Modeling Social Networking Privacy Carolina Dania IMDEA Software - - PowerPoint PPT Presentation

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Modeling Social Networking Privacy Carolina Dania IMDEA Software - - PowerPoint PPT Presentation

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Modeling Social Networking Privacy Carolina Dania IMDEA Software Institute - Spain Universidad Complutense de Madrid (Partially funded by NeSSOS) Supervisors Manuel Clavel Marina Egea IMDEA Software Institute Atos Research & Innovation

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Modeling Social Networking Privacy

Carolina Dania

IMDEA Software Institute - Spain Universidad Complutense de Madrid

(Partially funded by NeSSOS)

Supervisors

Manuel Clavel

IMDEA Software Institute Universidad Complutense de Madrid

Marina Egea

Atos Research & Innovation Dept.

Tuesday, February 21, 12

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SLIDE 2

Outline

  • Social Networks
  • Research project
  • Privacy
  • Facebook
  • Goals
  • Requirements
  • Preliminary results
  • Research plan
  • Example

Tuesday, February 21, 12

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Outline

  • Social Networks
  • Research project
  • Privacy
  • Facebook
  • Goals
  • Requirements
  • Preliminary results
  • Research plan
  • Example

Tuesday, February 21, 12

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SLIDE 4

Social Networks

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Social Networks

  • online services that reflect social relations

among people. E.g. shared interests and/or activities

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Social Networks

  • Many people act as “Internet natives”
  • online services that reflect social relations

among people. E.g. shared interests and/or activities

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Social Networks

  • Many people act as “Internet natives”
  • when they need information, they open a

browser and search for it

  • online services that reflect social relations

among people. E.g. shared interests and/or activities

Tuesday, February 21, 12

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Social Networks

  • Many people act as “Internet natives”
  • when they need information, they open a

browser and search for it

  • when they want to share information, they

post it on a social network

  • online services that reflect social relations

among people. E.g. shared interests and/or activities

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Facebook

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Facebook

  • is the leader among social networking sites

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Facebook

  • created by Mark Zuckerberg in 2004
  • is the leader among social networking sites

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Facebook

  • has more than 800 million users,
  • the users upload, on average, 250 million

photos per day

  • created by Mark Zuckerberg in 2004
  • some figures:
  • is the leader among social networking sites

Tuesday, February 21, 12

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SLIDE 13

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Everybody knows Facebook

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You are in Facebook! Everybody knows Facebook

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SLIDE 21

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SLIDE 22

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SLIDE 23

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SLIDE 24

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SLIDE 25

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Privacy on social networks

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Privacy on social networks

  • is a growing concern among the users of

social networking sites, and their developers

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Privacy on social networks

  • is a growing concern among the users of

social networking sites, and their developers “I also understand that many people are just naturally skeptical of what it means for hundreds of millions of people to share so much personal information online, especially using any one service...” M. Zuckerberg. Nov 2011

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Privacy on social networks

  • is a growing concern among the users of

social networking sites, and their developers “I also understand that many people are just naturally skeptical of what it means for hundreds of millions of people to share so much personal information online, especially using any one service...” M. Zuckerberg. Nov 2011 “Many policies and procedures that are in

  • peration are not formally documented.

This should be remedy.” Irish Data Protection

  • Commissioner. Dec 2011

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Privacy

  • n Facebook

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Privacy

  • n Facebook
  • is difficult to understand

e.g. when tagging policies and privacy settings conflict each other

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Privacy

  • n Facebook
  • is difficult to understand

e.g. when tagging policies and privacy settings conflict each other

  • has been in a constant state of flux and is

prompted to change again soon

Tuesday, February 21, 12

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Privacy

  • n Facebook
  • is difficult to understand

e.g. when tagging policies and privacy settings conflict each other

  • has been in a constant state of flux and is

prompted to change again soon

  • is only informally and partially described

Tuesday, February 21, 12

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SLIDE 34

Outline

  • Social Networks
  • Research project
  • Privacy
  • Facebook
  • Goals
  • Requirements
  • Preliminary results
  • Research plan
  • Example

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SLIDE 35

Posting and Tagging

(from Facebook Help Center)

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Posting and Tagging

(from Facebook Help Center)

  • What is tagging and how does it work? A tag links

a person (...) to something that you post.

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Posting and Tagging

(from Facebook Help Center)

  • When I tag someone in a photo or post, who can

see it?

  • What is tagging and how does it work? A tag links

a person (...) to something that you post.

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Posting and Tagging

(from Facebook Help Center)

  • When I tag someone in a photo or post, who can

see it?

  • 1. The audience you selected for your post
  • 2. Friends of the person you tagged (if the audience is

set to ‘Friends’ or more)

  • What is tagging and how does it work? A tag links

a person (...) to something that you post.

