I
n
t
e
r
n
at
ion
al
Jou
r
n
a
l
of
I
n
f
o
r
m
at
ics
an
d
Com
m
u
n
icat
ion
T
e
c
h
n
ol
ogy
(
I
J
-
I
CT
)
Vo
l
.
1
4
,
N
o
.
2
,
A
ugus
t
20
2
5
,
pp.
438
~
445
I
S
S
N:
2252
-
8776
,
DO
I
:
10
.
11591/i
ji
c
t
.
v
1
4
i
2
.
pp
43
8
-
445
438
Jou
r
n
al
h
o
m
e
page
:
ht
tp:
//
ij
ict
.
iaes
c
or
e
.
c
om
E
n
h
a
n
c
e
d
n
-
p
ar
t
y
D
if
f
ie
H
e
ll
m
an
k
e
y
e
xc
h
an
ge
al
gor
ith
m
u
si
n
g
t
h
e
d
iv
id
e
an
d
c
on
q
u
e
r
al
gor
ith
m
Nw
an
z
e
Chu
k
wud
i
As
h
iob
a,
P
at
r
ick
Ogh
ol
o
r
u
n
wal
om
i
E
j
e
h
,
Az
a
k
a
M
ad
u
ab
u
c
h
u
k
u
D
e
pa
r
tm
e
nt
of
C
o
mput
e
r
S
c
i
e
n
c
e
,
F
a
c
ul
t
y
of
C
omput
in
g
,
D
e
nn
is
O
s
a
de
ba
y
U
ni
ve
r
s
it
y
,
A
s
a
ba
, N
ig
e
r
ia
Ar
t
ic
l
e
I
n
f
o
AB
S
T
RA
CT
A
r
ti
c
le
h
is
tor
y
:
R
e
c
e
i
ve
d
J
u
l
25,
2024
R
e
vi
s
e
d
De
c
4
,
2024
A
c
c
e
pt
e
d
De
c
15
,
2024
Cr
y
p
t
o
g
rap
h
i
c
al
g
o
r
i
t
h
m
s
g
u
aran
t
ee
d
at
a
an
d
i
n
fo
r
mat
i
o
n
s
ec
u
r
i
t
y
v
i
a
a
c
o
mmu
n
i
c
at
i
o
n
s
y
s
t
em
a
g
ai
n
s
t
u
n
au
t
h
o
ri
z
ed
u
s
e
rs
o
r
i
n
t
ru
d
e
rs
.
N
u
me
r
o
u
s
e
n
c
r
y
p
t
i
o
n
t
ec
h
n
i
q
u
e
s
h
a
v
e
b
een
em
p
l
o
y
ed
t
o
s
afeg
u
ard
t
h
i
s
d
at
a
an
d
i
n
fo
r
m
at
i
o
n
fro
m
h
a
ck
e
rs
.
B
y
s
u
p
p
l
y
i
n
g
a
d
i
s
t
i
n
c
t
s
h
are
d
s
ec
r
e
t
k
ey
,
t
h
e
n
-
p
art
y
D
i
ff
i
e
H
el
l
m
a
n
k
ey
e
x
c
h
a
n
g
e
ap
p
ro
ach
h
as
b
ee
n
u
s
ed
t
o
p
ro
t
ec
t
d
at
a
fro
m
h
a
ck
e
rs
.
U
s
i
n
g
a
q
u
a
d
rat
i
c
t
i
me
co
m
p
l
e
x
i
t
y
,
t
h
e
n
-
p
art
y
D
i
ffi
e
-
H
e
l
l
m
an
me
t
h
o
d
i
s
s
l
o
w
w
h
en
m
u
l
t
i
p
l
e
u
s
e
rs
u
s
e
t
h
e
c
r
y
p
t
o
g
ra
p
h
i
c
k
ey
i
n
t
e
r
c
h
a
n
g
e
s
y
s
t
em
.
T
o
s
o
l
v
e
t
h
i
s
i
s
s
u
e,
t
h
e
r
e
s
e
ar
c
h
e
rs
c
r
e
at
e
d
an
e
ff
ec
t
i
v
e
s
h
ar
ed
h
i
d
d
e
n
k
ey
fo
r
t
h
e
n
-
p
art
y
D
i
ffi
e
H
el
l
m
a
n
k
ey
e
x
ch
an
g
e
o
f
a
c
r
y
p
t
o
g
rap
h
i
c
s
y
s
t
em
u
s
i
n
g
t
h
e
d
i
v
i
d
e
-
an
d
-
c
o
n
q
u
e
r
s
t
rat
e
g
y
.
T
h
e
c
u
rr
en
t
re
s
e
ar
c
h
rec
o
mmen
d
s
t
h
e
u
s
e
o
f
t
h
e
d
i
v
i
d
e
an
d
co
n
q
u
e
r
a
l
g
o
ri
t
h
m,
w
h
i
c
h
b
re
a
k
s
d
o
w
n
t
h
e
m
ai
n
p
ro
b
l
em
i
n
t
o
s
m
al
l
e
r
s
u
b
p
ro
b
l
em
s
u
n
t
i
l
i
t
re
a
ch
e
s
t
h
e
b
as
e
s
o
l
u
t
i
o
n
,
w
h
i
ch
i
s
t
h
e
n
me
rg
ed
t
o
g
en
e
rat
e
t
h
e
s
o
l
u
t
i
o
n
o
f
t
h
e
m
a
i
n
p
ro
b
l
em
.
T
h
e
c
o
m
p
arat
i
v
e
a
n
al
y
s
i
s
i
n
d
i
c
at
e
s
t
h
at
t
h
e
d
e
v
el
o
p
e
d
s
y
s
t
em
g
en
e
rat
e
s
a
s
h
are
d
s
ec
r
e
t
k
ey
fas
t
e
r
t
h
a
n
t
h
e
cu
rr
e
n
t
n
-
p
art
y
D
i
ff
i
e
H
e
l
l
m
an
s
y
s
t
em
.
K
e
y
w
o
r
d
s
:
As
y
mm
e
t
r
i
c
c
r
y
pto
gr
a
phy
C
r
y
pt
o
gr
a
phy
C
r
y
pt
o
s
y
s
t
e
m
K
e
y
e
x
c
h
a
n
g
e
P
r
i
va
t
e
ke
y
S
y
mm
e
t
r
i
c
c
r
y
pt
o
g
r
a
phy
Th
i
s
i
s
a
n
o
p
en
a
c
ces
s
a
r
t
i
c
l
e
u
n
d
e
r
t
h
e
CC
B
Y
-
SA
l
i
cen
s
e.
C
or
r
e
s
pon
din
g
A
u
th
or
:
Nw
a
nz
e
C
h
ukwud
i
As
hi
o
b
a
De
pa
r
t
m
e
n
t
o
f
C
o
m
put
e
r
S
c
i
e
n
c
e
,
F
a
c
u
l
t
y
o
f
C
o
m
put
i
n
g,
De
nni
s
O
s
a
de
b
a
y
U
ni
ve
r
s
i
t
y
As
a
b
a
,
De
l
t
a
S
t
a
t
e
,
Ni
ge
r
i
a
E
m
a
i
l
:
n
wa
n
z
e
.
a
s
hi
o
b
a
@
do
u.
e
du.
n
g
1.
I
NT
RODU
C
T
I
ON
W
h
e
n
c
o
nv
e
y
e
d
f
r
o
m
o
n
e
r
e
g
i
o
n
to
a
di
f
f
e
r
e
n
t
l
o
c
a
t
i
o
n
o
r
r
e
gi
o
n
w
i
t
hi
n
t
h
e
c
o
n
t
e
x
t
o
f
c
o
m
m
u
ni
c
a
t
i
o
n
,
da
t
a
,
a
n
d
i
nf
o
r
m
a
t
i
o
n
a
r
e
a
l
w
a
y
s
v
u
l
n
e
r
a
bl
e
to
da
n
ge
r
a
n
d
a
tt
a
c
ke
r
s
.
S
e
v
e
r
a
l
c
r
y
pt
o
gr
a
phi
c
t
e
c
h
ni
que
s
h
a
v
e
b
e
e
n
us
e
d
to
s
e
c
ur
e
t
h
e
s
e
da
t
a
a
n
d
i
nf
o
r
m
a
t
i
o
n
.
A
s
hi
o
ba
a
n
d
Yo
r
o
[
1]
p
r
e
s
e
n
t
e
d
c
r
y
pt
o
g
r
a
phy
a
s
a
t
e
c
h
ni
que
f
o
r
c
o
nf
i
r
mi
ng
t
h
e
c
o
nf
i
de
n
t
i
a
li
t
y
a
n
d
a
ut
h
e
n
t
i
c
i
t
y
o
f
da
t
a
.
T
h
e
Gr
e
e
k
t
e
r
m
s
“
kr
y
pt
o
s
,
”
whi
c
h
m
e
a
n
s
u
n
d
i
s
c
l
o
s
e
d,
a
n
d
“
gr
a
p
hy,
”
whi
c
h
m
e
a
n
s
wr
i
t
i
n
g
,
a
r
e
t
h
e
r
oot
o
f
c
r
y
pt
o
gr
a
phy
[
2
]
.
It
’
s
a
s
c
i
e
n
t
i
f
i
c
t
e
c
hni
que
f
o
r
e
n
c
r
y
pt
i
n
g
m
e
s
s
a
ge
s
to
ke
e
p
h
a
c
ke
r
s
a
wa
y
.
I
nf
o
r
m
a
t
i
o
n
c
a
n
b
e
m
o
d
i
f
i
e
d
s
c
i
e
n
t
i
f
i
c
a
ll
y
us
i
ng
c
r
y
pto
gr
a
phy
t
o
t
h
wa
r
t
a
tt
a
c
ks
[
3]
.
E
s
s
e
n
t
i
a
l
ly
,
c
r
y
pt
o
gr
a
phy
i
s
t
h
e
pr
o
c
e
s
s
o
f
e
nc
r
y
pt
i
n
g
da
t
a
to
gua
r
d
a
ga
i
n
s
t
i
n
t
r
us
i
o
n
o
v
e
r
s
h
a
k
y
c
o
m
m
u
ni
c
a
t
i
o
n
c
h
a
nn
e
l
s
[
4]
,
[
5]
.
I
t
m
o
s
t
l
y
m
a
ke
s
u
s
e
o
f
t
h
e
m
a
t
h
e
m
a
t
i
c
a
l
i
de
a
t
h
a
t
pr
o
duc
e
s
a
v
a
r
i
e
t
y
o
f
pr
o
c
e
dur
e
s
kn
o
wn
a
s
c
r
y
pto
gr
a
phi
c
a
l
go
r
i
t
hm
s
[
6]
.
T
h
e
ga
t
h
e
r
i
n
g
o
f
c
r
y
pt
o
gr
a
phi
c
m
e
t
h
o
ds
a
s
we
l
l
a
s
t
he
ke
y
m
a
n
a
ge
m
e
n
t
pr
o
c
e
dur
e
s
t
h
a
t
e
n
a
bl
e
t
h
e
us
e
o
f
t
h
e
se
t
e
c
h
ni
que
s
i
n
e
v
e
r
y
k
i
nd
o
f
e
nvi
r
o
nm
e
n
t
a
r
e
r
e
f
e
r
r
e
d
t
o
a
s
c
r
y
pt
o
gr
a
phy
i
n
t
hi
s
s
e
ns
e
[
7]
.
As
y
mm
e
t
r
i
c
ke
y
c
r
y
pt
o
gr
a
phy
a
n
d
s
ymm
e
t
r
i
c
ke
y
c
r
y
pt
o
s
y
s
t
e
m
s
a
r
e
t
h
e
t
wo
t
y
pe
s
o
f
c
r
y
pt
o
gr
a
ph
y
[
8]
,
[
9
]
.
