Rodrigo de Magalhães Marques dos Santos Silva

Co-advisor: M. Pupo Correia


Deduplication vs Privacy Tradeoffs in Cloud Storage


Tese submetida para provas de mestrado em Engenharia Informática e de Computadores Instituto Superior Técnico, Universidade de Lisboa.

Abstract

To ensure the privacy of their data when stored in the cloud, users can choose to encrypt files before exporting them. Unfortunately, without additional mechanisms, encrypted data storage makes it impossi- ble to implement server-side deduplication techniques, as two identical files will have different encrypted versions. In this thesis, we address the problem of reconciling the need to encrypt data with the ad- vantages of deduplication. In particular, we study techniques that achieve this objective while avoiding frequency analysis attacks (an attack that allows an adversary to infer the content of an encrypted file based on how frequently the file is stored and/or accessed). We propose a new protocol to assign en- cryption keys to files that leverages the use of trusted execution environments to hide the frequency of a file from the adversary.

Publicações

Deduplication vs Privacy Tradeoffs in Cloud Storage
Rodrigo de Magalhães Marques dos Santos Silva
MSc Thesis. Instituto Superior Técnico, Universidade de Lisboa.
November 2022.
Available BibTeX, MSC Thesis, and extended abstract, and mid-term report.
Ataques de Frequência em Deduplicação Cifrada na Nuvem.
R. Silva, C. Correia, M. Correia and L. Rodrigues.
Actas do décimo segundo Simpósio de Informática (Inforum), Guarda, Portugal, Sep. 2022.
Available BibTeX, extended report (pdf).
Deduplication vs Privacy Tradeoffs in Cloud Storage
R. Silva, C. Correia, M. Correia and L. Rodrigues.
Proceedings of the The 38th ACM/SIGAPP Symposium On Applied Computing (SAC), Tallinn Estonia, March 2023.

Luís Rodrigues