Private Counting of Distinct and k-Occurring Items in Time Windows
Private Counting of Distinct and k-Occurring Items in Time Windows
复制标题
时间窗口中不同和 k 次出现的项目的私有计数
DOI:
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发表时间:
2022
期刊:
影响因子:
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通讯作者:
Jelani Nelson
中科院分区:
文献类型:
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作者:
Badih Ghazi;Ravi Kumar;Pasin Manurangsi;Jelani Nelson
In this work, we study the task of estimating the numbers of distinct and $k$-occurring items in a time window under the constraint of differential privacy (DP). We consider several variants depending on whether the queries are on general time windows (between times $t_1$ and $t_2$), or are restricted to being cumulative (between times $1$ and $t_2$), and depending on whether the DP neighboring relation is event-level or the more stringent item-level. We obtain nearly tight upper and lower bounds on the errors of DP algorithms for these problems. En route, we obtain an event-level DP algorithm for estimating, at each time step, the number of distinct items seen over the last $W$ updates with error polylogarithmic in $W$; this answers an open question of Bolot et al. (ICDT 2013).