Self-Sovereign Identity

/sɛlf-ˈsɑvrən aɪˈdɛntəti/

A decentralized identification mechanism that gives individuals control over what, when, and to whom their personal information is shared.

An identification document (ID) is a crucial part of every individual’s life, in that it is often a prerequisite for accessing a variety of services—ranging from creating a bank account to enrolling children in school to buying alcoholic beverages to signing up for an email account to voting in an election—and also a proof of simply being. This system poses fundamental problems, which a field report by The GovLab on Blockchain and Identity frames as follows:

“One of the central challenges of modern identity is its fragmentation and variation across platform and individuals. There are also issues related to interoperability between different forms of identity, and the fact that different identities confer very different privileges, rights, services or forms of access. The universe of identities is vast and manifold. Every identity in effect poses its own set of challenges and difficulties—and, of course, opportunities.”

A report published in New America echoed this point, by arguing that:

“Societally, we lack a coherent approach to regulating the handling of personal data. Users share and generate far too much data—both personally identifiable information (PII) and metadata, or “data exhaust”—without a way to manage it. Private companies, by storing an increasing amount of PII, are taking on an increasing level of risk. Solution architects are recreating the wheel, instead of flying over the treacherous terrain we have just described.”

SSI is dubbed as the solution for those identity problems mentioned above. Identity Woman, a researcher and advocate for SSI, goes even further by arguing that generating “a digital identity that is not under the control of a corporation, an organization or a government” is essential “in pursuit of social justice, deep democracy, and the development of new economies that share wealth and protect the environment.”

To inform the analysis of blockchain-based Self-Sovereign Identity (SSI), The GovLab report argues that identity is “a process, not a thing” and breaks it into a 5-stage lifecycle, which are provisioning, administration, authentication, authorization, and auditing/monitoring. At each stage, identification serves a unique function and poses different challenges.

With SSI, individuals have full control over how their personal information is shared, who gets access to it, and when. The New America report summarizes the potential of SSI in the following paragraphs:

“We believe that the great potential of SSI is that it can make identity in the digital world function more like identity in the physical world, in which every person has a unique and persistent identity which is represented to others by means of both their physical attributes and a collection of credentials attested to by various external sources of authority.”

[…]

“SSI, in contrast, gives the user a portable, digital credential (like a driver’s license or some other document that proves your age), the authenticity of which can be securely validated via cryptography without the recipient having to check with the authority that issued it. This means that while the credential can be used to access many different sites and services, there is no third-party broker to track the services to which the user is authenticating. Furthermore, cryptographic techniques called “zero-knowledge proofs” (ZKPs) can be used to prove possession of a credential without revealing the credential itself. This makes it possible, for example, for users to prove that they are over the age of 21 without having to share their actual birth dates, which are both sensitive information and irrelevant to a binary, yes-or-no ID transaction.”

Some case studies on the application of SSI in the real world presented on The GovLab Blockchange website include a government-issued self-sovereign ID using blockchain technology in the city of Zug in Switzerland; a mobile election voting platform, secured via smart biometrics, real-time ID verification and the blockchain for irrefutability piloted in West Virginia; and a blockchain-based land and property transaction/registration in Sweden.

Nevertheless, on the hype of this new and emerging technology, the authors write:

“At their core, blockchain technologies offer new capacity for increasing the immutability, integrity, and resilience of information capture and disclosure mechanisms, fostering the potential to address some of the information asymmetries described above. By leveraging a shared and verified database of ledgers stored in a distributed manner, blockchain seeks to redesign information ecosystems in a more transparent, immutable, and trusted manner. Solving information asymmetries may turn out to be the real contribution of blockchain, and this—much more than the current enthusiasm over virtual currencies—is the real reason to assess its potential.

“It is important to emphasize, of course, that blockchain’s potential remains just that for the moment—only potential. Considerable hype surrounds the emerging technology, and much remains to be done and many obstacles to overcome if blockchain is to achieve the enthusiasts’ vision of “radical transparency.”

Further readings: