Strengthening Passwords

Martin Abadi
Digital Equipment Corporation
Systems Research Center
ma@pa.dec.com

T. Mark A. Lomas
Goldman Sachs International
Information Security Department
Mark.Lomas@gs.com

Roger Needham
University of Cambridge
Computer Laboratory
and
Microsoft Research
Roger.Needham@cl.cam.ac.uk

Abstract

 
Despite their notorious vulnerability, traditional passwords remain important for security. In this paper we describe a method for strengthening passwords. Our method does not require users to memorize or to write down long passwords, and does not rely on smart-cards or other auxiliary hardware. The main cost of our method is that it lengthens the process of checking a password.

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