## Cryptology ePrint Archive: Report 1997/013

Visual Authentication and Identification

Moni Naor, Benny Pinkas.

Abstract: The problems of authentication and identification have received wide interest in cryptographic research. However, there has been no satisfactory solution for the problem of authentication by a human recipient who does not use any trusted computational device. The problem of authentication arises for example in the context of smartcard--human interaction, in particular in the context of electronic wallets. The problem of identification is ubiquitous in communication over insecure networks.

This paper introduces visual authentication and visual identification methods, which are authentication and identification methods for human users based on visual cryptography. These methods are very natural and easy to use, and can be implemented using very common low tech'' technology. The methods we suggest are efficient in the sense that a single transparency can be used for several authentications or for several identifications. The visual authentication methods we suggest are not limited to authenticating textual messages, and can be used to authenticate any image.

An important contribution of this paper is the introduction of a framework for proving the security of protocols in which humans take an active part. We rigorously prove the security of our schemes using this framework.

Category / Keywords:

Publication Info: Appeared in the THEORY OF CRYPTOGRAPHY LIBRARY and has been included in the ePrint Archive.