sybil attacks against mobile users

_ _

I did my PhD @

University

College

London

<PhD>

Ratings on ...

Ratings on phones

Why ratings on mobiles?

Situation: People exchange

digital content

People

The problem is ...

drowning user (content overload)

help!

who will come to the rescue?

Proposal: Accept content onlyfrom reputable people

UseStore

UseStoreMobiRate[Ubicomp08]

UseStore LDTP[ICDM07]

MobiRate[Ubicomp08]

MobID

Collaborative applications:

track trustworthiness of IDs

one misbehaves & creates bogus identities

(goes untraceable)

Traditional Solutions

pki

p2p socnet

fast mixing & no churn

1. u’ve got friends: honest & key-enabled!2. u don’t move randomly3. homophily: P(honesthonest)=HIGH

assumptions

“A meets B”@A:1. B&co. into its network2. rank B3. accept/reject B

device keeps 2 nets & reasons on them

1. B&co. into networks2. 2 ranks for B3. accept/reject B 4. update networks`

“A meets B”

GoodRank

BadRank BC

D E FG

L

M NO

P

GoodRank

BadRank B

C

DE F

G

L

M N

O

P

Does it work?

issue 1: social exclusion

MobID + FriendSensing

FriendSensing ((.))

Keep Bluetooth on(record who is around)

Upload records

People you may know

People You May Know

Forrest Gump

Bambie

Barack Obama

Add to Friends

Add to Friends

Add to Friends

MobID + FriendSensing

If you are looking for Kinky boots

issue 2

whether you are …

a woman…

or a man a woman…

Thorny problem:

… or a woman…How to keep it secret