@inproceedings{dwork2007the, author = {Dwork, Cynthia and McSherry, Frank and Talwar, Kunal}, title = {The Price of Privacy and the Limits of LP Decoding}, booktitle = {Proceedings of the 39th Annual ACM Symposium on Theory of Computing (STOC)}, year = {2007}, month = {June}, abstract = {This work is at the intersection of two lines of research. One line, initiated by Dinur and 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 [14, 7, 13, 11]) and explicitly connected to error-correcting codes by Candès and Tao ([4]; see also [5, 3]), is in the use of linear programming for error correction. Our principal result is the discovery of a sharp threshhold ρ∗ ≈ 0.239, so that if ρ < ρ∗ and A is a random m×n encoding matrix of independently chosen standard Gaussians, where m = O(n), then with overwhelming probability over choice of A, for all x ∈Rn, LP decoding corrects bρmc arbitrary errors in the encoding Ax, while decoding can be made to fail if the error rate exceeds ρ∗. Our bound resolves an open question of Candès, Rudelson, Tao, and Vershyin [3] and (oddly, but explicably) refutes empirical conclusions of Donoho [11] and Candès et al [3]. By scaling and rounding we can easily transform these results to obtain polynomialtime decodable random linear codes with polynomial-sized alphabets tolerating any ρ < ρ∗ ≈ 0.239 fraction of arbitrary errors. In the context of privacy-preserving datamining our results say that any privacy mechanism, interactive or noninteractive, providing reasonably 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.}, publisher = {Association for Computing Machinery, Inc.}, url = {http://approjects.co.za/?big=en-us/research/publication/the-price-of-privacy-and-the-limits-of-lp-decoding/}, pages = {85-94}, isbn = {978-1-59593-631-8}, edition = {Proceedings of the 39th Annual ACM Symposium on Theory of Computing (STOC)}, }