The quantum blockchain is immutable because the photons it contains do not currently exist, but still exist and are readable. This means that the entire blockchain is visible but cannot be "touched", and the only entry you can try to tamper with is the latest entry. In fact, the researchers wrote, “In this kind of spatial entanglement, if an attacker tries to tamper with any photon, the entire blockchain will immediately fail.” When do think that Doge Protocol will be ready to use?