According to the source, IBM has publicly demonstrated the 127-qubit Eagle in 2021 and the 433-qubit Osprey in 2022, and unveiled the 1,121-qubit Condor in 2023, as documented in the IBM Research quantum roadmap and announcements. NIST states that cryptographically relevant, fault-tolerant quantum computers do not yet exist and has initiated a multi-year migration to post-quantum standards, per NIST’s Post-Quantum Cryptography standardization updates in 2022 and 2024. For Bitcoin’s secp256k1 ECDSA, resource estimates indicate very large error-corrected qubit counts and long runtimes are required for Shor-based attacks, far beyond today’s devices, per Roetteler et al. 2017 and NIST assessments. In practice, only outputs whose public keys are revealed at spend are directly exposed before any upgrade, while P2PKH, P2WPKH, and Taproot outputs reveal the pubkey only on spending, limiting immediate on-chain attack surface, per the Bitcoin.org Developer Guide.