Opinion: Bitcoin's quantum threat timeline is roughly within the next decade, consensus within the community is extremely challenging

May 28: Scroll co-founder Sandy Peng argues in a new article that the quantum computing threat to Bitcoin isn’t a physical hurdle—it’s a governance and coordination challenge, not a technical one. A March whitepaper from Google Quantum AI estimates breaking Bitcoin’s secp256k1 elliptic curve with an optimized Shor’s algorithm would require roughly 1,200 logical qubits; that’s nearly 20 times fewer than projections from five years ago. IonQ’s official roadmap targets 1,600 logical qubits by 2028, while IBM plans to launch its 2,000-qubit Blue Jay system by 2033. This puts the quantum threat timeline at roughly a decade, possibly even shorter. Attacks will unfold in waves. The most vulnerable targets are early P2PK-formatted Bitcoin addresses, where public keys are permanently recorded on the blockchain. This includes over 1 million bitcoins mined by Satoshi Nakamoto in Bitcoin’s early days—funds that can’t be moved to secure them because the private key’s holder is unknown. Additionally, a so-called “collect first, decrypt later” attack could already be underway: intelligence agencies don’t need to wait for full quantum computer maturity to exploit this, as they can simply store encrypted data now to decrypt it later once quantum tech advances. Once quantum computers are ready, unconfirmed transactions in the mempool will face real-time double-spend attacks within Bitcoin’s typical 10-minute confirmation window. Though NIST released post-quantum cryptography algorithm standards in 2024, migrating Bitcoin to these standards comes with steep costs: studies suggest network throughput would drop by 52% to 57%, transaction fees would double or triple, and storage requirements would rise significantly. This amounts to a “defensive downgrade”: costs hit immediately, while benefits are abstract and far in the future. That makes consensus near-impossible for the Bitcoin community, which took nearly two years to even reach agreement on the SegWit upgrade. By contrast, Vitalik Buterin has already rolled out an Ethereum quantum emergency roadmap that lets individual accounts switch to quantum-resistant signatures autonomously—no network-wide vote required. Peng warns Bitcoin won’t collapse to zero, but its survival path is narrower than optimists claim, and the quantum threat window almost exactly overlaps with the 10 to 15 years the Bitcoin community will need to build consensus. Early Bitcoin holders are advised to check their address formats and migrate promptly, while institutional investors should integrate a “post-quantum migration roadmap” into their due diligence frameworks.