1

Steven Whang, Hector Garcia-Molina Stanford University

Managing Information Leakage

2

3

4

5

6

7

8

Information Leakage

Joseph

9

Joseph

Information Leakage

10

Model

•  p = {<N,n1>,<C,c1>,<C,c2>,<P,p1>,<A,a1>} • D ={s={<N,n1>,<C,c1>,<P,p1>},

t= {<N,n1>,<C,c2>}} • M(x,y) = true if same N,C or N,P •  µ(x,y) = x U y

11

Record Leakage

•  p = {<N,n1>,<C,c1>,<C,c2>,<P,p1>,<A,a1>} •  r = {<N,n1>,<C,c1>,<P,x>} • Lr(p, r) = |p∩r|-|r-p| = 2-1 = 1 –  In general, Lr can be any function

12

Query Leakage

•  q = {<N,n1>,<C,c1>}

13

Query Leakage

•  q = {<N,n1>,<C,c1>}

14

Query Leakage

•  q = {<N,n1>,<C,c1>}

15

q

t s

Query Leakage

•  q = {<N,n1>,<C,c1>}

16

q

t s

µ(q,s)

Query Leakage

•  q = {<N,n1>,<C,c1>} • Lq(p, q, D)

= max{Lr(p, µ(q,s))} = max{3} = 3

17

q

t s

µ(q,s)

Database Leakage

• Ld(p, D) = max{Lq(p, s, D-{s}), Lq(p, t, D-{t})} = max{Lr(p, s), Lr(p, t)} = max{3, 2} = 3

18

Key Features

•  Incorporated Entity Resolution •  Privacy: NOT all or nothing

• Uncertainty •  Incorrect Information

19

No privacy Perfect privacy

Interesting Problems

• Releasing Critical Information • Comparing Entity Resolution Algorithms • Releasing Disinformation

20

Releasing Disinformation

Joseph

21

Joseph

Releasing Disinformation

22

Joseph

XXX

Releasing Disinformation

23

YYY

Joseph

XXX

Releasing Disinformation

24

Releasing Disinformation

• Minimize Ld(p, DUS) s.t.

25

Conclusion

• We have formalized information leakage –  Incorporated Entity Resolution –  Privacy: NOT all or nothing –  Uncertainty –  Incorrect Information

• We have listed several challenges for managing information leakage

26

Thanks!

27

Releasing Critical Information

•  u={<N,n1>,<C,c2>,<P,p1>} • Ld(p, D1) = 3 • Ld(p, D2) = 3

28

Online shopping websites

Releasing Critical Information

•  u={<N,n1>,<C,c2>,<P,p1>} • Ld(p, D1) = 3 Ld(p, D1U{u}) = 3 • Ld(p, D2) = 3 Ld(p, D2U{u}) = 4

29

Online shopping websites

Related Work

• ReputationDefender –  Promotes positive information

• Track-Me-Not –  Obfuscates search queries

30

Current Work

• Model –  Distinguish attributes, better leakage measures,

update/delete, utility, privacy measure, …

•  Implementation –  Bogus creation, scalability, …

• More problems –  Negative effect of disinformation, promoting good

information, enhance record, check hypothesis, …

31