TenderWallet: A Private Access and Compliant Collateralized CBDC System

We present TenderWallet, a CBDC system that offers a balance of inclusive privacy-preserving access and complete regulatory compliance. Our proposed system provides a CBDC functionality that is responsive to user behaviour, and in case of non-compliance by the user while availing the CBDC service, compensates the indirect monetary loss induced to the nation state, through collateralization. The TenderWallet system is also hybrid, such that it dynamically works as one variant of two well established offline CBDC models, thereby reducing the computational overhead of the service. We detail the behaviour of the TenderWallet system, analyze its deployment characteristics, and argue that it is superior to other potential hybrid CBDC designs. We conclude by showing that TenderWallet is near optimal, while considering compensation to the state and low-compute privacy and transparency of users as the main requirements of a CBDC system.