Bitcoin does face a theoretical security risk from future quantum computers, but that risk is distant and manageable rather than an immediate threat, according to a new research note from digital asset manager CoinShares.
The firm said fears that quantum computing could suddenly break Bitcoin’s cryptography are often overstated. Even under aggressive assumptions, CoinShares estimates that a practical quantum attack capable of threatening Bitcoin is likely at least a decade away, given how far current technology still is from that level of capability.
Bitcoin’s security is built on cryptographic systems that protect private keys and validate transactions. In theory, sufficiently powerful quantum computers using algorithms such as Shor’s algorithm could one day derive private keys from public keys, potentially allowing attackers to steal funds from certain types of addresses. However, CoinShares stressed that only a small portion of Bitcoin’s supply would even be exposed in such a scenario.
According to the report, roughly 8% of Bitcoin is held in older “legacy” addresses where public keys are already visible on the blockchain. Even within that group, only a fraction would be immediately vulnerable in a way that could pose a systemic risk to the network. Most modern Bitcoin address formats do not reveal public keys until funds are spent, significantly reducing exposure.
CoinShares also highlighted that Bitcoin’s core hashing function, SHA-256, remains robust. While quantum computers could theoretically speed up brute-force attacks, the advantage would not be large enough under realistic assumptions to break Bitcoin’s mining process or transaction security.
The firm described the quantum risk as manageable because Bitcoin is not a static system. The network has upgraded its cryptography before and could adopt quantum-resistant signature schemes through future software updates if the threat becomes more concrete. In addition, holders of older addresses can already reduce their risk by moving funds to newer address formats.
CoinShares cautioned against rushing into drastic changes, such as premature hard forks or deploying untested cryptographic methods. The report warned that unnecessary or poorly designed upgrades could introduce bugs or undermine decentralization, creating new risks that outweigh the theoretical quantum threat.
For investors, the firm’s conclusion was clear: quantum computing represents a long-term engineering challenge, not an existential crisis for Bitcoin today. CoinShares said the ecosystem has ample time to monitor developments, prepare defenses, and implement safeguards well before quantum computers pose a realistic danger to Bitcoin’s security.
