English

Computing $\varphi(N)$ for an RSA module with a single quantum query

Cryptography and Security 2025-10-10 v4 Quantum Physics

Abstract

In this paper we give a polynomial time algorithm to compute φ(N)\varphi(N) for an RSA module NN using as input the order modulo NN of a randomly chosen integer. This provides a new insight in the very important problem of factoring an RSA module with extra information. In fact, the algorithm is extremely simple and consists only on a computation of a greatest common divisor, two multiplications and a division. The algorithm works with a probability of at least 11N1/2ϵ1-\frac{1}{N^{1/2-\epsilon}}, where ϵ\epsilon is any small positive constant.

Keywords

Cite

@article{arxiv.2406.04061,
  title  = {Computing $\varphi(N)$ for an RSA module with a single quantum query},
  author = {Luis Víctor Dieulefait and Jorge Urróz},
  journal= {arXiv preprint arXiv:2406.04061},
  year   = {2025}
}

Comments

Some corrections pointed out by referees have been incorporated

R2 v1 2026-06-28T16:55:51.626Z