Blockchain-Enabled Central Bank Digital Currency: Technological Architecture, Privacy, and Institutional Design

This paper develops an analytical framework for the joint design of central bank digital currency (CBDC) and its underlying ledger architecture. We treat a digital monetary system as a tuple M = (S, R, C, I)—supply state, rule set, circulation parameters, and incentive structure—and read centralized, permissioned-distributed, and hybrid ledger designs as parameter settings on M. Two analytical propositions extend the framework. Proposition A locates a threshold above which a retail holding cap ceases to bind, building on the Brunnermeier–Niepelt neutrality condition. Proposition B characterizes the fixed point of the rule-update map under bounded policy shocks and reports its mean-square convergence rate. Each proposition is paired with a stylized numerical exercise; neither claims empirical validation. A comparative section then traces how the institutional environments of Singapore, the European Union, the United States, and China fix admissible regions in M before any architectural choice. What we contribute is a parametric vocabulary for techno-institutional comparison, not a new architecture; the principal limitation is the absence of pilot-data calibration, which we list as the highest-priority continuation.