Modern databases and data-warehousing systems separate query processing and durable storage. Storage systems have idiosyncratic bugs and security vulnerabilities, thus attacks that compromise only storage are a realistic threat. In this paper, we show that encryption alone is not sufficient to protect databases from compromised storage. Using MongoDB WiredTiger as a concrete example, we demonstrate that sizes of encrypted writes to a durable write-ahead log can reveal sensitive information about the inputs and activities of MongoDB applications. We then design, implement, and evaluate BigFoot, a WAL modification that mitigates size leakage.
Cite
@article{arxiv.2111.09374,
title = {BigFoot: Exploiting and Mitigating Leakage in Encrypted Write-Ahead Logs},
author = {Jialing Pei and Vitaly Shmatikov},
journal= {arXiv preprint arXiv:2111.09374},
year = {2021}
}