Title
The price of privacy and the limits of LP decoding
Abstract
This work is at theintersection of two lines of research. One line, initiated by Dinurand Nissim, investigates the price, in accuracy, of protecting privacy in a statistical database. The second, growing from an extensive literature on compressed sensing (see in particular the work of Donoho and collaborators [4,7,13,11])and explicitly connected to error-correcting codes by Candès and Tao ([4]; see also [5,3]), is in the use of linearprogramming for error correction. Our principal result is the discovery of a sharp threshhold ρ*∠ 0.239, so that if ρ A is a random m x n encoding matrix of independently chosen standardGaussians, where m = O(n), then with overwhelming probability overchoice of A, for all x ∈ Rn, LP decoding corrects ⌊ ρ m⌋ arbitrary errors in the encoding Ax, while decoding can be made to fail if the error rate exceeds ρ*. Our boundresolves an open question of Candès, Rudelson, Tao, and Vershyin [3] and (oddly, but explicably) refutesempirical conclusions of Donoho [11] and Candès et al [3]. By scaling and rounding we can easilytransform these results to obtain polynomial-time decodable random linear codes with polynomial-sized alphabets tolerating any ρ In the context of privacy-preserving datamining our results say thatany privacy mechanism, interactive or non-interactive, providingreasonably accurate answers to a 0.761 fraction of randomly generated weighted subset sum queries, and arbitrary answers on the remaining 0.239 fraction, is blatantly non-private.
Year
DOI
Venue
2007
10.1145/1250790.1250804
STOC
Keywords
Field
DocType
error correction,random m,arbitrary error,arbitrary answer,error rate,encoding matrix,encoding ax,lp decoding,decodable random linear code,thatany privacy mechanism,compressed sensing,polynomial time,basis pursuit,linear code,privacy,error correction code,linear program
Discrete mathematics,Subset sum problem,Combinatorics,Computer science,Basis pursuit,Error detection and correction,Decoding methods,Statistical database,Compressed sensing
Conference
ISSN
Citations 
PageRank 
0737-8017
64
8.00
References 
Authors
14
3
Name
Order
Citations
PageRank
Cynthia Dwork19137821.87
Frank McSherry24289288.94
Kunal Talwar34423259.79