BIP-361: Should One-Third of All Bitcoins Be Frozen to Counter the Quantum Threat?
📋 En bref (TL;DR)
- BIP-361: a proposal from 6 developers (including Jameson Lopp of Casa) to freeze bitcoins vulnerable to quantum computers
- 34% of Bitcoin’s supply (6.7 million BTC, roughly $420 billion) would be affected
- Satoshi’s coins (~1 million BTC) would be frozen, as they’re stored in addresses exposed since 2009
- Adam Back (Blockstream) opposes the forced freeze and advocates for voluntary upgrades instead
- BitMEX proposes an alternative: a “canary fund” that only freezes coins if a quantum attack is proven
- Timeline: experts place a credible quantum threat between 2030 and 2035
Should one-third of all bitcoins in circulation be frozen to protect the network from a threat that doesn’t exist yet? That’s the explosive debate sparked by BIP-361, a proposal published on April 15, 2026 on GitHub by six Bitcoin developers.
The proposal tackles a fundamental problem: quantum computers could one day break the cryptography protecting Bitcoin users’ private keys. And among the most vulnerable coins, those belonging to Satoshi Nakamoto — Bitcoin’s anonymous creator — are first in line.
BIP-361: freezing coins to protect them
BIP-361, officially titled “Post Quantum Migration and Legacy Signature Sunset”, is authored by Jameson Lopp (CTO of Casa) and five other developers. The plan unfolds in three phases over five years.
Phase A (3 years after activation): prohibit sending funds to legacy vulnerable address formats. Users can still withdraw their funds, but can’t receive new ones. The goal is to push everyone toward quantum-resistant addresses.
Phase B (5 years after activation): invalidation of all classic cryptographic signatures (ECDSA and Schnorr). Any bitcoin that hasn’t been migrated becomes frozen — impossible to spend.
Phase C (future): a rescue mechanism using zero-knowledge proofs would allow owners who still have their recovery phrase to unlock their funds.
Lopp himself acknowledges the unpopularity of his proposal: “I don’t like BIP-361. I wrote it because I like the alternative even less.” He hopes the measure will never be needed, but prefers having a plan ready.
The Satoshi case: 1 million BTC at stake
Satoshi’s coins represent the most emblematic case. Roughly 1 million BTC (estimated value: $74 billion) are stored in P2PK addresses — Bitcoin’s oldest format, where the public key is directly visible on the blockchain.
This format is the most vulnerable to quantum attacks. A sufficiently powerful quantum computer could derive the private key from the public key, then steal the funds. Since Satoshi vanished in 2010, these coins will never be voluntarily migrated.
In total, 6.7 million BTC (about 34% of total supply) are exposed. Among them, 5.6 million haven’t moved in over a decade. The BIP-361 authors cite Satoshi himself to justify their approach: “Lost coins only make everyone else’s coins worth slightly more. Coins stolen by a quantum computer only make them worth less.”
Adam Back: “Voluntary upgrades are enough”
Adam Back, Blockstream founder and one of the most respected figures in the Bitcoin ecosystem, opposes the forced freeze. According to him, quantum computers remain “essentially laboratory experiments” with “incremental” progress over 25 years.
Back instead advocates for voluntary, optional upgrades integrated within the existing Taproot framework. He gives users roughly a decade to migrate at their own pace. Blockstream is already testing quantum-resistant signatures on Liquid, Bitcoin’s sidechain.
The fundamental disagreement between both camps: Lopp believes developers won’t be able to coordinate quickly in an emergency. Back bets on the opposite. “Bugs have been identified and fixed in hours. When something becomes urgent, it focuses attention.”
The BitMEX alternative: the “canary fund”
BitMEX Research proposes a third way: an early warning system rather than an imposed timeline. The idea: create a special Bitcoin address whose private key is mathematically unknown. Anyone can deposit BTC as a bounty.
