A significant shortcoming of all existing DID systems is the fact that they require a high level of technology to function. This fact effectively marginalizes the 45% of the world’s population who do not have smartphones.
DID Alliance proposes to solve this problem by providing a set of protocols through which users can employ a trust proxy to interact with a DID system of their choice.
Registration with the proxy will be available at kiosks or at trusted, sponsoring institutions (such as banks or government offices) and users will be issued inexpensive authentication tokens (such as smart cards) at registration time. These tokens may be biometrically bound to the individual user through a template-less algorithm, or may simply be imprinted with a photograph. Service providers will be equipped with GADI-authorized token readers.
A user wishing to authenticate inserts his or her token into the reader and instructs the GADI trust proxy to authenticate on the user’s behalf. The trust proxy then retrieves the appropriate data for the transaction and performs the (possibly zero-knowledge) authentication protocol with the service provider’s system.
Thus, with a single token, a user can prove to any GADI service provider that he or she is over eighteen years of age, is eligible for state medical benefits, or lives in the Kaifeng municipality — all without revealing the user’s name, date of birth, state identification number, or home address.