls
h
a
v
e
b
e
e
n
p
ro
p
o
se
d
.
T
o
re
so
lv
e
th
e
se
c
u
rit
y
a
n
d
e
ff
ici
e
n
c
y
p
ro
b
lem
s
o
f
ECC
-
b
a
se
d
tw
o
-
f
a
c
to
r
a
u
th
e
n
ti
c
a
ti
o
n
p
r
o
to
c
o
ls,
Jia
n
g
e
t
a
l
.
p
r
o
p
o
se
d
a
p
riv
a
c
y
-
a
wa
re
tw
o
-
f
a
c
to
r
a
u
th
e
n
ti
c
a
ti
o
n
p
ro
to
c
o
l
b
a
se
d
o
n
ECC
f
o
r
W
S
Ns
.
Ho
w
e
v
e
r,
th
is
p
a
p
e
r
p
e
rf
o
rm
s
a
v
u
ln
e
ra
b
il
it
y
a
n
a
ly
sis
o
n
Jia
n
g
e
t
a
l
.
’s
a
u
t
h
e
n
ti
c
a
ti
o
n
p
r
o
to
c
o
l
a
n
d
sh
o
w
s
th
a
t
it
h
a
s
se
c
u
rit
y
p
ro
b
lem
s,
su
c
h
a
s
a
lac
k
o
f
m
u
tu
a
l
a
u
th
e
n
ti
c
a
ti
o
n
,
a
risk
o
f
S
ID
m
o
d
if
ica
ti
o
n
a
n
d
Do
S
a
tt
a
c
k
s,
a
lac
k
o
f
se
n
so
r
a
n
o
n
y
m
it
y
,
a
n
d
we
a
k
ID an
o
n
y
m
it
y
.
K
ey
w
o
r
d
:
C
r
y
p
tan
a
l
y
s
is
Vu
l
n
er
ab
ilit
y
a
n
al
y
s
i
s
W
ir
eless
s
en
s
o
r
n
et
w
o
r
k
s
Co
p
y
rig
h
t
©
2
0
1
8
In
stit
u
te o
f
A
d
v
a
n
c
e
d
E
n
g
i
n
e
e
rin
g
a
n
d
S
c
ien
c
e
.
All
rig
h
ts
re
se
rv
e
d
.
C
o
r
r
e
s
p
o
nd
ing
A
uth
o
r
:
Yo
u
n
s
u
n
g
C
h
o
i
,
Dep
ar
t
m
en
t o
f
C
y
b
er
Sec
u
r
it
y
,
Ho
w
o
n
U
n
i
v
er
s
it
y
,
6
4
,
3
-
g
il,
Gu
n
s
a
n
,
J
eo
llab
u
k
-
d
o
,
5
4
0
5
8
,
R
ep
u
b
lic
o
f
Ko
r
ea
.
E
m
ail: l
s
n
t
l@
cc
u
.
ed
u
.
t
w
1.
I
NT
RO
D
UCT
I
O
N
W
ir
eless
s
e
n
s
o
r
n
et
w
o
r
k
s
(
W
SNs
)
ca
n
b
e
u
s
ed
to
p
er
f
o
r
m
r
ea
l
-
ti
m
e
m
o
n
ito
r
in
g
i
n
v
ar
io
u
s
en
v
ir
o
n
m
e
n
t
s
.
Net
w
o
r
k
ed
s
e
n
s
o
r
s
ca
n
ea
s
i
l
y
b
e
s
ta
tio
n
ed
i
n
v
ar
io
u
s
e
n
v
ir
o
n
m
e
n
t
s
(
e.
g
.
,
f
o
r
f
o
r
est
d
etec
tio
n
an
d
h
ar
m
f
u
l
g
as
m
o
n
ito
r
in
g
)
[
1
]
.
Gen
er
all
y
,
th
e
g
ate
w
a
y
n
o
d
e
h
as
s
u
f
f
icie
n
t
p
o
w
er
an
d
ca
p
ac
it
y
,
w
h
i
le
th
e
w
ir
ele
s
s
s
e
n
s
o
r
s
lac
k
s
u
f
f
ic
i
en
t
C
P
U
p
o
w
er
,
m
e
m
o
r
y
,
c
o
m
p
u
tatio
n
al
ca
p
ab
ilit
y
,
an
d
s
to
r
ag
e
ca
p
ac
it
y
.
T
h
er
ef
o
r
e,
g
en
er
all
y
,
a
u
s
er
n
e
ed
s
to
co
n
n
ec
t
w
it
h
s
e
n
s
o
r
s
d
i
r
ec
tl
y
to
ac
q
u
ir
e
th
e
s
en
s
ed
d
a
ta
[
2
]
.
C
o
n
s
id
er
in
g
th
e
r
eso
u
r
ce
s
o
f
s
en
s
o
r
s
,
th
e
u
s
er
a
u
t
h
en
t
icatio
n
p
r
o
to
co
l
f
o
r
W
SNs
s
h
o
u
ld
b
e
ef
f
icien
t
i
n
ter
m
s
o
f
co
m
p
u
tatio
n
co
s
t.
T
h
er
ef
o
r
e,
t
h
e
p
o
w
er
co
n
s
u
m
p
tio
n
o
f
t
h
e
cr
y
p
to
g
r
ap
h
ic
al
g
o
r
it
h
m
s
u
s
ed
s
h
o
u
ld
b
e
r
ed
u
ce
d
w
h
ile
ad
d
r
ess
in
g
t
h
e
s
ec
u
r
i
t
y
r
eq
u
ir
e
m
en
ts
.
T
o
r
e
s
o
lv
e
th
e
d
i
f
f
icu
l
t
y
o
f
d
es
ig
n
i
n
g
a
s
ec
u
r
e
t
w
o
-
f
ac
to
r
au
th
e
n
tica
tio
n
p
r
o
to
co
l,
a
p
r
iv
ac
y
-
a
w
ar
e
t
w
o
-
f
ac
to
r
p
r
o
to
c
o
l
th
at
ad
d
r
ess
ed
v
ar
io
u
s
s
ec
u
r
it
y
p
r
o
b
lem
s
w
it
h
th
e
r
eso
u
r
ce
s
e
n
s
o
r
s
a
n
d
s
en
s
e
d
d
ata
w
a
s
d
esi
g
n
ed
in
[
3
]
.
I
n
2
0
0
9
,
Das
f
ir
s
t
ap
p
lied
t
w
o
-
f
ac
to
r
au
t
h
e
n
ticatio
n
co
m
b
i
n
i
n
g
t
h
e
p
as
s
w
o
r
d
a
n
d
s
m
ar
t
ca
r
d
to
s
o
lv
e
th
e
s
ec
u
r
it
y
p
r
o
b
lem
s
o
f
W
S
N
s
.
I
t
p
r
esen
ted
a
n
e
w
d
ir
ec
tio
n
f
o
r
u
s
er
a
u
t
h
en
t
icatio
n
f
o
r
W
SNs
[
4
]
.