C
r
y
pt
o
s
y
s
t
e
m
s
t
h
a
t
us
e
a
s
y
m
m
e
t
r
i
c
ke
y
c
r
y
pt
o
gr
a
phy
us
e
s
e
pa
r
a
t
e
ke
y
s
f
o
r
de
c
r
y
pt
i
o
n
a
n
d
e
n
c
r
y
pt
i
o
n
[
10]
.
T
h
e
r
e
i
s
a
m
a
t
h
e
m
a
t
i
c
a
l
r
e
l
a
t
i
o
n
s
hi
p
b
e
t
we
e
n
t
h
e
ke
y
s
[
11]
.
An
a
s
ymm
e
t
r
i
c
ke
y
c
r
y
pt
o
s
y
s
t
e
m
,
o
f
t
e
n
kn
o
wn
a
s
a
publi
c
ke
y
c
r
y
pt
o
s
y
s
t
e
m
,
us
e
s
b
o
t
h
pr
i
v
a
t
e
a
n
d
publ
i
c
ke
y
s
to
e
n
c
r
y
pt
a
n
d
de
c
r
y
pt
da
t
a
.
T
h
e
f
a
c
t
t
h
a
t
e
a
c
h
us
e
r
’
s
vi
s
i
b
l
e
ke
y
i
s
m
a
de
hi
dde
n
pr
e
v
e
n
t
s
us
e
r
s
f
r
o
m
s
h
a
r
i
ng
o
r
di
s
c
l
o
s
i
ng
pr
i
v
a
t
e
i
nf
o
r
m
a
t
i
o
n
(
ke
y
s
)
.
A
c
o
m
m
o
n
s
e
c
r
e
t
ke
y
i
s
us
e
d
i
n
s
ymm
e
t
r
i
c
ke
y
c
r
y
pt
o
gr
a
phy
to
e
n
c
r
y
pt
a
n
d
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t
J
I
n
f
&
C
o
m
m
u
n
T
e
c
hn
o
l
I
S
S
N:
2252
-
8776
E
nhanc
e
d
n
-
par
ty
Di
ff
ie
He
ll
man
k
e
y
e
x
c
hange
al
gor
it
hm
us
ing
…
(
N
w
anz
e
C
huk
w
udi
A
s
hioba
)
439
de
c
r
y
pt
da
t
a
a
n
d
i
nf
o
r
m
a
t
i
o
n
[
10]
.
F
or
s
y
mm
e
t
r
i
c
ke
y
c
r
y
pt
o
gr
a
phy
to
o
pe
r
a
t
e
c
o
r
r
e
c
t
l
y
a
n
d
e
f
f
i
c
i
e
nt
l
y
,
b
o
t
h
t
h
e
pe
r
s
o
n
s
e
n
d
i
ng
t
h
e
m
e
s
s
a
ge
a
n
d
t
h
e
r
e
c
e
i
v
e
r
o
f
t
h
e
m
e
s
s
a
ge
m
u
s
t
b
e
m
i
nd
f
u
l
o
f
a
n
d
us
e
th
e
s
a
m
e
c
o
nf
i
de
n
t
i
a
l
k
e
y
w
he
n
c
o
m
m
u
ni
c
a
t
i
n
g
[
12]
.
R
e
a
c
hi
ng
a
n
a
gr
e
e
m
e
n
t
o
n
a
l
o
ne
hi
dde
n
ke
y
t
h
a
t
o
nl
y
t
he
pa
r
t
i
e
s
c
o
n
c
e
r
n
e
d
a
r
e
a
wa
r
e
o
f
i
s
t
h
e
tr
i
a
l
w
i
t
h
s
ym
m
e
t
r
i
c
ke
y
c
r
y
pt
o
gr
a
phy
.
I
n
1977,
W
hi
t
e
f
i
e
l
d
D
i
f
f
i
e
a
nd
M
a
r
t
i
n
He
l
lm
a
n
pu
bli
s
he
d
a
pa
pe
r
s
ugge
s
t
i
n
g
a
ke
y
i
n
t
e
r
c
h
a
n
g
e
m
e
c
h
a
ni
s
m
a
s
a
r
e
m
e
d
y
t
o
t
h
i
s
pr
o
bl
e
m
,
p
r
o
p
o
s
i
n
g
t
h
e
f
i
r
s
t
f
e
a
s
i
bl
e
r
e
s
u
l
t
.
I
n
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
g
e
t
e
c
hn
o
l
o
g
y
pa
r
t
i
c
i
pa
n
t
s
c
o
m
m
u
ni
c
a
t
e
o
v
e
r
a
n
o
pe
n
c
h
a
nn
e
l
t
o
de
t
e
r
m
i
ne
a
c
o
m
m
o
n
ke
y
w
i
t
h
o
ut
d
i
s
c
l
o
s
i
ng
t
h
e
c
o
nf
i
de
n
t
i
a
l
ke
yi
ng
i
nf
o
r
m
a
t
i
o
n
e
a
r
l
i
e
r
[
12]
.
T
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
g
e
,
a
l
s
o
kn
o
wn
a
s
e
x
po
n
e
n
t
i
a
l
ke
y
e
x
c
h
a
n
ge
,
i
s
a
t
e
c
hni
qu
e
f
o
r
s
e
c
ur
e
ly
s
w
a
pp
i
n
g
c
r
y
pt
o
gr
a
phi
c
ke
y
s
o
v
e
r
a
n
e
r
r
a
t
i
c
c
h
a
nn
e
l
.
I
t
i
s
t
h
e
b
a
s
i
c
c
o
n
s
t
r
uc
t
i
o
n
bl
o
c
k
o
f
nu
m
e
r
o
us
pr
ot
e
c
t
e
d
c
o
m
m
u
ni
c
a
t
i
o
n
pr
oto
c
o
l
s
i
nc
l
ud
i
ng
s
e
c
u
r
e
s
o
c
ke
t
s
l
a
y
e
r
(
SSL
)
,
t
r
a
n
s
po
r
t
l
a
y
e
r
s
e
c
ur
i
t
y
(
T
L
S
)
,
a
n
d
s
e
c
ur
e
s
h
e
ll
(
SSH
)
.
An
i
nn
o
v
a
t
i
o
n
i
n
pu
bli
c
ke
y
c
r
y
pt
o
gr
a
phy
wa
s
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
i
n
t
e
r
c
h
a
n
g
e
m
e
c
h
a
ni
s
m
t
h
a
t
pe
r
m
i
t
s
pa
r
t
i
c
i
pa
n
t
s
to
s
tr
o
n
g
l
y
pr
o
duc
e
a
c
o
l
l
e
c
t
i
v
e
hi
dde
n
ke
y
f
o
r
i
n
t
e
r
a
c
t
i
o
n
.
T
o
e
n
s
ur
e
m
u
l
t
i
c
a
s
t
f
i
de
li
t
y
,
t
h
e
pr
o
c
e
dur
e
c
r
e
a
ted
a
c
o
m
m
o
n
u
n
de
r
gr
o
un
d
ke
y
f
o
r
a
c
l
u
s
t
e
r
o
f
pa
r
t
i
c
i
pa
n
t
s
.
Va
r
i
o
us
p
l
a
n
s
h
a
v
e
b
e
e
n
put
o
u
t
o
v
e
r
t
i
m
e
.
T
h
e
r
e
s
e
a
r
c
h
e
s
[
13]
,
[
14]
c
r
e
a
t
e
d
a
n
e
f
f
e
c
t
i
ve
D
i
f
f
i
e
-
He
l
lm
a
n
-
M
AC
k
e
y
e
x
c
h
a
n
ge
s
y
s
t
e
m
by
e
m
p
l
o
yin
g
a
m
e
s
s
a
ge
a
ut
h
e
n
t
i
c
a
t
i
o
n
c
o
de
(
MA
C
)
h
a
s
h
f
un
c
t
i
o
n
.
R
e
s
t
r
uc
t
u
r
e
d
i
n
t
e
r
n
e
t
a
r
c
hi
t
e
c
t
ur
e
by
[
15
]
r
e
duc
e
d
t
h
e
p
o
s
s
i
bil
i
t
y
o
f
s
t
e
a
l
t
hy
n
e
t
wo
r
k
a
tt
a
c
ks
.
B
y
a
dd
i
n
g
m
o
r
e
s
e
c
ur
i
t
y
c
o
de
s
to
t
h
e
c
ur
r
e
n
t
m
e
t
h
o
d,
t
h
e
y
im
pr
o
v
e
d
t
h
e
e
n
c
r
y
pt
i
o
n
pr
oto
c
o
l
’
s
s
e
c
ur
i
t
y
.
J
h
a
a
n
d
P
a
t
i
l
[
16
]
c
r
e
a
t
e
d
a
Di
f
f
i
e
-
He
l
lm
a
n
a
l
go
r
i
t
hm
e
nh
a
n
c
e
m
e
n
t
.
T
o
e
n
s
ur
e
t
h
e
s
e
c
ur
i
t
y
o
f
t
h
e
t
r
a
n
s
m
i
s
s
io
n
,
t
h
e
y
im
p
l
e
m
e
n
t
e
d
s
pe
c
i
f
i
c
m
a
t
h
e
m
a
t
i
c
a
l
t
e
c
hni
que
s
.
Adr
i
a
n
e
t
al.
[
17
]
c
r
e
a
t
e
d
a
bl
o
w
f
i
s
h
e
n
c
r
y
pt
i
o
n
t
e
c
hni
que
-
b
a
s
e
d
ve
r
s
i
o
n
o
f
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
xc
h
a
n
ge
a
l
go
r
i
t
hm
f
o
r
n
e
t
wo
r
k
s
e
c
ur
i
t
y
.
2.
L
I
T
E
RA
T
UR
E
RE
VI
E
W
P
a
t
h
a
k
a
n
d
S
a
n
g
hi
[
18]
c
r
e
a
t
e
d
a
t
w
o
-
pa
s
s
wo
r
d
-
b
a
s
e
d
s
im
p
l
e
t
h
r
e
e
-
pa
r
t
y
k
e
y
e
x
c
h
a
n
ge
pr
o
to
c
o
l
vi
a
t
h
e
t
wi
n
-
D
i
f
f
i
e
-
He
l
lm
a
n
a
l
go
r
i
t
hm
.
T
he
a
l
go
r
i
t
hm
pr
o
vi
de
d
gr
e
a
t
e
r
s
e
c
ur
i
t
y
a
n
d
e
f
f
i
c
i
e
n
c
y
t
h
a
n
t
h
e
c
o
m
put
a
t
i
o
n
a
l
-
b
a
s
e
d
D
i
f
f
i
e
-
He
l
lm
a
n
pr
o
to
c
o
l
.
T
h
e
pr
o
to
c
o
l
s
we
r
e
v
e
r
i
f
i
e
d
u
s
i
ng
a
ut
o
m
a
t
e
d
v
a
li
da
t
i
o
n
o
f
i
n
t
e
r
n
e
t
s
e
c
ur
i
t
y
pr
o
to
c
o
l
a
n
d
a
pp
li
c
a
t
i
o
n
(
A
VI
S
P
A
)
.
A
pa
s
s
wo
r
d
-
b
a
s
e
d
ke
y
i
n
t
e
r
c
h
a
n
ge
m
e
c
h
a
ni
s
m
w
a
s
a
n
t
i
c
i
p
a
t
e
d
by
[
19]
a
n
d
i
t
wa
s
u
s
e
d
to
s
e
c
ur
e
c
o
m
m
u
ni
c
a
t
i
o
n
b
e
t
we
e
n
pa
r
t
i
c
i
pa
n
t
s
.
