[MPZ20] Unifying Generic Group Models

Authors: Maurer, Ueli; Portmann, Christopher; Zhu, Jiamin | Venue: ePrint 2020/996 | Source

Abstract

Several different generic group models have appeared in the literature, making it difficult to compare results and match lower and upper bounds. This paper develops a unifying framework: a model is viewed as a set of games with the same type of adversary interactions, and models are compared via standard game reductions. Using this framework, the authors establish a hierarchy of GGM variants parameterized by the set of queries available to the adversary, and disprove the claimed equivalence between Shoup’s and Maurer’s formulations by exhibiting a separation. They show that the two models differ in how equality-testing interacts with the group presentation, and clarify exactly which reductions between them hold.