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Succinct non-interactive arguments (SNARGs) enable verifying NP statements with lower complexity than required for classical NP verification. Traditionally, the focus has been on minimizing the length of such arguments; nowadays researches have focused also on minimizing verification time, by drawing motivation from the problem of delegating computation. A(More)
The goal of general-purpose program obfuscation is to make an arbitrary computer program " unin-telligible " while preserving its functionality. At least as far back as the work of Diffie and Hellman in 1976, researchers have contemplated applications of general-purpose obfuscation. However, until 2013, even heuristic constructions for general-purpose(More)
This work attempts to clarify to what extent simulation-based security (SIM-security) is achievable for functional encryption (FE) and its relation to the weaker indistinguishability-based security (IND-security). Our main result is a compiler that transforms any FE scheme for the general circuit functionality (which we denote by Circuit-FE) meeting(More)
A function <i>f</i> is extractable if it is possible to algorithmically "extract," from any adversarial program that outputs a value <i>y</i> in the image of <i>f;</i> a preimage of <i>y</i>. When combined with hardness properties such as one-wayness or collision-resistance, extractability has proven to be a powerful tool. However, so far, extractability(More)
An obfuscator O is Virtual Grey Box (VGB) for a class C of circuits if, for any C ∈ C and any predicate π, deducing π(C) given O(C) is tantamount to deducing π(C) given unbounded computational resources and polynomially many oracle queries to C. VGB obfuscation is often significantly more meaningful than indistinguishability obfuscation (IO). In fact, for(More)
The traditional notion of <i>program obfuscation</i> requires that an obfuscation ~Prog of a program Prog computes the exact same function as Prog, but beyond that, the code of ~Prog should not leak any information about Prog. This strong notion of <i>virtual black-box</i> security was shown by Barak et al. (CRYPTO 2001) to be impossible to achieve, for(More)
An evasive circuit family is a collection of circuits C such that for every input x, a random circuit from C outputs 0 on x with overwhelming probability. We provide a combination of definitional, constructive, and impossibility results regarding obfuscation for evasive functions: 1. The (average case variants of the) notions of virtual black box(More)
Public-coin zero-knowledge and concurrent zero-knowledge (cZK) are two classes of zero knowledge protocols that guarantee some additional desirable properties. Still, to this date no protocol is known that is both public-coin and cZK for a language outside BPP. Furthermore , it is known that no such protocol can be black-box ZK [Pass et.al, Crypto 09]. We(More)
This is an out of date draft. The paper was merged with How to Construct Extractable Functions against Uniform Adversaries [BCP13] to form On the Existence of Extractable One-Way Functions [BCPR14]. Abstract We show that if there exist indistinguishability obfuscators for all circuits then there do not exist auxiliary-input extractable one-way functions. In(More)