General Security Definition and Composability for Quantum & Classical Protocols

TL;DR

This paper extends the universally composable security framework to quantum protocols, introducing a new model that simplifies and naturally handles protocols with multiple layers of sub-protocols.

Contribution

It generalizes Canetti's UC security definition to the quantum setting and develops a new, more adaptable model for quantum and classical protocols.

Findings

Unified framework for quantum and classical protocol composition

Simplified security definitions for multi-layer protocols

Model naturally accommodates protocols with arbitrary sub-protocol layers

Abstract

We generalize the universally composable definition of Canetti to the Quantum World. The basic idea is the same as in the classical world. The main contribution is that we unfold the result in a new model which is well adapted to quantum protocols. We also simplify some aspects of the classical case. In particular, the case of protocols with an arbitrary number of layers of sub-protocols is naturally covered in the proposed model.