# Quantum-secure Pseudorandom Permutations

This is a long due note concerning constructing quantum-secure pseudorandom permutations (QPRP), a problem that has made my collaborators (Andrew Childs, Shih-Han Hung, Zhengfeng Ji) and myself excited as well as disappointed a couple of times over the past few years. In a way this makes it a perfect fit for the debut post of this blog. A while ago, Mark Zhandry observed in a note that some existing constructions are immediately quantum-secure for simple reasons, hence confirming the existence of QPRPs.