No abstract

We consider the rational secret sharing problem introduced by Halpern and Teague[3], where players prefer to get the secret than not to get the secret and with lower preference, prefer that as few of the other players get the secret. The impossibility of a deterministic protocol for rational secret sharing is proved by Halpern and Teague [3]. The impossibility result is based on the fact that a rational player always chooses a dominating strategy and so there is no incentive for a player to send his secret share. This rational behavior makes secret sharing impossible, but there is an interesting way by which we can force rational players to cooperate for achieving successful secret sharing. A rational player may be deterred from exploiting his short term advantage by the threat of punishment that reduces his long term payoff. This can be captured by the repeated interaction of players. Hence, we study rational secret sharing in a scenario, where players interact repeatedly in several rounds which enables the possibility of secret sharing among rational players. In our model, the dealer, instead of sending shares, forms polynomials of the secret shares and sends points on that polynomial (say subshares) to the players. The dealer constructs polynomials in a manner that the degrees of polynomials used differ by at most one and each player is not aware of the degree of polynomial employed for others. The players distribute shares in terms of subshares. We show a surprising result on the deterministic protocol for rational secret sharing problem in synchronous model. This is the first protocol that achieves rational secret sharing in a reasonable model to the best of our knowledge.

No abstract

No abstract

<abstract><p>Chemical engineers can model numerous interactions in a process using incidence graphs. They are used to methodically map out a whole network of interconnected processes and controllers to describe each component's impact on the others. It makes it easier to visualize potential process paths or a series of impacts. A Pythagorean fuzzy set is an effective tool to overcome ambiguity and vagueness. In this paper, we introduce the concept of Pythagorean fuzzy incidence graphs. We discuss the incidence path and characterize the strongest incidence path in Pythagorean fuzzy incidence graphs. Furthermore, we propose the idea of Pythagorean fuzzy incidence cycles and Pythagorean fuzzy incidence trees in Pythagorean fuzzy incidence graphs and give some essential results. We illustrate the notions of Pythagorean fuzzy incidence cut vertices, Pythagorean fuzzy incidence bridges, and Pythagorean fuzzy incidence cut pairs. We also establish some results about Pythagorean fuzzy incidence cut pairs. Moreover, we study the types of incidence pairs and determine some crucial results concerning strong incidence pairs in the Pythagorean fuzzy incidence graph. We also obtain the characterization of Pythagorean fuzzy incidence cut pairs using $ \alpha $-strong incidence pairs and find the relation between Pythagorean fuzzy incidence trees and $ \alpha $-strong incidence pairs. Finally, we provide the application of Pythagorean fuzzy incidence graphs in the illegal wildlife trade.</p></abstract>