ppoprf

An implementation of the Puncturable Partially Oblivious Pseudorandom Function designed in https://arxiv.org/abs/2109.10074.

lib.rs:

This module defines the combined functionality for producing a puncturable partially oblivious pseudorandom function (PPOPRF) protocol. The protocol combines the PPOPRF of Tyagi et al. with the classic GGM puncturable PRF.

The result is a POPRF that can provide forward-security guarantees related to the pseudorandomness of client-side outputs, by allowing the puncturing of metadata tags from the server secret key. Such guarantees hold when clients reveal POPRF outputs for a metadata tag t, after t has been punctured from the secret key. This functionality is used to provide forward-secure randomness to clients in the STAR protocol.