CoinShares says quantum threat to Bitcoin is real but still years away

Bitcoin faces a theoretical security risk from future quantum computers, but the threat is manageable and not imminent, according to a new research note from digital asset manager CoinShares.

The firm said concerns that quantum computing could break Bitcoin’s (BTC) cryptography are often overstated, noting that the technology required to carry out such an attack remains far beyond current capabilities.

Even in the most aggressive scenarios, CoinShares estimates that a practical quantum threat to Bitcoin is likely at least a decade away.

Why quantum threat to Bitcoin matters

Bitcoin’s security relies on cryptographic tools that protect private keys and validate transactions. In theory, powerful quantum computers running algorithms such as Shor’s algorithm could one day derive private keys from public keys, allowing attackers to steal funds from certain types of Bitcoin addresses.

However, CoinShares said only a limited subset of Bitcoin is exposed. Roughly 8% of the total supply sits in older “legacy” addresses where public keys are already visible on the blockchain. Even within that group, far fewer coins would be immediately vulnerable in a way that could destabilize the network.

Bitcoin’s core hashing function, SHA-256, is also considered resilient. Quantum computers could speed up brute-force attacks, but not enough to break Bitcoin’s mining or transaction security under realistic assumptions, the report said.

Why the risk is considered manageable

CoinShares emphasized that Bitcoin is not static and has successfully upgraded its cryptography before. The network could transition to quantum-resistant signature schemes through future software upgrades if the threat becomes more concrete.

In addition, holders of older Bitcoin addresses can already protect themselves by moving funds to newer address formats that do not expose public keys until a transaction is spent.

The firm warned against rushing into drastic changes, such as premature hard forks or untested cryptographic schemes, arguing that unnecessary action could introduce bugs or weaken decentralization.

What it means for investors

For investors, CoinShares’ conclusion is straightforward: quantum computing is a long-term engineering challenge, not an existential crisis for Bitcoin today.

The report suggests the market has ample time to prepare, monitor technological progress, and implement safeguards well before quantum computers pose a realistic threat to Bitcoin’s security.