[Resource Topic] 2015/1115: Efficient Threshold Secret Sharing Schemes Secure against Rushing Cheaters

Welcome to the resource topic for 2015/1115

Title:
Efficient Threshold Secret Sharing Schemes Secure against Rushing Cheaters

Authors: Avishek Adhikari, Kirill Morozov, Satoshi Obana, Partha Sarathi Roy, Kouichi Sakurai, Rui Xu

Abstract:

In this paper, we consider three very important issues namely detection, identification and robustness of k-out-of-n secret sharing schemes against rushing cheaters who are allowed to submit (possibly forged) shares {\em after} observing shares of the honest users in the reconstruction phase. Towards this we present five different schemes. Among these, first we present two k-out-of-n secret sharing schemes, the first one being capable of detecting (k-1)/3 cheaters such that |V_i|=|S|/\epsilon^3 and the second one being capable of detecting n-1 cheaters such that |V_i|=|S|/\epsilon^{k+1}, where S denotes the set of all possible secrets, \epsilon denotes the successful cheating probability of cheaters and V_i denotes set all possible shares. Next we present two k-out-of-n secret sharing schemes, the first one being capable of identifying (k-1)/3 rushing cheaters with share size |V_i| that satisfies |V_i|=|S|/\epsilon^k. This is the first scheme whose size of shares does not grow linearly with n but only with k, where n is the number of participants. For the second one, in the setting of public cheater identification, we present an efficient optimal cheater resilient k-out-of-n secret sharing scheme against rushing cheaters having the share size |V_i|= (n-t)^{n+2t}|S|/\epsilon^{n+2t}. The proposed scheme achieves {\em flexibility} in the sense that the security level (i.e. the cheater(s) success probability) is independent of the secret size. Finally, we design an efficient (k, \delta) robust secret sharing secure against rushing adversary with optimal cheater resiliency. Each of the five proposed schemes has the smallest share size having the mentioned properties among the existing schemes in the respective fields.

ePrint: https://eprint.iacr.org/2015/1115

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .