Prime Factorization

Improve the constant factor in the exponent of GNFS.

Notability: Breakthrough
Solved: No
Contributor: Epoch Staff
Field: Number Theory

About the problem

The best known classical algorithm for factoring large integers is the general number field sieve (GNFS). It is exponential in the number of digits of the number to be factored. While polynomial time quantum algorithms are known for integer factorization, it is not known whether polynomial time classical algorithms exist. It is more likely, however, that significant improvements to GNFS are possible.

The goal of this problem is to find such an improvement. We verify solutions numerically, by testing proposed algorithms on challenge integers with limited computational resources (e.g., running on a laptop). The challenges are selected to ensure that the only way to succeed would be to generate an improvement at least as good as a significant improvement in the constant factor in the exponent in GNFS runtime.

This would be a major breakthrough in computational number theory.

Warm-up: we ask for a program that can handle numbers of a size that is doable with existing techniques and software.

Attempts by AI

We have evaluated the following models on this problem. “Warm-up” refers to an easier variant of the problem with a known solution.

Model
Problem
Solved
Logs
GPT-5.2 Pro
Warm-up
Yes
GPT-5.2 Pro
Full Problem
No
Gemini 3 Deep Think
Full Problem
No

AI Prompts

The difficulty level can be tuned by setting the size of number to factor. 90 digits should be doable just using existing software. 150 digits is likely in "breakthrough" territory.

Warm-up

Produce an algorithm that can factor balanced 90-digit semiprimes on a typical modern laptop in under ten minutes.

Full problem

Produce an algorithm that can factor balanced 150-digit semiprimes on a typical modern laptop in under ten minutes.

Mathematician survey

The author assessed the problem as follows.

# of mathematicians highly familiar with the problem: a majority of those working in a subfield (≈100)
# of mathematicians who have made a serious attempt to solve the problem: 10–50
Rough guess of how long it would take an expert human to solve the problem: 3–10 years
Notability of a solution: a major advance in a broader field; one of the best results of the year
A solution would be published: in a leading general journal
Likelihood of a solution generating more interesting math: very likely: any solution would lead to a rich set of follow-on work
Probability that the problem is solvable as stated: 80–95%