[PPT] - User authentication on the web Joseph Bonneau jcb82@cl.cam.ac.uk PowerPoint Presentation

SLIDE 1

User authentication on the web

Joseph Bonneau jcb82@cl.cam.ac.uk

Computer Laboratory

SOCIALNETS workshop November 18, 2010

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 1 / 10

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Looming authentication challenges

1

The old world

2

The emerging world

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 1 / 10

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WEIS 2010: Large study of password deployments

“Identity” websites

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 2 / 10

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WEIS 2010: Large study of password deployments

“E-Commerce” websites

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 2 / 10

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WEIS 2010: Large study of password deployments

“Content” websites

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 2 / 10

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WEIS 2010: Large study of password deployments

Mozilla Firefox v 3.5.8 with: Autofill Forms 0.9.5.2 CipherFox 2.3.0 Cookie Monster 0.98.0 DOM Inspector 2.0.4 Greasemonkey 0.8.20100211.5 Screengrab 0.96.2 Tamper Data 11.0.1

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 2 / 10

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WEIS 2010: Large study of password deployments

feature scoring enrolment Password selection advice given +1 pt Minimum password length required +1 pt Dictionary words prohibited +1 pt Numbers or symbols required +1 pt User list protected from probing +1 pt Cleartext password sent in email after enrolment −1 pt login Password hashed in-browser before POST +1 pt Limits placed on password guessing +1 pt User list protected from probing +1 pt Federated identity login accepted +1 pt password update Password re-entry required to authorise update +1 pt Notification email sent after password reset +1 pt password recovery Password update required after recovery +1 pt Cleartext password sent in email upon request −1 pt User list protected from probing +1 pt encryption Full TLS for all password submission +2 pts POST only TLS for password submission +1 pt

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 2 / 10

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The realities of web authentication

100 200 300 400 500 Traffic rank 0.0 0.2 0.4 0.6 0.8 1.0 Proportion of sites collecting passwords

Frequency of password collection

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 2 / 10

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The realities of web authentication

∼ all websites collect email address as username ∼ all websites use email for password reset ∼ all websites use persistent login cookies by default

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 3 / 10

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Many schoolbook errors are quite common

29-50% of sites store passwords in the clear

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Many schoolbook errors are quite common

RockYou SQL injection hack January 2010

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Many schoolbook errors are quite common

countermeasure I E C Tot. CAPTCHA 11 2 1 14 timeout 2 1 2 5 reset 1 3 1 5 none 37 43 46 126 Many websites allow unlimited brute-force guessing

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Many schoolbook errors are quite common

Ask

User probing is rarely prevented

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Many schoolbook errors are quite common

interface I E C Tot. enrolment 4 1 1 6 login 43 41 38 132 reset 11 7 2 20 all 1 1 2 User probing is rarely prevented

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Many schoolbook errors are quite common

0.0 0.2 0.4 0.6 0.8 1.0 success rate α 5 10 15 20 25 30 35 40 marginal guesswork ˜ µα

Password [RockYou] Password [Klein] Password [Spafford] Password [Schneier]

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Many schoolbook errors are quite common

TLS Deployment I E C Tot. Full 10 39 10 59 Full/POST 3 1 1 5 Inconsistent 14 6 5 25 None 23 4 34 61 TLS deployment remains uneven, poorly done

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Many schoolbook errors are quite common

Firesheep

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 4 / 10

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Security policies vary far more than requirements

1 2 3 4 5 6 7 8 9 10

No TLS, no password requirements, cleartext passwords emailed, no guessing or user probing restrictions, email addresses verified No TLS, no password requirements or advice, emailed temp. passwords for reset, no password advice, no guessing or user probing restrictions, email addresses verified TLS deployed, 6 char. min. password, emailed reset links, no password advice, no guessing or user probing restrictions, email addresses not verified No TLS, 6 char. min. password, personal knowledge questions for reset, no password advice, no guessing or user probing restrictions, email addresses verified TLS deployed, 6 char. min. password, emailed reset links, no password advice, guessing restrictions in place, email addresses verified

