Repeated Games for Generating Randomness in Encryption

Abstract

In encryption schemes, the sender may not generate randomness properly if generating randomness is costly, and the sender is not concerned about the security of a message. The problem was studied by the first author (2016), and was formalized in a game-theoretic framework. In this work, we construct an encryption scheme with an optimal round complexity on the basis of the mechanism of repeated games.

Perfectly Secure Message Transmission Against Rational Adversaries

“…Since then, rational secret sharing has been intensively studied [9], [10], [11], [12], [13], [14], [15]. Moreover, there have been many studies using game-theoretic analysis of cryptographic primitives/protocols, including two-party computation [16], [17], leader election [18], [19], Byzantine agreement [20], consensus [21], public-key encryption [22], [23], delegation of computation [24], [25], [26], [27], [28], [29], and protocol design [30], [31]. Among them, several works [20], [24], [25], [27], [30] used the rationality of adversaries to circumvent the impossibility results.…”

Perfectly Secure Message Transmission Against Rational Timid Adversaries

“…Since then, rational secret sharing has been intensively studied [1,19,31,32,4,12,30]. Moreover, there have been many studies using game-theoretic analysis of cryptographic primitives/protocols, including two-party computation [3,21], leader election [20,2], Byzantine agreement [22], consensus [26], public-key encryption [40,42], delegation of computation [5,23,7,24,8,28], and protocol design [16,17]. Among them, several works [22,5,23,24,16] used the rationality of adversaries to circumvent the impossibility results.…”