Quantum Hardware Progress
Tracking the path from noisy physical qubits to fault-tolerant logical qubits—and what it means for cryptocurrency timelines
Why Hardware Progress Matters
Quantum threat timelines depend on real hardware milestones, not hypothetical capabilities. This page tracks measurable progress toward cryptographically relevant quantum computers—from physical qubit counts to error correction breakthroughs to logical qubit demonstrations. Understanding these metrics helps cryptocurrency projects assess when migration becomes urgent.
Key Metrics That Determine Timelines
Headlines focus on raw qubit counts, but several interconnected metrics determine when quantum computers become dangerous to cryptography:
Physical vs. Logical Qubits
Physical qubits are raw, error-prone quantum bits. Logical qubits are error-corrected encodings built from hundreds of physical qubits. Breaking cryptocurrency requires ~1,500 logical qubits, not physical ones. Current systems: 1,000+ physical, ~5-10 logical.
Error Rates & Thresholds
Below the fault-tolerance threshold, error correction can suppress noise as you scale. Gate fidelities (99.9%+ needed) and correlated error management determine whether adding more qubits helps or hurts.
Error Correction Overhead
Current surface codes require 100-1,000 physical qubits per logical qubit. This physical-to-logical ratio is the primary bottleneck. Breakthroughs reducing overhead from 1000:1 to 100:1 would compress timelines dramatically.
Circuit Depth & Runtime
It’s not just qubit count—can systems execute the circuit depth required (millions of gates) before decoherence ruins computation? Shor’s algorithm for breaking ECDSA needs sustained coherence across deep calculations.
Current State: Where We Stand
As of early 2025, quantum hardware has achieved significant milestones but remains far from breaking cryptography. The table below summarizes progress across major qubit technologies:
| Platform | Physical Qubits | Gate Fidelity | Logical Qubit Status | Leading Companies |
|---|---|---|---|---|
| Superconducting | 1,000+ | 99-99.9% | ~5-10 demonstrated | IBM, Google, Rigetti |
| Trapped Ion | 30-100 | 99.9%+ | Early demonstrations | IonQ, Quantinuum |
| Neutral Atom | 100-1,000 | 99-99.5% | Research phase | Atom Computing, QuEra |
| Photonic | Variable | Varies | Early stage | Xanadu, PsiQuantum |
Key insight: We’re at roughly 0.5% of the logical qubits needed for CRQC. However, progress is exponential—qubit counts and quality have historically doubled every 1-2 years.
Milestones That Actually Move Timelines
Not all quantum announcements matter equally. These specific achievements would significantly change Q-Day estimates:
- Repeatable logical qubits: Not one-off demonstrations, but production systems routinely creating dozens of logical qubits with competitive error rates.
- Complete logical gate set: Clifford+T gates (or equivalent) with low overhead, benchmarked at depth sufficient for cryptographic algorithms.
- Scaling roadmap validation: Proven path from tens to hundreds of logical qubits with documented yield, cost, and timeline data.
- Correlated error mitigation: Demonstrated techniques for handling crosstalk and spatially correlated errors that plague large arrays.
- End-to-end cryptographic circuits: Actual implementation of Shor’s algorithm at non-trivial scales, not just simulations or toy problems.
Watch for these specific milestones in company announcements and academic papers. Generic claims about “quantum advantage” or record qubit counts often don’t indicate progress toward cryptographically relevant machines.
What This Means for Cryptocurrency
Hardware progress translates directly to cryptocurrency risk:
- Store now, decrypt later attacks are viable today: Adversaries can capture encrypted transactions now and wait for quantum computers to decrypt them. Use hybrid key exchange (ECDH+Kyber) for any sensitive channels immediately.
- Migration timelines must account for hardware acceleration: Error correction breakthroughs could compress the 2030-2035 consensus estimate to 2028-2030. Conservative projects start migration now rather than waiting for “proof” CRQC is imminent.
- Monitor logical qubit milestones specifically: Physical qubit announcements are marketing; logical qubit progress is substance. When the first system demonstrates 100+ logical qubits, migration becomes urgent.
- Layer-2 solutions can hedge uncertainty: While Layer-1 migration requires years of coordination, some Layer-2s can deploy post-quantum cryptography independently in 6-18 months, providing fallback options.
Explore Related Topics
Detailed Hardware Timeline
Company-by-company analysis of IBM, Google, IonQ, and other quantum computing leaders—tracking their roadmaps and milestones.
Threat Timeline
How hardware milestones, funding decisions, and error correction breakthroughs combine to determine Q-Day estimates.
Prepare for Hardware Acceleration
See which cryptocurrency projects are responding to quantum hardware progress—and which are waiting too long.