Ho
w
e
v
er
,
th
e
au
th
e
n
ticatio
n
p
r
o
to
co
l
Das
p
r
o
p
o
s
ed
d
o
es
n
o
t
p
r
o
v
id
e
u
s
er
an
o
n
y
m
it
y
,
s
e
s
s
io
n
k
e
y
n
e
g
o
tiatio
n
,
o
r
m
u
tu
al
a
u
t
h
e
n
ticatio
n
.
I
n
ad
d
itio
n
,
it
is
v
u
ln
er
ab
le
to
s
e
v
er
al
attac
k
s
,
s
u
c
h
as
g
ate
w
a
y
n
o
d
e
b
y
p
as
s
i
n
g
,
o
f
f
l
in
e
p
ass
w
o
r
d
g
u
e
s
s
i
n
g
,
s
e
n
s
o
r
n
o
d
e
ca
p
tu
r
e,
an
d
d
en
ial
-
of
-
s
er
v
i
ce
attac
k
s
.
T
h
u
s
,
v
ar
io
u
s
i
m
p
r
o
v
ed
au
t
h
en
t
icatio
n
p
r
o
to
co
ls
f
o
r
W
SN
s
w
er
e
p
r
o
p
o
s
ed
to
r
eso
lv
e
th
e
v
ar
io
u
s
s
ec
u
r
it
y
p
r
o
b
lem
s
[
5
-
7
]
.
I
n
ad
d
itio
n
,
in
u
s
er
au
th
e
n
tica
tio
n
p
r
o
to
co
ls
b
ase
d
o
n
th
e
s
y
m
m
e
tr
ic
k
e
y
ap
p
r
o
ac
h
,
a
n
u
m
b
er
o
f
ellip
tic
c
u
r
v
e
cr
y
p
to
g
r
ap
h
y
(
E
C
C
)
-
b
ased
a
u
th
e
n
ticat
io
n
p
r
o
to
co
ls
h
av
e
b
ee
n
p
r
o
p
o
s
ed
.
Yeh
et
a
l
.
f
o
u
n
d
th
at
t
h
e
p
r
o
to
co
l
o
f
C
h
en
et
a
l
.
d
o
es
n
o
t
p
r
o
v
id
e
a
u
s
er
p
as
s
w
o
r
d
u
p
d
ati
n
g
m
ec
h
a
n
is
m
a
n
d
is
v
u
l
n
er
ab
le
to
i
n
s
id
er
atta
ck
s
.
T
h
u
s
,
Ye
h
et
al.
p
r
o
p
o
s
ed
an
E
C
C
-
b
ased
t
w
o
-
f
ac
to
r
au
th
e
n
ticat
io
n
p
r
o
to
co
l.
Ho
w
e
v
er
,
i
n
Yeh
et
a
l
.
’
s
s
c
h
e
m
e,
t
h
e
u
s
er
a
n
d
s
en
s
o
r
ca
n
n
o
t
m
u
t
u
all
y
au
t
h
e
n
ticate
ea
c
h
o
th
er
[
8
]
.
T
o
s
o
lv
e
th
e
p
r
o
b
le
m
s
o
f
Ye
h
et
a
l
.
’
s
s
c
h
e
m
e,
Sh
i
et
a
l
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
0
8
8
-
8708
I
n
t J
E
lec
&
C
o
m
p
E
n
g
,
Vo
l.
8
,
No
.
1
,
Feb
r
u
ar
y
201
8
:
6
0
5
–
6
1
0
606
p
r
o
p
o
s
ed
an
im
p
r
o
v
ed
E
C
C
-
b
ased
au
th
e
n
ticatio
n
p
r
o
to
co
l.
C
o
m
p
ar
ed
w
ith
t
h
e
p
r
o
to
co
l
o
f
Yeh
et
a
l
.
,
th
e
p
r
o
to
co
l o
f
Sh
i
et
a
l
.
p
r
o
v
id
es
m
o
r
e
d
iv
er
s
e
s
ec
u
r
it
y
f
ea
t
u
r
es
an
d
p
er
f
o
r
m
s
b
etter
in
ter
m
s
o
f
co
m
p
u
tatio
n
a
n
d
co
m
m
u
n
icatio
n
[
9
]
.
Ho
w
e
v
er
,
in
2
0
1
4
,
C
h
o
i
et
a
l
.
r
ev
ea
led
th
at
th
e
au
th
e
n
ticatio
n
p
r
o
to
co
l
o
f
S
h
i
et
a
l
.
i
s
v
u
l
n
er
ab
le
to
u
n
k
n
o
w
n
k
e
y
s
h
ar
e,
s
to
len
s
m
ar
t
ca
r
d
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s
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o
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n
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e
s
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r
it
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ea
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n
e
s
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e
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al
s
o
p
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ed
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en
h
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ce
d
a
u
th
e
n
ticatio
n
p
r
o
to
co
l
[
1
]
.
Un
f
o
r
tu
n
atel
y
,
t
h
e
p
r
o
to
co
l
o
f
C
h
o
i
et
a
l
.
s
ti
ll
ca
n
n
o
t
ac
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e
a
n
o
n
y
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i
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d
u
n
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ac
ea
b
i
lit
y
.
T
o
s
o
lv
e
th
e
v
ar
io
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s
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ec
u
r
it
y
w
ea
k
n
ess
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o
f
E
C
C
-
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ased
t
w
o
-
f
ac
to
r
au
t
h
en
ticatio
n
p
r
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to
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ls
,
J
ian
g
et
a
l
.
p
r
o
p
o
s
ed
a
p
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ac
y
-
a
w
ar
e
t
w
o
-
f
ac
to
r
au
th
e
n
tica
tio
n
p
r
o
to
co
l
b
ased
o
n
E
C
C
f
o
r
W
SNs
.
J
ian
g
et
a
l
.
clai
m
th
eir
p
r
o
to
co
l
ac
h
ie
v
e
s
v
ar
io
u
s
s
ec
u
r
it
y
an
d
u
s
ab
ilit
y
f
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tu
r
es
n
ec
e
s
s
ar
y
f
o
r
r
ea
l
-
li
f
e
ap
p
licatio
n
e
n
v
ir
o
n
m
e
n
t
s
[
2
]
.
Ho
w
e
v
er
,
th
is
p
ap
er
an
al
y
ze
s
J
ian
g
et
a
l
.
’
s
p
r
o
to
co
l
an
d
s
h
o
w
s
t
h
at
it
h
a
s
s
ec
u
r
it
y
v
u
ln
er
a
b
ilit
ies,
s
u
c
h
as
a
lac
k
o
f
m
u
t
u
al
au
t
h
e
n
ticatio
n
,
a
r
is
k
o
f
SID
m
o
d
i
f
icatio
n
an
d
Do
S
attac
k
s
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a
lac
k
o
f
s
e
n
s
o
r
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o
n
y
m
i
t
y
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a
n
d
w
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k
I
D
an
o
n
y
m
it
y
.
