Spheres of Identity

The article argues that digital identity systems are better understood through their topologies, and it uses four models (siloed, centralised, federated and user-centric) to trace who controls identity, where risk lies and how each model affects complexity, economic sustainability and sovereignty. It adds that real identity systems resist these neat categories, since each model's boundaries shift with use, legal circumstances, perspective and technology. The text draws on Laurent-Maknavicius and Bouzefrane's terminology of users, identity providers and service providers, and it cites Microsoft Passport as a failed centralised project, partly due to suspicion of Microsoft's motives. It presents Kim Cameron's "Laws of Identity" as leading to the federated model.