Trust management systems (TMS) are crucial for managing trust in distributed environments. The rise of decentralized systems and blockchain has sparked interest in credential-based decentralized trust management systems (DTMS). This paper bridges the gap between theory and practice through a systematic review of credential-based DTMS. We analyze existing DTMS solutions through multiple dimensions, including their architectural designs, credential mechanisms, and trust evaluation models. Our survey provides a detailed taxonomy of credential-based DTMS approaches and establishes comprehensive evaluation criteria for assessing DTMS implementations. Through extensive analysis of current systems and implementations, we identify critical challenges and promising research directions in the field. Our examination offers valuable insights for researchers and practitioners working on DTMS, particularly in areas such as access control, reputation systems, and blockchain-based trust frameworks.

As a typical instance of human–computer interaction, the notion of decentralized autonomous organization (DAO) represents an organization constructed by automatically executed rules, such as via smart contracts, incorporating features of the permissionless committee, transparent proposals, and fair contributions by stakeholders. As of May 2023, DAO has impacted over $24.3B market caps. However, there are limited studies focused on this emerging field. To fill the gap, we start from the ground truth by empirically studying the breadth and depth of the DAO markets in mainstream public chain ecosystems in this article. We dive into the most widely adoptable DAO launchpad,Snapshot, which covers 95% of the wild DAO projects for data collection and analysis. By integrating extensively enrolled DAOs and corresponding data measurements, we explore statistical resources from Snapshot and analyze data from 581 DAO projects, encompassing 16 246 proposals over the course of 3+ years. Our empirical research has uncovered a multitude of previously unknown facts about DAOs, spanning topics such as their status, features, performance, threats, and ways of improvement. We have distilled these findings into a series of key insights and takeaway messages, emphasizing their significance. Notably, our study is the first of its kind to comprehensively examine the DAO ecosystem with a focus on scale and scope of data, real-time relevance, practical implementations, and comprehensive metrics, addressing critical gaps in the current literature.

As Artificial Intelligence (AI) integrates into diverse areas, particularly in content generation, ensuring rightful ownership and ethical use becomes paramount, AI service providers are expected to prioritize responsibly sourcing training data and obtaining licenses from data owners. However, existing studies primarily center on safeguarding static copyrights, which simply treat metadata/datasets as non-fungible items with transferable/trading capabilities, neglecting the dynamic nature of training procedures that can shape an ongoing trajectory. In this paper, we presentIBis, a blockchain-based framework tailored for AI model training workflows. Our design can dynamically manage copyright compliance and data provenance in decentralized AI model training processes, ensuring that intellectual property rights are respected throughout iterative model enhancements and licensing updates. Technically,IBisintegrates on-chain registries for datasets, licenses and models, alongside off-chain signing services to facilitate collaboration among multiple participants. Further,IBisprovides APIs designed for seamless integration with existing contract management software, minimizing disruptions to established model training processes. We implementIBisusing Daml on the Canton blockchain. Evaluation results showcase the feasibility and scalability ofIBisacross varying numbers of users, datasets, models, and licenses.

Decentralized autonomous organizations (DAOs) are critical to the blockchain ecosystem as they enable decentralized decision-making and governance, and facilitate the creation of decentralized applications (DApps) and organizations. However, despite significant importance, there is currently a lack of a comprehensive overview and detailed understanding of DAOs. To address the gap, this work presents a primary investigation of DAOs (35+). We category, examine and evaluate existing DAOs regarding their operational features, (non-)functionalities and real-world performance. In addition, we provide a consolidated exploration of DAOs by conducting a literature review [1] and an empirical study on mainstream projects, particularly Snapshot [2]. Our research contributes to a better understanding of DAOs and their potential impact on the blockchain ecosystem.

Ensuring the integrity of product manufacture information and securely verifying the authenticity of a component is critical for both manufacturers and customers. However, traditional product identifying solutions offer little protection over counterfeit and cyber-attack. We propose a Blockchain-based product identification and certification system called Universal Identifier of Things (UIT) that enables fast product authenticity verification using low-cost devices. We leverage additive manufacturing technologies to embed a unique identifier into a product. The identifier is then digitalized by generating a digital certificate which is stored on Blockchain during the whole product life cycle for various applications/services (provenance, traceability, product warranty and call-back, etc.). We prove this concept by integrating 3D printing and Hyperledger Blockchain technologies to demonstrate that we can ensure the integrity of products with UIT by bridging the cyber and physical worlds.