The production of large amounts of sensitive data raises grow-ing concerns on confidentiality guarantees. Considering this, it isnatural that data owners have an interest in how their data arebeing used. In this work, we propose Data aNd Application Track-ing (DNAT), a trustworthy platform for tracking the executionsof applications over sensitive data in untrusted environments. Fortraceability purposes, we use blockchain and smart contracts, andto guarantee execution confidentiality and, especially, enforce thatoperations are appropriately logged in the blockchain, we use IntelSGX. Experiments show that tracking costs on Ethereum variesfrom 1 to 61 cents of a US dollar, depending on the operation andurgency for consolidation. The time cost of confidential executionis associated with the SGX overhead. It increases non-linearly ini-tially but has a linear growth rate when data and application sizegets much higher than the available enclave page cache (≈93 MB).
Where: DEBS 2020 - 14TH ACM INTERNATIONAL CONFERENCE ON DISTRIBUTED AND EVENT-BASED SYSTEMS - July 2020 (Quebec, Canada)