CKB and Quantum Threat

The Quantum Threat to Nervos, Part 4: What Has to Happen Next Part four of a four-part series on what quantum computing actually means for Nervos Network and its native token, CKB (Common Knowledge Base). Disclosure: I hold CKB. This series presents information, not recommendations, and nothing in it is investment advice. Part 2 established that spending a coin publishes the public key a future quantum computer would attack. Part 3 established that Nervos can replace its signature scheme without a fork, because on CKB the signature rule is a program rather than a consensus rule — and that the same property means nobody can ever force the migration. Which leaves the question this series has been circling for three installments. The capability exists. What has to happen for it to matter? This part is the list. Some of it is encouraging, some of it is uncomfortable, and one item on it is a problem I did not expect to find. I will also settle a debt: Part 3 promised to come back with the real cost of a post-quantum transaction on mainnet, and that number is here. One wallet Start with the simplest measurement, because it is the one that decides everything else. Nervos' own documentation lists twelve wallets for CKB: Neuron, JoyID, imToken, CKBull, SafePal, Ledger, imKey, OneKey, UTXO Global, Rei, Gate, and Quantum Purse. As of September 2026, exactly one of them supports the quantum-resistant lock , and it is the one built by a community developer rather than by the foundation, an exchange, or a hardware manufacturer. Quantum Purse deserves credit. It is self-custodial, runs on Windows, macOS and Linux, ships a browser demo, supports all twelve standardized parameter sets, encrypts locally, and syncs as a light client rather than asking you to run a full node. That is more than most chains have. It also has constraints the marketing does not lead with. Hardware wallet support is "coming soon," which means today the only way to hold quantum-safe CKB is with a key that…