Securely Obfuscating Re-Encryption
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Adaptive Garbled RAM from Laconic Oblivious Transfer
Adaptive Garbled RAM from Laconic Oblivious Transfer Sanjam Garg?1, Rafail Ostrovsky??2, and Akshayaram Srinivasan1 1 University of California, Berkeley fsanjamg,[email protected] 2 UCLA [email protected] Abstract. We give a construction of an adaptive garbled RAM scheme. In the adaptive setting, a client first garbles a \large" persistent database which is stored on a server. Next, the client can provide garbling of mul- tiple adaptively and adversarially chosen RAM programs that execute and modify the stored database arbitrarily. The garbled database and the garbled program should reveal nothing more than the running time and the output of the computation. Furthermore, the sizes of the garbled database and the garbled program grow only linearly in the size of the database and the running time of the executed program respectively (up to poly logarithmic factors). The security of our construction is based on the assumption that laconic oblivious transfer (Cho et al., CRYPTO 2017) exists. Previously, such adaptive garbled RAM constructions were only known using indistinguishability obfuscation or in random oracle model. As an additional application, we note that this work yields the first constant round secure computation protocol for persistent RAM pro- grams in the malicious setting from standard assumptions. Prior works did not support persistence in the malicious setting. 1 Introduction Over the years, garbling methods [Yao86,LP09,AIK04,BHR12b,App17] have been extremely influential and have engendered an enormous number of applications ? Research supported in part from DARPA/ARL SAFEWARE Award W911NF15C0210, AFOSR Award FA9550-15-1-0274, AFOSR YIP Award, DARPA and SPAWAR under contract N66001-15-C-4065, a Hellman Award and research grants by the Okawa Foundation, Visa Inc., and Center for Long-Term Cybersecurity (CLTC, UC Berkeley). -
Prediction from Partial Information and Hindsight, with Application to Circuit Lower Bounds
comput. complex. c Springer Nature Switzerland AG 2019 DOI 10.1007/s00037-019-00177-4 computational complexity PREDICTION FROM PARTIAL INFORMATION AND HINDSIGHT, WITH APPLICATION TO CIRCUIT LOWER BOUNDS Or Meir and Avi Wigderson Abstract. Consider a random sequence of n bits that has entropy at least n − k, where k n. A commonly used observation is that an average coordinate of this random sequence is close to being uniformly distributed, that is, the coordinate “looks random.” In this work, we prove a stronger result that says, roughly, that the average coordinate n looks random to an adversary that is allowed to query ≈ k other co- ordinates of the sequence, even if the adversary is non-deterministic. This implies corresponding results for decision trees and certificates for Boolean functions. As an application of this result, we prove a new result on depth-3 cir- cuits, which recovers as a direct corollary the known lower bounds for the parity and majority functions, as well as a lower bound on sensi- tive functions due to Boppana (Circuits Inf Process Lett 63(5):257–261, 1997). An interesting feature of this proof is that it works in the frame- work of Karchmer and Wigderson (SIAM J Discrete Math 3(2):255–265, 1990), and, in particular, it is a “top-down” proof (H˚astad et al. in Computat Complex 5(2):99–112, 1995). Finally, it yields a new kind of a random restriction lemma for non-product distributions, which may be of independent interest. Keywords. Certificate complexity, Circuit complexity, Circuit com- plexity lower bounds, Decision tree complexity, Information theoretic, Query complexity, Sensitivity Subject classification. -
Statistical Queries and Statistical Algorithms: Foundations and Applications∗
