The Methodology

How we measure, verify, and visualize quantum computing progress.

Understanding the Shor's Progress Bar Scale

The Shor's Progress Bar uses a hybrid logarithmic scale (specifically, log-squared) that weights progress by computational difficulty rather than raw bit count. This is a deliberate design choice to ensure the visualization honestly represents how far we are from breaking RSA-2048 encryption.

Why Not a Linear Scale?

A linear scale would show 48 bits as 2.3% of 2048 bits. While mathematically correct for bit count, this misrepresents the challenge. The computational resources required to factor larger numbers grow exponentially, not linearly.

Showing "2.3% progress" implies we're roughly 1/43rd of the way there. In reality, the engineering gap between factoring 48 bits and 2048 bits is astronomically larger than 43x.

Why Not a Pure Logarithmic Scale?

A pure logarithmic scale would show 48 bits at ~40% of the bar. This treats each "doubling" of bits as equal progress (4→8 bits = same visual distance as 1024→2048 bits).

While logarithmic scales are mathematically principled, we believe 40% visual progress for a disputed 48-bit claim undermines our mission to "debunk hype at a glance." It makes incremental achievements appear more significant than the engineering reality warrants.

Our Approach: Hybrid Log-Squared Scale

We apply a squared transformation to the logarithmic position. This compresses the low-end of the scale more aggressively, ensuring that:

  • The verified record (6 bits / integer 35) appears near the starting point (~1%)
  • Disputed claims like 48 bits appear at ~16%, not 40%
  • The vast gap to 2048 bits remains "comically obvious"

Note: At the upper end (512 bits+), spacing is roughly equal between doublings. This reflects engineering reality: moving from 1024 to 2048 bits is mathematically "just one step," but represents a massive generation of effort comparable to the step before it.

The formula: position = ((log₂(bits) - log₂(4)) / (log₂(2048) - log₂(4)))² × 100%

Bits FactoredLinear ScalePure Log ScaleOur Hybrid Scale
6 (verified) — integer 350.29%~6.5%~1%
48 (disputed) — Schnorr method2.3%~40%~16%
25612.5%~67%~44%
2048 (target) — ~10617100%100%100%

Our Commitment to Honesty

We acknowledge that any scale choice involves trade-offs. We chose the hybrid log-squared scale because it best serves our mission: providing an instant, visual reality check that calms panic without minimizing genuine progress. The scale is mathematically consistent and fully documented here for transparency.

If you believe a different scale would better serve public understanding, we welcome the discussion. Reach out via our contact channels.

Display Format: Integers + Bits

We display both the integer and its bit-length on the progress bar to serve different audiences:

  • For laypeople: "35" is viscerally small and memorable—most people can factor it mentally
  • For technical users: "6 bits" aligns with cryptographic nomenclature
  • For the target: "~10617" communicates the incomprehensible scale—a 617-digit number

The parallel structure (integer + bits for both verified and target) creates an instant visual comparison: 35 vs ~10617. This is the gap quantum computers must bridge.

Verified Record Criteria

The "Current Verified Record" displayed on Shor's Progress Bar represents the largest integer (in bits) factored using Shor's algorithm on verified quantum hardware. We apply strict criteria to ensure this number reflects genuine scientific progress.

Acceptance Requirements

  • Peer-reviewed publication

    Published in a recognized journal or reputable preprint server (arXiv with institutional affiliation)

  • Actual quantum hardware

    Factorization must be performed on physical quantum computers, not simulators or hybrid classical systems

  • Shor's algorithm implementation

    Must use a genuine implementation of Shor's algorithm, not alternative factoring methods

  • Independent verification

    Results acknowledged by at least one independent expert or institution

  • No active disputes

    Not currently subject to retraction, major corrections, or credible expert challenges

Current Record

As of our last update, the verified record stands at 6 bits (factoring 35 = 5 × 7), achieved in late 2025 via a Regev algorithm implementation that validates the scalable approach to period-finding. While larger factorizations have been claimed (48-bit, 90-bit), they use fundamentally different methods (Schnorr's algorithm with quantum annealing) that experts say do not scale to RSA-2048.

The 2025 Denominator Shift

In May 2025, Craig Gidney at Google Quantum AI published a landmark paper that dramatically revised the resource requirements for breaking RSA-2048.

The Shift

Previous Estimate (2019)
~20 million
physical qubits
New Estimate (2025)
<1 million
physical qubits

This 20x reduction was achieved through innovations in approximate residue arithmetic, yoked surface codes, and magic state cultivation—not by building better hardware, but by making the algorithm more efficient.

Why This Matters

The progress bar tracks our position (bits factored), but the finish line also matters. This theoretical breakthrough effectively moved the finish line 20x closer without changing our current position. The threat timeline shortened not because we advanced, but because the destination got nearer.

Source: arXiv:2505.15917 (Gidney, May 2025)

Why Regev's Algorithm Matters

The 2025 factorization of 35 is significant not because of its size, but because it validates Regev's algorithm—a 2023 improvement to Shor's original approach that trades circuit depth for circuit runs.

The Evolution

Original Shor's (1994)

O(n²) circuit depth—requires long coherence times that current hardware can't sustain

Regev's Improvement (2023)

O(n^1.5) circuit depth—shallower circuits run multiple times, with classical post-processing

This is the algorithm that will eventually scale to RSA-2048. The 2025 demonstration proves it works on real hardware, not just in theory.

Source: arXiv:2511.18198 (Regev Algorithm Implementation, Dec 2025)

What We Don't Track (And Why)

To maintain signal quality, we explicitly exclude certain metrics and claims from our verified tracking.

