Private Data Objects: an Overview
This addresses the challenge of privacy in smart contracts for parties in distributed systems, though it is an incremental approach building on existing technologies like SGX and ledgers.
The paper tackles the problem of enabling mutually untrusted parties to execute smart contracts over private data by integrating a distributed ledger with Intel SGX secure enclaves, resulting in a system that preserves data confidentiality and execution integrity while recording transactions on a ledger for verification.
We present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Secure Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs [5, 7].