Existing digital identity management systems fail to deliver the desirable properties of control by the users of their own identity data, credibility of disclosed identity data, and network-level anonymity. The recently proposed Self-Sovereign Identity (SSI) approach promises to give users these properties. However, we argue that without addressing privacy at the network level, SSI systems cannot deliver on this promise. In this paper we present the design and analysis of our solution TCID, created in collaboration with the Dutch government. TCID is a system consisting of a set of components that together satisfy seven functional requirements to guarantee the desirable system properties. We show that the latency incurred by network-level anonymization in TCID is significantly larger than that of identity data disclosure protocols but is still low enough for practical situations. We conclude that current research on SSI is too narrowly focused on these data disclosure protocols.

This paper looks at the development of blockchain technologies that promise to bring new tools for the management of private data, providing enhanced security and privacy to individuals. Particular interest presents solutions aimed at reorganizing data flows in the Internet of Things (IoT) architectures, enabling the secure and decentralized exchange of data between network participants. However, as this paper argues, the promised benefits are counterbalanced by a significant shift towards the propertization of private data, underlying these proposals. Considering the unique capacity of blockchain technology applications to imitate and even replace traditional institutions, this aspect may present certain challenges, both of technical and ethical character. In order to highlight these challenges and associated concerns, this paper identifies the underlying techno-economic factors and normative assumptions defining the development of these solutions amounting to technologically enabled propertization. It is argued that without careful consideration of a wider impact, such blockchain applications could have effects opposite to the intended ones, thus contributing to the erosion of privacy for IoT users.

This paper argues that the practical implementation of blockchain technology can be considered an institution of property similar to legal institutions. Invoking Penner's theory of property and Hegel's system of property rights, and using the example of bitcoin, it is possible to demonstrate that blockchain effectively implements all necessary and sufficient criteria for property without reliance on legal means. Blockchains eliminate the need for a third‐party authority to enforce exclusion rights, and provide a system of universal access to knowledge and discoverability about the property rights of all participants and how the system functions. The implications of these findings are that traditional property relations in society could be replaced by or supplemented with blockchain models, and implemented in new domains.

New network technologies are framed as eliminating ‘transaction costs’, a notion first developed in economic theory that now drives the design of market systems. However, the actual promise of the elimination of transaction costs seems unfeasible, because of a cyclical pattern in which network technologies that make that promise create processes of institutionalization that create new forms transaction costs. Nonetheless, the promises legitimize the exemption of innovations of network technologies from critical scrutiny.

No abstract