Article ID: 2022CIP0008
Central bank digital currencies require the implementation of eKYC to verify whether a trading customer is eligible online. This research uses delegatable anonymous credential and zero-knowledge proof to protect customer privacy when exchanging information across various security domains. A basic method of incorporating this mechanism into a government-issued national ID card is proposed. In this method, the customer obtains zero-knowledge proof of attributes such as biometrics, assets, social reputation, or time stamp from multiple PKI organizations in a privacy-protected manner. Zero-knowledge proof is applied to prove the inequality between two time stamps by the time stamp server (signature presentation, public key revocation, or non-revocation) without disclosing the signature content and stamped time. It makes it possible to prove that the registration information of the national ID card is valid or invalid while keeping the user's personal information anonymous. This research aims to contribute to the realization of a sustainable financial system based on self-sovereign identity management with privacy-enhanced PKI.