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Example (friendship)

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Example (friendship)

Alice

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Example (friendship)

Alice Bob

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Example (friendship)

Alice Ted Bob

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Example (friendship)

Alice Ted Bob Peter

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Example (friendship)

Alice Ted Bob Peter

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Example (friendship)

Alice Ted Bob Peter

Bob is friend of Alice and Ted

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Example (friendship)

Alice Ted Bob Peter

Bob is friend of Alice and Ted Ted is friend

  • f Peter

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Example (friendship)

Alice Ted Bob Peter

Bob is friend of Alice and Ted Ted is friend

  • f Peter
  • Peter is not friend of Alice and Bob

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Example (friendship)

Alice Ted Bob Peter

Bob is friend of Alice and Ted Ted is friend

  • f Peter
  • Peter is not friend of Alice and Bob
  • Ted is not friend of Alice

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Example . .

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Example . .

Alice Ted Bob Peter

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Bob tags Ted in this photo

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Can Peter see this photo in Alice’s wall?

Bob tags Ted in this photo

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Can Peter see this photo in Alice’s wall? Yes

Bob tags Ted in this photo

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Can Peter see this photo in Alice’s wall?

Scenario 2: Bob posts a photo in Alice’s wall where the default audience is set to ‘Friends’

Yes

Bob tags Ted in this photo

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Can Peter see this photo in Alice’s wall?

Scenario 2: Bob posts a photo in Alice’s wall where the default audience is set to ‘Friends’

Yes

Bob tags Ted in this photo Bob tags Ted in this photo

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Can Peter see this photo in Alice’s wall?

Scenario 2: Bob posts a photo in Alice’s wall where the default audience is set to ‘Friends’

Yes Can Peter see this photo in Alice’s wall?

Bob tags Ted in this photo Bob tags Ted in this photo

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Can Peter see this photo in Alice’s wall?

Scenario 2: Bob posts a photo in Alice’s wall where the default audience is set to ‘Friends’

Yes No. Can Peter see this photo in Alice’s wall?

Bob tags Ted in this photo Bob tags Ted in this photo

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Example . .

Scenario 1: Alice posts a photo in her wall and set its audience to “Friends”

Alice Ted Bob Peter

Can Peter see this photo in Alice’s wall?

Scenario 2: Bob posts a photo in Alice’s wall where the default audience is set to ‘Friends’

Yes No. Can Peter see this photo in Alice’s wall?

Bob tags Ted in this photo Bob tags Ted in this photo

Why?

Tuesday, February 21, 12

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Outline

  • Social Networks
  • Research project
  • Privacy
  • Facebook
  • Goals
  • Requirements
  • Preliminary results
  • Research plan
  • Example

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SLIDE 61

Goals

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Goals

  • develop a methodology for modeling and

analyzing social networking privacy policies

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Goals

  • modeling means for us to use formal model

with rigorous semantics

  • develop a methodology for modeling and

analyzing social networking privacy policies

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Goals

  • analyzing means for us to use formal

methods (as automated as possible)

  • modeling means for us to use formal model

with rigorous semantics

  • develop a methodology for modeling and

analyzing social networking privacy policies

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Goals

  • analyzing means for us to use formal

methods (as automated as possible)

  • modeling means for us to use formal model

with rigorous semantics

  • develop a methodology for modeling and

analyzing social networking privacy policies

  • validate this methodology with a case study:

modeling and analyzing Facebook’s privacy

policy

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Requirements

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Requirements

  • [modeling] it is crucial to use a language able

to formalize fine-grained access control policies (dynamic access control)

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Requirements

  • [modeling] it is crucial to use a language able

to formalize fine-grained access control policies (dynamic access control)

E.g. Can Peter see a photo in Alice’s wall if Peter is a friend of Alice?

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Requirements

  • [modeling] it is crucial to use a language able

to formalize fine-grained access control policies (dynamic access control)

E.g. Can Peter see a photo in Alice’s wall if Peter is a friend of Alice?

simple RBAC is not sufficient

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Requirements

  • [modeling] it is crucial to use a language able

to formalize fine-grained access control policies (dynamic access control)

E.g. Can Peter see a photo in Alice’s wall if Peter is a friend of Alice?

  • [analyzing] it is crucial to use a language with

a formal semantics

simple RBAC is not sufficient

Tuesday, February 21, 12

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Requirements

  • [modeling] it is crucial to use a language able

to formalize fine-grained access control policies (dynamic access control)

E.g. Can Peter see a photo in Alice’s wall if Peter is a friend of Alice?

