Bitcoin’s quantum problem is still years away, but Bernstein says the 1.7 million BTC sitting in early-type addresses could be among the most vulnerable if the technology ever manages to get there.

This includes an estimated 1.1 million BTC linked to Satoshi Nakamoto, which would only matter if quantum machines became powerful enough to break today’s encryption.

Legacy wallets in the spotlight

Bernstein’s view is not like this Bitcoin there is a threat of collapse soon. The company’s analysts describe the issue as a “manageable update cycle” rather than an “existential risk,” and say the threat is concentrated in legacy wallets and addresses that reuse public keys. Newer wallet practices including avoiding address reuse, lower exposure.

The report it also draws a line between portfolio risk and mining risk. Bitcoin’s SHA-256 mining process is not seen as particularly vulnerable to attacks quantum attackseven if future machines become powerful enough to compromise some wallet signatures.

Bernstein said the most vulnerable address types include pay-to-public-key, pay-to-multisig and pay-to-Taproot formats.

🚨 CRYPTO: BERNSTEIN’S RESEARCH SHOWS THAT BITCOIN HAS 3-5 YEARS TO PREPARE FOR THE QUANTUM THREAT

Bernstein Research, a Societe Generale brokerage, said quantum computing poses a credible but manageable threat to Bitcoin, estimating that the industry is three to five years ancient… pic.twitter.com/6QFMObpXjn

— BSCN (@BSCNews) April 8, 2026

Longer timeline than panic

The company pointed to recent Google research this is one of the reasons why the threat is now taken more seriously. This work has reduced the resources considered necessary to break newfangled encryption, but Bernstein still says it will take many years to build a machine capable of compromising Bitcoin due to grave technical barriers and high costs.

His estimates give the crypto industry about three to five years to prepare for post-quantum security improvements.

This timeline leaves room for the Bitcoin developer community to operate as part of the normal update process. Bernstein said open source developers and core developers will likely handle any step toward quantum-resistant standards, and changes will be proposed and adopted by consensus rather than force.

The report is also based on a broader view of the industry. According to Bernstein’s chart, quantum experts typically give a 10-year timetable for cryptographically significant quantum computers, or machines capable of breaking today’s encryption. This vulnerability is part of the reason the company says the problem is real but not urgent enough to cause panic.

What Bitcoin puts first

For now, the pressure is on the ancient holding companies, not the network as a whole. Bernstein stated that the risk is uneven, with older wallets being more vulnerable because public keys are already apparent on-chain. On the other hand, newfangled apply of wallets and better practices around key elements reduce the risk of attack.

The abrasive figure Bernstein cited – around 1.7 million BTC in early P2PK addresses – shows why the topic keeps coming up. These coins wouldn’t be the first target of any 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, though not infinite, to prepare.

Featured image from Meta, chart from TradingView