T
h
e
r
e
m
ai
n
d
er
o
f
t
h
i
s
p
ap
er
is
o
r
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an
ized
a
s
f
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llo
w
s
.
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n
2
ex
p
lain
s
J
ian
g
et
a
l
.
’
s
p
r
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ac
y
-
a
w
ar
e
t
w
o
-
f
ac
to
r
au
th
e
n
tica
tio
n
p
r
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to
co
l
b
ased
o
n
E
C
C
f
o
r
W
SNs
.
Sectio
n
3
s
h
o
w
s
th
a
t
J
ian
g
et
a
l
.
’
s
a
u
t
h
en
ticatio
n
p
r
o
to
co
l
h
as t
h
e
s
ec
u
r
it
y
v
u
ln
er
ab
ilit
ies
n
o
ted
ab
o
v
e.
Sectio
n
4
co
n
clu
d
es th
is
p
ap
er
.
2.
RE
VI
E
W
O
F
J
I
AN
G
E
T
A
L
.
’
T
WO
-
F
ACTOR
A
UT
H
E
NT
I
CA
T
I
O
N
P
RO
T
O
CO
L
J
ian
g
et
a
l
.
’
s
p
r
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to
co
l
is
b
as
ed
o
n
E
C
C
f
o
r
W
SN
s
.
I
t
co
n
s
i
s
ts
o
f
f
o
u
r
p
h
a
s
es:
r
eg
i
s
tr
a
tio
n
,
lo
g
i
n
,
au
th
e
n
tica
tio
n
,
an
d
p
ass
w
o
r
d
ch
an
g
e.
T
ab
le
1
s
h
o
w
s
t
h
e
n
o
tatio
n
s
u
s
ed
in
t
h
is
p
ap
er
[
2
]
.
T
h
e
E
C
C
p
r
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v
id
es
b
etter
ef
f
icien
c
y
t
h
a
n
R
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t
Sh
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ir
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A
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m
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tr
e
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it
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m
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ize.
Sp
ec
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C
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n
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S
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tr
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t
h
[
1
0
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,
[
1
1
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.
T
h
e
ellip
tic
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u
r
v
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e
q
u
atio
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is
d
ef
i
n
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i
n
t
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e
f
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m
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E
p
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a,
b
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3
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m
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d
4a
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b
2
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0
(
m
o
d
p
).
T
ab
le
1
.
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tatio
n
s
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a
t
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O
R
2.
1
.
Reg
is
t
ra
t
io
n
P
ha
s
e
P
r
io
r
to
s
tar
tin
g
J
ian
g
et
a
l
.
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s
au
th
e
n
tica
tio
n
p
r
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to
co
l,
GW
N
s
elec
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th
e
f
in
i
te
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g
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ated
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ield
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ip
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r
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h
en
,
G
WN
r
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d
o
m
l
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o
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n
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m
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r
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ate
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tes
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r
r
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li
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d
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ate
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ter
s
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et
k
e
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d
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S
.
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h
en
,
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W
N
s
to
r
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x
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d
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r
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ce
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te
m
p
ar
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eter
s
{
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(
F
p
)
,
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P
,
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}.
Fig
u
r
e
1
s
h
o
w
s
th
e
u
s
e
r
r
eg
is
tr
atio
n
p
r
o
ce
s
s
.
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t
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m
ed
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a
t
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c
o
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m
u
n
icatio
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c
h
a
n
n
el
b
et
w
e
en
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e
p
ar
ticip
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t
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ec
u
r
e.
(
R
1
-
U)
W
h
e
n
a
u
s
er
U
i
r
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te
r
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,
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i
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i
s
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o
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p
ass
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r
d
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a
n
d
r
an
d
o
m
l
y
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o
o
s
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n
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m
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er
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i
.
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h
en
,
U
i
ca
lcu
late
s
HP
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i
=
H
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P
W
i
|
|
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r
i
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d
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en
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s
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HP
W
i
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to
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.
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R
2
-
U)
Af
ter
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ec
ei
v
i
n
g
t
h
e
r
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q
u
est,
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WN
c
h
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k
s
t
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it
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m
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r
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ir
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tit
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o
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h
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m
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alr
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d
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r
eg
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ter
ed
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n
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h
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if
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tio
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tab
le.
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h
en
,
G
WN
co
m
p
u
te
s
TC
i
=
H
(
K
GWN
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U
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D
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a
n
d
P
TC
i
=
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i
⊕
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.
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W
N
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to
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(
ID
i
,
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i
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in
th
e
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icat
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ll
y
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e
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th
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d
,
w
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m
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r
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{
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(
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y
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TE
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,
P
TC
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}
to
U
i
.
(
R
3
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U)
U
i
co
m
p
u
te
s
HP
W
’
i
=
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h
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I
D
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W
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||
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mo
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m
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s
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p
ass
w
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r
d
g
u
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in
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k
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[
1
2
]
.
T
h
en
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U
i
h
o
ar
d
s
r
i
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d
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s
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S
j
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r
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it
s
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it
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S
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D
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to
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s
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n
g
a
s
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r
e
ch
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(
R
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G
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co
m
p
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G
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tial
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h
en
,
G
W
N
r
ep
lie
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j
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it
h
{
TC
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Evaluation Warning : The document was created with Spire.PDF for Python.
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ter
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u
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1
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in
p
u
ts
ID
i
,
PW
i
.
(
L
2
)
T
h
e
s
m
ar
t c
ar
d
ca
lcu
lates
HP
W
’
i
=
H
(
h
(
I
D
i
||
P
W
i
|| r
i
)
mo
d
m
)
.
I
f
t
h
e
co
m
p
ar
is
o
n
HP
W
*
i
?
=
HP
W
’
i
is
n
o
t th
e
s
a
m
e,
th
e
ca
r
d
r
ej
ec
ts
th
e
r
eq
u
est.
O
th
er
w
i
s
e,
it c
o
n
t
i
n
u
e
s
to
co
m
p
u
te
TC
i
=
P
T
C
i
⊕
H(
P
W
i
||
I
D
i
|| r
i
)
.
2.
3
.
Aut
hentic
a
t
io
n P
ha
s
e
Su
b
s
eq
u
e
n
t
to
th
e
lo
g
in
p
h
ase,
th
e
co
m
m
u
n
icati
n
g
ag
e
n
ts
(
U
i
,
S
j
,
an
d
GWN
)
m
u
tu
all
y
a
u
th
e
n
tica
te
ea
ch
o
th
er
an
d
estab
li
s
h
a
s
e
s
s
io
n
k
e
y
a
s
f
o
llo
w
s
.
Fi
g
u
r
e
2
d
ep
icts
th
ese
p
h
ases
.
