1. 1 Dr. Xiao Qin Auburn University http://www.eng.auburn.edu/~xqin xqin@auburn.edu Spring, 2011 COMP 7370 Advanced Computer and Network Security Generalizing Data to Provide Anonymity when Disclosing Information

2. 2 Review Re-identifying anonymous data Link to outside data DB: Private data Other data Remove Private Data DB_release: Private data Other data Re-identify: Linking DB_outside: Private-data’ Other-data’ Private-data’+ Other data Quasi- identifier

3. 3 Review Re-identifying anonymous data Link to outside data

4. 4 Formal Definitions

5. 5 K-anonymity If each quasi-identifier in the released data satisfies k-anonymity, then the combination of released data to external sources cannot match lower than k individuals.

6. 6 Achieving K-anonymity change unusual information to typical values, insert complementary records swapping entries scrambling records

7. 7 Example

8. 8

9. 9