The most ambitious one imho is qbitcoin[1]. It's based on quantum teleportation and quantum digital signatures. That gives it quite a low Technology Readiness

The most ambitious one imho is qbitcoin[1]. It's based on quantum teleportation and quantum digital signatures. That gives it quite a low Technology Readiness Level[2], but hey, we see articles about actual implementation of quantum teleportation everyday, so who knows? 1. https://arxiv.org/abs/1708.04955 https://arxiv.org/abs/1708.04955 2. https://fr.wikipedia.org/wiki/Technology_readiness_level https://fr.wikipedia.org/wiki/Technology_readiness_level