(
A
1
)
U
i
s
elec
ts
a
r
a
n
d
o
m
n
u
m
b
er
a
∈
Z
*
p
-
1
an
d
ca
lc
u
late
s
A
i
=
aP
,
D
i
=
ay
=
a
xP
,
DI
D
i
=
ID
i
⊕
H(
A
i
||
D
i
)
,
an
d
C
i
=
H
(
I
D
i
||
TS
1
||
D
i
||
A
i
||
TC
i
)
,
w
h
er
e
TS
1
is
th
e
ti
m
esta
m
p
o
f
t
h
e
c
u
r
r
en
t
co
m
p
u
ti
n
g
p
latf
o
r
m
.
Fin
all
y
,
U
i
f
o
r
w
ar
d
s
{
DI
D
i
, A
i
,
TS
1
, C
i
}
to
GW
N
.
(
A
2
)
On
r
ec
eiv
i
n
g
{
DI
D
i
,
A
i
,
TS
1
,
C
i
},
GW
N
v
er
i
f
ie
s
th
e
f
r
es
h
n
e
s
s
o
f
TS
1
.
I
f
TS
1
is
n
o
t
f
r
es
h
,
G
W
N
r
e
f
u
s
es
th
e
r
eq
u
e
s
t;
o
th
er
w
i
s
e,
G
WN
ca
lcu
late
s
D
i
=
xA
=
xa
P
,
ID
i
=
DI
D
i
⊕
H(
A
i
||
D
i
)
,
a
n
d
TC
i
=
H
(
K
GWN
-
U
||
I
D
i
||
TE
i
)
an
d
c
h
ec
k
s
w
h
e
t
h
er
H(
I
D
i
||
TS
1
||
D
i
||
A
i
||
T
C
i
)
i
s
t
h
e
s
a
m
e
as
C
i
.
I
f
t
h
ese
t
w
o
v
alu
e
s
ar
e
n
o
t
t
h
e
s
a
m
e,
G
WN
r
ef
u
s
e
s
th
e
r
eq
u
e
s
t;
o
t
h
er
w
is
e,
G
WN
ch
o
o
s
es
a
s
e
n
s
o
r
S
j
an
d
ca
l
cu
lates
TC
j
=
H(
K
GWN
-
S
||
S
I
D
j
)
,
DI
D
GWN
=I
D
i
⊕
H(
DI
D
i
||
TC
j
||
TS
5
)
,
an
d
C
GWN
=
H
(
I
D
i
||
TC
j
||
A
i
||
TS
2
)
,
w
h
er
e
TS
2
is
t
h
e
ti
m
e
s
ta
m
p
o
f
th
e
cu
r
r
en
t
co
m
p
u
tin
g
p
latf
o
r
m
.
F
i
n
all
y
,
G
WN
s
e
n
d
s
{
TS
2
,
DI
D
i
,
DI
D
GWN
,
C
GWN
,
A
i
}
to
th
e
S
j
.
(
A
3
)
O
n
r
ec
eiv
in
g
{
TS
2
,
DI
D
i
,
DI
D
GWN
,
C
GWN
,
A
i
},
S
j
ch
ec
k
s
t
h
e
f
r
es
h
n
ess
o
f
TS
2
.
I
f
TS
2
i
s
i
n
v
alid
,
S
j
r
ej
ec
ts
th
e
r
eq
u
est;
o
th
er
w
i
s
e,
S
j
co
m
p
u
te
s
ID
i
=
DI
D
GWN
⊕
H(
DI
D
i
||
TC
j
||
TS
2
)
an
d
ch
ec
k
s
w
h
e
th
er
H(
I
D
i
|
|
T
C
j
||A
i
|
|
T
S
2
)
an
d
C
GWN
ar
e
eq
u
al.
I
f
t
h
e
s
e
t
w
o
v
alu
e
s
ar
e
u
n
eq
u
al,
S
j
ter
m
in
a
tes
t
h
e
c
u
r
r
e
n
t
s
ess
io
n
; o
th
er
w
i
s
e,
S
j
g
e
n
er
ates a
r
an
d
o
m
k
e
y
b
∈
Z
*
P
-
1
an
d
c
o
m
p
u
tes
B
j
=
bP
,
SK
ij
= H
(
b
A
i
)
= H
(
a
b
P
)
,
an
d
C
j
=
H
(
T
C
j
||
I
D
i
||
S
I
D
j
||
B
j
||
TS
3
)
,
w
h
er
e
T
S
3
is
th
e
c
u
r
r
en
t
ti
m
es
ta
m
p
.
S
j
th
e
n
s
e
n
d
s
{
S
I
D
j
,
TS
3
,
C
j
, B
j
}
to
GWN
.
(
A
4
)
Af
ter
ch
ec
k
i
n
g
t
h
e
le
g
iti
m
ac
y
o
f
TS
3
,
G
WN
c
h
ec
k
s
wh
eth
er
H(
T
C
j
||
I
D
i
||
S
I
D
j
||
B
j
||
TS
3
)
a
n
d
C
j
ar
e
th
e
s
a
m
e.
I
f
th
e
s
e
t
w
o
v
al
u
es
ar
e
n
o
t
eq
u
al,
GWN
s
to
p
s
th
e
cu
r
r
en
t
s
es
s
io
n
;
o
t
h
er
w
is
e,
G
W
N
co
n
f
ir
m
s
th
at
S
j
i
s
a
u
th
e
n
tica
ted
.
Fin
a
ll
y
,
G
WN
ca
lc
u
late
s
E
GWN
=
H
(
I
D
i
||
T
C
i
||
D
i
||
B
j
||
TS
4
)
,
wh
er
e
TS
4
i
s
t
h
e
ti
m
e
s
ta
m
p
o
f
t
h
e
c
u
r
r
en
t c
o
m
p
u
ti
n
g
p
lat
f
o
r
m
,
an
d
s
e
n
d
s
{
S
I
D
j
,
TS
4
, B
j
, E
GWN
}
to
U
i
.
(
A
5
)
A
f
ter
c
h
ec
k
in
g
t
h
e
f
r
e
s
h
n
es
s
o
f
TS
4
,
U
i
co
m
p
u
tes
a
n
d
ch
ec
k
s
w
h
eth
er
H
(
I
D
i
||
T
C
i
|
|
D
i
||
B
j
||
TS
4
)
an
d
E
GWN
ar
e
eq
u
al.
I
f
t
h
ese
t
w
o
v
alu
es
ar
e
n
o
t
th
e
s
a
m
e,
U
i
s
to
p
s
t
h
e
c
u
r
r
en
t
s
es
s
io
n
; o
t
h
er
w
i
s
e,
U
i
co
n
f
ir
m
s
th
at
S
j
an
d
G
WN
ar
e
a
u
th
e
n
t
icate
d
.
Fin
all
y
,
U
i
co
m
p
u
tes
th
e
s
h
ar
ed
s
es
s
io
n
k
e
y
SK
ij
=
H(
a
B
j
)
=
H(
a
b
P
)
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
0
8
8
-
8708
I
n
t J
E
lec
&
C
o
m
p
E
n
g
,
Vo
l.
