Interactive Proof Systems


Volume 480 of the series Lecture Notes in Computer Science pp 263-274


Interactive proof systems and alternating time-space complexity

  • Lance FortnowAffiliated withDept. of Computer Science, University of Chicago
  • , Carsten LundAffiliated withDept. of Computer Science, University of Chicago

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We show a rough equivalence between alternating time-space complexity and a public-coin interactive proof system with the verifier having a polynomial related time-space complexity. Special cases include

  • All of NC has interactive proofs with a log-space polynomial-time public-coin verifier vastly improving the best previous lower bound of LOGCFL for this model [8].

  • All languages in P have interactive proofs with a polynomial-time public-coin verifier using o(log2 n) space.

  • All exponential-time languages have interactive proof systems with public-coin polynomial-space exponential-time verifiers.