According to the paper, breaking Bitcoin’s elliptic curve encryption (ECDSA-256) would require fewer than 500,000 physical qubits, down sharply from previous estimates of several million. At the same time, the attack window could be shortened to about 9 minutes, just within Bitcoin’s average 10-minute block confirmation cycle. In theory, this would allow attackers to intercept transactions before they are confirmed.

The news has divided the crypto community. Some warn that Bitcoin could collapse, while others argue that the findings remain theoretical. More importantly, amid weakening market risk appetite, Bitcoin’s technical structure is also deteriorating. A bearish flag pattern continues to form, with the $60,000 level becoming a key battleground between bulls and bears.

Key Breakthroughs in Google’s Research

The paper highlights two major breakthroughs. First is the sharp reduction in resource requirements. Previously, academic models suggested that millions of physical qubits would be needed to break Bitcoin encryption, a milestone believed to be at least 15–20 years away. Google’s research shows that only around 1,200 to 1,450 logical qubits are required to solve the elliptic curve discrete logarithm problem. Under superconducting architectures, this translates to fewer than 500,000 physical qubits.

This significantly accelerates the timeline of quantum threats. Google now places the defensive window at around 2029, which is six years earlier than the 2030–2035 timeframe previously outlined by the U.S. National Institute of Standards and Technology (NIST).

The second breakthrough is the establishment of a “9-minute attack window.” Bitcoin transactions typically take about 10 minutes to be confirmed. Google’s model suggests that if a quantum computer precomputes part of the process, it could derive the private key from an exposed public key in approximately 9 minutes. This would allow attackers to send a fraudulent transaction before the original one is confirmed. The paper estimates a success probability of about 41% for a single machine, with multiple machines significantly increasing efficiency.

Google’s research outlines three layers of quantum threat to Bitcoin. The first is immediate transaction interception risk. Known as an “on-spend attack,” it exploits the time gap between transaction broadcast and confirmation. Even partial success could undermine trust in Bitcoin’s final settlement, since blockchain transactions are irreversible.

The second threat is a “time bomb” affecting existing holdings. The study estimates that around 6.9 million Bitcoins, roughly one-third of total supply, are vulnerable due to exposed public keys. This includes approximately 1.7 million BTC from early P2PK addresses and 5.2 million BTC from reused addresses. Even the 2021 Taproot upgrade may have unintentionally expanded future attack surfaces due to its default key exposure design.

The third threat is the race toward post-quantum migration. While experts agree that transitioning to post-quantum cryptography is inevitable, Bitcoin’s decentralized governance makes upgrades slow and difficult. Even major upgrades like Taproot took years. With a 2029 deadline suggested by Google, the timeline is becoming increasingly tight. As one expert noted, “Time is being compressed from both sides — quantum computing is advancing while blockchain upgrades take time.”

How Close Is the Real Threat?

Despite these concerns, the quantum threat remains theoretical for now. Google’s most advanced chip, “Willow,” has only about 105 physical qubits, far from the estimated 500,000 required. Meanwhile, Bitcoin developers are actively working on solutions, such as the proposed BIP-360 upgrade to reduce public key exposure without disrupting network consensus.

However, the key issue is how markets perceive the probability of such attacks. On April 3, Bitcoin’s daily chart showed a clear bearish continuation pattern. Prices remain within the $60,000 to $73,000 range, with repeated failures to break above resistance levels.

The $60,000 level is a critical psychological and technical support. A breakdown could lead to further downside toward $52,500. On the upside, a sustained move above $76,000 would be required to invalidate the current bearish structure.

Market activity reflects caution. Open interest remains below $20 billion, and negative funding rates have not translated into sustained bullish momentum. This suggests the market is in a “wait-for-catalyst” phase.

Between April 2 and 3, Bitcoin experienced sharp volatility, swinging between $68,800 and $65,700, with over 153,000 traders liquidated. While immediate drivers included geopolitical tensions and institutional selling, the long-term shadow of quantum risk is beginning to reshape how the market values Bitcoin as a store of value.