Joe Kilian, Erez Petrank

We consider noninteractive zero-knowledge proofs in the shared random

string model proposed by Blum, Feldman and Micali \cite{bfm}. Until

recently there was a sizable polynomial gap between the most

efficient noninteractive proofs for {\sf NP} based on general

complexity assumptions \cite{fls} versus those based on specific

algebraic assumptions \cite{Da}. ...
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Pavel Pudlak

We consider some problems about pairs of disjoint $NP$ sets.

The theory of these sets with a natural concept of reducibility

is, on the one hand, closely related to the theory of proof

systems for propositional calculus, and, on the other, it

resembles the theory of NP completeness. Furthermore, such

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Pavel Pudlak

We define propositional quantum Frege proof systems and compare it

with classical Frege proof systems.

Olaf Beyersdorff, Johannes Köbler, Sebastian Müller

Motivated by strong Karp-Lipton collapse results in bounded arithmetic, Cook and Krajicek have recently introduced the notion of propositional proof systems with advice.

In this paper we investigate the following question: Do there exist polynomially bounded proof systems with advice for arbitrary languages?

Depending on the complexity of the ...
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Alessandro Chiesa, Michael Forbes

We present three contributions to the understanding of QMA with multiple provers:

1) We give a tight soundness analysis of the protocol of [Blier and Tapp, ICQNM '09], yielding a soundness gap $\Omega(N^{-2})$, which is the best-known soundness gap for two-prover QMA protocols with logarithmic proof size. Maybe ...
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Olaf Beyersdorff, Samir Datta, Andreas Krebs, Meena Mahajan, Gido Scharfenberger-Fabian, Karteek Sreenivasaiah, Michael Thomas, Heribert Vollmer

In this paper we initiate the study of proof systems where verification of proofs proceeds by NC0 circuits. We investigate the question which languages admit proof systems in this very restricted model. Formulated alternatively, we ask which languages can be enumerated by NC0 functions. Our results show that the answer ... more >>>

Rafail Ostrovsky, Ivan Visconti

In FOCS 2001, Barak, Goldreich, Goldwasser and Lindell conjectured that the existence of ZAPs, introduced by Dwork and Naor in FOCS 2000, could lead to the design of a zero-knowledge proof system that is secure against both resetting provers and resetting verifiers. Their conjecture has been proven true by Deng, ... more >>>

Andreas Krebs, Nutan Limaye

We define DLOGTIME proof systems, DLTPS, which generalize NC0 proof systems.

It is known that functions such as Exact-k and Majority do not have NC0 proof systems. Here, we give a DLTPS for Exact-k (and therefore for Majority) and also for other natural functions such as Reach and k-Clique. Though ...
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Olaf Beyersdorff, Leroy Chew

Circumscription is one of the main formalisms for non-monotonic reasoning. It uses reasoning with minimal models, the key idea being that minimal models have as few exceptions as possible. In this contribution we provide the first comprehensive proof-complexity analysis of different proof systems for propositional circumscription. In particular, we investigate ... more >>>

Olaf Beyersdorff, Leroy Chew

In this paper we compare two proof systems for minimal entailment: a tableau system OTAB and a sequent calculus MLK, both developed by Olivetti (J. Autom. Reasoning, 1992). Our main result shows that OTAB-proofs can be efficiently translated into MLK-proofs, i.e., MLK p-simulates OTAB. The simulation is technically very involved ... more >>>

Olaf Beyersdorff, Leroy Chew, Renate Schmidt, Martin Suda

We examine the existing Resolution systems for quantified Boolean formulas (QBF) and answer the question which of these calculi can be lifted to the more powerful Dependency QBFs (DQBF). An interesting picture emerges: While for QBF we have the strict chain of proof systems Q-Resolution < IR-calc < IRM-calc, the ... more >>>