8
,
No
.
1
,
Feb
r
u
ar
y
201
8
:
6
0
5
–
6
1
0
608
Fig
u
r
e
2
.
L
o
g
i
n
an
d
au
th
e
n
tic
atio
n
p
h
ase
o
f
J
ia
n
g
et
a
l
.
’
s
p
r
o
to
co
l
2
.
4
.
P
a
s
s
w
o
rd
Cha
ng
e
P
ha
s
e
(
P
C
1
)
1
I
f
U
i
w
a
n
ts
to
u
p
d
ate
h
is
/
h
er
o
w
n
p
ass
w
o
r
d
,
h
e
o
r
s
h
e
i
n
p
u
t
s
h
is
/
h
er
o
w
n
ca
r
d
in
to
a
ter
m
in
al
a
n
d
en
ter
s
ID
i
an
d
PW
i
.
Fi
g
u
r
e
3
s
h
o
w
s
t
h
e
p
ass
w
o
r
d
ch
an
g
e
p
h
ase
o
f
J
ian
g
et
al.
’
s
p
r
o
to
co
l
(
P
C
2
)
T
h
e
s
m
ar
t
ca
r
d
ca
lc
u
lat
es
H
(
h
(
I
D
i
||
P
W
i
||
r
i
)
mo
d
m
)
.
I
f
th
e
eq
u
atio
n
s
HP
W
*
i
?
=
HP
W
’
i
ar
e
n
o
t
th
e
s
a
m
e,
t
h
e
ca
r
d
r
ef
u
s
e
s
th
e
r
eq
u
est.
Ot
h
er
w
is
e,
U
i
i
n
p
u
t
s
th
e
o
ld
PW
i
,
s
elec
ts
a
n
e
w
P
W
′
i
,
ca
lcu
late
s
P
TC
′
i
=
TC
i
⊕
RPW
i
⊕
H
(
r
||
P
W
’
i
)
,
a
n
d
r
ep
lace
s
P
TC
i
w
it
h
P
TC
′
i
.
Fig
u
r
e
3
.
P
ass
w
o
r
d
ch
an
g
e
p
h
ase
o
f
J
ian
g
et
a
l
.
’
s
p
r
o
to
co
l
3.
CRYP
T
AN
AL
Y
SI
S O
N
J
I
ANG
E
T
A
L
.
’
S
T
WO
-
F
AC
T
O
R
AUTHEN
T
I
CAT
I
O
N
P
RO
T
O
CO
L
T
h
is
p
ap
er
an
al
y
ze
s
J
ian
g
et
a
l
.
’
s
au
th
e
n
ticat
io
n
p
r
o
to
co
l
an
d
d
eter
m
i
n
e
s
v
ar
io
u
s
s
ec
u
r
it
y
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t J
E
lec
&
C
o
m
p
E
n
g
I
SS
N:
2088
-
8708
C
r
yp
ta
n
a
lysi
s
o
n
P
r
iva
cy
-
a
w
a
r
e
Tw
o
-
f
a
cto
r
A
u
th
en
tica
tio
n
P
r
o
to
co
l
f
o
r
….
(
Yo
u
n
s
u
n
g
C
h
o
i)
609
v
u
l
n
er
ab
ilit
ie
s
,
in
cl
u
d
in
g
a
lac
k
o
f
m
u
t
u
al
au
t
h
e
n
ticatio
n
,
a
r
is
k
o
f
SID
m
o
d
u
latio
n
an
d
Do
S
attac
k
s
,
a
lack
o
f
s
en
s
o
r
an
o
n
y
m
i
t
y
,
a
n
d
w
ea
k
I
D
an
o
n
y
m
it
y
.
3
.
1
.
L
a
c
k
o
f
M
utua
l A
uthent
ica
t
io
n
Mu
t
u
al
a
u
t
h
en
t
icatio
n
m
ea
n
s
th
at
t
w
o
o
r
t
h
r
ee
p
ar
ties
a
u
t
h
en
t
icate
ea
c
h
o
t
h
er
.
A
ll
o
f
t
h
e
p
ar
tie
s
(
e.
g
.
,
clien
t/
u
s
er
,
g
ate
w
a
y
,
a
n
d
s
en
s
o
r
s
)
ar
e
as
s
u
r
ed
o
f
t
h
e
o
t
h
er
s
’
id
en
tit
y
.
T
h
e
u
s
er
an
d
g
a
te
w
a
y
a
u
t
h
en
ticate
ea
ch
o
th
er
u
s
i
n
g
ID
i
a
n
d
TC
i
,
w
h
ile
t
h
e
g
ate
w
a
y
a
n
d
s
en
s
o
r
s
au
th
e
n
ticate
ea
c
h
o
th
er
u
s
in
g
TC
j
an
d
C
GWN
.
Ho
w
e
v
er
,
m
u
tu
a
l
au
t
h
e
n
ticati
o
n
b
et
w
ee
n
th
e
u
s
er
a
n
d
s
en
s
o
r
s
is
n
o
t
p
r
o
v
id
ed
.
T
h
e
s
en
s
o
r
s
ca
n
au
t
h
en
t
icate
th
e
u
s
er
w
i
th
t
h
e
g
ate
w
a
y
’
s
h
elp
.
Ho
w
e
v
er
,
th
e
u
s
er
ca
n
n
o
t
au
th
e
n
ticate
t
h
e
s
e
n
s
o
r
s
.
T
h
u
s
,
th
e
u
s
er
ca
n
n
o
t
v
er
if
y
w
h
eth
er
t
h
e
s
e
n
s
o
r
S
I
D
j
is
n
o
r
m
al.
3
.
2
.
Ris
k
o
f
SI
D
M
o
difica
t
io
n At
t
a
ck
s
T
h
e
u
s
er
r
ec
eiv
es
{
S
I
D
j
,
TS
2
,
B
j
,
E
GWN
}
f
r
o
m
G
WN
an
d
ch
ec
k
s
t
h
e
m
e
s
s
a
g
e’
s
ac
cu
r
ac
y
a
n
d
f
r
es
h
n
e
s
s
.
Ho
w
e
v
er
,
t
h
er
e
i
s
n
o
i
n
f
o
r
m
atio
n
i
n
d
icati
n
g
t
h
at
S
I
D
j
in
{
S
I
D
j
,
TS
2
,
B
j
,
E
GWN
}
i
s
n
o
w
au
th
e
n
tica
ted
b
y
G
WN
,
s
o
a
n
attac
k
er
ca
n
p
er
f
o
r
m
a
SID
m
o
d
if
icatio
n
attac
k
.
W
h
e
n
t
h
e
a
ttack
er
m
o
d
i
f
ies
th
e
S
I
D
j
in
{
S
I
D
j
,
TS
2
,
B
j
,
E
GW
N
}
to
S
I
D
attacker
,
th
e
u
s
er
is
u
n
a
war
e
o
f
t
h
e
ch
a
n
g
e.
