TY - GEN

T1 - Private matchings and allocations

AU - Hsu, Justin

AU - Huang, Zhiyi

AU - Roth, Aaron

AU - Roughgarden, Tim

AU - Wu, Zhiwei Steven

PY - 2014

Y1 - 2014

N2 - We consider a private variant of the classical allocation problem: given κ goods and n agents with individual, private valuation functions over bundles of goods, how can we partition the goods amongst the agents to maximize social welfare? An important special case is when each agent desires at most one good, and specifies her (private) value for each good: in this case, the problem is exactly the maximum-weight matching problem in a bipartite graph. Private matching and allocation problems have not been considered in the differential privacy literature, and for good reason: they are plainly impossible to solve under differential privacy. Informally, the allocation must match agents to their preferred goods in order to maximize social welfare, but this preference is exactly what agents wish to hide! Therefore, we consider the problem under the relaxed constraint of joint differential privacy: for any agent i, no coalition of agents excluding i should be able to learn about the valuation function of agent i. In this setting, the full allocation is no longer published - instead, each agent is told what good to get. We first show that with a small number of identical copies of each good, it is possible to efficiently and accurately solve the maximum weight matching problem while guaranteeing joint differential privacy. We then consider the more general allocation problem, when bidder valuations satisfy the gross substitutes condition. Finally, we prove that the allocation problem cannot be solved to non-trivial accuracy under joint differential privacy without requiring multiple copies of each type of good.

AB - We consider a private variant of the classical allocation problem: given κ goods and n agents with individual, private valuation functions over bundles of goods, how can we partition the goods amongst the agents to maximize social welfare? An important special case is when each agent desires at most one good, and specifies her (private) value for each good: in this case, the problem is exactly the maximum-weight matching problem in a bipartite graph. Private matching and allocation problems have not been considered in the differential privacy literature, and for good reason: they are plainly impossible to solve under differential privacy. Informally, the allocation must match agents to their preferred goods in order to maximize social welfare, but this preference is exactly what agents wish to hide! Therefore, we consider the problem under the relaxed constraint of joint differential privacy: for any agent i, no coalition of agents excluding i should be able to learn about the valuation function of agent i. In this setting, the full allocation is no longer published - instead, each agent is told what good to get. We first show that with a small number of identical copies of each good, it is possible to efficiently and accurately solve the maximum weight matching problem while guaranteeing joint differential privacy. We then consider the more general allocation problem, when bidder valuations satisfy the gross substitutes condition. Finally, we prove that the allocation problem cannot be solved to non-trivial accuracy under joint differential privacy without requiring multiple copies of each type of good.

KW - Ascending auction

KW - Differential privacy

KW - Gross substitutes

KW - Matching

UR - http://www.scopus.com/inward/record.url?scp=84904329113&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84904329113&partnerID=8YFLogxK

U2 - 10.1145/2591796.2591826

DO - 10.1145/2591796.2591826

M3 - Conference contribution

AN - SCOPUS:84904329113

SN - 9781450327107

T3 - Proceedings of the Annual ACM Symposium on Theory of Computing

SP - 21

EP - 30

BT - STOC 2014 - Proceedings of the 2014 ACM Symposium on Theory of Computing

PB - Association for Computing Machinery

T2 - 4th Annual ACM Symposium on Theory of Computing, STOC 2014

Y2 - 31 May 2014 through 3 June 2014

ER -