Lec11a - k individuals 1 o Anonymity constraint: (see...

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COMP7370 Advanced Computer and Network Security Generalizing Data to Provide Anonymity when Disclosing Information (2) Comments on homework 2. Topics: 1. Problem description a. How to define a term formally? Review: Problem Description Motivation: o Protect individual-specific (private) data - e.g., name, address, phone number, SSN o Limitation: (see slide09b, p2) - Re-identifying anonymous data - Link to outside data (public data) - e.g., voting list - use DOB (12%); DOB+gender (29%); DOB+Zip (69%) Private-data’+ Other data DB_outside: Private-data’ Other-data’ Re-identify: Linking DB_release: Private data Other data Remove Private Data DB: Private data Other data Quasi-identifier - PT (or Private Table) = DB_release - QI_PT = (u1, …, u_m) in PT (released DB) - Goal: how to control QI_PT? or what info should be released to public? e.g.: QI_PT1= (DOB, gender, zip, marital status, problem) or QI_PT2= (gender, zip, marital status, problem) or QI_PT3= (DOB, marital status, problem) To match at least
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Unformatted text preview: k individuals 1 o Anonymity constraint: (see Lec11a, p4) DB_release + DB_outside -> at least k individual Each Quasi-identifier Question: Why only consider one quasi-identifier? (see Lec11a.ppt, p5) Answer: If each quasi-identifier in the released data satisfy k-anonymity, then the combination of released data to external sources cannot match lower than k individuals Topic 2: Generalization of PT (private table, DB_release) Related K-anonymity ideas: o change unusual information to typical values, e.g. 4/1/1969 -> 1/1/1969 o insert complementary records o swapping entries o scrambling records New idea: re-coding values -> make more general o e.g.: zip code 02139 -> 02130 (last digit is replaced by 0, less informative) Domain: o e.g.: zip code domain, number domain, string domain. Every attribute is in the ground domain Key: Less informative domain generalization hierarchy 2 value generalization hierarchy Question: give Eo, can you provide E1? 3...
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Lec11a - k individuals 1 o Anonymity constraint: (see...

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