When will the Quantum Black Swan land? 1.7 million BTC risk exposure and the public chain defense battle

The shift from theoretical black swans to real threats is accelerating. In the past, the risk of quantum attacks on Bitcoin was mostly confined to academic discussions—this black swan theory was widely mentioned but often set aside. However, with rapid advancements in quantum computing technology, this “black swan” has flown from the distant horizon closer, triggering widespread vigilance within the crypto community.

Recent controversy arose from a long article by Nic Carter, co-founder of Castle Island Ventures. He pointed out that Bitcoin’s underlying elliptic curve cryptography (ECC) could theoretically be broken by Shor’s algorithm, and that quantum computing is only “an engineering challenge” away from realization. This statement has caused a storm in the community—some accuse it of deliberately inciting panic, while others see it as a critical survival crisis that must be faced. But the deeper question is: even if the technology can defend against it, does the Bitcoin community have the capacity to keep pace in this race against time?

The Black Swan Emerges: From Theory to Engineering Challenge

Google recently announced a quantum processor that outperforms the world’s most powerful supercomputers on specific tasks. While this breakthrough does not directly threaten Bitcoin, it has reignited discussions about risks. Satoshi Nakamoto had anticipated this threat when designing Bitcoin, but at the time, it was more like a distant theoretical hypothesis.

Now, the situation is different. NIST (National Institute of Standards and Technology) has mandated the deprecation of existing cryptographic algorithms between 2030 and 2035. Significant progress has been made in quantum error correction and funding. Renowned quantum theorist Scott Aaronson describes the hurdles to cracking Bitcoin as “extremely difficult engineering problems”—in other words, it’s no longer about discovering new physics but about engineering implementation.

Black swan theory emphasizes the unpredictability of low-probability, high-impact events. The quantum threat is gradually shifting from “impossible” to “possible but distant,” and now to “requiring serious attention.” Currently, approximately 6.7 million BTC (worth over $600 billion) are directly exposed to quantum attack risks, notably about 1.7 million BTC belonging to Satoshi and early miners in P2PK addresses, which are in a “permanently lost” state.

These early addresses reveal their full public key when spent or received. In theory, quantum computers could reverse-engineer the private key from the public key. Once the defenses are breached, these assets will be the first to be compromised. Even if Bitcoin completes a quantum-resistant upgrade, these unclaimed “zombie coins” cannot automatically migrate.

At the Crossroads: Slow Governance and the Race Against Time

If black swan theory describes unpredictable external threats, Bitcoin’s real dilemma stems from internal issues—governance efficiency.

On the technical front, quantum-resistant signature schemes already exist. Bitcoin could theoretically implement a soft fork to adopt post-quantum (PQ) signature schemes. But the challenge lies in execution difficulty. A16z’s recent report sharply pointed out two practical dilemmas:

Inefficient governance. Bitcoin’s upgrade process is extremely slow. Based on the histories of SegWit and Taproot, discussions, development, and consensus for a quantum-resistant migration could take up to ten years. Such sluggishness is fatal for emergency tasks. Moreover, if the community cannot reach consensus, it could trigger a destructive hard fork—potentially more damaging than the quantum attack itself, destroying confidence first.

User initiative dilemma. Upgrading cannot be passive—users must actively transfer assets to new addresses. It’s estimated that millions of Bitcoin could be vulnerable to quantum attacks if left unclaimed, with a total value in the hundreds of billions of dollars at current market prices. These “dormant coins” will be permanently unprotected.

Blockstream CEO Adam Back believes Bitcoin will remain secure for at least 20 to 40 years, and NIST has approved post-quantum cryptography standards, providing ample time. But others argue that black swans often arrive suddenly within seemingly sufficient time, and the countdown has already begun. Charles Edwards, founder of Capriole Investment, issued a more aggressive warning—defenses should be built before 2026.

