Verifiable Random Functions: Relations to Identity-Based Key Encapsulation and New Constructions

Informally, a VRF (Verifiable Random Functions) behaves like a pseudo-random function but also allows for efficient verification. More precisely, this means that there is a public key pk and a function F associated with a secret key sk (the seed) such that the following properties are satisfied. In this paper the authors show a relation between the notions of Verifiable Random Functions (VRFs) and Identity-Based Key Encapsulation Mechanisms (IB-KEMs). In particular, they propose a class of IB-KEMs that they call VRF-suitable, and they propose a direct construction of VRFs from VRF-suitable IB-KEMs.