Blockchain technology, although in its growing phase, is envisioned to fundamentally change inter-networked systems. Although trust and security for on-chain data management has achieved significant improvements, research effort is still needed to integrate off-chain data in a scalable and reliable way. Together with off-chain data management comes the need to ensure content-providing users the required level of privacy, while at the same time providing end-users a significant trust level on the withdrawn data.

In this project, we propose a scalable distributed oracles system, in which off-chain data to be stored in Ontoblocks pass through a consensus process autonomously handled by the involved oracles. In particular, we propose to exploit a correlation model in order to enforce trust between oracles. Based on the proposed model, we also propose a data traceability framework, in which content to be inserted in the ONTOCHAIN comes together with oracle-measured contextual information. This provides the end user a reliable system, in which products or data can be traced back to their origin.

Figure 1 - Overview of the existing coexistence architectures.