Insights Crypto BIP-361 bitcoin quantum proposal How to save vulnerable BTC
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Crypto

19 Apr 2026

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BIP-361 bitcoin quantum proposal How to save vulnerable BTC *

BIP-361 bitcoin quantum proposal aims to freeze and recover billions of BTC but leaves 1.7M at risk.

The BIP-361 bitcoin quantum proposal aims to protect older coins from future quantum hacks by blocking, freezing, and then recovering unmoved BTC. Cardano founder Charles Hoskinson says the plan cannot save about 1.7 million pre-2013 coins, including Satoshi’s stash, leaving major value exposed if Q-Day arrives. Bitcoin faces a new kind of clock. Quantum computers may one day break the cryptography that guards many old coins. A new plan, called the BIP-361 bitcoin quantum proposal, tries to get ahead of that day. It would push holders to move funds to safer addresses and freeze coins that do not move in time. Supporters call it a bold defense. Critics say it will still leave a big hole.

What the BIP-361 bitcoin quantum proposal tries to do

The idea is simple to state and hard to execute. The network would flag older signature schemes that quantum computers could crack first. It would then:

  • Stop new deposits into vulnerable address types.
  • Freeze legacy coins that do not move after a set deadline.
  • Offer a recovery path later for owners who missed earlier windows.
  • The goal is to save as much as 34% of Bitcoin’s supply. That is more than 7 million BTC—hundreds of billions of dollars—by moving them to quantum-resistant addresses. The “block, freeze, recover” rhythm creates time pressure. It nudges silent holders to act before an attacker does. In theory, many sleeping wallets would wake up, sign a safe move, and keep value intact.

    Why some coins may still be lost

    Charles Hoskinson, the founder of Cardano and a co-founder of Ethereum, says a large slice cannot be rescued. He argues that about 1.7 million coins from before 2013 will remain exposed. That pool likely includes at least 1.1 million BTC linked to Satoshi Nakamoto. His claim rests on how early coins were created and stored.

    Before BIP-39 introduced seed phrases in 2013, many users relied on wallets and address types that reveal more information on-chain. Some early outputs use pay-to-pubkey scripts, which show a public key even before the first spend. If a quantum attacker can derive the private key from a visible public key, those funds become low-hanging fruit. Even if the network blocks new inflows and later freezes these coins, proving ownership without the old keys is not possible. If the keys are lost or the owner is gone, no recovery phase can conjure them back.

    Supporters of the BIP-361 bitcoin quantum proposal accept that not every coin can be saved. Still, they see the plan as a way to secure most of what can still move. Hoskinson, while critical, also says it is not a bad plan—it is simply not a full cure.

    How the phases work, in plain language

    Phase 1: Stop the bleeding

    The network would stop deposits into address types known to be weak against quantum attacks. This step makes sure the problem does not grow. If you keep sending BTC into a risky format, you increase what a future attacker can target. Blocking new inflows caps that exposure.

    Phase 2: Freeze the sleepers

    After a public deadline, coins that did not move to quantum-safe addresses would be frozen. Frozen does not mean destroyed. It means the network refuses to spend them under old rules. The freeze is designed to push owners to upgrade. It also limits the window where a quantum thief could strike as machines improve.

    Phase 3: Late recovery

    For users who missed the earlier windows, the proposal imagines a last-chance path to claim funds. This could involve special proofs or a migration process. Hoskinson’s critique targets this phase. If the original keys are lost, he says, no path can prove ownership. For very old outputs—and for coins that never moved at all—there may be no viable way back.

    The quantum clock is ticking

    “Q-Day” is the name many use for the moment quantum computers can break today’s crypto systems. No one knows the date. But the trend is clear. In March, Google urged a move to post-quantum cryptography by 2029 for its own systems. That does not mean Bitcoin will break in 2029. It does show that major firms see the need to upgrade soon.

    Bitcoin uses elliptic curve cryptography to secure keys and signatures. Quantum algorithms, like Shor’s, could one day solve the math that keeps those keys safe. Addresses that reveal their public key before a spend will fail first. Addresses that reveal it only at spend time are safer for now—but only until they are used. Once the public key is on-chain, the race begins: can a thief compute the private key before you can move the funds again?

    Community friction: ossification versus agility

    The debate is not just technical. It is cultural. Bitcoin is proud of stability and careful change. Many call this “ossification,” meaning the base protocol should change slowly, if at all. Other chains, like Cardano, Polkadot, and Tezos, point to on-chain governance as a way to make big moves fast. Hoskinson argues that with on-chain governance, a complex migration would be easier to coordinate. Maximalists push back: slow change protects Bitcoin’s neutrality and security.

    A plan like this needs consensus, code, review, and time. It affects users who may not be watching crypto news. It touches “lost coins” lore and the idea that unmoved BTC can rest forever. Freezing anything, even for safety, will draw strong views. That is why the discussion around the BIP-361 bitcoin quantum proposal is so intense.

