Multi-User Security of the Sum of Truncated Random Permutations (Full Version)

Web: https://iacr.org/news/item/19116

ePrint Report: Multi-User Security of the Sum of Truncated Random Permutations (Full Version)

Wonseok Choi, Hwigyeom Kim, Jooyoung Lee, Yeongmin Lee

For several decades, constructing pseudorandom functions from pseudorandom permutations, so-called Luby-Rackoff backward construction, has been a popular cryptographic problem. Two methods are well-known and comprehensively studied for this problem: summing two random permutations and truncating partial bits of the output from a random permutation. In this paper, by combining both summation and truncation, we propose new Luby-Rackoff backward constructions, …

eprint report full random security user security version