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Computing, IT & AI

PCP theorem and hardness of approximation

1992 CESanjeev Arora, Rajeev Motwani, Madhu Sudan, with Carsten Lund, Mario Szegedy and Shmuel SafraProof verification and the hardness of approximation problems (FOCS 1992; JACM 1998)Diaspora (work abroad)

1992

Any mathematical proof can be rewritten so that it can be checked by reading only a few randomly chosen bits.

Dated
1992
As scholars put it
1992 CE
Originator
Sanjeev Arora, Rajeev Motwani, Madhu Sudan, with Carsten Lund, Mario Szegedy and Shmuel Safra
Source text
Proof verification and the hardness of approximation problems (FOCS 1992; JACM 1998)
Region
Diaspora (work abroad)
Discipline
Computing, IT & AI
Evidence
Documented
Confidence
High
Verification
Verified-web

Background

Building on work on interactive proofs, Arora and Safra, and then Arora, Lund, Motwani, Sudan and Szegedy, proved in 1992 that every problem in NP has probabilistically checkable proofs. Three of the five authors (Arora, Motwani, Sudan) were Indian-born.

Significance

Showed that for many optimisation problems even a good approximate solution is as hard to find as an exact one, which created the field of hardness of approximation. It won the 2001 Gödel Prize.

Path to modern innovation

Underpins modern proof systems, including succinct proofs used in cryptography.

1992PCP theorem and hardness of approximation

Global impact

  • Tells algorithm designers which problems cannot be approximated efficiently.
  • Ideas used in verifiable computation and zero-knowledge proof systems.

Primary sources

Further reading

Related

Corrections and additional sources: edit IND-394 on GitHub.