# Authentication by Witness Functions

## TL;DR

This paper extends witness functions from proving secrecy to verifying authentication in cryptographic protocols, demonstrating their safe application and analyzing a modified Woo-Lam protocol for authentication correctness.

## Contribution

It introduces the use of witness functions for authentication and provides a method to analyze protocols for authentication correctness.

## Key findings

- The modified Woo-Lam protocol is correct with respect to authentication.
- Witness functions can be safely extended from secrecy to authentication.
- The paper offers a new approach to protocol analysis for authentication.

## Abstract

Witness functions have recently been introduced in cryptographic protocols' literature as a new powerful way to prove protocol correctness with respect to secrecy. In this paper, we extend them to the property of authentication. We show how to use them safely and we run an analysis on a modified version of the Woo-Lam protocol. We show that it is correct with respect to authentication.