The root of this disagreement lies in the judgment of “how much time is left.” Wang Chun, co-founder of F2Pool, considers quantum computing still a “bubble,” and even following Moore’s Law, cracking Bitcoin’s cryptography standards would still take 30 to 50 years. But once a quantum breakthrough occurs, everything could change instantly—this is the terrifying aspect of the black swan theory.

Sprinting to the Defense: Practical Deployment of Public Blockchains

Unlike the hesitant Bitcoin community, other public chains have already begun defensive measures against black swan risks.

Ethereum has incorporated post-quantum cryptography (PQC) into its long-term roadmap, especially as a key goal during the Splurge phase. The strategy involves layered upgrades—using Layer 2 solutions as testing grounds for quantum-resistant algorithms, including lattice-based and hash-based cryptography. Ethereum co-founder Vitalik Buterin warns that quantum computers could crack Ethereum’s elliptic curve encryption by 2028, urging completion of upgrades within four years.

Aptos recently announced the AIP-137 proposal, which plans to support quantum-resistant digital signatures at the account level to address long-term risks of quantum computing. This will be an optional feature, not affecting existing accounts. Aptos intends to support the hash-based signature scheme SLH-DSA, standardized as FIPS 205.

Solana Foundation has partnered with post-quantum security firm Project Eleven to advance quantum-resistant security deployment. Project Eleven has conducted comprehensive quantum threat assessments of the Solana ecosystem, covering core protocols, user wallets, validator security, and cryptographic assumptions. They successfully prototyped transactions with post-quantum digital signatures on the testnet, demonstrating the feasibility and scalability of end-to-end quantum-resistant transactions in real-world environments.

Cardano adopts a gradual approach to future threats, such as establishing post-quantum checkpoints using the Mithril protocol. This approach is akin to placing lifeboats on the deck to observe whether a storm truly forms, rather than hurriedly transforming the entire ship before the storm arrives. Once hardware acceleration matures, post-quantum schemes will be gradually integrated into the main chain.

Zcash has developed a quantum-recovery mechanism, allowing users to migrate old assets to more secure post-quantum modes.

Investment Logic of the Black Swan

Bitcoin expert Willy Woo adds a key insight: the magnitude of risk depends on how and when Bitcoin is stored. Newer Bitcoin addresses do not expose the full public key on-chain, making them less susceptible to quantum attacks. Most assets held by ordinary users are unlikely to face immediate threats.

This means that if the market crashes due to quantum panic, it could actually be a good entry point for long-term investors. Black swan events often trigger irrational market volatility, and calm participants can profit from these fluctuations.

Another perspective comes from MicroStrategy CEO Michael Saylor. He emphasizes that Bitcoin’s essence is a monetary protocol, and its lack of rapid change and frequent iteration is an advantage, not a flaw. If Bitcoin does upgrade successfully, active holdings will migrate to secure addresses, while those with lost private keys or unable to operate will be permanently frozen. This would reduce the effective supply and strengthen Bitcoin’s scarcity and value.

Within this framework, the appearance of a black swan might not be a bad thing—it forces the crypto ecosystem to confront its vulnerabilities.

An Uncertain Future

Grayscale, in its “2026 Digital Asset Outlook,” states that although quantum threats are real, they are only a “false alarm” for the 2026 market and will not affect short-term valuations. A16z also points out that the likelihood of computers capable of cracking modern cryptography appearing before 2030 is extremely low.

But this optimism may underestimate the possibility of a black swan event. As Charles Hoskinson, founder of Cardano, notes, the assessment of whether quantum risks are at a usable stage should refer to DARPA’s quantum benchmarking program (expected to evaluate feasibility by 2033). Until then, all predictions remain uncertain.

The core lesson of black swan theory is: although we cannot precisely predict the timing of low-probability events, once they occur, their impact will be profound. The reality of quantum threats is no longer debatable; the key question is—can the Bitcoin community and the crypto ecosystem prepare before the black swan truly arrives? The race of time and governance has only just begun.