论文标题
差异私人部分设置盖,并附有到设施位置的应用
Differentially Private Partial Set Cover with Applications to Facility Location
论文作者
论文摘要
在\ citet {gupta2009differential}中观察到,在差异隐私下,设置覆盖问题具有强烈的不可能结果。在我们的工作中,我们观察到,当我们转向部分设定盖问题时,这些硬度结果就会消失,在该问题中,我们只需要覆盖宇宙中元素的$ρ$分数,仅需(0,1,1)$即可提供$ρ\。我们表明,这种放松使我们能够避免不可能的结果:在输入集系统上的宽松条件下,我们提供了差异的私有算法,该算法输出了具有非平衡近似保证的显式设置盖。特别是,这是第一个差异私有算法,该算法会输出显式设置盖。 使用我们的部分套件盖作为子例程,我们为设施位置问题提供了差异性私有(双晶法)近似算法,该算法概括了$ k $ cum-center/$ k $ -k $ -supplier与异常值。与设定盖问题一样,由于高灵敏度和不可能的结果,因此没有算法能够为$ k $ center/$ k $ - $ supplier-type设施的位置问题提供非平整保证。我们的算法表明,放宽覆盖要求仅服务于人口的$ρ$分数,以$ρ\ in(0,1)$,使我们能够绕开固有的硬度。总体而言,我们的工作是解决和理解不可能结果以私人组合优化的结果的重要一步。
It was observed in \citet{gupta2009differentially} that the Set Cover problem has strong impossibility results under differential privacy. In our work, we observe that these hardness results dissolve when we turn to the Partial Set Cover problem, where we only need to cover a $ρ$-fraction of the elements in the universe, for some $ρ\in(0,1)$. We show that this relaxation enables us to avoid the impossibility results: under loose conditions on the input set system, we give differentially private algorithms which output an explicit set cover with non-trivial approximation guarantees. In particular, this is the first differentially private algorithm which outputs an explicit set cover. Using our algorithm for Partial Set Cover as a subroutine, we give a differentially private (bicriteria) approximation algorithm for a facility location problem which generalizes $k$-center/$k$-supplier with outliers. Like with the Set Cover problem, no algorithm has been able to give non-trivial guarantees for $k$-center/$k$-supplier-type facility location problems due to the high sensitivity and impossibility results. Our algorithm shows that relaxing the covering requirement to serving only a $ρ$-fraction of the population, for $ρ\in(0,1)$, enables us to circumvent the inherent hardness. Overall, our work is an important step in tackling and understanding impossibility results in private combinatorial optimization.