E
a
c
h
pa
r
t
y
in
t
hi
s
pr
oto
c
o
l
c
o
m
put
e
s
a
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
w
i
t
h
t
h
e
ot
h
e
r
pa
r
t
i
e
s
u
s
i
ng
a
pa
s
s
wo
r
d.
A
pa
r
a
l
l
e
l
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
xc
h
a
n
ge
(
P
DH
K
E
)
pr
oto
c
o
l
w
a
s
s
ugg
e
s
t
e
d
b
y
T
s
e
un
g
a
n
d
W
u
i
n
2008.
F
o
r
t
h
r
e
e
o
r
m
o
r
e
pa
r
t
i
c
ipan
t
s
,
t
h
e
pr
oto
c
o
l
wa
s
a
n
e
x
pa
n
s
i
o
n
o
f
t
h
e
r
e
gu
l
a
r
Di
f
f
i
e
-
He
l
lm
a
n
ke
y
e
xc
h
a
n
ge
.
Us
i
n
g
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
ha
n
ge
,
e
a
c
h
pa
r
t
y
i
n
t
h
e
pr
oto
c
o
l
c
om
put
e
s
a
s
ha
r
e
d
s
e
c
r
e
t
ke
y
w
i
t
h
e
ve
r
y
o
t
h
e
r
pa
r
t
y
.
A
gr
o
up
Di
f
f
i
e
-
He
ll
m
a
n
k
e
y
e
x
c
h
a
n
ge
pr
o
to
c
o
l
f
o
r
t
w
o
o
r
m
o
r
e
pa
r
t
i
c
i
pa
n
t
s
wa
s
c
r
e
a
t
e
d
by
[
20]
.
F
o
r
t
w
o
or
m
o
r
e
pa
r
t
i
c
i
pa
n
t
s
,
t
h
e
pr
oto
c
o
l
i
s
a
n
e
xt
e
n
s
i
o
n
o
f
t
h
e
c
o
n
ve
n
t
i
o
na
l
D
if
f
i
e
-
He
ll
m
a
n
ke
y
e
xc
h
a
n
g
e
.
Un
de
r
t
hi
s
pr
oto
c
o
l
,
t
h
e
D
i
f
f
i
e
-
H
e
l
lm
a
n
ke
y
e
x
c
ha
n
ge
i
s
e
m
p
l
o
y
e
d
by
e
a
c
h
pa
r
t
y
to
c
o
m
put
e
a
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
w
i
t
h
a
l
l
o
t
h
e
r
pa
r
t
i
e
s
.
T
h
e
r
e
s
e
a
r
c
h
e
s
[
21]
,
[
2
2]
pr
e
s
e
n
t
e
d
a
m
e
t
h
o
do
l
o
gy
t
h
a
t
us
e
d
a
n
i
n
t
e
r
a
c
t
i
v
e
z
e
r
o
-
kn
o
w
l
e
dge
pr
oo
f
to
a
l
t
e
r
t
h
e
Di
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
ha
n
ge
a
l
go
r
i
t
hm
.
T
h
e
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
’
s
kn
o
wn
a
tt
a
c
ks
we
r
e
t
h
wa
r
t
e
d
by
t
h
e
pr
oto
c
o
l
.
Al
a
m
[
23]
de
v
e
l
o
pe
d
a
n
i
m
pr
o
v
e
d
ke
y
e
x
c
h
a
n
ge
pr
o
to
c
o
l
b
a
s
e
d
o
n
a
t
hi
r
d
-
pa
r
t
y
a
ut
h
e
n
t
i
c
a
t
i
o
n
s
c
h
e
m
e
w
hi
c
h
e
l
im
i
na
t
e
d
t
h
e
m
a
n
-
in
-
m
i
dd
l
e
a
t
t
a
c
k
o
n
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
ha
n
ge
pr
oto
c
o
l
.
W
u
[
24]
c
r
e
a
t
e
d
t
h
e
v
e
r
i
f
i
e
r
-
b
a
s
e
d
n
-
pa
r
t
y
pa
s
s
wo
r
d
-
a
ut
h
e
n
t
i
c
a
t
e
d
ke
y
e
x
c
h
a
n
ge
(
P
AK
E
)
pr
oto
c
o
l
,
whi
c
h
s
e
c
ur
e
s
t
h
e
e
x
c
h
a
n
g
e
o
f
pa
s
s
wo
r
d
a
ut
h
e
n
t
i
c
a
t
i
o
n
ke
y
s
.
T
h
e
n
-
pa
r
t
y
c
o
m
m
u
ni
c
a
t
e
d
o
v
e
r
a
n
un
pr
o
t
e
c
t
e
d
c
h
a
nne
l
u
s
i
ng
t
h
e
pr
oto
c
o
l
.
I
n
t
hi
s
pr
o
to
c
o
l
,
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
i
s
c
o
m
put
e
d
by
e
a
c
h
p
a
r
t
y
w
i
t
h
e
v
e
r
y
ot
h
e
r
pa
r
t
y
us
i
n
g
a
pa
s
s
wo
r
d,
a
n
d
i
t
i
s
v
a
li
da
t
e
d
by
a
v
e
r
i
f
i
e
r
.
A
t
e
c
hni
qu
e
t
h
a
t
f
a
c
il
i
t
a
t
e
s
s
e
c
ur
e
c
o
m
m
u
ni
c
a
t
i
o
n
b
e
t
we
e
n
s
e
v
e
r
a
l
pa
r
t
i
e
s
i
s
t
h
e
P
DH
K
E
m
e
c
h
a
ni
s
m
,
w
h
e
r
e
i
n
e
v
e
r
y
pa
r
t
y
us
e
s
t
h
e
s
a
m
e
e
xpo
n
e
n
t
to
p
r
o
duc
e
pe
e
r
-
to
-
pe
e
r
ke
y
s
[
25]
.
I
n
a
dd
i
t
i
o
n
,
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
ge
h
a
s
be
e
n
i
n
s
t
r
u
m
e
n
t
a
l
i
n
t
h
e
de
v
e
l
o
p
m
e
n
t
o
f
gr
o
up
ke
y
e
s
t
a
bl
i
s
h
m
e
n
t
m
e
t
h
o
ds
t
h
a
t
a
r
e
c
us
to
m
i
z
e
d
f
o
r
a
v
a
r
i
e
t
y
o
f
s
i
t
ua
t
i
o
ns
,
i
nc
l
ud
i
n
g
m
u
l
t
i
c
a
s
t
gr
o
ups
a
n
d
a
d
h
o
c
n
e
t
w
o
r
ks
.
B
a
s
e
d
o
n
t
h
e
t
w
o
-
pa
r
t
y
D
i
f
f
i
e
-
He
ll
m
a
n
t
e
c
hni
que
,
m
e
t
h
o
ds
s
uc
h
a
s
t
h
e
g
r
o
up
-
Di
f
f
i
e
-
H
e
l
lm
a
n
pr
oto
c
o
l
h
a
v
e
b
e
e
n
pr
o
p
o
s
e
d
to
i
m
pr
o
v
e
c
o
n
t
r
i
b
ut
o
r
y
gr
o
up
ke
y
e
x
c
h
a
n
ge
[
26]
.
R
i
m
a
ni
e
t
al.
[
27
]
de
v
e
l
o
pe
d
a
n
i
m
a
ge
r
e
g
i
s
t
r
a
t
i
o
n
wi
t
h
ke
y
f
o
ur
i
e
r
tr
a
n
s
f
o
r
m
f
o
r
Di
f
f
i
e
-
He
ll
m
a
n
ke
y
e
xc
h
a
n
g
e
pr
oto
c
o
l
.
T
h
e
a
l
go
r
i
t
hm
c
r
e
a
t
e
d
a
tr
a
n
s
f
o
r
m
a
t
i
o
n
b
e
t
we
e
n
i
m
a
ge
s
f
o
r
r
e
c
o
v
e
r
i
n
g
t
h
e
ke
y
by
t
h
e
r
e
c
e
i
v
e
r
.
F
ur
t
h
e
r
m
o
r
e
,
dy
n
a
mi
c
gr
o
up
D
i
f
f
i
e
-
He
ll
m
a
n
pr
oto
c
o
l
s
a
r
e
de
s
i
g
n
e
d
t
o
a
c
c
o
m
m
o
da
t
e
c
i
r
c
u
m
s
t
a
n
c
e
s
i
n
w
hi
c
h
gr
o
up
m
e
m
be
r
s
hi
p
v
a
r
i
e
s
,
a
l
l
o
w
i
ng
pa
r
t
i
c
i
pa
n
t
s
to
e
n
t
e
r
a
n
d
qu
i
t
t
h
e
gr
o
up
wi
t
h
e
a
s
e
a
t
a
ny
t
i
m
e
.
P
r
ot
e
c
t
i
n
g
s
e
c
ur
i
t
y
a
n
d
e
f
f
i
c
i
e
n
c
y
i
s
s
t
i
ll
e
s
s
e
n
t
i
a
l
f
o
r
m
o
de
r
n
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
xc
h
a
n
ge
s
y
s
t
e
m
s
.
I
n
r
e
s
o
ur
c
e
-
c
o
n
s
t
r
a
i
n
e
d
c
o
n
t
e
x
t
s
s
uc
h
a
s
l
o
c
a
t
i
o
n
-
a
i
d
e
d
m
o
bil
e
a
d
-
h
o
c
n
e
t
wor
ks
,
t
e
c
h
ni
qu
e
s
s
uc
h
a
s
e
m
p
l
o
yi
ng
e
l
li
pt
i
c
c
ur
v
e
D
i
f
f
i
e
-
He
ll
m
a
n
i
ns
t
e
a
d
o
f
c
o
n
v
e
n
t
i
o
n
a
l
D
if
f
i
e
-
He
ll
m
a
n
h
a
ve
b
e
e
n
i
nv
e
s
t
i
g
a
t
e
d
to
im
pr
o
v
e
e
f
f
i
c
i
e
nc
y
[
28]
.
A
dd
i
t
i
o
n
a
ll
y
,
t
e
c
h
ni
que
s
s
uc
h
a
s
ut
i
li
z
i
ng
t
h
e
Di
f
f
i
e
-
He
ll
m
a
n
m
e
t
h
o
d
i
n
t
hi
r
d
pa
r
ty
a
ud
i
t
o
r
(
T
P
A
)
i
n
t
e
r
a
c
t
i
o
n
s
h
a
v
e
be
e
n
pr
o
p
o
s
e
d
to
i
m
p
r
o
v
e
a
udi
t
i
n
g
pe
r
f
o
r
m
a
n
c
e
,
a
n
d
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
ha
n
ge
h
a
s
b
e
e
n
f
o
un
d
i
n
c
o
r
po
r
a
t
e
s
i
n
c
l
o
ud
s
tor
a
ge
a
ud
i
t
i
n
g
[
29]
.
F
r
a
n
c
i
s
e
t
al.
[
30
]
p
r
o
p
o
s
e
d
t
h
e
D
i
f
f
i
e
-
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
S
N
:
2252
-
8776
I
n
t
J
I
n
f
&
C
o
m
m
u
n
T
e
c
hn
o
l
,
Vo
l
.
1
4
,
N
o.
2
,
A
ugus
t
20
2
5
:
438
-
445
440
He
l
lm
a
n
ke
y
e
x
c
ha
n
ge
a
l
go
r
i
t
hm
b
a
s
e
d
o
n
i
m
a
ge
da
t
a
e
n
c
r
y
pt
i
o
n
t
o
pr
ot
e
c
t
t
h
e
pr
i
va
c
y
a
n
d
c
o
nf
i
d
e
nt
i
a
li
t
y
o
f
s
e
n
s
i
t
i
ve
da
t
a
o
v
e
r
un
r
e
l
i
a
bl
e
c
h
a
nn
e
l
s
.
