Kirby: A Robust Permutation-Based PRF Construction

ePrint Report: Kirby: A Robust Permutation-Based PRF Construction

Charlotte Lefevre, Yanis Belkheyar, Joan Daemen

We present a construction, called Kirby, for building a variable-input-length pseudorandom function (VIL-PRF) from a $b$-bit permutation. For this construction we prove a tight bound of $b/2$ bits of security on the PRF distinguishing advantage in the random permutation model and in the multi-user setting. Similar to full-state keyed sponge/duplex, it supports full-state absorbing and additionally supports full-state squeezing, where the latter can at most squeeze …

bits called construction eprint report function input length prove random report security variable