Multiparty Computation meets Blockchain: Decentralized Marketplaces, Privacy Preserving Smart Contracts and more (Robert Bosch GmbH)

Topic

This research collaboration focused on the potential and opportunities of combining secure multiparty computation with blockchain technology for the next generation of industry and internet.

Motivation and Goals

The blockchain technology, despite being a relatively young innovation, has gained worldwide attention initiating changes in various markets and industries. Another less-known but equally promising cryptographic concept is secure multiparty computation (MPC). MPC enables a group of parties to jointly compute a function on their private inputs, ensuring that nothing beyond the output of the function is revealed. Although both cryptographic tools have been heavily studied individually on the academic and industrial sides, the opportunities that arise from combining the two technologies have been little explored in practice. The goal of this project was to find, develop and potentially prototype solutions for industrial applications based on the combination of MPC with blockchain technology.

Results

The project has yielded concepts for a decentralized manufacturing market place, a platform for private smart contracts, and a privacy-preserving computation platform, as well as a prototype of the latter.

The decentralized manufacturing market place provides a platform on which clients can submit manufacturing requests and receive quotes from suitable manufacturers without revealing the request details to the manufacturers or the manufacturer’s pricing and utilization details to the clients. If the clients find a suitable quote, they can accept it and trigger the order and the payment via the platform.

The platform for private smart contracts is a MPC-based solution that can be applied on top of conventional smart contract platforms, such as Ethereum, enabling them to support smart contracts with private state, which is not possible with traditional smart contracts.

The privacy preserving computation platform allows consumers to request computations on private data provided by data producers and receive the result of the computation without learning any additional information about the private data. The computation is performed by a cluster of computation servers using MPC techniques, ensuring that no malicious subset of parties is capable of breaking the confidentiality of the private data. A broker, realized as a smart contract, manages data offerings, computation offerings, computation requests, and payments in a decentralized manner.

Funding

The project was funded by the Robert Bosch GmbH and carried out jointly as a research collaboration between Robert Bosch GmbH and TU Darmstadt.