T
h
e
r
e
s
e
a
r
c
h
e
s
[
31]
,
[
32]
i
m
pr
o
v
e
d
c
o
n
f
i
d
e
n
t
i
a
l
i
t
y
,
i
n
t
e
gr
i
t
y
,
a
ut
h
e
n
t
i
c
a
t
i
o
n
,
a
n
d
pr
i
v
a
c
y
i
n
t
h
e
c
o
n
t
e
x
t
o
f
t
h
e
i
n
t
e
r
n
e
t
o
f
t
hi
n
gs
(
I
o
T
)
by
i
n
t
e
gr
a
t
i
n
g
t
h
e
e
l
l
i
pt
i
c
c
ur
v
e
s
(
E
C
GH
)
a
n
d
t
h
e
t
r
a
di
t
i
o
n
a
l
pu
bli
c
ke
y
i
n
f
r
a
s
t
r
uc
t
u
r
e
.
3.
RE
S
E
AR
CH
M
E
T
HO
D
3.
1
.
N
-
p
ar
t
y
Dif
f
ie
-
Hell
m
an
c
on
c
e
p
t
u
al
f
r
am
e
w
or
k
T
h
e
c
o
n
c
e
pt
ua
l
f
r
a
m
e
wo
r
k
o
f
t
h
e
n
-
pa
r
t
y
D
i
f
f
i
e
-
H
e
l
lm
a
n
a
l
go
r
i
t
hm
w
i
t
h
t
h
r
e
e
pa
r
t
i
c
i
pa
n
t
s
i
s
s
h
o
wn
i
n
F
i
gur
e
1.
E
a
c
h
o
f
t
h
e
t
h
r
e
e
pa
r
t
i
c
i
p
a
n
t
s
h
a
s
t
h
e
i
r
o
wn
s
e
t
o
f
pr
i
v
a
t
e
a
n
d
publi
c
ke
y
s
.
T
h
e
pr
i
v
a
t
e
ke
y
s
a
r
e
ke
pt
s
e
c
r
et
,
b
ut
t
h
e
publ
i
c
ke
y
i
s
e
xc
h
a
n
ge
d
a
m
o
n
g
t
h
e
us
e
r
s
i
n
t
h
e
c
o
m
m
u
ni
c
a
t
i
o
n
.
F
i
gur
e
1.
F
r
a
m
e
wo
r
k
o
f
t
h
e
n
-
pa
r
t
y
D
i
f
f
i
e
-
He
ll
m
a
n
a
l
go
r
i
t
hm
T
h
e
d
i
a
gr
a
m
i
n
F
i
gur
e
1
s
h
o
ws
t
h
a
t
t
h
e
n
u
m
be
r
of
s
wa
pp
i
ng
o
pe
r
a
t
i
o
n
s
f
o
r
t
h
r
e
e
pa
r
t
i
c
i
pa
n
t
s
i
s
3
.
In
(
1)
ge
n
e
r
a
l
ly
i
nd
i
c
a
t
e
s
t
h
e
n
u
m
be
r
o
f
n
-
pa
r
t
y
D
i
f
f
i
e
-
He
ll
m
a
n
a
l
go
r
i
t
hm
s
wa
pp
i
ng
o
pe
r
a
t
i
o
n
s
f
o
r
n
pa
r
t
i
c
i
pa
n
t
s
[
3]
.
=
(
−
1
)
2
=
2
+
2
(
1)
T
h
e
r
e
f
o
r
e
,
t
h
e
t
i
m
e
c
o
m
p
l
e
xi
t
y
f
o
r
t
h
e
n
-
pa
r
t
i
e
s
D
if
f
i
e
-
He
ll
m
a
n
a
l
go
r
i
t
hm
i
s
t
h
e
qua
dr
a
t
i
c
r
e
l
a
t
i
o
n
s
hip
s
h
o
w
n
by
(
2
)
.
=
(
2
)
(2
)
T
h
e
a
l
go
r
i
t
hm
t
a
ke
s
p
l
e
n
t
y
o
f
t
i
m
e
to
c
o
m
put
e
t
h
e
n
u
m
be
r
o
f
s
wa
pp
i
ng
o
pe
r
a
t
i
o
ns
i
n
t
h
e
pr
o
c
e
s
s
wh
e
n
t
h
e
n
u
m
be
r
o
f
pa
r
t
i
c
i
pa
n
t
s
i
s
l
a
r
ge
.
3.
2
.
Al
gor
it
h
m
of
t
h
e
n
-
p
ar
t
y
Hel
lm
a
n
k
e
y
e
x
c
h
an
ge
ap
p
r
oac
h
I
n
a
c
r
y
pt
o
g
r
a
phi
c
s
y
s
t
e
m
,
a
n
a
l
go
r
i
t
hm
l
a
y
s
o
ut
i
n
s
t
r
uc
t
i
o
n
s
t
h
a
t
de
s
c
r
i
be
h
o
w
to
ge
n
e
r
a
t
e
t
h
e
s
ha
r
e
d
s
e
c
r
e
t
ke
y
c
o
n
s
e
c
ut
i
v
e
ly
[
33]
.
T
h
e
s
t
e
ps
i
n
c
l
ude
:
i)
T
h
e
pa
r
t
i
e
s
a
gr
e
e
d
o
n
t
w
o
p
o
s
i
t
i
v
e
n
u
m
be
r
s
,
p
a
n
d
q
.
ii
)
A
pr
i
v
a
t
e
ke
y
i
s
s
e
l
e
c
t
e
d
a
t
r
a
n
do
m
by
e
a
c
h
pa
r
t
y
,
s
a
y
x
i
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t
J
I
n
f
&
C
o
m
m
u
n
T
e
c
hn
o
l
I
S
S
N:
2252
-
8776
E
nhanc
e
d
n
-
par
ty
Di
ff
ie
He
ll
man
k
e
y
e
x
c
hange
al
gor
it
hm
us
ing
…
(
N
w
anz
e
C
huk
w
udi
A
s
hioba
)
441
ii
i
)
E
a
c
h
pa
r
t
y
c
a
l
c
u
l
a
t
e
s
t
h
e
publi
c
ke
y
.
=
,
=
,
…
,
=
i
v)
T
o
c
o
m
put
e
t
h
e
c
o
m
m
o
n
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
,
a
l
l
pa
r
ti
e
s
s
wa
p
o
r
e
x
c
h
a
n
ge
t
h
e
i
r
pu
bli
c
ke
y
s
.
=
…
3.
3
.
Divid
e
an
d
c
on
q
u
e
r
al
go
r
it
h
m
A
pr
o
bl
e
m
-
s
o
l
vi
ng
s
t
r
a
t
e
gy
k
n
o
wn
a
s
t
h
e
d
i
vi
d
e
a
n
d
c
o
n
que
r
a
l
go
r
i
t
hm
,
a
ppr
o
a
c
h
,
or
pr
i
n
c
i
p
l
e
wo
r
ks
by
b
r
e
a
k
i
ng
t
h
e
m
a
i
n
pr
o
bl
e
m
do
w
n
i
n
t
o
s
m
a
ll
e
r
pr
o
bl
e
m
s
t
h
a
t
a
r
e
s
ub
s
e
que
n
t
l
y
f
ur
t
h
e
r
d
i
vided
i
n
t
o
s
m
a
l
l
e
r
pr
o
bl
e
m
s
t
h
a
t
a
r
e
s
o
l
v
e
d
s
e
pa
r
a
t
e
l
y
,
a
n
d
th
e
n
m
e
r
g
i
n
g
o
r
c
o
m
bi
n
i
ng
t
h
e
m
t
o
f
i
nd
t
h
e
s
o
l
ut
i
o
n
to
t
h
e
o
r
i
g
i
na
l
pr
o
bl
e
m
[
34]
.
T
h
e
r
e
c
ur
s
i
v
e
e
qua
t
i
o
n
o
f
t
h
e
d
i
vi
d
e
a
n
d
c
o
n
que
r
a
ppr
o
a
c
h
i
s
s
h
o
w
n
i
n
(
3
).
=
2
+
(
)
(3
)
W
h
e
r
e
n
i
s
t
h
e
n
u
m
be
r
o
f
pa
r
t
i
c
i
pa
n
t
s
i
n
t
h
e
c
o
mm
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
,
2
i
s
t
h
e
t
i
m
e
t
a
ke
n
t
o
c
o
m
p
ut
e
t
h
e
s
o
l
ut
i
o
ns
o
f
t
h
e
s
u
b
pr
o
bl
e
m
s
,
a
n
d
T
n
i
s
t
h
e
t
i
m
e
t
a
ke
n
t
o
c
o
m
put
e
t
h
e
s
o
l
ut
i
o
n
o
f
t
h
e
m
a
i
n
pr
o
bl
e
m
.
T
h
e
t
i
me
c
o
m
p
l
e
xi
t
y
o
f
t
h
e
a
l
go
r
i
t
hm
i
s
e
qua
l
t
o
t
h
e
n
um
be
r
o
f
d
i
v
i
de
-
a
n
d
-
c
o
n
que
r
o
pe
r
a
t
i
o
ns
pe
r
f
o
r
m
e
d
by
t
h
e
n
-
p
ar
t
y
a
n
d
i
s
s
h
o
wn
i
n
(
4
).
=
(
2
)
(
4)
3.
4
.
Conce
p
t
u
al
d
e
s
ign
of
n
-
p
ar
t
y
Dif
f
ie
-
Hellm
an
al
gor
it
h
m
u
s
in
g
d
ivi
d
e
an
d
c
on
q
u
e
r
al
go
r
it
h
m
T
h
e
c
o
n
c
e
pt
ua
l
f
r
a
m
e
wo
r
k
o
f
t
h
e
n
-
pa
r
t
y
D
i
f
f
i
e
-
H
e
l
lm
a
n
us
i
ng
t
h
e
d
i
vi
d
e
a
n
d
c
o
n
que
r
a
l
go
r
i
t
hm
t
o
ge
n
e
r
a
t
e
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
i
n
a
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
i
s
il
l
us
t
r
a
t
e
d
i
n
F
i
gur
e
2
.
I
t
c
o
n
t
a
i
n
s
t
h
r
e
e
pa
r
t
i
c
i
pa
n
t
s
i
n
t
h
e
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
,
wh
e
r
e
e
a
c
h
pa
r
t
y
h
a
s
a
pr
i
v
a
t
e
ke
y
t
h
a
t
i
s
ke
pt
s
e
c
r
e
t
a
n
d
a
publ
i
c
ke
y
t
h
a
t
i
s
ge
n
e
r
a
t
e
d
us
i
n
g
m
o
du
l
a
r
e
x
po
n
e
n
t
i
a
t
i
o
n
.
T
h
e
pa
r
t
i
c
i
pa
n
t
s
’
publi
c
ke
y
s
we
r
e
d
i
vided
i
n
t
o
s
ub
-
pa
r
t
i
c
i
pa
n
t
s
un
t
i
l
t
h
e
b
a
s
e
pa
r
t
i
c
i
pa
n
t
wa
s
r
e
a
c
h
e
d.
T
h
e
s
o
l
ut
i
o
ns
o
f
t
h
e
b
a
s
e
pa
r
t
i
c
i
pa
n
t
s
a
r
e
m
e
r
ge
d
to
o
b
t
a
i
n
t
h
e
s
o
l
ut
i
o
n
t
o
t
h
e
m
a
i
n
pr
o
bl
e
m
(
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
)
.