If a quantum computer manages to spend those funds, that’s on-chain proof that the threat is real. This automatically triggers a protective soft fork. No arbitrary deadline, no preemptive freeze.
The criticism? A rational attacker could ignore the canary and directly target the richest wallets.
How real is the quantum threat?
Today, no quantum computer can break Bitcoin’s cryptography. Current machines have a few thousand qubits. Breaking Bitcoin’s ECDSA algorithm would require between 500,000 and 13 million qubits, according to estimates.
But research is advancing. A Google Quantum AI paper published in late March 2026 with Stanford and the Ethereum Foundation claims a quantum computer could break ECDSA in nine minutes — close to Bitcoin’s block time. The required resources have been reduced by 20x compared to previous estimates.
The Presidio Bitcoin report places the probability at 50% for a capable quantum computer between 2030 and 2035. Google plans its own transition to post-quantum cryptography by 2029.
The debate is no longer “will quantum break Bitcoin?” but “when, and will Bitcoin be ready?” The 5-year window proposed by BIP-361 matches the low-end estimates for when capable machines arrive.
Glossary
- Quantum computer: a machine that exploits quantum physics properties (superposition, entanglement) to perform certain calculations exponentially faster than a classical computer.
- ECDSA: the digital signature algorithm used by Bitcoin to prove ownership of a private key without revealing it. This is the cryptography that quantum threatens.
- BIP (Bitcoin Improvement Proposal): a formal document proposing changes to the Bitcoin protocol. Anyone can submit one, but adoption requires community consensus.
- Soft fork: a backwards-compatible Bitcoin protocol upgrade. Old nodes continue to function, but new rules apply to updated nodes.
- P2PK (Pay-to-Public-Key): Bitcoin’s oldest address format. The public key is directly visible on the blockchain, making it particularly vulnerable to quantum attacks.
- Qubit: the basic unit of quantum computing, equivalent to a classical bit. A qubit can exist in multiple states simultaneously thanks to quantum superposition.
Frequently Asked Questions
Frequently Asked Questions
Can quantum computers steal my bitcoins today?
No, not today. Current quantum computers are far from being able to break Bitcoin’s cryptography. Experts estimate the threat could become real between 2030 and 2035. Learn more about crypto risks
What exactly does BIP-361 propose?
BIP-361 proposes freezing all bitcoins that haven’t migrated to quantum-resistant addresses within a 5-year window. This affects about 34% of total supply, including Satoshi Nakamoto’s coins.
Are Satoshi Nakamoto's bitcoins in danger?
The ~1 million BTC attributed to Satoshi are stored in P2PK format, the most vulnerable. Since Satoshi disappeared, these coins will never be voluntarily migrated and would be frozen under BIP-361. Who is Satoshi Nakamoto?
Are my bitcoins on a modern wallet protected?
Modern addresses (SegWit, Taproot) only expose the public key at transaction time. This offers better protection, but not total. Migration to post-quantum formats will eventually be necessary.
Does BIP-361 have a chance of being adopted?
It’s unlikely in the short term. The proposal is controversial because it challenges Bitcoin’s core principle: unconditional coin ownership. It’s an initial draft to anticipate the threat. Understanding Bitcoin
Sources
This article is based on the following sources:
- CoinDesk — Bitcoin’s quantum debate splits as Adam Back pushes optional upgrades
- Bitcoin Magazine — Bitcoin Developers Propose Quantum Migration Plan
- Decrypt — New Bitcoin Proposal Would Freeze Coins to Counter Quantum Threat
- CoinDesk — Jameson Lopp says it’s better to freeze 5.6 million BTC
- Bitcoin.com — Scarcity Pump or Monetary Suicide? The Radical Argument Against BIP-361
How to cite this article:
Fibo Crypto. (2026). BIP-361: Should One-Third of All Bitcoins Be Frozen to Counter the Quantum Threat?. Retrieved April 16, 2026 from https://fibo-crypto.fr/en/blog/bip-361-bitcoin-quantum-threat-freeze-coins
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