A new report from ARK Invest warns that approximately 6.9 million Bitcoin — worth an estimated $483 billion at an average price of $70,000 — could be vulnerable to future quantum computer attacks.
This threat focuses on elliptic curve cryptography (ECC), which underpins Bitcoin ownership security through digital signatures. Specifically, Bitcoin uses the Elliptic Curve Digital Signature Algorithm (ECDSA) on the secp256k1 curve to ensure transaction safety.
The Bitcoin supply is vulnerable to quantum threats | Source: Ark Invest and UnchainedAccording to ARK’s analysis, quantum computers capable of running algorithms like Shor’s algorithm could theoretically extract private keys from public keys. This would allow malicious actors to steal assets from Bitcoin wallets. However, this threat is not uniform across the entire network.
The report estimates that about 1.7 million Bitcoin are currently stored in old address formats like P2PK, where the public key has been publicly revealed on the blockchain. Most of these Bitcoins are believed to be lost and cannot be transferred to more secure addresses.
Additionally, around 5.2 million Bitcoin are also technically vulnerable. However, these can be protected if owners move their assets to new address formats before quantum technology reaches dangerous levels.
In total, roughly one-third of the total Bitcoin supply could be at risk in a worst-case quantum scenario.
Nevertheless, experts emphasize that current quantum technology is not advanced enough to pose an immediate threat. Today’s quantum computers are still in the so-called “Noisy Intermediate-Scale Quantum” (NISQ) era.
Current experimental systems have fewer than 100 logical qubits and face high error rates. To break Bitcoin’s 256-bit elliptic curve, thousands of stable logical qubits and billions of quantum operations would be required.
Therefore, ARK’s report concludes that the quantum threat to Bitcoin is a gradual technological evolution, not an abrupt or unexpected event.
Although the threat is not imminent, the Bitcoin ecosystem has begun preparing for this scenario. A recent upgrade proposal, BIP-360, aims to introduce address structures resistant to quantum attacks while remaining compatible with Taproot. This will help the Bitcoin network gradually transition to post-quantum cryptography solutions when necessary.
Currently, the biggest challenge is not immediate quantum attacks but closely monitoring technological developments and timely moving vulnerable assets to safer formats.
In other words, the threat from quantum computers to Bitcoin depends not only on the pace of technological advancement but also on the network’s ability to adapt and upgrade before a “storm” actually hits.