    Winners, losers, and unintended effects

    Who benefits if it works

  • Active holders who can sign and move funds to quantum-safe addresses.
  • Exchanges and custodians who can migrate large balances in time.
  • The network at large, by shrinking the pool that attackers can target later.
  • Who remains at risk

  • Pre-2013 wallets with lost keys or deceased owners.
  • Early outputs that reveal public keys and never made a spend.
  • Users who ignore deadlines and cannot later produce valid proofs.
  • Possible side effects

  • Confusion for less technical users who miss announcements.
  • Heated politics about freezing, property rights, and Bitcoin’s ethos.
  • Short-term volatility if large dormant wallets suddenly move.
  • What holders can do now

    You do not need to wait for a hard deadline to reduce risk. Simple steps help today:

  • Audit your addresses. Identify any very old outputs or reused addresses.
  • Plan a clean migration into modern, widely used address types managed by reputable wallets.
  • Avoid address reuse. Each spend should reveal as little as possible about your keys.
  • Back up seed phrases securely. Test recovery on a spare device before you need it.
  • Watch credible channels for any network-wide migration guidance.
  • If BIP-361 or a similar plan goes live, you will need to act within posted windows. Do a dry run with a small amount first. Move larger balances only after you are confident.

    Numbers that shape the debate

  • Up to 34% of the total Bitcoin supply could be secured by migration, according to the plan’s goals.
  • About 1.7 million BTC from before 2013 may not be recoverable, Hoskinson says.
  • Satoshi’s presumed 1.1 million BTC sits inside that at-risk group.
  • Google’s post-quantum push targets 2029 for its infrastructure upgrade.
  • These figures are not destiny, but they anchor the stakes. Saving millions of coins matters to individual holders and to the market’s long-term trust.

    Bitcoin is built to survive storms. The quantum storm is not here yet, but the clouds are on the horizon. The BIP-361 bitcoin quantum proposal is an attempt to prepare the levees before the rain. It may not save every coin—especially silent, pre-2013 treasure—but it could protect a vast share of what can still move. Clear rules, early education, and simple tools will decide whether the plan, or any version of it, can work in practice. As the community debates trade-offs, one point is plain: doing nothing is also a choice, and it loads risk onto the future. If Q-Day comes, the network will either have moved first—or wished it had.

    (Source: https://decrypt.co/364676/cardano-charles-hoskinson-bitcoin-quantum-debate)

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    FAQ

    Q: What is the BIP-361 bitcoin quantum proposal? A: The BIP-361 bitcoin quantum proposal is a Bitcoin improvement proposal that aims to protect older coins from future quantum attacks by blocking deposits into vulnerable address types, freezing legacy coins that don’t move, and offering a later recovery path. It seeks to save as much as 34% of Bitcoin’s supply—more than 7 million BTC valued at $536 billion—by migrating funds to quantum-resistant addresses. Q: How would the three phases of the BIP-361 bitcoin quantum proposal operate? A: Under the plan the network would first stop new deposits into address types known to be weak, then freeze legacy coins after a public deadline, and finally provide a recovery path for owners who missed earlier windows. The freeze and recovery steps are designed to limit the attack window and nudge dormant holders to migrate to quantum-resistant addresses. Q: Why does Cardano founder Charles Hoskinson say the proposal won’t save all vulnerable BTC? A: Hoskinson argues that about 1.7 million BTC from before 2013 cannot be rescued because many early outputs revealed public keys and if the original private keys are lost there is no way to prove ownership. He also pointed out that at least 1.1 million of those coins are linked to Satoshi Nakamoto, according to Arkham Intelligence. Q: Which specific coins would remain at risk under the BIP-361 bitcoin quantum proposal? A: Pre-2013 wallets and early outputs that reveal public keys—such as pay-to-pubkey scripts that expose a public key before any spend—are most at risk because a quantum attacker could derive private keys if they are visible on-chain. The proposal accepts it cannot save coins where keys are lost or owners are deceased, which Hoskinson estimates totals about 1.7 million BTC. Q: What is “Q-Day” and how does it connect to the BIP-361 bitcoin quantum proposal? A: “Q-Day” refers to the hypothetical point when quantum computers can break Bitcoin’s elliptic curve cryptography, and that risk is the main driver behind proposals like the BIP-361 bitcoin quantum proposal. Google’s call for a post-quantum transition by 2029 is cited in the article as a sign that major organizations see the need to upgrade soon. Q: What practical steps can Bitcoin holders take now to reduce quantum risk even before any migration plan? A: Holders should audit addresses for very old or reused outputs, migrate funds into modern, widely used address types managed by reputable wallets, avoid address reuse, and back up seed phrases securely. The article also recommends testing recovery on a spare device and doing a dry run with a small amount before moving larger balances. Q: Who would benefit if the BIP-361 bitcoin quantum proposal succeeds, and who might be harmed? A: Active holders who can sign and move funds, exchanges and custodians able to migrate large balances, and the network as a whole would benefit by shrinking the pool attackers can target. Those harmed include pre-2013 wallets with lost keys, early outputs that reveal public keys, and users who miss deadlines and cannot later produce valid proofs. Q: What are the main community concerns about implementing the BIP-361 bitcoin quantum proposal? A: Critics point to Bitcoin’s cultural preference for slow, cautious change—often called ossification—and argue that freezing coins raises heated political issues around property rights and coordination. Supporters and observers like Charles Hoskinson say chains with on-chain governance could handle complex migrations more easily, but any plan still needs consensus, careful code review, and broad education to work in practice.

    * The information provided on this website is based solely on my personal experience, research and technical knowledge. This content should not be construed as investment advice or a recommendation. Any investment decision must be made on the basis of your own independent judgement.

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