Unconditionally secure social secret sharing scheme

Abstract

We introduce the notion of a Social Secret Sharing Scheme, in which shares are allocated based on a player's reputation and the way he interacts with other participants. During the social tuning phase, weights of players are adjusted such that participants who cooperate will end up with more shares than those who defect. Alternatively, newcomers are able to be enrolled in the scheme while corrupted players are disenrolled immediately. In other words, this scheme proactively renews shares at each cycle without changing the secret, and allows trusted participants to gain more authority. Our motivation is that, in real world applications, components of a secure scheme may have different levels of importance (i.e., the number of shares a player has) as well as reputation (i.e., cooperation with other players for the share renewal or secret recovery). Therefore, a good construction should balance these two factors respectively. In the proposed schemes, both the passive and active mobile adversaries are considered in an unconditionally secure setting. 1

Combinatorial repairability for threshold schemes

“…The enrollment protocol from [10,9] was introduced to create a share for a new player in a threshold scheme, without requiring the participation of the dealer who initially set up the scheme. It was also described in a setting where threshold of the scheme was to be altered.…”

“…We study two approaches to repairing. The first method is based on the "enrollment protocol" from [9] which was originally developed to add a new player to a threshold scheme (without the participation of the dealer) after the scheme was set up. The second method distributes "multiple shares" to each player, as defined by a suitable combinatorial design.…”

Socio-Rational Secret Sharing as a New Direction in Rational Cryptography

“…Now we review social secret sharing, introduced by Nojoumian et al [25], where the shares are allocated based on a player's reputation and the way she interacts with other parties. In other words, weights of players are adjusted such that participants who cooperate receive more shares compared to non-cooperative parties.…”

“…Before providing our solution to the rational secret sharing problem, we briefly introduce the notion of social secret sharing [25,26] in which players are either honest or malicious. In this protocol, weights of the players, i.e., the number of shares each player can hold, are periodically updated such that the players who cooperate receive more shares than those who defect.…”

A New Secret Sharing Scheme With Priority in Order of Sharing and its Application in Multi Authority E-voting Systems

“…There are some works which updates shares of members based on their interactions which is known as social secret sharing. For example in [Nojoumian, 2010] proposed an scheme to change the parties without changing the secret based on participants' cooperation.…”