T
h
er
ef
o
r
e,
t
h
e
u
s
er
m
is
tak
e
n
l
y
b
eliev
es
th
at
S
I
D
attacker
i
s
a
n
o
r
m
al
s
e
n
s
o
r
n
o
d
e
an
d
t
h
u
s
co
m
p
u
te
s
t
h
e
s
ess
io
n
k
e
y
SK
ij
f
o
r
s
ec
u
r
e
co
m
m
u
n
icatio
n
w
it
h
S
I
D
attacker
ev
en
t
h
o
u
g
h
th
e
a
ttack
er
ca
n
n
o
t
k
n
o
w
t
h
e
SK
ij
.
Mo
r
eo
v
er
,
w
h
e
n
S
I
D
j
r
eq
u
ests
co
m
m
u
n
icatio
n
,
th
e
u
s
er
ca
n
n
o
t
k
n
o
w
w
h
et
h
er
S
I
D
j
is
an
a
u
t
h
en
t
icate
d
s
e
n
s
o
r
n
o
d
e,
s
o
th
e
y
ca
n
n
o
t
co
m
m
u
n
icate
w
it
h
ea
ch
o
t
h
er
.
3
.
3
.
L
a
c
k
o
f
Sens
o
r
Ano
ny
m
it
y
An
o
n
y
m
it
y
is
a
d
esira
b
le
s
ec
u
r
it
y
f
ea
t
u
r
e,
an
d
it
p
r
o
v
id
es
id
en
ti
f
icatio
n
a
n
d
k
e
y
a
g
r
ee
m
en
t
o
f
th
e
u
s
er
an
d
s
en
s
o
r
s
d
u
r
in
g
th
e
lo
g
in
a
n
d
au
th
e
n
ticat
io
n
p
h
a
s
es.
T
h
u
s
,
J
ian
g
et
a
l
.
’
s
a
u
th
en
ticatio
n
p
r
o
to
co
l
p
r
o
v
id
es
th
e
u
s
er
’
s
d
y
n
a
m
ic
i
d
en
tific
atio
n
DI
D
i
to
p
r
o
tect
t
h
e
u
s
er
’
s
an
o
n
y
m
it
y
.
Mo
r
eo
v
e
r
,
th
is
p
r
o
to
co
l
u
s
e
s
DI
D
GWN
to
p
r
o
tect
t
h
e
g
ate
w
a
y
n
o
d
e’
s
id
en
ti
f
icat
io
n
.
Ho
w
e
v
er
,
J
ian
g
et
a
l
.
’
s
au
t
h
e
n
ticati
o
n
p
r
o
to
co
l
d
o
es
n
o
t
p
r
o
v
id
e
an
o
n
y
m
it
y
o
f
th
e
s
e
n
s
o
r
n
o
d
e.
T
h
er
ef
o
r
e,
an
attac
k
er
ca
n
k
n
o
w
w
h
ic
h
s
e
n
s
o
r
n
o
d
e
is
co
m
m
u
n
icati
n
g
w
it
h
u
s
er
s
.
I
n
ad
d
itio
n
,
th
e
attac
k
er
ca
n
ab
u
s
e
th
e
s
e
n
s
o
r
n
o
d
e’
s
id
en
ti
f
icatio
n
,
b
ec
au
s
e
S
I
D
j
ca
n
b
e
ea
s
il
y
k
n
o
w
n
b
y
t
h
e
attac
k
er
.
T
h
er
ef
o
r
e,
th
e
an
o
n
y
m
it
y
o
f
s
e
n
s
o
r
n
o
d
es
n
ee
d
s
to
b
e
p
r
o
v
id
ed
.
First,
S
j
ch
ec
k
s
th
e
f
r
es
h
n
e
s
s
o
f
TS
2
.
T
h
en
,
if
TS
2
is
v
alid
,
S
j
co
m
p
u
te
s
ID
i
=
DI
D
GWN
⊕
H(
DI
D
i
||
TC
j
||
TS
2
)
an
d
ch
ec
k
s
w
h
et
h
er
H
(
I
D
i
|
|
T
C
j
||A
i
|
|
T
S
2
)
an
d
th
e
r
ec
eiv
ed
C
GWN
ar
e
eq
u
al.
3
.
4
.
Do
S At
t
a
ck
A
Do
S
attac
k
i
s
an
atte
m
p
t
t
o
m
ak
e
a
m
ac
h
i
n
e
o
r
n
et
w
o
r
k
r
eso
u
r
ce
u
n
av
a
ilab
le
s
o
r
eg
u
lar
u
s
er
s
ca
n
n
o
t
u
s
e
t
h
e
s
y
s
te
m
’
s
r
eso
u
r
ce
s
.
A
lt
h
o
u
g
h
th
e
m
et
h
o
d
s
,
m
o
tiv
es,
an
d
tar
g
et
s
o
f
Do
S
atta
ck
s
m
a
y
v
ar
y
,
t
h
e
y
g
en
er
all
y
i
n
v
o
l
v
e
e
f
f
o
r
ts
to
te
m
p
o
r
ar
il
y
o
r
in
d
ef
i
n
itel
y
i
n
ter
r
u
p
t o
r
s
u
s
p
en
d
t
h
e
s
er
v
ices o
f
a
h
o
s
t c
o
n
n
ec
ted
to
th
e
I
n
ter
n
et.
I
n
J
ian
g
et
a
l
.
’
s
a
u
th
e
n
tica
tio
n
p
r
o
to
co
l,
s
en
s
o
r
n
o
d
es c
an
v
er
if
y
t
h
e
f
r
es
h
n
es
s
o
f
a
m
es
s
ag
e
u
s
in
g
TS
2
.
T
h
er
ef
o
r
e,
w
h
en
a
n
atta
ck
er
s
en
d
s
a
p
r
ev
io
u
s
m
es
s
a
g
e
to
th
e
s
e
n
s
o
r
n
o
d
e,
th
e
s
en
s
o
r
n
o
d
e
k
n
o
w
s
w
h
et
h
er
th
is
m
es
s
ag
e
is
a
c
u
r
r
en
t
m
es
s
ag
e
o
r
a
p
r
ev
io
u
s
m
e
s
s
a
g
e.
Ho
w
e
v
er
,
af
ter
a
n
attac
k
er
g
et
s
t
h
e
p
r
ev
io
u
s
m
es
s
ag
e
{
TS
2
,
DI
D
i
,
DI
D
GWN
,
C
GWN
,
A
i
},
t
h
e
a
ttack
er
s
e
n
d
s
t
h
e
m
es
s
ag
e
c
h
an
g
i
n
g
o
n
l
y
TS
2
to
th
e
cu
r
r
e
n
t
ti
m
esta
m
p
.
T
o
ch
ec
k
th
e
le
g
it
i
m
ac
y
o
f
t
h
e
m
e
s
s
a
g
e,
th
e
s
e
n
s
o
r
n
o
d
e
n
ee
d
s
to
ex
ec
u
te
v
ar
io
u
s
co
m
p
u
tatio
n
s
,
s
u
c
h
as
h
a
s
h
f
u
n
ct
io
n
(
t
w
ice)
,
v
er
if
icatio
n
f
u
n
ct
io
n
(
t
w
ice)
,
a
n
d
ti
m
esta
m
p
ch
ec
k
i
n
g
(
o
n
ce
)
.
T
h
e
s
en
s
o
r
n
o
d
e
h
as
li
m
ited
b
atter
y
p
o
w
er
an
d
co
m
p
u
tati
o
n
al
ab
ilit
y
,
s
o
it
is
p
o
s
s
ib
le
th
at
a
s
en
s
o
r
n
o
d
e
ca
n
n
o
t p
er
f
o
r
m
i
ts
n
o
r
m
al
f
u
n
ctio
n
s
w
h
en
a
n
attac
k
er
ex
ec
u
t
es a
Do
S a
ttack
o
n
t
h
e
s
e
n
s
o
r
n
o
d
e.
3
.
5
.
Wea
k
I
D
Ano
ny
m
it
y
I
n
J
ian
g
et
a
l
.
’
s
a
u
th
e
n
tica
tio
n
p
r
o
to
co
l,
th
e
u
s
er
ca
n
m
a
in
tain
th
e
I
D
a
n
o
n
y
m
i
t
y
u
s
i
n
g
DI
Di
.
An
attac
k
er
ca
n
n
o
t
co
m
p
u
te
ID
i
f
r
o
m
DI
D
i
,
b
ec
au
s
e
t
h
e
attac
k
er
d
o
es
n
o
t
k
n
o
w
H
(
A
i
||
D
i
)
in
DI
D
i
=
ID
i
⊕
H(
A
i
||
D
i
).
Ho
w
e
v
er
,
ID
i
ca
n
b
e
ex
p
o
s
ed
in
th
e
s
en
s
o
r
n
o
d
es
g
ain
ed
b
y
th
e
attac
k
er
.
T
h
e
s
en
s
o
r
n
o
d
es
ar
e
s
ca
tter
ed
in
v
ar
io
u
s
p
lace
s
,
s
o
th
e
att
ac
k
er
ca
n
f
i
n
d
th
e
s
en
s
o
r
n
o
d
es
an
d
o
b
tain
t
h
eir
au
t
h
o
r
it
y
.
T
h
er
ef
o
r
e,
th
e
attac
k
er
ca
n
co
m
p
u
te
t
h
e
u
s
er
’
s
id
en
tit
y
u
s
in
g
ID
i
=
DI
D
GW
N
⊕
H(
DI
D
i
||
TC
j
||
TS
2
)
,
b
ec
au
s
e
th
e
s
en
s
o
r
n
o
d
es k
n
o
w
TC
j
,
w
h
ic
h
is
s
h
ar
ed
in
th
e
s
en
s
o
r
r
eg
is
tr
atio
n
p
h
ase.
He
n
ce
,
th
e
attac
k
er
ca
n
g
et
ID
i
af
ter
g
ai
n
i
n
g
th
e
s
e
n
s
o
r
n
o
d
es,
an
d
t
h
e
an
o
n
y
m
i
t
y
o
f
th
is
p
r
o
to
co
l is n
o
t st
r
o
n
g
.
4.
CO
NCLU
SI
O
N
J
ian
g
et
a
l
.
p
r
o
p
o
s
ed
a
p
r
iv
ac
y
-
a
w
ar
e
t
w
o
-
f
ac
to
r
a
u
th
e
n
tica
ti
o
n
p
r
o
to
co
l u
s
in
g
E
C
C
f
o
r
W
SNs
.
T
h
e
y
in
s
i
s
t
th
at
t
h
eir
p
r
o
to
co
l
ac
h
i
ev
es
v
ar
io
u
s
s
ec
u
r
it
y
a
n
d
u
s
a
b
ilit
y
f
ea
t
u
r
es
n
ec
e
s
s
ar
y
f
o
r
r
ea
l
-
li
f
e
ap
p
licatio
n
en
v
ir
o
n
m
e
n
t
s
w
h
ile
m
ai
n
tai
n
i
n
g
ac
ce
p
tab
le
ef
f
icie
n
c
y
.
Ho
w
e
v
er
,
th
i
s
p
ap
er
an
aly
ze
d
J
ian
g
et
a
l
.
’
s
p
r
o
to
co
l
Evaluation Warning : The document was created with Spire.PDF for Python.
I
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I
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&
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Vo
l.
8
,
No
.
1
,
Feb
r
u
ar
y
201
8
:
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–
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610
an
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r
o
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r
it
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t
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h
e
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ticatio
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r
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o
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m
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icatio
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ticatio
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o
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n
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atio
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R
E
NC
E
S
[1
]
Y.
Ch
o
i
e
t
a
l.
,
“
S
e
c
u
rit
y
e
n
h
a
n
c
e
d
u
se
r
a
u
t
h
e
n
ti
c
a
ti
o
n
p
ro
t
o
c
o
l
f
o
r
w
irele
s
s
se
n
so
r
n
e
tw
o
rk
s
u
sin
g
e
ll
ip
ti
c
c
u
rv
e
s
c
r
y
p
to
g
ra
p
h
y
,
”
S
e
n
so
rs
,
v
o
l.
1
4
(
6
),
p
p
.
1
0
0
8
1
-
1
0
1
0
6
,
2
0
1
4
.
[2
]
Q.
Jia
n
g
e
t
a
l.
,
“
A
p
riv
a
c
y
‐
a
wa
re
tw
o
‐
f
a
c
to
r
a
u
th
e
n
ti
c
a
ti
o
n
p
r
o
to
c
o
l
b
a
se
d
o
n
e
ll
i
p
ti
c
c
u
rv
e
c
r
y
p
to
g
ra
p
h
y
f
o
r
w
irele
ss
se
n
so
r
n
e
tw
o
rk
s
,
”
.
In
ter
n
a
ti
o
n
a
l
J
o
u
rn
a
l
o
f
Ne
two
rk
M
a
n
a
g
e
me
n
t
.
,
v
o
l
2
7
(
3
),
2
0
1
7
.
[3
]
S
.
Ku
m
a
ri
e
t
a
l.
,
“
Us
e
r
a
u
th
e
n
ti
c
a
ti
o
n
sc
h
e
m
e
s
f
o
r
w
irele
s
s
se
n
so
r
n
e
tw
o
rk
s:
A
r
e
v
ie
w
,
”
Ad
Ho
c
N
e
two
rk
s
,
v
o
l
2
7
,
p
p
.
1
5
9
-
1
9
4
,
2
0
1
5
.
[4
]
M
.
L
.
