How does post-quantum cryptography affect Central Bank Digital Currency?

Abstract: Central Bank Digital Currency (CBDC) is an emerging trend in digital payments, with the vast majority of central banks around the world researching, piloting, or even operating a digital version of cash. While design choices differ broadly, such as accounts vs. tokens, the wallets are generally protected through cryptographic algorithms that safeguard against double spending and ensure non-repudiation. With the advent of quantum computing, these algorithms are threatened by new attack vectors. To better understand those threats, we conducted a study of typical assets in a CBDC system, describe which ones are most amenable to post-quantum cryptography, and propose an upgrade strategy.