Bitcoin’s quantum problem is still years away, but Bernstein says 1.7 million BTC in early address types could be among the most exposed if the technology ever comes along.
Related reading
That includes an estimated 1.1 million BTC tied to Satoshi Nakamoto, which would only matter if quantum machines become strong enough to break current encryption.
Legacy wallets in pictures
Bernstein’s view is not Bitcoin faces a short-term collapse. The company’s analysts describe the problem as a “manageable upgrade cycle,” rather than an “existential risk,” saying the danger is concentrated in older wallets and addresses that reuse public keys. Newer wallet practices including avoiding address reuse, lower exposure.
The report also draws a line between portfolio risk and mining risk. Bitcoin’s SHA-256 mining process is not considered meaningfully vulnerable quantum attackseven if future machines become powerful enough to threaten some wallet signatures.
Bernstein said the most exposed address types are the pay-to-public-key, pay-to-multisig and pay-to-Taproot formats.
🚨 CRYPTO: BERNSTEIN RESEARCH SAYS BITCOIN 3-5 YEARS TO PREPARE FOR QUANTUM COMPUTING THREAT
Bernstein Research, the brokerage of Societe Generale, said quantum computing poses a credible but manageable threat to Bitcoin, estimating that the industry still has three to five years… pic.twitter.com/6QFMObpXjn
— BSCN (@BSCNews) April 8, 2026
A longer timeline than panic
The company pointed out recently Google research This is one of the reasons why the threat is now being taken more seriously. That work reduced the resources deemed necessary to break modern encryption, but Bernstein still said building a machine that could compromise Bitcoin is still years away due to major technical barriers and high costs.
The estimate gives the crypto industry about three to five years to prepare for post-quantum security upgrades.
That timeline leave room for the Bitcoin developer community to deal through the normal upgrade process. Bernstein said open source contributors and core developers would likely tackle any move toward quantum-resistant standards, with changes proposed and adopted through consensus rather than by force.
The report also draws on a broader view of the sector. Quantum experts typically give a ten-year timeline for cryptographically relevant quantum computers, or machines that can break current encryption, according to Bernstein’s chart. This gap is part of why the company claims the problem is real, but not urgent enough to cause panic.
Related reading
What Bitcoin will face first
For the time being, the pressure is on old holding companies, not on the network as a whole. Bernstein said the risk is uneven, with older legacy wallets facing more exposure because public keys are already visible on-chain. Modern wallet usage and better key practices, on the other hand, reduce the likelihood of attacks.
The rough number Bernstein cited – about 1.7 million BTC in early P2PK addresses – shows why the topic keeps coming back. These coins wouldn’t be the first target of a quantum attack, but they are the clearest example of what could be at stake if the hardware advances faster than the network’s response. For now, Bernstein’s message is that Bitcoin has time, but not endless, to prepare.
Featured image from Meta, chart from TradingView