TLDR
- Google’s Quantum AI paper says a future quantum computer could derive a Bitcoin private key from a public key in ~9 minutes
- Around 6.9 million BTC (roughly one-third of all supply) sit in wallets with permanently exposed public keys, making them vulnerable
- Bitcoin’s average block confirmation time is ~10 minutes, giving an attacker a ~41% chance to steal funds mid-transaction
- Coinbase CEO Brian Armstrong said he will personally work on making Bitcoin quantum-resistant “sooner rather than later”
- Quantum-resistant tokens surged on the news: QRL jumped 51%, Algorand gained 42% in seven days
Google published a paper this week saying a future quantum computer could crack the math protecting every Bitcoin wallet. The paper, from Google’s Quantum AI division, landed on March 31 and sent shockwaves through crypto markets.
BREAKING: Coinbase CEO Brian Armstrong says Bitcoin’s quantum threat “needs to be solved soon,” as he pushes for upgrades to make BTC quantum-resistant. pic.twitter.com/CDy4r63jhH
— SwanDesk (@SwanDesk) April 3, 2026
Bitcoin was trading near $66,900 as the news spread. The Crypto Fear and Greed Index dropped to 11, deep in “extreme fear” territory.
The core issue is how Bitcoin transactions work. When you send Bitcoin, your wallet uses a private key to sign the transaction. That signature exposes your public key to the network, where it waits in a pool of unconfirmed transactions called the mempool.
Right now, no computer can reverse-engineer a private key from a public key in any useful amount of time. But Google’s paper says a quantum computer running a known algorithm could do it in about nine minutes.
Bitcoin blocks confirm roughly every 10 minutes. That means an attacker using a powerful enough quantum computer would have a roughly 41% chance of stealing your funds before your transaction goes through.
Google estimates such a machine would need fewer than 500,000 physical qubits. For context, today’s most advanced quantum chips have around 1,000.
The Bigger Threat: Exposed Wallets
The nine-minute attack gets the headlines, but security researchers say the larger problem is already sitting on the blockchain.
An estimated 6.9 million Bitcoin — about one-third of all supply — are held in wallets where the public key is permanently visible. These include early-era addresses and any wallet that has reused an address.
These coins are more vulnerable because an attacker wouldn’t need to race the clock. They could work through exposed keys one by one, at any time.
Bitcoin’s 2021 Taproot upgrade made things slightly worse by making public keys visible on-chain by default, widening the pool of exposed wallets.
Among the exposed holdings are an estimated 1.1 million BTC attributed to Bitcoin’s pseudonymous creator, Satoshi Nakamoto.
Industry Response
Coinbase CEO Brian Armstrong responded within hours of the paper’s release. He said he would personally work on the issue and called for a solution “sooner rather than later.” Coinbase is assembling a group of Bitcoin core developers to coordinate a move to quantum-safe cryptography.
Blockstream Research pointed to post-quantum work already underway on the Liquid sidechain.
Not everyone sees an emergency. Grayscale called the quantum panic a “red herring,” noting that if quantum computers break Bitcoin’s encryption, global banking and internet infrastructure face the same problem. Former Binance CEO Changpeng Zhao said crypto will “adapt and survive.”
The National Institute of Standards and Technology has already published post-quantum standards that Bitcoin developers could adopt. A Bitcoin Improvement Proposal called BIP-360 outlines a migration path, though coordinating changes across Bitcoin’s decentralized network is a challenge.
Bitcoin’s mining process uses a separate algorithm called SHA-256, which quantum computers cannot meaningfully attack with current approaches. Blocks would still be produced.
Quantum-resistant tokens moved sharply on the news. QRL jumped 51% over the past week. Algorand, cited 32 times in Google’s paper for its post-quantum research, gained 42% in seven days.