F
i
gur
e
2
s
h
o
ws
t
h
a
t
t
h
e
n
u
m
be
r
o
f
s
wa
pp
i
ng
o
pe
r
a
t
i
o
n
s
pe
r
f
o
r
m
e
d
by
t
h
e
pa
r
t
i
c
i
pa
n
t
s
i
n
ge
n
e
r
a
t
i
n
g
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
,
us
i
ng
t
h
e
d
i
vi
de
a
n
d
c
o
n
que
r
a
ppr
o
a
c
h
,
i
s
2.
T
h
e
r
e
f
o
r
e
,
t
h
e
t
i
m
e
c
o
m
p
l
e
xi
t
y
o
f
t
h
e
d
i
vi
d
e
a
n
d
c
o
n
que
r
a
l
go
r
i
t
hm
i
n
ge
n
e
r
a
t
i
n
g
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
o
f
t
h
e
Di
f
f
i
e
-
He
ll
m
a
n
a
l
go
r
i
t
hm
o
f
n
pa
r
t
i
c
i
pa
n
t
s
i
s
e
qua
l
to
t
h
e
n
u
m
be
r
o
f
di
vi
de
a
n
d
c
o
n
que
r
o
pe
r
a
t
i
o
n
s
pe
r
f
o
r
m
e
d
by
t
h
e
n
-
pa
r
t
y
a
n
d
i
s
s
h
o
w
n
i
n
(
4
).
F
i
gur
e
2.
F
r
a
m
e
wo
r
k
o
f
t
h
e
d
i
vi
de
a
n
d
c
o
n
que
r
a
l
g
o
r
i
t
hm
i
n
n
-
pa
r
t
y
D
i
f
f
i
e
-
He
ll
m
a
n
a
ppr
o
a
c
h
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
S
N
:
2252
-
8776
I
n
t
J
I
n
f
&
C
o
m
m
u
n
T
e
c
hn
o
l
,
Vo
l
.
1
4
,
N
o.
2
,
A
ugus
t
20
2
5
:
438
-
445
442
3.
5
.
Al
gor
it
h
m
of
t
h
e
p
r
op
os
e
d
s
y
s
t
e
m
T
h
e
s
t
e
ps
o
f
t
h
e
pr
o
p
o
s
e
d
s
y
s
t
e
m
i
nc
l
ude
:
i)
T
h
e
pa
r
t
i
e
s
a
gr
e
e
d
o
n
t
w
o
p
o
s
i
t
i
v
e
n
u
m
be
r
s
,
p
a
n
d
q.
ii
)
A
pr
i
v
a
t
e
ke
y
i
s
s
e
l
e
c
t
e
d
a
t
r
a
n
do
m
by
e
a
c
h
pa
r
t
y
,
s
a
y
x
i
.
ii
i
)
E
a
c
h
pa
r
t
y
c
a
l
c
u
l
a
t
e
s
t
h
e
publi
c
ke
y
.
=
,
=
,
…
,
=
i
v)
T
h
e
pa
r
t
i
e
s
a
r
e
di
vi
d
e
d
i
n
t
o
t
w
o
(
2)
s
ub
-
pa
r
t
i
e
s
us
in
g
r
e
c
ur
s
i
o
n
.
v)
S
o
l
v
e
t
h
e
s
m
a
l
l
e
r
s
u
b
-
pa
r
t
i
e
s
r
e
c
ur
s
i
ve
ly
t
o
f
i
n
d
t
h
e
b
a
s
e
s
o
l
ut
i
o
n
.
vi
)
C
o
m
bi
ne
t
h
e
s
o
l
ut
i
o
n
s
o
f
t
h
e
s
u
b
-
pa
r
t
i
e
s
r
e
c
ur
s
i
v
e
ly
to
f
i
n
d
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
K
ab
=
q
x
y
…n
m
o
d
p
.
3.
RE
S
UL
T
S
AN
D
DI
S
CU
S
S
I
ON
T
a
bl
e
1
pr
e
s
e
n
t
s
t
h
e
da
t
a
c
o
l
l
e
c
t
e
d,
a
n
d
t
h
e
r
e
s
u
l
t
s
o
b
t
a
i
n
e
d
f
r
o
m
t
h
e
a
n
a
ly
s
i
s
o
f
t
h
e
a
l
go
r
i
t
hm
s
f
o
r
20
pa
r
t
i
c
i
pa
n
t
s
i
n
t
h
e
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
.
T
a
bl
e
1
i
s
pr
e
s
e
n
t
e
d
gr
a
phi
c
a
l
ly
i
n
F
i
gur
e
3.
T
h
e
r
e
s
u
l
t
f
r
o
m
F
i
gur
e
3
s
h
o
ws
t
h
a
t
t
h
e
di
vi
de
a
n
d
c
o
n
que
r
a
ppr
oa
c
h
t
a
ke
s
l
e
s
s
t
i
m
e
t
o
ge
n
e
r
a
t
e
a
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
t
h
a
n
t
h
e
D
i
f
f
i
e
-
He
ll
m
a
n
a
l
go
r
i
t
hm
w
h
e
n
t
h
e
n
u
m
be
r
o
f
pa
r
t
i
c
i
pa
t
i
n
g
pa
r
t
i
e
s
i
s
v
e
r
y
l
a
r
ge
.
S
i
n
c
e
t
h
e
pe
r
f
o
r
m
a
n
c
e
o
f
a
s
y
s
t
e
m
i
s
i
nv
e
r
s
e
ly
pr
o
por
t
i
o
n
a
l
t
o
t
h
e
t
i
m
e
t
a
ke
n
,
t
h
e
r
e
l
a
t
i
o
ns
hi
p
i
s
s
h
o
w
n
m
a
t
h
e
m
a
t
i
c
a
ll
y
i
n
(
5)
.
T
a
bl
e
1.
T
i
m
e
c
o
m
p
l
e
xi
t
y
a
n
a
ly
s
i
s
be
t
we
e
n
qua
dr
a
t
i
c
a
n
d
l
o
ga
r
i
t
hm
i
c
D
if
f
i
e
-
He
ll
m
a
n
a
l
go
r
i
t
hm
s
I
nput
s
iz
e
n
N
-
pa
r
t
y
D
i
f
f
i
e
-
H
e
ll
ma
n
a
lg
o
r
it
hm
D
if
f
i
e
-
H
e
ll
ma
n a
lg
or
it
hm us
in
g di
v
id
e
a
nd c
o
nqu
e
r
a
lg
or
it
hm
2
4
,
000
1
,
000
3
9
,
000
1
,
585
4
16
,
000
2
,
000
5
25
,
000
2
,
322
6
36
,
000
2
,
585
7
49
,
000
2
,
807
8
64
,
000
3
,
000
9
81
,
000
3
,
170
10
100
,
000
3
,
322
11
121
,
000
3
,
459
12
144
,
000
3
,
585
13
169
,
000
3
,
700
14
196
,
000
3
,
807
15
225
,
000
3
,
907
16
256
,
000
4
,
000
17
289
,
000
4
,
087
18
324
,
000
4
,
170
19
361
,
000
4
,
248
20
400
,
000
4
,
322
F
i
gur
e
3.
A
n
a
ly
s
i
s
o
f
t
h
e
e
xe
c
ut
i
o
n
t
i
m
e
o
f
t
h
e
D
i
f
f
i
e
-
He
l
lm
a
n
a
l
go
r
i
t
hm
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t
J
I
n
f
&
C
o
m
m
u
n
T
e
c
hn
o
l
I
S
S
N:
2252
-
8776
E
nhanc
e
d
n
-
par
ty
Di
ff
ie
He
ll
man
k
e
y
e
x
c
hange
al
gor
it
hm
us
ing
…
(
N
w
anz
e
C
huk
w
udi
A
s
hioba
)
443
=
(
5)
W
h
e
r
e
:
P
A
=
pe
r
f
o
r
m
a
n
c
e
o
f
t
h
e
l
o
ga
r
i
t
hmi
c
D
i
f
f
i
e
-
He
l
lm
a
n
ke
y
e
x
c
h
a
n
ge
a
ppr
o
a
c
h
.
P
B
=
pe
r
f
o
r
m
a
n
c
e
o
f
t
h
e
qua
dr
a
t
i
c
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
ge
a
l
go
r
i
t
hm
.
T
A
=
t
i
m
e
t
a
ke
n
f
o
r
n
pa
r
t
i
c
i
p
a
n
t
i
n
t
h
e
l
o
ga
r
i
t
hm
i
c
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
g
e
a
ppr
o
a
c
h
.
T
B
=
t
i
m
e
t
a
ke
n
f
o
r
n
pa
r
t
i
c
i
pa
n
t
s
i
n
t
h
e
qua
dr
a
t
i
c
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
ge
a
l
go
r
i
t
hm
.
W
i
t
h
20
pa
r
t
i
c
i
pa
n
t
s
,
we
h
a
v
e
:
=
=
400
4
.
322
=
92
.
55
≈
93
T
hi
s
s
h
o
ws
t
h
a
t
t
h
e
l
o
gr
i
a
t
hmi
c
D
if
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
ha
n
ge
a
ppr
o
a
c
h
pe
r
f
o
r
m
s
93
t
i
m
e
s
b
e
t
t
e
r
t
h
a
n
t
h
e
qua
dr
a
t
i
c
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
ge
a
ppr
o
a
c
h
i
n
ge
n
e
r
a
t
i
n
g
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
i
n
a
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
.
4.
CONC
L
USI
ON
R
e
c
e
n
t
o
b
s
e
r
va
t
i
o
ns
s
h
o
w
t
h
a
t
t
h
e
n
-
pa
r
t
y
D
i
f
f
i
e
-
He
l
lm
a
n
ke
y
e
x
c
h
a
n
g
e
a
ppr
o
a
c
h
h
a
s
b
e
e
n
us
e
d
to
ge
n
e
r
a
t
e
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
i
n
a
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
.
F
r
o
m
t
h
e
s
t
udy
i
t
wa
s
o
b
s
e
r
v
e
d
t
h
a
t
t
h
e
n
-
pa
r
t
y
D
i
f
f
i
e
-
He
ll
m
a
n
k
e
y
e
x
c
h
a
n
g
e
a
ppr
o
a
c
h
t
a
ke
s
pl
e
n
t
y
o
f
t
i
m
e
to
ge
n
e
r
a
t
e
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
i
n
a
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
.
T
hi
s
s
t
ud
y
c
o
m
pa
r
e
s
t
h
e
pe
r
f
o
r
m
a
n
c
e
o
f
t
h
e
l
o
ga
r
i
t
hm
i
c
ke
y
e
x
c
h
a
n
ge
t
e
c
h
ni
que
w
i
t
h
t
h
e
t
i
m
e
pa
r
a
m
e
t
e
r
a
ga
i
n
s
t
t
h
e
qua
dr
a
t
i
c
ke
y
e
x
c
h
a
n
ge
a
l
go
r
i
t
hm
.
Our
f
i
n
d
i
ng
s
pr
o
v
e
t
h
a
t
t
h
e
l
o
ga
r
i
t
hm
ic
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
x
c
h
a
n
ge
a
ppr
o
a
c
h
i
s
f
a
s
t
e
r
t
h
a
n
t
h
e
qua
dr
a
t
i
c
D
i
f
f
i
e
-
He
ll
m
a
n
ke
y
e
xc
h
a
n
ge
a
pp
r
o
a
c
h
i
n
ge
n
e
r
a
t
i
n
g
t
h
e
s
h
a
r
e
d
s
e
c
r
e
t
ke
y
o
f
l
a
r
ge
pa
r
t
i
c
i
pa
nt
s
i
n
a
c
o
m
m
u
ni
c
a
t
i
o
n
s
y
s
t
e
m
.
