- Only 8% of Bitcoin sits in legacy addresses that could be threatened by quantum tech decades from now.
- Breaking Bitcoin’s encryption needs millions of qubits—current tech is far from capable.
- Users can safely move coins to secure addresses; aggressive protocol changes aren’t needed yet.
Bitcoin’s cryptographic security faces growing speculation around quantum computing, but experts stress the threat is manageable, not imminent. CoinShares highlights that while Shor’s algorithm could theoretically expose ECDSA and Schnorr signatures, practical risks remain decades away.
Approximately 1.6 million BTC, or 8% of total supply, reside in legacy P2PK addresses with visible public keys. However, only about 10,200 BTC sit in UTXOs large enough to disrupt the market if stolen. The rest remain in smaller amounts, making targeted attacks prohibitively expensive.
The conversation revolves around differentiating hype and evidence-based analysis. Bitcoin uses elliptic curve digital signatures for transaction authorization and SHA-256 hashes for protecting addresses. Quantum computers cannot modify or eliminate the supply limit of 21 million or validation directness.
Besides, modern addresses such as P2PKH and P2SH encrypt the public keys until the funds are spent. As such, the purported 25% of the Bitcoins that can be compromised in the long term are overstated, as best practices for behavioral responses can overcome temporary challenges.
Timeline and Technical Feasibility
Experts agree that breaking secp256k1 within a practical timeframe requires millions of logical qubits. “To break current asymmetric cryptography, one would need something in the order of millions of qubits. Willow, Google’s current computer, is 105 qubits,” said Ledger CTO Charles Guillemet.
Achieving this scale remains at least a decade away. Long-term attacks on dormant P2PK coins could take years, whereas short-term mempool attacks would require impossible <10-minute computations. Additionally, even under optimistic projections, stealing coins from 32,607 individual ~50 BTC UTXOs would take millennia.
Caution Over Aggressive Interventions
Proposals for soft forks or burning vulnerable coins carry risks. Prematurely introducing quantum-resistant addresses could create bugs, undermine decentralization, or waste developer resources.
Dr. Adam Back emphasized, “Bitcoin can adopt post-quantum signatures. Schnorr signatures paved the way for more upgrades, and Bitcoin can continue evolving defensively.” Users can voluntarily migrate funds as quantum technology progresses, making drastic interventions unnecessary.