# Quantum Identity Authentication

## Functionality[edit]

Authentication is a building block which proves something is true or genuine between two parties, the suppliant (prover) and the authenticator (verifier). There are two types of authentication, data authentication and identity authentication. In data authentication, the authenticator checks the claim in a non-interactive process called offline mode, i.e. there is no interaction after the message has been sent. In identity authentication, the parties perform an interactive protocol where suppliant proves the possession of some unique data. For classical data authentication, an information-theoretic secure (unconditionally secure) protocol has been provided in (1). For quantum data authentication, see Authentication of Quantum Messages. For identity authentication, the classical schemes are based on computational hardness assumptions of some problem and are further secured by public-key algorithms but it is known that quantum computers pose a threat to public key cryptography and can do exponentially better with such computational problems, thus rendering classical protocols insecure.

## Properties[edit]

- The security of the protocol requires that no sensitive information is exchanged during its execution can leak to the eavesdropper.