Sac. Bee

philly.com

Nashv. Scene

Victoria’s S. $ Macy’s $ eBooks

Huff. Post

USA Today Ask Jeeves TalkBizNow EmailAccount Topeka C.-J. PhotoBucket $ Mail2World Canada.com Mail.com StumbleUpon Football Fan. Indian Express Fertility Fr. CD Wow Milwaukee J. S. Florida-Times U. The Pirate Bay SoftHome The Guardian TCPalm SF Chronicle LiveMocha Last.fm The Drum NY Times Forbes Truthdig The Tennessean The Courier-J. PhillyBurbs Lincoln J. S. AOL Children’s Place $ Xanga ESPN Ticket Web $ TicketMaster $ Gap $ Barnes & Noble $ IMDB Art Beads

Sus. Bus.

Seattle Weekly New York Post

Ft. Worth S.-T.

Spiegel $ Shoplet Blick Weather Und.

Fin. Times

$ Dallas M. N. Reddit CBS Sports Bodybuilding $ 3Dup Two Peas in a B. Weather Channel Post-Tribune Orlando Sent. Miami.com LA Times Houston Chron. Chicago Trib. Wasabi Sonico hi5 Gawab Rand McNally Oriental Trad. Hermes Frederick’s $ Anthropologie $ The Economist SJ Mercury News CNN CNET Bill O’Reilly ResearchGate aNobii Sierra T. P. $ Lucky Vitamin efollet.com Eddie Bauer Costco $

A. & Fitch

Times Online Press-Telegram Bloomberg Swiss Mail Plaxo Zappos! $ REI $ Overstock $ Home Depot $ DVD Empire $ Build-A-Bear W. Best Buy $ Bath & Body W. Reuters $ Walmart $ Things Rem. Target $ ShopBop $ Sephora $ Sears $ NewEgg $ Horchow $ Amazon $ ZZ Network TigerDirect $ rediff Times of India On The Snow Topix

Ass. Cont.

Twitter

W. S. Journal

LinkedIn Digg Craigslist Deviant Art $ Hushmail Fairfax Dig. Cafe Press $ MS Live Wordpress

Wash. Post

Yahoo! Ebay $ Mixx Wikipedia LiveJournal $ CNBC Facebook $ Gamespot AliBaba $ Google $ MySpace IKEA Godmail JCPenney $ Buy.com $ The Golf World Legend Identity site E-commerce site Content site Payment $ Cluster of sites

score

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 5 / 10

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More popular sites do better

10 1E-2 1E-1 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 password score page views per million E-commerce News/Customization User interaction

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 6 / 10

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Economic failures

Bad websites can do real damage to good ones Password insecurity is a negative externality Password over-collection is a tragedy of the commons

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 7 / 10

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Economic failures

Bad websites can do real damage to good ones Password insecurity is a negative externality Password over-collection is a tragedy of the commons

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 7 / 10

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Economic failures

Bad websites can do real damage to good ones Password insecurity is a negative externality Password over-collection is a tragedy of the commons

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 7 / 10

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Looming authentication challenges

1

The old world

2

The emerging world

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 7 / 10

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OpenID—Single sign-on

R Relying party (www.example.com) P OpenID Provider (Facebook, Google, etc.) UE End user (a human) UA User agent (a browser) UE − → R I’m U@P!

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

R Relying party (www.example.com) P OpenID Provider (Facebook, Google, etc.) UE End user (a human) UA User agent (a browser) UE − → R I’m U@P! R ← → P KR-P, n ← D-H key exchange

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

R Relying party (www.example.com) P OpenID Provider (Facebook, Google, etc.) UE End user (a human) UA User agent (a browser) UE − → R I’m U@P! R ← → P KR-P, n ← D-H key exchange UE ← − R OK, go verify with P (HTTP 302) UE − → P I want to talk to R, who you share n with

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

R Relying party (www.example.com) P OpenID Provider (Facebook, Google, etc.) UE End user (a human) UA User agent (a browser) UE − → R I’m U@P! R ← → P KR-P, n ← D-H key exchange UE ← − R OK, go verify with P (HTTP 302) UE − → P I want to talk to R, who you share n with UE ← − P Sure you want to talk to R?

