🔬 Discovery

NP-completeness (Cook-Levin) and P vs NP

NP-completitud (teorema de Cook-Levin) y problema P vs NP

Date
1971 · confidence high
Place
Toronto, Canada
Credited to
Stephen Cook (1971); Leonid Levin (Moscow, 1973, independent); Richard Karp's 21 NP-complete problems (1972)
People
👤 Leonid Levin1948–👤 Stephen Cook1939–
Field
Knowledge & symbols

⚠️ Disputed: the sources disagree.

What was discovered

Boolean satisfiability is NP-complete: if it were solved in polynomial time, every problem whose solution can be verified quickly would be too. It formulates the central question of theoretical computer science, whether P equals NP, still open.

Levin obtained the result independently in the USSR, with delayed publication; Karp showed in 1972 how ubiquitous NP-completeness is.

What it led to

  • computational complexity theory
  • hardness-based cryptography
  • approximation algorithms and heuristics
  • the Millennium Problems
🕸️ View in the graph

Built on

Made possible

  • industrial SAT solvers
  • hardware verification

📄 Original publication

The complexity of theorem-proving proceduresStephen A. Cook · Proceedings of the third annual ACM symposium on Theory of computing - STOC '71 · 1971

Links

Sources✓ verified 2026-09-25