According to a research study by CoinShares, only a small portion of coins are vulnerable to the real threat of “quantum hacking,” and the practical possibility of such an attack is decades away
Concerns about the imminent threat to Bitcoin's security from quantum computers are greatly exaggerated, according to a study by management company CoinShares, which concluded that only a small portion of coins capable of influencing the market are at real risk.
Until recently, the threat of quantum computers to cryptocurrencies was considered remote. However, in 2025, the situation changed, and more and more major players are considering the potential threat to be a real market risk. Some argue that the very fact of the danger is already putting pressure on prices and may influence investment decisions.
The essence of the threat is that quantum computers theoretically make it possible to calculate a private key from a public one for some Bitcoin addresses of an outdated format. This is not “hacking” in the usual sense, but a loss of cryptographic protection, which potentially allows someone to spend other people's coins.
To put it simply, with the right quantum computer, an attacker can find a wallet address that has bitcoins, see the public key associated with it, and calculate the private key from it (as if the shape of the key could be restored from the lock number). After that, they simply sign the transaction and spend the coins from that wallet, and the network accepts it as completely valid.
The CoinShares report disputes the assessment that bitcoins stored at addresses (especially older types) are theoretically vulnerable to quantum attacks in the near future. Analysts have identified the main risk group — the outdated Pay-to-Public-Key (P2PK) type of Bitcoin addresses, which are likely to be the first target if quantum computers become capable of cracking cryptography.
According to CoinShares estimates, these addresses hold about 1.6 million BTC (approximately $112 billion at the exchange rate on February 9), or 8% of the total Bitcoin supply. But even this estimate is significantly exaggerated — the company has identified only 10,200 BTC (more than $710 million) concentrated in a small number of addresses, meaning that only this amount of Bitcoin would be available for a sharp sell-off after a potential hack, which could destabilize the market.
The bulk of vulnerable coins (1.6 million BTC) are distributed across more than 32,600 separate addresses, averaging 50 BTC each. This means that even with a powerful enough quantum computer, an attacker would have to hack each address individually, making the attack extremely slow and economically inefficient in terms of its impact on the market.
“Even in the most optimistic scenarios of technological progress in quantum computing, it would take millennia to unlock these bitcoins,” CoinShares wrote, adding that the first “dangerous” quantum computers may not appear until the 2030s, while other estimates indicate that they will not appear for another 10-20 years.
Power for hacking Bitcoin
The report emphasizes that quantum computers 100,000 times more powerful than modern counterparts would be required to crack Bitcoin's cryptography. It is estimated that a system with millions of qubits would be needed to calculate the private key in a day, whereas the largest modern machines, such as Google's Willow computer, only have hundreds of qubits.
Similar estimates of the power required to successfully “hack” Bitcoin have been voiced by experts for several years. For example, entrepreneur and former Google product manager Kevin Rose pointed out that a successful attack would require a quantum computer with approximately 13 million qubits, only then would it be able to do so within a day.
Ledger's technical director, Charles Guillaume, whose opinion is cited in the report, also confirmed that millions of qubits would be needed for an attack. Thus, CoinShares views the quantum threat not as an emergency, but as a long-term engineering problem. And the Bitcoin community has enough time for a smooth transition without risking the security of the blockchain. The company advocates the gradual introduction of post-quantum cryptographic standards, which is in line with the position of many leading network developers.
Solving this problem
Experts suggest several options for protecting against quantum computers. Some, such as Michael Saylor, founder of Strategy, the largest corporate holder of Bitcoin, propose updating the Bitcoin code base with built-in protection mechanisms.
Other options include introducing a new type of address. Many Bitcoin developers share this view, considering quantum computing to be a distant and largely theoretical problem, writes Coindesk. Discussions among developers are shifting toward preparing for a smooth transition, as evidenced by initiatives such as BIP-360, which proposes new address formats for the gradual migration of users.
