Results 1 - 10 of 846

Smooth minimization of nonsmooth functions

by Yu. Nesterov - Math. Programming , 2005
"... In this paper we propose a new approach for constructing efficient schemes for nonsmooth convex optimization. It is based on a special smoothing technique, which can be applied to the functions with explicit max-structure. Our approach can be considered as an alternative to black-box minimization. F ..."
Abstract - Cited by 523 (1 self) - Add to MetaCart
In this paper we propose a new approach for constructing efficient schemes for nonsmooth convex optimization. It is based on a special smoothing technique, which can be applied to the functions with explicit max-structure. Our approach can be considered as an alternative to black-box minimization

Keying hash functions for message authentication

by Mihir Bellare, Ran Canetti, Hugo Krawczyk , 1996
"... The use of cryptographic hash functions like MD5 or SHA for message authentication has become a standard approach inmanyInternet applications and protocols. Though very easy to implement, these mechanisms are usually based on ad hoc techniques that lack a sound security analysis. We present new cons ..."
Abstract - Cited by 611 (39 self) - Add to MetaCart
of the underlying hash function. In addition our schemes are e cient and practical. Their performance is essentially that of the underlying hash function. Moreover they use the hash function (or its compression function) as a black box, so that widely available library code or hardware can be used to implement them

How to Go Beyond the Black-Box Simulation Barrier

by Boaz Barak - In 42nd FOCS , 2001
"... The simulation paradigm is central to cryptography. A simulator is an algorithm that tries to simulate the interaction of the adversary with an honest party, without knowing the private input of this honest party. Almost all known simulators use the adversary’s algorithm as a black-box. We present t ..."
Abstract - Cited by 228 (13 self) - Add to MetaCart
the first constructions of nonblack-box simulators. Using these new non-black-box techniques we obtain several results that were previously proven to be impossible to obtain using black-box simulators. Specifically, assuming the existence of collision resistent hash functions, we construct a new

Self-Testing/Correcting with Applications to Numerical Problems

by Manuel Blum, Michael Luby, Ronitt Rubinfeld , 1990
"... Suppose someone gives us an extremely fast program P that we can call as a black box to compute a function f . Should we trust that P works correctly? A self-testing/correcting pair allows us to: (1) estimate the probability that P (x) 6= f(x) when x is randomly chosen; (2) on any input x, compute ..."
Abstract - Cited by 361 (27 self) - Add to MetaCart
Suppose someone gives us an extremely fast program P that we can call as a black box to compute a function f . Should we trust that P works correctly? A self-testing/correcting pair allows us to: (1) estimate the probability that P (x) 6= f(x) when x is randomly chosen; (2) on any input x, compute

Constructive membership in black-box groups

by P. E. Holmes, S. A. Linton, E. A. O’brien, A. J. E. Ryba, R. A. Wilson - J. Group Theory , 2008
"... We present an algorithm to reduce the constructive membership problem for a black-box group G to three instances of the same problem for involution centralisers in G. If G is a simple group of Lie type in odd characteristic, then this reduction can be performed in (Monte Carlo) polynomial time. 1 ..."
Abstract - Cited by 11 (4 self) - Add to MetaCart
We present an algorithm to reduce the constructive membership problem for a black-box group G to three instances of the same problem for involution centralisers in G. If G is a simple group of Lie type in odd characteristic, then this reduction can be performed in (Monte Carlo) polynomial time. 1

Exploratory Mining and Pruning Optimizations of Constrained Associations Rules

by Raymond T. Ng, Laks V.S. Lakshmanan, Alex Pang, Jiawei Hah , 1998
"... From the standpoint of supporting human-centered discovery of knowledge, the present-day model of mining association rules suffers from the following serious shortcom- ings: (i) lack of user exploration and control, (ii) lack of focus, and (iii) rigid notion of relationships. In effect, this model f ..."
Abstract - Cited by 313 (44 self) - Add to MetaCart
functions as a black-box, admitting little user interaction in between. We propose, in this paper, an architecture that opens up the black-box, and supports constraintbased, human-centered exploratory mining of associations. The foundation of this architecture is a rich set of con- straint constructs

On the (im)possibility of obfuscating programs

by Boaz Barak, Oded Goldreich, Russell Impagliazzo, Steven Rudich, Amit Sahai, Salil Vadhan, Ke Yang - Lecture Notes in Computer Science , 2001
"... Informally, an obfuscator O is an (efficient, probabilistic) “compiler ” that takes as input a program (or circuit) P and produces a new program O(P) that has the same functionality as P yet is “unintelligible ” in some sense. Obfuscators, if they exist, would have a wide variety of cryptographic an ..."
Abstract - Cited by 348 (24 self) - Add to MetaCart
and complexity-theoretic applications, ranging from software protection to homomorphic encryption to complexity-theoretic analogues of Rice’s theorem. Most of these applications are based on an interpretation of the “unintelligibility ” condition in obfuscation as meaning that O(P) is a “virtual black box

Black-box garbled RAM

by Sanjam Garg, Steve Lu, Rafail Ostrovsky - In Annual Symposium on Foundations of Computer Science, FOCS , 2015
"... Garbled RAM, introduced by Lu and Ostrovsky, enables the task of garbling a RAM (Random Access Machine) program directly, there by avoiding the inefficient process of first converting it into a circuit. Garbled RAM can be seen as a RAM analogue of Yao’s garbled circuit construction, except that know ..."
Abstract - Cited by 3 (1 self) - Add to MetaCart
that known realizations of Garbled RAM make non-black-box use of the underlying cryptographic primitives. In this paper we remove this limitation and provide the first black-box construction of Garbled RAM with polylogarithmic overhead. Our scheme allows for garbling multiple RAM programs being executed on a

Black-box analysis of the block-cipher-based hash-function constructions from pgv

by John Black, Phillip Rogaway, Thomas Shrimpton - In Advances in Cryptology – CRYPTO ’02 (2002 , 2002
"... Abstract. Preneel, Govaerts, and Vandewalle [6] considered the 64 most basic ways to construct a hash function H: {0, 1} ∗ →{0, 1} n from a block cipher E: {0, 1} n ×{0, 1} n →{0, 1} n. They regarded 12 of these 64 schemes as secure, though no proofs or formal claims were given. The remaining 52 sc ..."
Abstract - Cited by 128 (16 self) - Add to MetaCart
schemes were shown to be subject to various attacks. Here we provide a formal and quantitative treatment of the 64 constructions considered by PGV. We prove that, in a black-box model, the 12 schemes that PGV singled out as secure really are secure: we give tight upper and lower bounds on their collision

Black-Box Non-Black-Box Zero Knowledge

by Vipul Goyal, Rafail Ostrovsky, Alessandra Scafuro, Ivan Visconti
"... Motivated by theoretical and practical interest, the challenging task of designing crypto-graphic protocols having only black-box access to primitives has generated various breakthroughs in the last decade. Despite such positive results, even though nowadays we know black-box con-structions for secu ..."
Abstract - Cited by 1 (1 self) - Add to MetaCart
for secure two-party and multi-party computation even in constant rounds, there still are in Cryptography several constructions that critically require non-black-box use of primitives in order to securely realize some fundamental tasks. As such, the study of the gap between black-box and non-black-box
Results 1 - 10 of 846