Title
pASSWORD tYPOS and How to Correct Them Securely
Abstract
We provide the first treatment of typo-tolerant password authentication for arbitrary user-selected passwords. Such a system, rather than simply rejecting a login attempt with an incorrect password, tries to correct common typographical errors on behalf of the user. Limited forms of typo-tolerance have been used in some industry settings, but to date there has been no analysis of the utility and security of such schemes. We quantify the kinds and rates of typos made by users via studies conducted on Amazon Mechanical Turk and via instrumentation of the production login infrastructure at Dropbox. The instrumentation at Dropbox did not record user passwords or otherwise change authentication policy, but recorded only the frequency of observed typos. Our experiments reveal that almost 10% of login attempts fail due to a handful of simple, easily correctable typos, such as capitalization errors. We show that correcting just a few of these typos would reduce login delays for a significant fraction of users as well as enable an additional 3% of users to achieve successful login. We introduce a framework for reasoning about typo-tolerance, and investigate the seemingly inherent tension here between security and usability of passwords. We use our framework to show that there exist typo-tolerant authentication schemes that can get corrections for "free": we prove they are as secure as schemes that always reject mistyped passwords. Building off this theory, we detail a variety of practical strategies for securely implementing typo-tolerance.
Year
DOI
Venue
2016
10.1109/SP.2016.53
2016 IEEE Symposium on Security and Privacy (SP)
Keywords
Field
DocType
Password,Typos,Authentication,Correction,Error,Mistakes
Internet privacy,Password strength,Computer security,Computer science,Login,Password psychology,S/KEY,One-time password,Password policy,Password,Cognitive password
Conference
ISSN
ISBN
Citations 
1081-6011
978-1-5090-0825-4
9
PageRank 
References 
Authors
0.47
23
5
Name
Order
Citations
PageRank
Rahul Chatterjee1458.47
Anish Athayle23419.83
Devdatta Akhawe357424.75
Ari Juels47263590.42
Thomas Ristenpart53390149.67