Tianhao Wang (Purdue University), Milan Lopuhaä-Zwakenberg (Eindhoven University of Technology), Zitao Li (Purdue University), Boris Skoric (Eindhoven University of Technology), Ninghui Li (Purdue University)

Local Differential Privacy (LDP) protects user privacy from the data collector. LDP protocols have been increasingly deployed in the industry. A basic building block is frequency oracle (FO) protocols, which estimate frequencies of values. While several FO protocols have been proposed, the design goal does not lead to optimal results for answering many queries. In this paper, we show that adding post-processing steps to FO protocols by exploiting the knowledge that all individual frequencies should be non-negative and they sum up to one can lead to significantly better accuracy for a wide range of tasks, including frequencies of individual values, frequencies of the most frequent values, and frequencies of subsets of values. We consider 10 different methods that exploit this knowledge differently. We establish theoretical relationships between some of them and conducted extensive experimental evaluations to understand which methods should be used for different query tasks.

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HFL: Hybrid Fuzzing on the Linux Kernel

Kyungtae Kim (Purdue University), Dae R. Jeong (KAIST), Chung Hwan Kim (NEC Labs America), Yeongjin Jang (Oregon State University), Insik Shin (KAIST), Byoungyoung Lee (Seoul National University)

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Qi Wang (University of Illinois Urbana-Champaign), Wajih Ul Hassan (University of Illinois Urbana-Champaign), Ding Li (NEC Laboratories America, Inc.), Kangkook Jee (University of Texas at Dallas), Xiao Yu (NEC Laboratories America, Inc.), Kexuan Zou (University Of Illinois Urbana-Champaign), Junghwan Rhee (NEC Laboratories America, Inc.), Zhengzhang Chen (NEC Laboratories America, Inc.), Wei Cheng (NEC Laboratories America,…

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