Why Post-Quantum Standards Still Raise Patent Questions
A new practice area focused on tracking research, standards, and patents so technology companies can implement or contribute to post-quantum cryptography without creating avoidable IP problems.
Technical work and legal analysis on cryptography, patent eligibility and the law of new technology.
Selected research
PQScope connects 4,444 research items with standards, implementations, contributors, policy, and patent evidence to investigate the technical and commercial decisions facing post-quantum teams.
Read the analysisTracked documents · PQScope, .
Current statuses, not a conversion funnel.
Loading published statistics…
A new practice area focused on tracking research, standards, and patents so technology companies can implement or contribute to post-quantum cryptography without creating avoidable IP problems.
Investor counsel reads a quantum startup's patent families twice, in the data room and in the public record at the USPTO and EPO. How to spend a limited patent budget so both tell the same story.
PQScope connects 4,444 research items with standards, implementations, contributors, policy, and patent evidence to investigate the technical and commercial decisions facing post-quantum teams.
Many quantum computing companies begin with a university license. The terms that most often need working out between the two, and why several of them are harder in quantum than in other fields.
The USPTO has granted more than 600 QKD patents and the EPO about 180. What those patents cover, who holds them, and where the field is still open.
The USPTO and the EPO grant quantum applications at different rates and for different reasons. What the examination records of 16,896 quantum applications mean for where a limited patent budget should go.
The USPTO Patent Trial and Appeal Board has ruled on a quantum-resistant cryptographic construction exactly once, in 2018, and the applicant won. What the near-empty record means for how a post-quantum patent portfolio should be drafted and prosecuted.
The precedential Ex parte Desjardins decision recalibrates how the USPTO examines AI and machine learning applications under Section 101, and what it means for claiming and specification strategy.
The August 4, 2025 USPTO memorandum sets a "close call" standard for Section 101 rejections, limits the mental process grouping, and restores broad neural network training claims. What it means for filing and drafting decisions.
Post-quantum research
Shor’s algorithm connects quantum computation to the mathematics underlying RSA and other widely used public-key systems. A sufficiently large, fault-tolerant quantum computer would change their security assumptions.
This small experiment makes one part of that idea tangible: how quantum order finding can help reveal the factors of a number. Measurements and continued fractions illustrate the underlying mathematics.
PQScope follows research, standards discussions and the people and organizations behind them. These figures describe PQScope’s coverage.
Loading published statistics…
Where post-quantum work is heading →
Standards and IP Strategy →
Shor’s algorithm · a small experiment
Measurements from a quantum Fourier distribution provide evidence of the hidden period.
Each run returns one value, not the whole distribution.
01 · MeasureNo measurements yet.
02 · ReconstructA continued fraction will suggest a denominator.
03 · Verify & factorThe period is not supplied to the reconstruction.
Q = 64 is below N² = 225. Small registers can work here, but lack the usual general precision guarantee.
This models complete dephasing of the exponent register in its computational basis. Its Fourier outcomes become uniform. Chance samples may still yield factors in these tiny examples; they no longer concentrate near the useful phases.
Changing the instance, register size, or coherence starts a new experiment.
The first 16 values of ax mod N. Equal values label the same state of the output register; their exponent amplitudes can interfere.
The Fourier chart is not a transform of these bar heights. It sums amplitudes within each group of equal function values, then adds the groups’ probabilities.
A sample gives y/Q ≈ k/r. Continued fractions produce possible reduced fractions; their denominators may be divisors of r. We keep candidates within half a Fourier bin, combine denominator hypotheses by least common multiples, and test aᴿ mod N = 1. A verified exponent is reduced by removing redundant prime factors to obtain the order r.
This is a bounded teaching implementation for N = 15 and 21. The usual textbook choice N² ≤ Q < 2N² gives Q = 256 and 512 respectively. Finite precision can produce incorrect candidates; the modular check is essential.
The latest continued fraction appears after a measurement.
| Run | y | Candidate k/r | aᵈ mod N |
|---|---|---|---|
| No measurements yet. | |||
Here f(x) = aˣ mod N, 0 ≤ x < Q, and 0 ≤ z < N. This is the normalized distribution when the output register is ignored, with no postselection. The simulator computes it from f(x), without using a known period. In the dephased model, P(y) = 1/Q.
An even order helps only when aʳᐟ² is a nontrivial square root of 1 modulo N. An odd order or aʳᐟ² ≡ −1 calls for a different base.