Hybrid Methods (Schnorr + Annealing)

Claims like 48-bit and 90-bit factorizations use Schnorr's classical algorithm with quantum optimization subroutines. Experts agree these methods do not scale to RSA-2048—they hit an exponential wall at larger sizes.

D-Wave "Supremacy" Claims

D-Wave's quantum annealing achievements (e.g., spin glass simulation) are in a different problem domain. Annealing architecture requires exponentially more qubits for factorization than gate-model computers.

Raw Physical Qubit Counts

"1,000 qubits!" headlines are meaningless without error correction context. What matters is logical qubits—error-corrected units that can sustain long computations. Current state: ~12 logical qubits verified. Needed: ~4,000+.

Vendor Press Releases

We require peer-reviewed publications or reputable preprints with institutional affiliation. Press releases without accompanying papers are excluded.

Ghost Bar Governance

The "Ghost Bar" represents unverified or disputed claims that have received significant media attention. This section documents the complete lifecycle for managing these claims.

1. Inclusion Criteria

A claim qualifies for Ghost Bar consideration if it meets all of the following:

  • Published paper or preprint — Press releases without papers are excluded
  • Significant media attention — Coverage in mainstream tech/science outlets
  • >25% improvement claim — Must claim substantial advancement over verified record
  • Editorial decision — QTI admin reviews and approves inclusion

2. Status & Context Requirements

All Ghost Bar entries must include:

  • Clear "Unverified/Disputed" label visible on hover/click
  • Link to the original paper/claim
  • Links to expert rebuttals or critical analyses when available
  • Date added and reason for disputed status

3. Promotion to Verified

A Ghost Bar claim is promoted to the Verified Record when:

  • Independent replication on quantum hardware by a separate team
  • Peer-review acceptance in a recognized journal
  • Expert consensus that the methodology is sound

4. Removal (Debunking)

A Ghost Bar claim is removed when any of the following occur:

  • Paper retraction by authors or journal
  • Expert consensus identifies fundamental methodological flaws
  • 12-month timeout without independent replication

Removed claims are archived in our records but no longer displayed on the Progress Bar.

Expert Whitelist

Our Expert Sentiment Index tracks opinions from leading quantum computing researchers. We monitor public statements, blog posts, and publications from the following experts:

Scott Aaronson

Professor of Computer Science, UT Austin

Theoretical computer scientist specializing in quantum computing complexity. Known for accessible explanations and skeptical analysis of overclaimed breakthroughs.

John Preskill

Richard P. Feynman Professor of Theoretical Physics, Caltech

Pioneer in quantum information theory. Coined the term "quantum supremacy" and leads Caltech's Institute for Quantum Information and Matter.

Sabine Hossenfelder

Research Fellow, Frankfurt Institute for Advanced Studies

Physicist known for critical analysis of hype in physics, including quantum computing. Popular science communicator with track record of debunking overclaims.

Gil Kalai

Professor of Mathematics, Hebrew University of Jerusalem

Mathematician and notable quantum computing skeptic. Argues that quantum error correction may face fundamental barriers. Provides valuable contrarian perspective.

Michele Mosca

Professor, University of Waterloo & Co-founder, Institute for Quantum Computing

Leading voice on quantum threat timelines and post-quantum cryptography transition. Created influential "Mosca's Theorem" for migration planning.

Craig Gidney

Research Scientist, Google Quantum AI

Author of landmark resource estimation papers. His 2025 analysis reduced the estimated qubit requirement for RSA-2048 by 20x, fundamentally shifting the threat timeline.

Peter Shor

Professor of Applied Mathematics, MIT

Creator of Shor's algorithm (1994). The definitive authority on what constitutes a valid implementation of the algorithm that bears his name.

Selection Criteria

Experts are selected based on: (1) recognized academic credentials in quantum computing or cryptography, (2) public track record of accurate predictions and analysis, (3) willingness to engage with and critique industry claims. We intentionally include both optimists and skeptics to ensure balanced sentiment tracking.

Hype Index Logic

The Hype Index measures media sensationalism around quantum computing. It uses a hybrid AI-human workflow to ensure accuracy while scaling content analysis.

The Workflow

AI
Aggregate
👤
Review
Publish

Step 1: AI Aggregation

AI system aggregates the top 50 quantum computing headlines from tracked sources (major news outlets, tech publications, academic press releases). Headlines are pre-scored for sensationalism markers: superlatives, fear language, timeline claims.

Step 2: Human Review

QTI admin reviews AI analysis, checking for: sarcasm detection failures, context the AI missed, nuanced claims that aren't simply "hype" or "accurate." Headlines are re-scored or discarded as needed.

Step 3: Final Score

The published Hype Index reflects human judgment, not raw AI output. The admin assigns the final weekly score (0-100) based on overall media temperature, weighted by outlet reach and claim severity.

Why Human-in-the-Loop?

Quantum computing coverage is uniquely challenging for AI analysis:

  • Technical nuance — A "breakthrough" in error correction is genuinely significant; a "breakthrough" in qubit count may not be
  • Source credibility — Press releases from quantum startups require different scrutiny than peer-reviewed publications
  • Sarcasm and criticism — Expert tweets mocking hype can be misread as endorsement by AI
  • Contextual history — Claims must be evaluated against prior promises from the same source

Update Cadence

The Hype Index is updated weekly, with emergency updates for major breaking news (e.g., a major "RSA broken" claim). Historical values are preserved in the Divergence Graph for trend analysis.