Cryptology ePrint Archive: Report 2022/051

Titanium: A Metadata-Hiding File-Sharing System with Malicious Security

Weikeng Chen and Thang Hoang and Jorge Guajardo and Attila A. Yavuz

Abstract: End-to-end encrypted file-sharing systems enable users to share files without revealing the file contents to the storage servers. However, the servers still learn metadata, including user identities and access patterns. Prior work tried to remove such leakage but relied on strong assumptions. Metal (NDSS '20) is not secure against malicious servers. MCORAM (ASIACRYPT '20) provides confidentiality against malicious servers, but not integrity.

Titanium is a metadata-hiding file-sharing system that offers confidentiality and integrity against malicious users and servers. Compared with MCORAM, which offers confidentiality against malicious servers, Titanium also offers integrity. Experiments show that Titanium is 5x-200x faster or more than MCORAM.

Category / Keywords: applications / oblivious RAM, malicious security, privacy, integrity

Original Publication (in the same form): NDSS 2022

Date: received 15 Jan 2022

Contact author: weikeng at dzk org

Available format(s): PDF | BibTeX Citation

Version: 20220118:153757 (All versions of this report)

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