Weikeng Chen (UC Berkeley), Raluca Ada Popa (UC Berkeley)

File-sharing systems like Dropbox offer insufficient privacy because a compromised server can see the file contents in the clear. Although encryption can hide such contents from the servers, metadata leakage remains significant. The goal of our work is to develop a file-sharing system that hides metadata---including user identities and file access patterns.

Metal is the first file-sharing system that hides such metadata from malicious users and that has a latency of only a few seconds. The core of Metal consists of a new two-server multi-user oblivious RAM (ORAM) scheme, which is secure against malicious users, a metadata hiding access control protocol, and a capability sharing protocol.

Compared with the state-of-the-art malicious-user file-sharing scheme PIR-MCORAM (Maffei et al.'17), which does not hide user identities, Metal hides the user identities and is 500x faster (in terms of amortized latency) or 10^5x faster (in terms of worst-case latency).

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Sivaramakrishnan Ramanathan (University of Southern California/Information Sciences Institute), Jelena Mirkovic (University of Southern California/Information Sciences Institute), Minlan Yu (Harvard University)

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Prevalence and Impact of Low-Entropy Packing Schemes in the...

Alessandro Mantovani (EURECOM), Simone Aonzo (University of Genoa), Xabier Ugarte-Pedrero (Cisco Systems), Alessio Merlo (University of Genoa), Davide Balzarotti (EURECOM)

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Strong Authentication without Temper-Resistant Hardware and Application to Federated...

Zhenfeng Zhang (Chinese Academy of Sciences, University of Chinese Academy of Sciences, and The Joint Academy of Blockchain Innovation), Yuchen Wang (Chinese Academy of Sciences and University of Chinese Academy of Sciences), Kang Yang (State Key Laboratory of Cryptology)

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OmegaLog: High-Fidelity Attack Investigation via Transparent Multi-layer Log Analysis

Wajih Ul Hassan (University of Illinois Urbana-Champaign), Mohammad A. Noureddine (University of Illinois Urbana-Champaign), Pubali Datta (University of Illinois Urbana-Champaign), Adam Bates (University of Illinois Urbana-Champaign)

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