CKB and Quantum Threat

The Quantum Threat to Nervos, Part 2: Is Your CKB at Risk? Part two 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 1 established the shape of the problem: Shor's algorithm breaks the elliptic-curve signatures protecting every major cryptocurrency, Grover's algorithm barely dents mining, and the machine needed to run Shor has been getting smaller much faster than most people realize. The threat is signatures, not hashrate. That narrows the question considerably. If the danger is that someone derives your private key from your public key, then everything depends on a single fact about each address you own: has its public key been published yet? This is not a rhetorical question. It has a definite answer for every address on the chain, you can check it yourself in about two minutes, and for most people reading this the answer is going to be uncomfortable. The one rule that governs everything A private key is only derivable from a public key. No public key, nothing to attack. That sounds obvious, and it has an enormously important consequence that gets lost in most coverage: quantum vulnerability is not a property of a blockchain. It is a property of an address. Two addresses on the same chain, holding the same amount, secured by the same algorithm, can have completely different risk profiles depending on nothing more than whether either has ever sent a transaction. So the useful question is never "is Nervos quantum-safe." It is "which of my addresses have already shown their hand." How a CKB address actually stores your key Here is the part Nervos gets right almost by accident, and it is worth understanding precisely. The default lock on CKB is called secp256k1_blake160_sighash_all . Ignore the name; what matters is what it stores. Its arguments field does not…