Truthful Decentralized Blockchain Oracles

Abstract

Summary Blockchain systems rely on oracles to bridge external information to the decentralized applications residing in the systems. Astraea protocols are decentralized oracle designs utilizing majority‐voting mechanism to determine the oracle outcomes and/or rewards to voters. However, the voters are indifferent between voting through a single or multiple identities, as the potential rewards by the decentralized oracles grow linearly with the voters stakes. Additionally, the majority‐voting mechanism may facilitate herd behaviors among the voters, as the voters are rewarded only if they are in agreement with the majority outcomes. In this paper, a novel oracle protocol is introduced by proposing a peer prediction‐based scoring scheme along with non‐linear staking rules, aiming at extracting subjective data truthfully. Specifically, an incentive compatible scoring scheme is designed so that voters uniquely maximize their expected score by honest reporting. The voters are rewarded when their report achieves a relatively high score compared to the rest of the voters, as opposed to the existing schemes, where a reward is only given when they agree to the majority. Furthermore, a non‐linear stake scaling rule is proposed to discourage Sybil attacks. Detailed simulation results are presented to show the operation of the proposed oracle protocol and its improvement compared to indicative mechanisms proposed in the existing literature.

MUFFLE: Multi-Modal Fake News Influence Estimator on Twitter

“…Experiments on a real-world dataset demonstrate the effectiveness of our proposed framework. Our proposed MUFFLE can be easily incorporated with decentralized oracles [61] to further detect the influence of misleading information or fake news. For future work, first, we can consider features that provide rich information on news influence on social media; e.g., images contained in news articles, geographic relationship between news events and online users, etc.…”

Graph-Based Profiling of Blockchain Oracles

“…The available number of participants influences the efficiency of the ASTRAEA protocol. Several protocols have been presented in the literature as an extension to the ASTRAEA protocol [15], [16]. In this paper, the proposed mechanism can also be considered voting-based.…”

“…There have been several studies to address this problem, e.g., [13]- [16]. A majority of these previous studies have employed voting/reputation-based mechanisms that are inspired by the crowdsourcing concept (wisdom of the crowd).…”

A Caching-Enabled Permissioned Blockchain Framework for Industrial Internet of Things based on Deep Reinforcement Learning

“…Under the assumption of rational people, the honest behavior of each participant is the Nash equilibrium solution of the system. On this basis, Cai et al [12] jointly determined the reward of voters through a lightweight scoring mechanism and a nonlinear voting weight scaling mechanism to avoid herding [13]. However, the above schemes have the problem of the need to determine results and the long voting period, which is not suitable for returning data sources with frequent result changes, such as real-time sensor data in IIoT.…”