Obfuscation-Based Non-black-box Simulation and Four Message Concurrent Zero Knowledge for NP
Obfuscation-Based Non-black-box Simulation and Four Message Concurrent Zero Knowledge for NP
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DOI:
10.1007/978-3-662-46497-7_25
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发表时间:
2015-03
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通讯作者:
Omkant Pandey;M. Prabhakaran;A. Sahai
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文献类型:
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作者:
Omkant Pandey;M. Prabhakaran;A. Sahai
We show the following result: Assuming the existence of public-coin differing-input obfuscation(pc-diO) for the class of all polynomial time Turing machines, then there exists a four message, fully concurrent zero-knowledge proof system for all languages inNPwith negligible soundness error. This result is constructive: given (pc-diO), our reduction yields an explicit protocol along with anexplicitsimulator that is “straight line” and runs in strict polynomial time. The obfuscation security property is used only to prove soundness.Public-coin differing-inputs obfuscation is a notion of obfuscation closely related to indistinguishability obfuscation. Most importantly for our result, (pc-diO) does not suffer from any known impossibility results: recent negative results on standard differing-inputs obfuscation do not apply to (pc-diO). Furthermore, candidate constructions for (pc-diO) for the class of all polynomial-time Turing Machines are known.Our reduction relies on a new non-black-box simulation technique which does not use the PCP theorem. We view the development of this new non-black-box simulation technique as the main contribution of our work. In addition to assuming (pc-diO), our reduction also assumes (standard and polynomial time) cryptographic assumptions such as collision-resistant hash functions.