RSA-based Password-Authenticated Key Retrieval using multiple servers

Abstract

A PAKR (Password-Authenticated Key Retrieval) protocol and its multi-server system allow one party (say, client), who has a rememberable password, to retrieve a long-term static key in an exchange of messages with at least one other party (say, server) that has a private key. In this paper, we propose an RSA-based PAKR (for short, RSA-PAKR) protocol using multiple n servers, and then show that the RSA-PAKR protocol provides security of passwords and static keys against an attacker who takes full control of n - 1 servers. Several aspects of the RSA-PAKR protocol and its extension (including efficiency improvements, implementation issue and extension for distinguishing on-line dictionary attacks) are followed.