AC
K
NOWL
E
DGE
M
E
NT
S
T
h
e
wr
i
t
e
r
s
wo
ul
d
l
i
ke
to
e
x
pr
e
s
s
t
h
e
i
r
gr
a
t
i
t
ude
to
f
r
i
e
n
ds
a
n
d
f
a
mi
ly
f
o
r
t
h
e
i
r
f
i
na
n
c
i
a
l
a
n
d
s
p
i
r
i
t
ua
l
s
uppo
r
t
i
n
ge
t
t
i
n
g
t
h
e
i
r
a
r
t
i
c
l
e
pu
bli
s
h
e
d.
F
UN
DI
NG
I
N
F
ORM
AT
I
ON
A
ut
h
o
r
s
s
t
a
t
e
n
o
f
u
n
d
i
ng
i
nv
o
l
v
e
d.
AU
T
HO
R
CONT
RI
B
UT
I
ONS
S
T
AT
E
M
E
NT
Nam
e
of
Aut
h
or
C
M
So
Va
Fo
I
R
D
O
E
Vi
Su
P
Fu
Nw
a
nz
e
C
h
ukwud
i
As
hi
o
ba
P
a
t
r
i
c
k
Ogh
o
l
o
r
un
wa
l
o
mi
E
j
e
h
A
z
a
k
a
M
a
dua
b
uc
h
uku
C
:
C
o
n
c
e
pt
ua
li
z
a
ti
o
n
M
:
M
e
th
o
d
o
l
o
g
y
So
:
So
f
twa
r
e
Va
:
Va
li
da
ti
o
n
Fo
:
Fo
r
ma
l
a
na
l
y
s
is
I
:
I
nve
s
ti
ga
ti
o
n
R
:
R
e
s
o
u
r
c
e
s
D
:
D
a
ta
C
ur
a
ti
o
n
O
:
W
r
it
in
g
-
O
r
ig
in
a
l
D
r
a
f
t
E
:
W
r
it
in
g
-
R
e
v
i
e
w
&
E
di
ti
ng
Vi
:
Vi
s
ua
li
z
a
ti
o
n
Su
:
Su
pe
r
v
is
io
n
P
:
P
r
o
j
e
c
t
a
dmi
n
is
tr
a
ti
o
n
Fu
:
Fu
ndi
ng a
c
qui
s
it
i
o
n
CONF
L
I
CT
OF
I
NT
E
RE
S
T
S
T
AT
E
M
E
NT
A
ut
h
o
r
s
s
t
a
t
e
n
o
c
o
nf
li
c
t
o
f
i
n
t
e
r
e
s
t
.
DA
T
A
AV
AI
L
AB
I
L
I
T
Y
T
h
e
a
ut
h
o
r
s
c
o
nf
i
r
m
t
h
a
t
t
h
e
da
t
a
s
upp
o
r
t
i
n
g
t
h
e
f
in
d
i
ngs
o
f
t
hi
s
s
t
ud
y
a
r
e
a
va
i
l
a
bl
e
w
i
t
hi
n
t
h
e
a
r
t
i
c
l
e
[
a
n
d/o
r
i
t
s
s
upp
l
e
m
e
n
t
a
r
y
m
a
t
e
r
i
a
l
s
]
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
S
N
:
2252
-
8776
I
n
t
J
I
n
f
&
C
o
m
m
u
n
T
e
c
hn
o
l
,
Vo
l
.
1
4
,
N
o.
2
,
A
ugus
t
20
2
5
:
438
-
445
444
RE
F
E
R
E
NC
E
S
[
1]
N
.
C
.
A
s
hi
o
ba
a
nd
R
.
E
.
Y
or
o
,
“
R
S
A
c
r
y
pt
o
s
y
s
te
m
us
in
g
o
b
je
c
t
-
o
r
i
e
nt
e
d
m
o
d
e
li
ng
te
c
hni
qu
e
,”
I
nt
e
r
nat
io
nal
J
our
nal
of
I
nf
or
m
at
io
n and C
om
m
uni
c
at
io
n T
e
c
hnol
ogy
R
e
s
e
a
r
c
h
, v
o
l.
4,
no
. 2, pp. 57
–
61, 2014.
[
2]
D
.
T
a
lu
kda
r
a
nd
P
.
L
.
P
.
S
a
ik
ia
,
“
A
r
e
v
ie
w
o
n
di
f
f
e
r
e
nt
e
n
c
r
y
pt
i
o
n
t
e
c
hni
qu
e
s
:
a
c
o
mpa
r
a
ti
v
e
s
tu
d
y
,”
I
nt
e
r
nat
io
nal
J
our
nal
of
E
ngi
ne
e
r
in
g R
e
s
e
ar
c
h and
G
e
ne
r
al
S
c
ie
nc
e
, v
o
l.
3, n
o
. 3, pp. 1
622
–
1625, 2015.
[
3]
B
. A
. F
o
r
o
u
z
a
n, “
C
r
y
p
t
o
gr
a
ph
y
,”
i
n
D
at
a C
om
m
uni
c
at
io
n and N
e
tw
or
k
in
g
, 4t
h E
di
ti
o
., N
e
w
Y
o
r
k, 2008, p
p. 931
–
960.
[
4]
A
.
K
a
us
hi
k
a
nd
S
a
t
v
ik
a
,
“
E
x
te
nd
e
d
di
f
f
i
e
-
he
ll
ma
n
a
lg
o
r
it
hm
f
o
r
k
e
y
e
xc
ha
ng
e
a
nd
ma
na
ge
me
nt
,”
P
r
oc
e
e
di
ngs
of
2nd
I
nt
e
r
nat
io
nal
C
onf
e
r
e
nc
e
on E
m
e
r
gi
ng T
r
e
nd
s
i
n E
ngi
ne
e
r
in
g a
nd M
anage
m
e
nt
, vo
l.
3, n
o
. 3, pp. 67
–
70, 2013.
[
5]
S
.
B
o
n
i,
J
.
B
ha
tt
,
a
nd
S
.
B
ha
t,
“
I
mpr
ov
in
g
th
e
D
i
f
f
ie
-
H
e
l
lm
a
n
ke
y
e
xc
ha
ng
e
a
lg
o
r
it
h
m
b
y
pr
o
p
o
s
in
g
th
e
mul
ti
pl
i
c
a
ti
ve
ke
y
e
xc
ha
nge
a
lg
o
r
i
th
m,”
I
nt
e
r
nat
io
nal
J
our
nal
of
C
om
put
e
r
A
ppl
ic
at
io
ns
,
vo
l.
130,
n
o
.
15,
pp.
7
–
10,
N
ov
.
2
015,
do
i:
10.5120/i
jc
a
2015907170.
[
6]
M
.
A
.
C
ha
v
a
n,
M
.
A
.
J
a
dha
v
,
M
.
S
.
K
umbha
r
,
M
.
I
.
J
o
s
hi
,
a
nd
M
.
I
.
J
o
s
hi
,
“
D
a
ta
t
r
a
ns
mi
s
s
io
n
us
in
g
R
S
A
a
lg
o
r
it
hm,”
I
nt
e
r
nat
io
nal
R
e
s
e
ar
c
h J
ou
r
nal
o
f
E
ngi
ne
e
r
in
g and T
e
c
hnol
ogy
, pp. 2008
–
2010, 2019, [
O
nl
in
e
]
. A
v
a
il
a
bl
e
:
w
w
w
.i
r
j
e
t.
n
e
t.
[
7]
O
.
A
ba
r
i,
J
.
S
h
o
la
,
a
nd
S
.
P
h
il
ip
,
“
C
o
mpa
r
a
ti
ve
a
na
l
y
s
is
of
di
s
c
r
e
t
e
l
o
ga
r
it
hm
a
nd
r
s
a
a
lg
or
it
hm
in
da
ta
c
r
y
pt
o
gr
a
p
h
y
,”
I
nt
e
r
nat
io
nal
J
our
nal
of
C
om
put
e
r
S
c
ie
nc
e
and I
n
f
or
m
at
io
n Se
c
ur
it
y
,
v
o
l.
13, pp. 24
–
31, 2015.
[
8]
M
.
F
.
M
us
ht
a
q,
S
.
J
a
ma
h,
A
.
H
.
D
is
in
a
,
Z
.
D
.
P
in
da
,
N
.
S
.
S
ha
ki
r
,
a
nd
M
.
M
.
D
e
r
is
,
“
R
e
v
i
e
w
o
n
c
o
mpa
r
a
ti
ve
s
tu
d
y
of
v
a
r
io
us
c
r
y
pt
o
g
r
a
ph
y
a
lg
o
r
it
h
m
,”
I
nt
e
r
nat
io
nal
J
our
nal
o
f
A
dv
anc
e
d
R
e
s
e
ar
c
h
in
C
om
put
e
r
Sc
ie
nc
e
and
So
f
tw
ar
e
E
ngi
ne
e
r
in
g
,
v
ol
.
5,
no
. 4, pp. 1
–
8, 2015.
[
9]
M
.
F
a
he
e
m,
S
.
J
a
me
l,
A
.
H
a
s
s
a
n,
Z
.
A
.,
N
.
S
ha
f
in
a
z
,
a
nd
M
.
M
a
t,
“
A
s
ur
v
e
y
on
th
e
c
r
y
pt
o
gr
a
phi
c
e
n
c
r
y
pt
i
o
n
a
lg
o
r
it
h
ms
,”
I
nt
e
r
nat
io
nal
J
our
nal
of
A
dv
anc
e
d
C
om
put
e
r
Sc
ie
nc
e
a
nd
A
ppl
ic
at
io
ns
,
vo
l.
8,
n
o
.
11,
pp.
333
–
344,
2017,
do
i:
10.14569/i
ja
c
s
a
.2017.081141.
[
10]
N
.
K
a
ur
a
nd
R
.
N
a
gpa
l,
“
A
ut
he
nt
ic
a
te
d
D
i
f
f
ie
-
H
e
ll
ma
n
ke
y
e
xc
ha
nge
a
lg
o
r
it
h
m,”
I
nt
e
r
nat
io
nal
J
our
nal
o
f
C
om
put
e
r
Sc
ie
n
c
e
and
I
nf
or
m
at
io
n T
e
c
hnol
ogi
e
s
,
v
ol
. 5, n
o
. 4, pp. 5404
–
5407, 2014, [
O
nl
in
e
]
. A
v
a
il
a
bl
e
:
w
w
w
.i
jc
s
it
.
c
o
m.
[
11]
S
.
M
.
S
e
th
a
nd
R
.
M
i
s
hr
a
,
“
C
o
mpa
r
a
ti
v
e
a
na
l
y
s
is
of
e
nc
r
ypt
io
n
a
lg
o
r
it
hms
f
o
r
da
ta
c
o
m
muni
c
a
ti
o
n,”
I
jc
s
t
,
vol
.
2,
no
.
2,
pp. 292
–
294, 2011.
[
12]
R
.
C
o
ll
e
g
e
,
“
A
n
a
ppr
o
a
c
h
t
o
publ
i
c
-
k
e
y
c
r
y
pt
o
g
r
a
ph
y
us
in
g
D
if
f
i
e
-
H
e
ll
ma
n
k
e
y
e
xc
ha
ng
e
a
lg
o
r
it
hm,”
I
n
te
r
nat
io
nal
J
our
nal
f
o
r
R
e
s
e
ar
c
h i
n E
ngi
ne
e
r
in
g A
ppl
ic
at
io
n &
M
anage
m
e
nt
(
I
J
R
E
A
M
)
, no
. 08, pp. 69
–
75, 2017.
[
13]
E
.
J
.
Y
oo
n
a
nd
K
.
Y
.