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

OpenID

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

R Relying party (www.example.com) P OpenID Provider (Facebook, Google, etc.) UE End user (a human) UA User agent (a browser) UE − → R I’m U@P! R ← → P KR-P, n ← D-H key exchange UE ← − R OK, go verify with P (HTTP 302) UE − → P I want to talk to R, who you share n with UE ← − P Sure you want to talk to R? UE − → P Yes, here’s my password: p

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

R Relying party (www.example.com) P OpenID Provider (Facebook, Google, etc.) UE End user (a human) UA User agent (a browser) UE − → R I’m U@P! R ← → P KR-P, n ← D-H key exchange UE ← − R OK, go verify with P (HTTP 302) UE − → P I want to talk to R, who you share n with UE ← − P Sure you want to talk to R? UE − → P Yes, here’s my password: p UE ← − P Okay, use MACKR-P(U, P) (HTTP 302) UE − → R MACKR-P(U, P)! See, I’m U@P

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

Yahoo!

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OpenID—Single sign-on

R Relying party (www.example.com) P OpenID Provider (Facebook, Google, etc.) UE End user (a human) UA User agent (a browser) UE − → R I’m U@P! R ← → P KR-P, n ← D-H key exchange UA ← − R OK, go verify with P (HTTP 302) UA − → P I want to talk to R, here’s my cookie c UA ← − P Okay, use MACKR-P(U, P) UA − → R MACKR-P(U, P)! See, I’m U@P (auth-immediate)

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OAuth—Delegating API access

The Dark Ages

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

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OAuth—Delegating API access

The Middle Ages

1

Facebook Connect

2

Google AuthSub

3

Yahoo BBAuth

4

Twitter API: HTTP basic-authentication

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

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OAuth—Delegating API access

1

App registration

2

Access request

3

User approval

4

API Access

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

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OAuth—Delegating API access

1

App registration

2

Access request

3

User approval

4

API Access

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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OAuth—Delegating API access

1

App registration

2

Access request

3

User approval

4

API Access

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 7 / 10

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OAuth—Delegating API access

PLAINTEXT: M||Kapp||Kuser HMAC_SHA1: MACKapp||Kuser(M) RSA_SHA1: SignKapp(M)

1

App registration

2

Access request

3

User approval

4

API Access

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 6 / 10

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OAuth—Delegating API access

Open issues

1

Standardisation

2

Branding

3

Security level

4

Service discovery

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 6 / 10

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Interaction via iframe

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 7 / 10

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Preventing surrepititious authentication

<img id="test" style="display:none"> <script> test = document.getElementById(’test’); var start = new Date(); test.onerror = function() { time = new Date() - start;} test.src = "http://www.example.com/"; </script>

Bortz et al. 2007

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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Preventing surrepititious authentication

# Send users to my detector... <iframe name="detector" width="0" height="0" frameborder="0" src="https://docs.google.com/document/d/ 1TUV9x1lFAQcVWvhP4EAHQZIPrVmo3_vrz5Sz8Wo"> </iframe>

Narayanan 2009

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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Preventing surrepititious authentication

Narayanan 2009

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 8 / 10

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Workable backup authentication

Web search

Reaching a head with OSNs

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)

SOCIALNETS November 18, 2010 9 / 10

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Workable backup authentication

0.0 0.2 0.4 0.6 0.8 1.0 success rate α 5 10 15 20 25 30 35 40 marginal guesswork ˜ µα

Forename Surname Password [RockYou] Password [Klein] Password [Spafford] Password [Schneier]

Personal knowledge worse than passwords (Bonneau et al. 2010)

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

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Workable backup authentication

Google—backup authentication by mobile phone

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

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Workable backup authentication

Schecther et al. 2008

MS Live (proposed)—social backup authentication

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

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Workable backup authentication

Schecther et al. 2008

MS Live (proposed)—social backup authentication

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

SLIDE 50

Workable backup authentication

Facebook—social questions backup

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

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Workable backup authentication

Facebook—social questions backup

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 9 / 10

SLIDE 52

Questions

jcb82@cl.cam.ac.uk

J. Bonneau (U. of Cambridge)

SOCIALNETS November 18, 2010 10 / 10