# Constructing Optimal Authentication Codes with Perfect Multi-fold Secrecy

## TL;DR

This paper presents a combinatorial design-based method for constructing optimal authentication codes that achieve perfect multi-fold secrecy, including an infinite class offering two-fold security and secrecy against spoofing attacks.

## Contribution

It introduces a new construction of optimal authentication codes with perfect multi-fold secrecy, extending previous work and answering an open question from 2009.

## Key findings

- First infinite class of optimal codes with two-fold security and secrecy
- Codes achieve perfect multi-fold secrecy using combinatorial designs
- Advances security in authentication codes against spoofing attacks

## Abstract

We establish a construction of optimal authentication codes achieving perfect multi-fold secrecy by means of combinatorial designs. This continues the author's work (ISIT 2009) and answers an open question posed therein. As an application, we present the first infinite class of optimal codes that provide two-fold security against spoofing attacks and at the same time perfect two- fold secrecy.