Combinatorial lower bounds for secret sharing schemes
β Scribed by Kaoru Kurosawa; Koji Okada
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 286 KB
- Volume
- 60
- Category
- Article
- ISSN
- 0020-0190
No coin nor oath required. For personal study only.
β¦ Synopsis
In a perfect secret sharing scheme, it holds that log, I%[ > H(S), where S denotes the secret and G denotes the set of the share of user i. On the other hand, it is well known that log213 > H(S) if S is not uniformly distributed, where ? denotes the set of secrets. In this case, log, @I > H(S) < log, ISI. Then, which is bigger, @I or lq? We first prove that I%( 2 ISI for any distribution on S by using a combinatorial argument. This is a more sharp lower bound on $1 for not uniformly distributed S. Our proof makes it intuitively clear why [VI must be so large. Next, we extend our technique to show that maxi log, [cl > 1.5 log, ISI for some access structure.
π SIMILAR VOLUMES
We present some new lower bounds on the optimal information rate and on the optimal average information rate of secret sharing schemes with homogeneous access structure. These bounds are found by using some covering constructions and a new parameter, the k-degree of a participant, that is introduced
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