  • [analyzing] it is crucial to use a language with

a formal semantics

simple RBAC is not sufficient

E.g. XACML currently lacks of a formal semantics

Tuesday, February 21, 12

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SecureUML

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SecureUML

  • formal language for modeling fine-grained

access control policies, both static and dynamic

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SecureUML

  • formal language for modeling fine-grained

access control policies, both static and dynamic

  • dynamic access control policies depend
  • n the run-time satisfaction of

authorization constraints

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OCL

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OCL

  • a strongly typed declarative language

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OCL

  • a strongly typed declarative language
  • using OCL you can:

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OCL

  • a strongly typed declarative language
  • using OCL you can:
  • refer to any, some, or all the elements in a

scenario

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OCL

  • a strongly typed declarative language
  • using OCL you can:
  • refer to the value of any properties of any

element in a scenario

  • refer to any, some, or all the elements in a

scenario

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OCL

  • a strongly typed declarative language
  • using OCL you can:
  • refer to the value of any properties of any

element in a scenario

  • perform standard operations on primitive

types, or collections of elements in a scenario

  • refer to any, some, or all the elements in a

scenario

Tuesday, February 21, 12

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Outline

  • Social Networks
  • Research project
  • Privacy
  • Facebook
  • Goals
  • Requirements
  • Preliminary results
  • Research plan
  • Example

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Modeling Facebook

(posting and tagging)

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Modeling Facebook

(posting and tagging)

  • Facebook’s profile, walls, posts, photos, tags,

etc, can be modeled as entities, and privacy settings can be modeled as attributes

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Modeling Facebook

(posting and tagging)

  • Facebook’s profile, walls, posts, photos, tags,

etc, can be modeled as entities, and privacy settings can be modeled as attributes

  • Facebook’s privacy clauses are modeled using

OCL

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Facebook data model

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Facebook data model

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Facebook

(authorization constraints)

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Facebook

(authorization constraints)

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Facebook

(authorization constraints)

  • anybody (@caller) can read any post (@post)

that is posted in his/her wall, independently of the creator of the post

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Facebook

(authorization constraints)

  • anybody (@caller) can read any post (@post)

that is posted in his/her wall, independently of the creator of the post

@caller=@post.posted.profile

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Facebook

(authorization constraints)

  • anybody (@caller) can read any post (@post)

that is posted in his/her wall, independently of the creator of the post

@caller=@post.posted.profile

  • anybody (@caller) can read any post (@post)

that is posted in a wall when he/she is a friend of the owner of the wall and the audience selected is “Friends”

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Facebook

(authorization constraints)

  • anybody (@caller) can read any post (@post)

that is posted in his/her wall, independently of the creator of the post

@caller=@post.posted.profile

  • anybody (@caller) can read any post (@post)

that is posted in a wall when he/she is a friend of the owner of the wall and the audience selected is “Friends”

@post.posted.profile.friends->includes(@caller) and @post.audience=‘Friends’

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Facebook

(authorization constraints)

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Facebook

(authorization constraints)

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  • anybody (@caller) can read any post (@post) that is

posted in a wall,

  • when the audience selected is “Friends”,
  • he/she is a friend of somebody tagged on the post,
  • he/she is not blocked by the owner of the wall, and
  • the owner of the post happens to be the creator of

the post

Facebook

(authorization constraints)

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  • anybody (@caller) can read any post (@post) that is

posted in a wall,

  • when the audience selected is “Friends”,
  • he/she is a friend of somebody tagged on the post,
  • he/she is not blocked by the owner of the wall, and
  • the owner of the post happens to be the creator of

the post

@post.audience=‘Friends’ and @post.tags.profiling.friends->includes(@caller) and @post.posted.profile.blocks->excludes(@caller) and @post.posted.profile=@post.creator

Facebook

(authorization constraints)

Tuesday, February 21, 12

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Outline

  • Social Networks
  • Research project
  • Privacy
  • Facebook
  • Goals
  • Requirements
  • Preliminary results
  • Research plan

Tuesday, February 21, 12

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Research plan

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Research plan

  • we have formalized, using SecureUML

+OCL, the Facebook’s privacy policy for tagging and posting

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Research plan

  • we have formalized, using SecureUML

+OCL, the Facebook’s privacy policy for tagging and posting

  • our understanding of this policy is based
  • n the available information and our

“experiments”.

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Research plan (cont.)

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Research plan (cont.)

  • we plan to formalize the whole Facebook’s

privacy policy (including for advertisements, applications, and so on).

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Research plan (cont.)

  • we plan to formalize the whole Facebook’s

privacy policy (including for advertisements, applications, and so on).

  • we are trying to contact Facebook: no

success yet :-) !!!

Tuesday, February 21, 12

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Research plan (cont.)

  • we plan to formalize the whole Facebook’s

privacy policy (including for advertisements, applications, and so on).

  • we are trying to contact Facebook: no

success yet :-) !!!

  • we plan to use existing mappings from

OCL to first order logic to apply theorem proving tools to analyze the Facebook’s privacy policy.

Tuesday, February 21, 12

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Potential impact

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Potential impact

  • a tool for checking whether a person can see

a post.

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Potential impact

  • a tool for checking whether a person can see

a post.

  • a tool for assessing the risk/posibility of a

post becoming visible for a person

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Potential impact

  • a tool for checking whether a person can see

a post.

  • a tool for assessing the risk/posibility of a

post becoming visible for a person

  • a tool for assessing the impact, on the

visibility of a post, of a default privacy policy

Tuesday, February 21, 12

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Thanks!! Questions?

Tuesday, February 21, 12