How to Identify and Authenticate Users in Massive Unsourced Random Access

TL;DR

This paper proposes a scheme that enables user identification and authentication in unsourced random access systems by integrating message authentication codes, addressing a key limitation of traditional U-RA protocols.

Contribution

It introduces a novel method to perform user identification and authentication within U-RA protocols using MACs, without compromising the core principles of U-RA.

Findings

The scheme successfully provides user authentication in U-RA systems.

It maintains the i.i.d. codeword selection principle of U-RA.

The approach enhances security without significant overhead.

Abstract

Identification and authentication are two basic functionalities of traditional random access protocols. In ALOHA-based random access, the packets usually include a field with a unique user address. However, when the number of users is massive and relatively small packets are transmitted, the overhead of including such field becomes restrictive. In unsourced random access (U-RA), the packets do not include any address field for the user, which maximizes the number of useful bits that are transmitted. However, by definition an U-RA protocol does not provide user identification. This paper presents a scheme that builds upon an underlying U-RA protocol and solves the problem of user identification and authentication. In our scheme, the users generate a message authentication code (MAC) that provides these functionalities without violating the main principle of unsourced random access: the selection of codewords from a common codebook is i.i.d. among all users.