Quantum Computing Threat to Bitcoin Is Real but Not Immediate; CoinShares

TLDR

• CoinShares says a practical quantum threat to Bitcoin is likely at least a decade away.
• About 8% of Bitcoin sits in older addresses, but less than 0.1% is realistically at risk.
• Breaking Bitcoin cryptography would need quantum machines far beyond current capacity.
• Bitcoin can adopt quantum-resistant upgrades if the threat becomes more concrete.
• CoinShares warns premature protocol changes could weaken network stability.

Concerns about quantum computers breaking Bitcoin security have resurfaced across the crypto market. However, digital asset manager CoinShares says the risk remains theoretical and far from immediate. In a new research note, the firm said Bitcoin has sufficient time and flexibility to respond before quantum computing becomes a practical threat.

The report frames quantum risk as a long-term technical challenge rather than a current danger to Bitcoin holders or the network.

Quantum Computing Seen as a Distant Challenge

CoinShares explained that Bitcoin relies on elliptic-curve cryptography to secure private keys and transactions. In theory, advanced quantum computers could use algorithms such as Shor’s algorithm to derive private keys from public ones.

However, the firm said the required quantum machines do not yet exist. According to the report, breaking Bitcoin’s cryptography within a short time frame would require millions of stable, error-corrected qubits. Current quantum computers operate with only a fraction of that capacity.

“Breaking secp256k1 within a practical amount of time needs far more logical qubits than exist today,” CoinShares said, adding that such technology is likely more than ten years away.

Only a Small Share of Bitcoin Is Exposed

The report also addressed how much Bitcoin could realistically be targeted. CoinShares estimated that around 1.6 million BTC, or about 8% of total supply, sits in older Pay-to-Public-Key addresses where public keys are already visible.

Even within that group, the firm said actual risk is far smaller. Only about 10,200 BTC is concentrated enough to create market disruption if stolen. This represents less than 0.1% of Bitcoin’s total supply.

Most of the remaining coins are spread across more than 32,000 separate unspent outputs. CoinShares said this distribution would make large-scale attacks slow and impractical, even with advanced quantum systems.

Bitcoin Hashing and Network Security Remain Strong

CoinShares also examined Bitcoin’s SHA-256 hashing function, which underpins mining and transaction validation. While quantum computers could speed up brute-force searches, the report said the advantage would not be enough to compromise Bitcoin under realistic assumptions.

The firm said mining security would remain intact even if quantum hardware improves steadily. It added that fears of sudden network collapse from quantum attacks are often overstated in public discussions.

The report stressed that Bitcoin’s design allows gradual adaptation without urgent disruption.

Upgrade Path Available Without Rushed Changes

CoinShares said Bitcoin is not static and has upgraded its cryptography before. If quantum risks become more concrete, the network could transition to quantum-resistant signature schemes through future software upgrades.

The firm also noted that holders of older addresses can already reduce exposure by moving funds to newer address formats. These formats hide public keys until coins are spent.

CoinShares warned against rushing protocol changes too early. It said untested cryptographic systems or forced upgrades could introduce new risks and weaken decentralization.