Combinatorial optimization: algorithms and complexity
Combinatorial optimization: algorithms and complexity
Visual cryptography for general access structures
Information and Computation
Construction of visual secret sharing schemes with almost optimal contrast
SODA '00 Proceedings of the eleventh annual ACM-SIAM symposium on Discrete algorithms
Contrast-optimal k out of n secret sharing schemes in visual cryptography
Theoretical Computer Science - computing and combinatorics
Visual Cryptography II: Improving the Contrast Via the Cover Base
Proceedings of the International Workshop on Security Protocols
Ideal contrast visual cryptography schemes with reversing
Information Processing Letters
Designs, Codes and Cryptography
Ideal contrast visual cryptography schemes with reversing
Information Processing Letters
Bounds for visual cryptography schemes
Discrete Applied Mathematics
Step construction of visual cryptography schemes
IEEE Transactions on Information Forensics and Security
Improving the visual quality of size invariant visual cryptography scheme
Journal of Visual Communication and Image Representation
Perfect reconstruction of black pixels revisited
FCT'05 Proceedings of the 15th international conference on Fundamentals of Computation Theory
Compatible ideal contrast visual cryptography schemes with reversing
ISC'05 Proceedings of the 8th international conference on Information Security
Improvements of a two-in-one image secret sharing scheme based on gray mixing model
Journal of Visual Communication and Image Representation
On the equivalence of two definitions of visual cryptography scheme
ISPEC'12 Proceedings of the 8th international conference on Information Security Practice and Experience
Flexible visual cryptography scheme without distortion
IWDW'11 Proceedings of the 10th international conference on Digital-Forensics and Watermarking
Multi-pixel encryption visual cryptography
Inscrypt'11 Proceedings of the 7th international conference on Information Security and Cryptology
Sharing more information in gray visual cryptography scheme
Journal of Visual Communication and Image Representation
Improved tagged visual cryptography by random grids
Signal Processing
On (k, n)*-visual cryptography scheme
Designs, Codes and Cryptography
Hi-index | 0.00 |
This paper shows that the largest possible contrast $C_{k,n}$ in a $k$-out-of-$n$ secret sharing scheme is approximately $4^{-(k-1)}$. More precisely, we show that $4^{-(k-1)} \leq C_{k,n} \leq 4^{-(k-1)}n^k/(n(n-1)\cdots(n-(k-1)))$. This implies that the largest possible contrast equals $4^{-(k-1)}$ in the limit when $n$ approaches infinity. For large $n$, the above bounds leave almost no gap. For values of $n$ that come close to $k$, we will present alternative bounds (being tight for $n=k$). The proofs of our results proceed by finding a relationship between the largest possible contrast in a secret sharing scheme and the smallest possible approximation error in problems occurring in approximation theory.