> ## Documentation Index > Fetch the complete documentation index at: https://docs.qbtc.net/llms.txt > Use this file to discover all available pages before exploring further. # Quantum Risk Assessment > When cryptographically-relevant quantum computers arrive: 2029-2035 published convergence, implications for dormant exposed-key BTC, and the migration window. **Coming soon.** A published expert-panel assessment will be hosted here. ## Summary of published findings Current published assessments converge on a window of roughly **2029 to 2035** for the arrival of cryptographically-relevant quantum computers (CRQCs), defined as quantum computers capable of breaking 256-bit elliptic-curve cryptography in practical time. This is the cryptography behind Bitcoin's ECDSA signatures. Methodologies vary across published assessments: * Some weight experimental progress on logical-qubit error rates. * Some weight observed scaling trends in physical-qubit counts. * Some weight institutional milestones (NIST PQC standardization, federal infrastructure migration mandates). The convergence across methodologies is the signal. ## Implications * **Dormant exposed-key UTXOs are at risk first.** \~1.7M BTC sit in Satoshi-era P2PK outputs whose public keys are permanently on-chain; \~3M+ additional BTC sit in reused P2PKH / P2WPKH addresses where the public key has been revealed by prior spending. These become spendable by whoever runs Shor's algorithm first. Per-category breakdown: [explorer.qbtc.net](https://explorer.qbtc.net). * **Live spending is at risk via the mempool window.** Any Bitcoin spend reveals the public key. A CRQC operator could race the spender to a competing transaction. * **The migration window is now.** Migrations of large-scale infrastructure take years. NIST has standardized post-quantum signatures (FIPS 204 / ML-DSA) on the assumption that public infrastructure should be substantially migrated well before CRQC arrival. ## See also * [The Quantum Threat to Bitcoin](../learn/quantum-threat.md), plain-language explainer. * [Quantum Resistance (ML-DSA)](../build/quantum-resistance.md), QBTC's cryptographic response.