PsiQuantum has begun building a facility intended to house a 1 million-qubit quantum computer, posting photos of a Chicago construction site where 500 tons of steel were put up in six days. The company, which announced a $1 billion funding round in September with involvement from Nvidia, says the plant will host fault-tolerant quantum machines and support “next-generation AI supercomputers.”
The project has revived debate about quantum computing’s threat to modern cryptography, especially Bitcoin’s key schemes. Large-scale quantum hardware running algorithms like Shor’s could, in principle, recover private keys from exposed public keys. That prospect worries some in the Bitcoin community because the network secures trillions in value; others, including Blockstream CEO Adam Back, argue such a threat is still at least a decade away. Bitcoin developers are weighing whether more immediate protocol changes—such as a hard fork to add quantum-resistant options—are necessary.
Not all coins are equally exposed. The greatest risk is to UTXOs associated with addresses that have never spent funds, because those addresses have publicly visible public keys. Many of those outputs date back to Bitcoin’s early years. Estimates for the quantum resources needed to break relevant keys differ and have generally trended downward as research advances; a recent preprint suggested roughly 100,000 qubits might be enough to break 2048-bit RSA keys, while Bitcoin uses 256-bit elliptic-curve keys. For context, one of the largest reported quantum machines to date has about 6,100 qubits.
PsiQuantum co-founder Terry Rudolph has said the company does not plan to use its machines to derive private keys. Research from CoinShares in February estimated about 10,230 BTC are both quantum-vulnerable and held at addresses with exposed public keys—a quantity that, if moved, would probably resemble ordinary market activity rather than trigger systemic instability. The construction marks a notable step toward much larger quantum systems, and it has renewed discussion about timelines and mitigations for post-quantum cryptography in cryptocurrency ecosystems.