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L
1
=Ro
Ro
+
F
+
F
+
F
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Lo
R
1
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1
,K
1
)
L
15
= R

14
R
2
= L
1
+ F(R
1
,K
2
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2
= R
1
R
15
= L
14
+ F(R
14
,K
15
)
+
F
R
16
= L
15
+ F(R
15

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16
)
L
16
= R
15
1,2,3,... 64
1,2,3,... 64
1,2,3,... 32
K
1
K
2
Kn
K
16
Hình 1:
Encryption computation
1,2,3,... 32
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1,2,3,..... 64
1,2,3,..... 28 1,2,3,..... 28
K

1
Kn
K
16
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Key Schedule Calculation
Key
Key Key
C
1
D
1
Cn Dn
C
16
D
16
S
1
S
2
S
3
S
6
S
5
S
7
S

4
S
8
P
32 bits
+
E
48 bits
K (
48 bits
)
5
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Hình 3
: Calculation of f(R,K)
6
4
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