Da
s,
“
Tw
o
-
fa
c
to
r
u
se
r
a
u
th
e
n
ti
c
a
ti
o
n
in
w
irele
ss
se
n
so
r
n
e
tw
o
rk
s”
.
IEE
E
T
r
a
n
sa
c
ti
o
n
s
o
n
W
ire
les
s
Co
mm
u
n
ica
ti
o
n
s
,
v
o
l
8
(
3
),
p
p
.
1
0
8
6
-
1
0
9
0
,
2
0
0
9
.
[5
]
M
.
K.
Kh
a
n
,
a
n
d
K.
A
lg
h
a
th
b
a
r,
“
Cr
y
p
tan
a
ly
sis
a
n
d
se
c
u
rit
y
i
m
p
ro
v
e
m
e
n
ts
o
f
t
w
o
-
f
a
c
to
r
u
se
r
a
u
th
e
n
ti
c
a
ti
o
n
in
w
irele
ss
se
n
so
r
n
e
tw
o
rk
s”
.
S
e
n
so
rs
,
v
o
l
1
0
(3
),
p
p
.
2
4
5
0
-
2
4
5
9
,
2
0
1
0
.
[6
]
T
.
H..
Ch
e
n
,
a
n
d
W
.
K.
S
h
ih
,
“
A
ro
b
u
st
m
u
tu
a
l
a
u
th
e
n
ti
c
a
ti
o
n
p
ro
to
c
o
l
f
o
r
w
irele
ss
se
n
so
r
n
e
tw
o
rk
s
”
.
ET
RI
jo
u
rn
a
l
,
v
o
l
3
2
(
5
),
p
p
.
7
0
4
-
7
1
2
,
2
0
1
0
.
[7
]
D.
He
e
t
a
l.
,
“
A
n
En
h
a
n
c
e
d
T
wo
-
f
a
c
to
r
Us
e
r
A
u
th
e
n
ti
c
a
ti
o
n
S
c
h
e
m
e
in
W
irele
ss
S
e
n
so
r
Ne
t
w
o
rk
s
.
”
Ad
h
o
c
&
se
n
so
r wire
les
s n
e
two
rk
s
,
v
o
l
1
0
(
4
),
p
p
3
6
1
-
3
7
1
,
2
0
1
0
.
[8
]
H.
L
.
Ye
h
,
e
t
a
l.
,
“
A
se
c
u
re
d
a
u
th
e
n
ti
c
a
ti
o
n
p
r
o
t
o
c
o
l
f
o
r
w
irele
ss
se
n
so
r
n
e
tw
o
rk
s
u
sin
g
e
ll
ip
ti
c
c
u
rv
e
s
c
r
y
p
to
g
ra
p
h
y
.
”
,
S
e
n
so
rs
,
v
o
l
1
1
(
5
),
p
p
.
4
7
6
7
-
4
7
7
9
,
2
0
1
1
[9
]
W
.
S
h
i
a
n
d
P
.
G
o
n
g
,
.
“
A
n
e
w
u
se
r
a
u
th
e
n
ti
c
a
ti
o
n
p
ro
t
o
c
o
l
f
o
r
w
irele
ss
se
n
so
r
n
e
tw
o
rk
s
u
sin
g
e
ll
ip
ti
c
c
u
r
v
e
s
c
r
y
p
to
g
ra
p
h
y
”
.
In
ter
n
a
ti
o
n
a
l
J
o
u
rn
a
l
o
f
Distri
b
u
ted
S
e
n
s
o
r Ne
two
rk
s
,
2
0
1
3
.
[1
0
]
D.
Ha
n
k
e
rso
n
e
t
a
l.
“
G
u
id
e
to
e
ll
i
p
ti
c
c
u
rv
e
c
ry
p
to
g
ra
p
h
y
,
”
.
S
p
rin
g
e
r S
c
ien
c
e
&
Bu
sin
e
ss
M
e
d
ia
,
2
0
0
6
.
[1
1
]
S
.
A
.
Ch
a
u
d
h
ry
e
t
a
l.
,
“
A
n
im
p
r
o
v
e
d
a
n
d
p
ro
v
a
b
ly
se
c
u
re
p
riv
a
c
y
p
re
s
e
rv
in
g
a
u
th
e
n
ti
c
a
ti
o
n
p
r
o
t
o
c
o
l
f
o
r
S
I
P
,
”
.
Pee
r
-
to
-
Pee
r Ne
two
rk
in
g
a
n
d
Ap
p
li
c
a
ti
o
n
s
,
v
o
l
1
0
(
1
),
p
p
.
1
-
1
5
,
2
0
1
7
.
[1
2
]
D.
W
a
n
g
,
“
A
n
o
n
y
m
o
u
s
t
w
o
-
f
a
c
t
o
r
a
u
th
e
n
ti
c
a
ti
o
n
in
d
istri
b
u
te
d
s
y
ste
m
s:
c
e
rtain
g
o
a
ls
a
re
b
e
y
o
n
d
a
tt
a
in
m
e
n
t,
”
IEE
E
T
ra
n
sa
c
ti
o
n
s
o
n
De
p
e
n
d
a
b
l
e
a
n
d
S
e
c
u
re
Co
m
p
u
ti
n
g
,
v
o
l
1
2
(
4
),
p
p
.
4
2
8
-
4
4
2
,
2
0
1
5
.
B
I
O
G
RAP
H
Y
O
F
AUTHO
R
Yo
u
n
s
u
n
g
Ch
o
i
re
c
e
i
v
e
d
th
e
B.
E
.
d
e
g
re
e
in
I
n
f
o
rm
a
ti
o
n
a
n
d
Co
m
m
u
n
ica
ti
o
n
E
n
g
in
e
e
rin
g
f
ro
m
f
ro
m
S
u
n
g
k
y
u
n
k
w
a
n
Un
iv
e
rsit
y
in
2
0
0
6
.
A
n
d
h
e
re
c
e
iv
e
d
th
e
M
.
S
.
a
n
d
P
H
.
D
d
e
g
re
e
s
o
n
In
f
o
rm
a
ti
o
n
S
e
c
u
rit
y
in
El
e
c
tro
n
ic
Co
m
p
u
ter
S
c
ien
c
e
a
n
d
En
g
in
e
e
ri
n
g
Div
iso
n
f
ro
m
S
u
n
g
k
y
u
n
k
w
a
n
Un
iv
e
rsit
y
,
in
2
0
0
7
a
n
d
2
0
1
5
.
He
is
n
o
w
a
n
a
ss
istan
t
p
ro
f
e
ss
o
r
in
H
o
w
o
n
Un
iv
e
rsity
.
His
c
u
rre
n
t
re
se
a
r
c
h
in
tere
sts in
c
lu
d
e
in
f
o
rm
a
ti
o
n
se
c
u
rit
y
,
c
r
y
p
to
g
ra
p
h
y
a
n
d
d
ig
it
a
l
f
o
re
n
sic
.
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