Y
oo
,
“
A
n
e
f
f
ic
i
e
nt
D
i
f
f
i
e
-
H
e
ll
ma
n
-
M
A
C
ke
y
e
xc
ha
nge
s
c
h
e
m
e
,”
2009
4t
h
I
nt
e
r
nat
io
nal
C
onf
e
r
e
nc
e
on
I
nnov
at
iv
e
C
om
put
in
g, I
nf
or
m
at
io
n an
d C
ont
r
ol
, I
C
I
C
I
C
2009
,
pp. 398
–
400, 2009, do
i:
10.1109/
I
C
I
C
I
C
.2009.80.
[
14]
N
.
L
i,
“
R
e
s
e
a
r
c
h
o
n
di
f
f
i
e
-
h
e
ll
ma
n
k
e
y
e
xc
ha
nge
pr
ot
o
c
o
l,
”
in
I
C
C
E
T
2010
-
2010
I
nt
e
r
nat
io
nal
C
onf
e
r
e
n
c
e
on
C
om
p
ut
e
r
E
ngi
ne
e
r
in
g and T
e
c
hnol
ogy
, P
r
oc
e
e
di
ngs
, 2010, v
o
l.
4, pp. V
4
-
634
-
V4
-
637, d
o
i:
10.1109/
I
C
C
E
T
.2010.5485276.
[
15]
V
in
o
th
in
i,
S
a
r
a
n
y
a
,
a
nd
V
a
s
uma
th
i,
“
A
s
tu
dy
o
n
D
i
f
f
i
e
-
H
e
l
lm
a
n
a
lg
o
r
it
hm
in
ne
tw
or
k
s
e
c
ur
it
y
,”
I
nt
e
r
nat
io
nal
J
our
nal
O
f
E
ngi
ne
e
r
in
g A
nd C
om
put
e
r
Sc
ie
nc
e
, v
o
l.
3, pp. 7346
–
7349, 20
14, [
O
nl
in
e
]
. A
v
a
il
a
bl
e
:
w
w
w
.i
j
e
c
s
.i
n.
[
16]
M
.
J
ha
a
nd
S
.
P
a
ti
l,
“
A
dv
a
nc
e
m
e
nt
in
D
i
f
f
i
e
-
H
e
ll
ma
n
a
lg
o
r
it
hm,”
J
our
nal
o
f
E
ngi
ne
e
r
in
g
R
e
s
e
a
r
c
h
and
A
ppl
ic
at
io
ns
,
v
ol
.
5,
no
. 7, pp. 01
–
02, 2015.
[
17]
A
.
A
dr
ia
n,
M
.
C
e
nda
na
,
a
nd
S
.
D
.
H
.
P
e
r
ma
na
,
“
D
i
f
f
i
e
-
H
e
ll
m
a
n
ke
y
e
x
c
ha
ng
e
m
o
di
f
ic
a
ti
o
n
u
s
in
g
bl
o
w
f
is
h
a
lg
or
it
hm
t
o
p
r
e
ve
nt
lo
gj
a
m a
tt
a
c
k,”
J
our
nal
of
T
e
le
c
o
m
m
uni
c
at
io
n, E
le
c
tr
oni
c
and
C
om
put
e
r
E
ngi
ne
e
r
in
g
, v
o
l.
10, n
o
. 4, pp. 1
–
7, 2018.
[
18]
H
.
K
.
P
a
th
a
k a
nd M
.
S
a
nghi
, “
S
im
pl
e
t
hr
e
e
-
pa
r
t
y
k
e
y
e
xc
ha
ng
e
pr
o
t
oc
o
l
v
ia
t
w
in
D
i
f
f
i
e
-
H
e
ll
ma
n
p
r
o
bl
e
m,
”
I
nt
e
r
nat
io
nal
J
our
nal
of
N
e
tw
or
k
S
e
c
ur
it
y
, v
o
l.
15, n
o
. 4, pp. 256
–
264, 2013.
[
19]
J
.
W
.
B
y
un
a
nd
D
.
H
.
L
e
e
,
“
N
-
pa
r
t
y
e
n
c
r
y
pt
e
d
D
i
f
f
i
e
-
H
e
ll
m
a
n
ke
y
e
xc
ha
nge
us
in
g
d
i
f
f
e
r
e
nt
pa
s
s
w
or
ds
,”
in
L
e
c
tu
r
e
N
ot
e
s
in
C
om
put
e
r
Sc
ie
n
c
e
, v
o
l.
3531, 2005, pp. 75
–
90.
[
20]
G
.
P
.
B
is
w
a
s
,
“
D
if
f
i
e
-
H
e
ll
ma
n
te
c
hni
qu
e
:
e
x
t
e
nd
e
d
to
mul
t
ip
le
tw
o
-
pa
r
t
y
ke
y
s
a
nd
o
ne
mul
ti
-
pa
r
t
y
ke
y
,”
I
E
T
I
nf
or
m
a
ti
on
Se
c
ur
it
y
, v
o
l.
2, n
o
. 1, pp. 12
–
18, M
a
r
. 2008, d
o
i:
10.1049/i
e
t
-
i
f
s
:2
0060142.
[
21]
M
.
K
.
I
br
a
hi
m,
“
M
o
di
f
i
c
a
ti
o
n
of
D
i
f
f
i
e
–
H
e
ll
ma
n
k
e
y
e
x
c
ha
nge
a
lg
o
r
it
h
m
f
or
z
e
r
o
kn
o
w
l
e
dg
e
p
r
oof
,”
E
ngi
ne
e
r
in
g
and
T
e
c
hnol
ogy
J
our
nal
, v
o
l.
30, n
o
. 3, pp. 443
–
453, J
a
n. 2012, doi
:
10.30684/e
tj
.30.3.9.
[
22]
C
.
B
.
P
r
a
ka
s
h
a
nd
S
.
S
ha
v
a
li
,
“
F
P
G
A
i
mpl
e
m
e
nt
a
ti
o
n
D
i
f
f
i
e
-
H
e
ll
ma
n
ke
y
e
xc
ha
nge
a
lg
o
r
it
hm
us
in
g
D
E
S
,”
I
nt
e
r
nat
io
nal
J
our
nal
of
I
nnov
at
iv
e
R
e
s
e
ar
c
h i
n E
le
c
tr
oni
c
s
and C
om
m
uni
c
at
io
ns
, v
ol
. 1, no
. 4, pp. 26
–
36, 2014
.
[
23]
B
.
A
la
m,
“
D
if
f
ie
-
H
e
l
lm
a
n
ke
y
e
xc
ha
ng
e
pr
o
t
oc
o
l
w
it
h
e
nt
i
ti
e
s
a
ut
he
nt
i
c
a
ti
o
n,”
I
nt
e
r
nat
io
nal
J
our
nal
O
f
E
ngi
ne
e
r
in
g
A
nd
C
om
put
e
r
Sc
ie
n
c
e
, v
o
l.
6
, n
o
. 4, Apr
. 2017, d
oi
:
10.18535/i
j
e
c
s
/v
6i
4.06.
[
24]
S
.
W
u,
“
S
e
c
u
r
it
y
a
na
l
y
s
is
a
nd
e
nha
nc
e
m
e
nt
s
of
v
e
r
i
f
i
e
r
-
ba
s
e
d
pa
s
s
w
o
r
d
-
a
ut
he
nt
i
c
a
t
e
d
ke
y
e
xc
ha
nge
pr
o
t
oc
o
ls
in
th
e
th
r
e
e
-
pa
r
t
y
s
e
tt
in
g,”
J
our
nal
of
I
n
f
or
m
at
io
n Sc
ie
n
c
e
and E
ngi
ne
e
r
in
g
, v
o
l.
27, no
. 3, pp
. 1059
–
1072, 2011, d
o
i:
10.1688/J
I
S
E
.2011.27.3.1
6.
[
25]
M
.
M
a
nul
is
,
“
G
r
o
up
k
e
y
e
xc
ha
nge
e
na
bl
in
g
o
n
-
d
e
ma
nd
de
r
i
v
a
ti
o
n
of
p
e
e
r
-
to
-
pe
e
r
ke
y
s
,”
L
e
c
tu
r
e
N
ot
e
s
in
C
om
put
e
r
S
c
i
e
nc
e
(
in
c
lu
di
ng
s
ubs
e
r
ie
s
L
e
c
tu
r
e
N
ot
e
s
in
A
r
ti
f
ic
ia
l
I
nt
e
ll
ig
e
nc
e
a
nd
L
e
c
tu
r
e
N
ot
e
s
i
n
B
io
in
f
or
m
at
ic
s
)
,
vo
l.
5536
L
N
C
S
,
pp.
1
–
19,
2009, do
i:
10.1007/978
-
3
-
642
-
01957
-
9_1.
[
26]
Y
.
M
.
T
s
e
ng
a
nd
T
.
Y
.
W
u,
“
A
n
a
l
y
s
is
a
nd
im
pr
o
ve
m
e
nt
o
n
a
c
o
nt
r
ib
ut
o
r
y
gr
o
up
ke
y
e
x
c
ha
ng
e
pr
o
t
oc
o
l
ba
s
e
d
o
n
th
e
D
if
f
i
e
-
H
e
ll
ma
n t
e
c
hni
qu
e
,”
I
nf
or
m
at
ic
a
, vo
l.
21, n
o
. 2
, pp. 247
–
258, J
a
n. 2010, do
i:
10.15388/i
n
f
o
r
ma
ti
c
a
.2010.286.
[
27]
R
.
R
im
a
ni
,
N
.
H
.
S
a
id
,
A
.
A
li
-
P
a
c
ha
,
a
nd
O
.
O
z
e
r
,
“
K
e
y
e
xc
ha
nge
ba
s
e
d
o
n
D
i
f
f
i
e
-
H
e
ll
ma
n
pr
o
t
oc
o
l
a
nd
im
a
ge
r
e
gi
s
tr
a
ti
o
n,”
I
ndone
s
ia
n
J
our
nal
of
E
le
c
t
r
ic
al
E
ngi
ne
e
r
in
g
and
C
om
put
e
r
Sc
ie
nc
e
,
v
o
l.
21,
n
o
.
3,
pp.
1751
–
1758,
M
a
r
.
2021,
do
i:
10.11591/i
je
e
c
s
.v
21.
i3
.pp1751
-
1758.
[
28]
E
.
B
r
e
s
s
o
n,
O
.
C
he
v
a
s
s
ut
,
a
nd
D
.
P
o
in
t
c
h
e
v
a
l,
“
P
r
ov
a
bl
y
a
ut
h
e
nt
i
c
a
te
d
gr
o
up
di
f
f
i
e
-
h
e
ll
ma
n
k
e
y
e
x
c
ha
ng
e
–
th
e
d
y
na
mi
c
c
a
s
e
,”
in
L
e
c
tu
r
e
N
ot
e
s
in
C
o
m
put
e
r
Sc
ie
n
c
e
(
in
c
l
udi
ng
s
ubs
e
r
ie
s
L
e
c
tu
r
e
N
ot
e
s
in
A
r
ti
f
ic
ia
l
I
nt
e
ll
ig
e
nc
e
and
L
e
c
tu
r
e
N
ot
e
s
in
B
io
in
f
or
m
at
ic
s
)
, v
o
l.
2248, 2001, pp. 290
–
309.
[
29]
R
.
K
.
Y
a
r
a
v
a
a
nd
R
.
P
.
S
in
gh,
“
E
f
f
i
c
i
e
nt
a
nd
s
e
c
u
r
e
c
l
o
u
d
s
to
r
a
ge
a
udi
ti
ng
ba
s
e
d
o
n
th
e
D
i
f
f
i
e
-
H
e
ll
ma
n
ke
y
e
x
c
ha
n
ge
,”
I
nt
e
r
nat
io
nal
J
our
nal
of
I
nt
e
ll
ig
e
nt
E
ngi
ne
e
r
in
g
an
d
Sy
s
te
m
s
,
v
o
l.
