Cryptology ePrint Archive: Report 2014/731

Secure modular password authentication for the web using channel bindings

Mark Manulis and Douglas Stebila and Nick Denham

Abstract: Secure protocols for password-based user authentication are well-studied in the cryptographic literature but have failed to see wide-spread adoption on the Internet; most proposals to date require extensive modifications to the Transport Layer Security (TLS) protocol, making deployment challenging. Recently, a few modular designs have been proposed in which a cryptographically secure password-based mutual authentication protocol is run inside a confidential (but not necessarily authenticated) channel such as TLS; the password protocol is bound to the established channel to prevent active attacks. Such protocols are useful in practice for a variety of reasons: security no longer relies on users' ability to validate server certificates and can potentially be implemented with no modifications to the secure channel protocol library.

We provide a systematic study of such authentication protocols. Building on recent advances in modelling TLS, we give a formal definition of the intended security goal, which we call password-authenticated and confidential channel establishment (PACCE). We show generically that combining a secure channel protocol, such as TLS, with a password authentication protocol, where the two protocols are bound together using either the transcript of the secure channel's handshake or the server's certificate, results in a secure PACCE protocol. Our prototype based on TLS is available as a cross-platform client-side Firefox browser extension and a server-side web application which can easily be installed on deployed web browsers and servers.

Category / Keywords: cryptographic protocols / password authentication, Transport Layer Security, channel binding

Original Publication (with major differences): 1st International Conference on Research in Security Standardisation (SSR) 2014

Date: received 19 Sep 2014

Contact author: stebila at qut edu au

Available format(s): PDF | BibTeX Citation

Version: 20140919:212023 (All versions of this report)

Short URL: ia.cr/2014/731

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