Cryptography Reference
In-Depth Information
Fig. 4.1.
The basic (2, 2)-VSS scheme.
Fig. 4.2.
Two codebooks for Naor and Shamirs (2, 2)-VSS scheme.
In order to improve the weaknesses of Naor and Shamirs scheme, Lukac and
Plataniotis proposed a bit-level secret sharing scheme. In Lukac and Platan-
iotiss scheme, the gray-scale image is represented by eight bit planes. The
example binary planes are shown in Fig. 4.4.
Lukac and Plataniotis regarded each plane as a secret image and used
Naor and Shamirs VSS encryption process to generate the sub-shadows. The
resultant sub-shadows of j-th plane are represented by α
j
and β
j
. Hence, the
final shadows are composed according to
S
i
= α
i
2
7
+ α
i
2
6
++ α
i
2
1
+ α
i
,
and
(4.2)
S
i
= β
i
2
7
+ β
i
2
6
++ β
i
2
1
+ β
i
,
(4.3)
