Quantum computing firm Alice & Bob published a 122-page resource estimate built on its cat qubits, covering RSA-2048 and secp256k1, the elliptic curve behind Bitcoin and Ethereum signatures.

The paper puts recovery of a secp256k1 private key from its public key at 61.8 minutes on at most 29,588 physical qubits, about a seventeenth of the ceiling in Google Quantum AI's March estimate.

The figures assume qubit stability far beyond anything measured so far. The company's largest error-correction chip has 12 cat qubits, and it expects hardware progress and falling resource requirements to converge in the early 2030s.

The main risk sits with coins whose public keys are already visible onchain, about 6.9 million BTC by Google's March count. Low-fee transactions waiting hours in the mempool could also be exposed at that speed.