Algorithms1994

Algorithms for Quantum Computation: Discrete Logarithms and Factoring

Autores: Peter W. Shor

Publicado: Proceedings 35th Annual Symposium on Foundations of Computer Science (1994)

En una frase

Shows a quantum computer can factor large integers exponentially faster than the best known classical algorithm — the result that launched quantum cryptanalysis.

Puntos clave

  • Gives a polynomial-time quantum algorithm for integer factoring and discrete logarithms.
  • Uses the quantum Fourier transform to find the period of a modular exponential function.
  • Directly threatens RSA and elliptic-curve cryptography, which rely on these problems being hard.

En lenguaje sencillo

Classical computers struggle to factor very large numbers, and that difficulty is what keeps RSA encryption secure. Shor showed that a sufficiently large, error-corrected quantum computer could factor those numbers quickly by turning factoring into a period-finding problem and solving it with quantum interference. No such machine exists yet — breaking RSA-2048 would need millions of high-quality qubits — but the algorithm proves the threat is mathematical, not hypothetical.

Por qué importa

Shor's algorithm is the single biggest reason quantum computing is treated as strategically important. It is why NIST standardized post-quantum cryptography and why 'harvest-now, decrypt-later' is a real concern today.

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