Tweakable Pseudorandom Permutation from Generalized Feistel Structure

Abstract

Tweakable pseudorandom permutations have wide applications such as the disk sector encryption, and the underlying primitive for efficient MACs and authenticated encryption schemes. Goldenberg et al. showed constructions of a tweakable pseudorandom permutation based on the Feistel structure. In this paper, we explore the possibility of designing tweakable pseudorandom permutations based on the Generalized Feistel Structure. We show that tweakable pseudorandom permutations can be obtained without increasing the number of rounds compared to the non-tweakable versions. We also present designs that take multiple tweaks as input.