Blockchain for data spaces: A survey of architectures, capabilities, and challenges

Data spaces have emerged as a promising paradigm for cross-organizational data sharing; however, their practical deployment still faces multiple technical and governance challenges. This paper presents a comprehensive survey of how blockchain technologies can support the construction and operation of data spaces. Specifically, we first analyze the key challenges encountered in existing data space initiatives, including identity verification, data sovereignty, assetization, contract fulfillment, compliance, governance, security, and cross-space interoperability. We then synthesize seven fundamental capabilities of blockchain that are relevant to addressing these challenges. Based on this capability-challenge perspective, we further organize and conceptualize a layered architectural framework for blockchain-enabled data spaces, consisting of identity, asset, circulation, usage, application, security, governance, and cross-space layers, illustrating how blockchain mechanisms may support each layer. A comprehensive review of representative academic studies and industrial practices is conducted to examine the current design patterns and technological approaches in this area. Finally, the paper summarizes open research challenges and outlines future research directions for integrating blockchain technologies into data spaces. Overall, this survey provides a structured perspective and research roadmap for the design of trustworthy, interoperable, and sustainable data spaces.