12,
n
o
.
3,
pp.
50
–
58,
J
un.
2
019,
do
i:
10.22266/
I
J
I
E
S
2019.0630.06.
[
30]
M
.
S
.
F
r
a
nc
is
,
J
.
D
.
S
w
e
e
tl
in
,
a
nd
M
.
S
a
ndhi
y
a
,
“
S
e
c
ur
e
im
a
ge
c
o
mm
uni
c
a
ti
o
n:
in
t
e
gr
a
ti
ng
D
i
f
f
i
e
-
H
e
ll
ma
n
ke
y
e
x
c
ha
ng
e
f
o
r
e
nha
nc
e
d
c
o
n
f
id
e
nt
ia
li
t
y
,”
in
2024
3r
d
I
nt
e
r
nat
io
nal
C
on
f
e
r
e
nc
e
on
A
r
ti
f
ic
ia
l
I
nt
e
ll
ig
e
nc
e
f
o
r
I
nt
e
r
ne
t
o
f
T
hi
ngs
,
A
I
I
oT
2024
,
M
a
y
2024, pp. 1
–
6, d
o
i
:
10.1109/AI
I
oT
58432.2024.10574682.
[
31]
A
.
S
e
bba
h
a
nd
K
.
B
e
na
ma
r
,
“
A
pr
iv
a
c
y
-
e
nha
n
c
e
d
s
c
he
m
e
w
it
hi
n
th
e
publ
i
c
ke
y
in
f
r
a
s
tr
uc
tu
r
e
f
or
th
e
in
te
r
n
e
t
of
th
in
gs
,
e
mpl
oy
in
g
e
ll
ip
ti
c
c
u
r
v
e
D
i
f
f
i
e
-
H
e
ll
ma
n
(
E
C
D
H
)
,”
I
ndone
s
ia
n
J
our
nal
o
f
E
le
c
t
r
ic
al
E
ngi
ne
e
r
in
g
and
I
nf
o
r
m
at
ic
s
,
v
o
l.
12,
n
o.
1,
pp. 65
–
74, F
e
b. 2024, d
o
i:
10.52549/i
je
e
i.
v
12i
1.5392.
[
32]
S
.
M
a
nda
l,
S
.
M
o
ha
nt
y
,
a
nd
B
.
M
a
jh
i,
“
A
n
I
D
-
ba
s
e
d
a
ut
he
nt
ic
a
te
d
th
r
e
e
-
pa
r
t
y
k
e
y
e
xc
ha
nge
pr
o
t
oc
o
l,
”
A
C
C
E
N
T
S
T
r
ans
ac
ti
ons
on I
nf
or
m
at
io
n Se
c
u
r
it
y
, v
o
l.
2, n
o
. 7, pp. 62
–
72, J
a
n. 2017, d
o
i
:
10.19101/t
is
.2017.27002.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t
J
I
n
f
&
C
o
m
m
u
n
T
e
c
hn
o
l
I
S
S
N:
2252
-
8776
E
nhanc
e
d
n
-
par
ty
Di
ff
ie
He
ll
man
k
e
y
e
x
c
hange
al
gor
it
hm
us
ing
…
(
N
w
anz
e
C
huk
w
udi
A
s
hioba
)
445
[
33]
A
.
N
.
C
hukwudi,
E
.
-
O
.
O
ba
r
o
,
O
.
C
.
U
.
O
.
K
pa
s
a
,
a
nd
N
.
N
.
D
a
ni
e
l,
“
M
o
d
e
li
ng
D
i
f
f
i
e
H
e
ll
ma
n
k
e
y
e
xc
ha
ng
e
a
lg
o
r
it
hm
us
in
g
o
bj
e
c
t
-
o
r
i
e
nt
e
d
a
na
l
y
s
is
a
nd
de
s
ig
n
te
c
hni
qu
e
,”
I
nt
e
r
nat
io
nal
J
our
nal
on
C
r
y
pt
ogr
aphy
and
I
n
f
or
m
at
io
n
Se
c
ur
it
y
,
v
o
l.
14,
no.
2,
pp. 01
–
08, J
un. 2024, do
i:
10.5121/i
j
c
is
.2024.
14201.
[
34]
M
.
Z
.
K
a
r
im
a
nd
N
.
A
kt
e
r
,
“
O
pt
im
um
pa
r
ti
ti
o
n
pa
r
a
m
e
t
e
r
of
di
v
id
e
-
a
nd
-
c
o
nque
r
a
lg
o
r
i
th
m
f
or
s
o
l
v
in
g
c
l
o
s
e
s
t
-
pa
ir
p
r
o
bl
e
m,”
I
nt
e
r
nat
io
nal
J
our
nal
of
C
om
put
e
r
S
c
ie
nc
e
and
I
n
f
or
m
at
io
n
T
e
c
hnol
ogy
,
vo
l.
3,
n
o
.
5,
pp.
211
–
219,
O
c
t.
2
011,
do
i:
10.5121
/i
jc
s
it
.2011.3519.
B
I
OG
RA
P
HI
E
S
OF
AU
T
HO
RS
N
w
a
n
z
e
C
huk
w
u
d
i
A
s
hi
o
ba
e
arn
ed
h
i
s
B
.
Sc
.
i
n
c
o
m
p
u
t
e
r
s
ci
e
n
ce
i
n
1
9
9
5
,
h
i
s
M
.
Sc
.
i
n
co
m
p
u
t
e
r
s
c
i
en
ce
i
n
2
0
0
7
,
an
d
h
i
s
P
h
.
D
.
i
n
co
m
p
u
t
e
r
s
ci
e
n
ce
i
n
2
0
1
4
,
al
l
fro
m
t
h
e
U
n
i
v
e
rs
i
t
y
o
f
Po
rt
-
H
ar
co
u
rt
,
R
i
v
e
rs
St
at
e
.
H
e
i
s
a
l
ec
t
u
re
r
i
n
t
h
e
D
e
p
art
me
n
t
o
f
C
o
m
p
u
t
e
r
Sci
en
ce
at
t
h
e
Fa
cu
l
t
y
o
f
C
o
m
p
u
t
i
n
g
at
D
e
n
n
i
s
O
s
ad
e
b
a
y
U
n
i
v
e
rs
i
t
y
i
n
A
n
w
ai
-
A
s
ab
a,
D
el
t
a
St
at
e
.
H
i
s
re
s
e
ar
c
h
i
n
t
e
r
e
s
t
s
an
d
s
p
ec
i
al
i
zat
i
o
n
are
as
i
n
c
l
u
d
e
s
o
ft
w
ar
e
en
g
i
n
ee
ri
n
g
,
m
a
c
h
i
n
e
l
e
ar
n
i
n
g
,
a
n
d
d
at
a
s
c
i
en
ce
.
H
e
i
s
a
mem
b
e
r
o
f
t
h
e
C
o
m
p
u
t
e
r
Pro
f
e
s
s
i
o
n
al
s
o
f
N
i
g
e
ri
a
(CPN
)
an
d
t
h
e
N
i
g
e
r
i
a
Co
m
p
u
t
e
r
So
ci
e
t
y
.
H
e
c
an
b
e
co
n
t
ac
t
e
d
at
em
a
i
l
:
n
w
an
z
e.
as
h
i
o
b
a@
d
o
u
.
ed
u
.
n
g
.
P
a
tri
ck
Og
h
o
l
o
r
un
w
a
l
o
m
i
Eje
h
r
ece
i
v
e
d
h
i
s
H
N
D
i
n
co
m
p
u
t
e
r
s
ci
e
n
ce
fro
m
t
h
e
F
e
d
e
ra
l
Po
l
y
t
ec
h
n
i
c
A
u
ch
i
,
E
d
o
St
at
e
i
n
2
0
0
6
;
M.
Sc
.
in
co
m
p
u
t
e
r
s
c
i
en
c
e
fr
o
m
N
o
rt
h
u
m
b
ri
a
U
n
i
v
e
rs
i
t
y
,
N
ew
cas
t
l
e
,
U
n
i
t
e
d
K
i
n
g
d
o
m
i
n
2
0
1
0
;
a
n
d
,
h
i
s
P
h
.
D
.
i
n
c
o
m
p
u
t
e
r
s
c
i
e
n
ce
fr
o
m
Su
n
d
e
r
l
an
d
U
n
i
v
e
rs
i
t
y
,
Su
n
d
e
r
l
an
d
,
U
n
i
t
ed
K
i
n
g
d
o
m
i
n
2
0
1
7
.
H
e
i
s
c
u
rr
en
t
l
y
a
l
ec
t
u
r
e
r
w
i
t
h
t
h
e
D
e
p
art
me
n
t
o
f
Co
m
p
u
t
e
r
S
c
i
en
ce
at
D
en
n
i
s
O
s
ad
e
b
ey
U
n
i
v
e
rs
i
t
y
,
A
s
ab
a,
D
el
t
a
St
at
e
.
H
i
s
r
e
s
e
ar
ch
i
n
t
e
r
e
s
t
s
i
n
c
l
u
d
e
;
art
i
f
i
ci
al
i
n
t
e
l
l
i
g
e
n
ce,
k
n
o
w
l
ed
g
e
m
a
n
ag
emen
t
,
d
at
a
s
c
i
e
n
ce,
an
d
t
h
e
i
n
t
e
r
n
e
t
o
f
t
h
i
n
g
s
.
H
e
i
s
al
s
o
a
mem
b
e
r
N
i
g
e
r
i
an
C
o
m
p
u
t
e
r
S
o
c
i
e
t
y
a
n
d
H
i
g
h
e
r
E
d
u
c
at
i
o
n
A
c
ad
emi
c
;
U
n
i
t
ed
K
i
n
g
d
o
m
.
H
e
c
a
n
b
e
c
o
n
t
ac
t
e
d
at
t
h
i
s
em
ai
l
:
p
at
ri
c
k
.
ej
e
h
@
d
o
u
.
ed
u
.
n
g
.
M
r
A
z
a
k
a
M
a
du
a
b
u
c
huku
rece
i
v
e
d
h
i
s
M.
S
c
.
a
n
d
PG
D
fr
o
m
t
h
e
N
at
i
o
n
a
l
O
p
e
n
U
n
i
v
e
rs
i
t
y
o
f
N
i
g
e
r
i
a
aft
e
r
o
b
t
ai
n
i
n
g
h
i
s
H
N
D
i
n
c
o
m
p
u
t
e
r
s
ci
en
ce
fro
m
N
ek
e
d
e,
O
w
e
rr
i
.
H
e
i
s
a
l
ec
t
u
r
e
r
i
n
t
h
e
D
e
p
art
men
t
o
f
Co
m
p
u
t
e
r
S
ci
e
n
ce,
D
en
n
i
s
O
s
ad
e
b
a
y
U
n
i
v
e
rs
i
t
y
A
s
ab
a
D
el
t
a
St
at
e
.
H
i
s
are
as
o
f
s
p
eci
al
i
z
at
i
o
n
i
n
cl
u
d
e
c
o
m
p
u
t
e
r
n
e
t
w
o
rk
i
n
g
,
h
ard
w
ar
e
m
ai
n
t
en
an
ce
,
an
d
p
ro
g
ra
mmi
n
g
.
H
e
c
a
n
b
e
c
o
n
t
ac
t
e
d
at
em
a
i
l
:
azak
a.
m
ad
u
ab
u
c
h
u
k
u
@
d
o
u
.
e
d
u
.
n
g
.
Evaluation Warning : The document was created with Spire.PDF for Python.