Open Source Summit Japan 2023

Digital identity has become indispensable with the increasing shift of our daily activities to the digital realm. Such usage escalates the risk of our identities being misused or tracked. W3C verifiable credentials offer a standardized solution, allowing us to convey our identities through cryptographically secure, privacy-respecting mechanisms. In this talk, Dan Yamamoto and Kazue Sako present the experimental implementation of Linked-Data-based verifiable credentials, where an individual can acquire and link multiple credentials signed by different issuers and then selectively disclose portions of them to service providers. This implementation enables the following situation: Assume an individual has an identification document as a verifiable credential claiming they live in a specific city, and there is another verifiable credential describing the city's population. Then, the individual can combine these two credentials to prove that they live in a city, say, larger than 1 million population, without disclosing their name or the city name. The role of open source here is crucial for anyone to validate its implementation, and for its wider adoption and future standardization. This talk will also introduce their latest open-source implementation, which includes significant updates from their previous presentation.