Statistical Queries and Statistical Algorithms: Foundations and Applications∗ Lev Reyzin Department of Mathematics, Statistics, and Computer Science University of Illinois at Chicago [email protected] Abstract We give a survey of the foundations of statistical queries and their many applications to other areas. We introduce the model, give the main definitions, and we explore the fundamental theory statistical queries and how how it connects to various notions of learnability. We also give a detailed summary of some of the applications of statistical queries to other areas, including to optimization, to evolvability, and to differential privacy. 1 Introduction Over 20 years ago, Kearns [1998] introduced statistical queries as a framework for designing machine learning algorithms that are tolerant to noise. The statistical query model restricts a learning algorithm to ask certain types of queries to an oracle that responds with approximately correct answers. This framework has has proven useful, not only for designing noise-tolerant algorithms, but also for its connections to other noise models, for its ability to capture many of our current techniques, and for its explanatory power about the hardness of many important problems. Researchers have also found many connections between statistical queries and a variety of modern topics, including to evolvability, differential privacy, and adaptive data analysis. Statistical queries are now both an important tool and remain a foundational topic with many important questions. The aim of this survey is to illustrate these connections and bring researchers to the forefront of our understanding of this important area. We begin by formally introducing the model and giving the main definitions (Section 2), we then move to exploring the fundamental theory of learning statistical queries and how how it connects to other notions of arXiv:2004.00557v2 [cs.LG] 14 May 2020 learnability (Section 3). -
The Gödel Prize 2020 - Call for Nominatonn
The Gödel Prize 2020 - Call for Nominatonn Deadline: February 15, 2020 The Gödel Prize for outntanding papern in the area of theoretial iomputer niienie in nponnored jointly by the European Annoiiaton for Theoretial Computer Siienie (EATCS) and the Annoiiaton for Computng Maihinery, Speiial Innterent Group on Algorithmn and Computaton Theory (AC M SInGACT) The award in prenented annually, with the prenentaton taaing plaie alternately at the Innternatonal Colloquium on Automata, Languagen, and Programming (InCALP) and the AC M Symponium on Theory of Computng (STOC) The 28th Gödel Prize will be awarded at the 47th Innternatonal Colloquium on Automata, Languagen, and Programming to be held during 8-12 July, 2020 in Beijing The Prize in named in honour of Kurt Gödel in reiogniton of hin major iontributonn to mathematial logii and of hin interent, diniovered in a leter he wrote to John von Neumann nhortly before von Neumann’n death, in what han beiome the famoun “P vernun NP” quenton The Prize iniluden an award of USD 5,000 Award Committee: The 2020 Award Commitee ionnintn of Samnon Abramnay (Univernity of Oxford), Anuj Dawar (Chair, Univernity of Cambridge), Joan Feigenbaum (Yale Univernity), Robert Krauthgamer (Weizmann Innnttute), Daniel Spielman (Yale Univernity) and David Zuiaerman (Univernity of Texan, Auntn) Eligibility: The 2020 Prize rulen are given below and they nupernede any diferent interpretaton of the generii rule to be found on webniten of both SInGACT and EATCS Any renearih paper or nerien of papern by a ningle author or by -
Obfuscating Compute-And-Compare Programs Under LWE
58th Annual IEEE Symposium on Foundations of Computer Science Obfuscating Compute-and-Compare Programs under LWE Daniel Wichs Giorgos Zirdelis Northeastern University Northeastern University [email protected] [email protected] Abstract—We show how to obfuscate a large and expres- that the obfuscated program can be simulated given black- sive class of programs, which we call compute-and-compare box access to the program’s functionality. Unfortunately, programs, under the learning-with-errors (LWE) assumption. they showed that general purpose VBB obfuscation is un- Each such program CC[f,y] is parametrized by an arbitrary polynomial-time computable function f along with a target achievable. This leaves open two possibilities: (1) achieving value y and we define CC[f,y](x) to output 1 if f(x)=y weaker security notions of obfuscation for general programs, and 0 otherwise. In other words, the program performs an and (2) achieving virtual black box obfuscation for restricted arbitrary computation f and then compares its output against classes of programs. y a target . Our obfuscator satisfies distributional virtual-black- Along the first direction, Barak et al. proposed a weaker box security, which guarantees that the obfuscated program does not reveal any partial information about the function f security notion called indistinguishability obfuscation (iO) or the target value y, as long as they are chosen from some which guarantees that the obfuscations of two functionally distribution where y has sufficient pseudo-entropy given f. equivalent programs are indistinguishable. In a breakthrough We also extend our result to multi-bit compute-and-compare result, Garg, Gentry, Halevi, Raykova, Sahai and Waters MBCC[f,y,z](x) z programs which output a message if [GGH+13b] showed how to iO-obfuscate all polynomial- f(x)=y. -
October 1983 Table of Contents
Fairfield Meeting (October 28-29)- Page 614 San Luis Obispo Meeting (November 11-12)-Page 622 Evanston Meeting (November 11-12)-Page 630 Notices of the American Mathematical Society October 1983, Issue 228 Volume 30, Number 6, Pages 569- 712 Providence, Rhode Island USA ISSN 0002-9920 Calendar of AMS Meetings THIS CALENDAR lists all meetings which have been approved by the Council prior to the date this issue of the Notices was sent to press. The summer and annual meetings are joint meetings of the Mathematical Association of America and the Ameri· can Mathematical Society. The meeting dates which fall rather far in the future are subject to change; this is particularly true of meetings to which no numbers have yet been assigned. Programs of the meetings will appear in the issues indicated below. First and second announcements of the meetings will have appeared in earlier issues. ABSTRACTS OF PAPERS presented at a meeting of the Society are published in the journal Abstracts of papers presented to the American Mathematical Society in the issue corresponding to that of the Notices which contains the program of the meet· ing. Abstracts should be submitted on special forms which are available in many departments of mathematics and from the office of the Society in Providence. Abstracts of papers to be presented at the meeting must be received at the headquarters of the Society in Providence, Rhode Island, on or before the deadline given below for the meeting. Note that the deadline for ab· stracts submitted for consideration for presentation at special sessions is usually three weeks earlier than that specified below. -
Exploring Differential Obliviousness∗
Exploring Differential Obliviousness∗ Amos Beimely Kobbi Nissimz Mohammad Zaherix October 4, 2019 Abstract In a recent paper, Chan et al. [SODA ’19] proposed a relaxation of the notion of (full) memory obliv- iousness, which was introduced by Goldreich and Ostrovsky [J. ACM ’96] and extensively researched by cryptographers. The new notion, differential obliviousness, requires that any two neighboring inputs exhibit similar memory access patterns, where the similarity requirement is that of differential privacy. Chan et al. demonstrated that differential obliviousness allows achieving improved efficiency for several algorithmic tasks, including sorting, merging of sorted lists, and range query data structures. In this work, we continue the exploration of differential obliviousness, focusing on algorithms that do not necessarily examine all their input. This choice is motivated by the fact that the existence of loga- rithmic overhead ORAM protocols implies that differential obliviousness can yield at most a logarithmic improvement in efficiency for computations that need to examine all their input. In particular, we explore property testing, where we show that differential obliviousness yields an almost linear improvement in overhead in the dense graph model, and at most quadratic improvement in the bounded degree model. We also explore tasks where a non-oblivious algorithm would need to explore different portions of the input, where the latter would depend on the input itself, and where we show that such a behavior can be maintained under differential obliviousness, but not under full obliviousness. Our examples suggest that there would be benefits in further exploring which class of computational tasks are amenable to differential obliviousness. arXiv:1905.01373v2 [cs.CR] 2 Oct 2019 ∗Work supported by NSF grant No. -
The Gödel Prize 2019 - Call for Nominations Deadline: February 15, 2019
The Gödel Prize 2019 - Call for Nominations Deadline: February 15, 2019 The Gödel Prize for outstanding papers in the area of theoretical computer science is sponsored jointly by the European Association for Theoretical Computer Science (EATCS) and the Association for Computing Machinery, Special Interest Group on Algorithms and Computation Theory (ACM SIGACT). The award is presented annually, with the presentation taking place alternately at the International Colloquium on Automata, Languages, and Programming (ICALP) and the ACM Symposium on Theory of Computing (STOC). The 27th Gödel Prize will be awarded at 51st Annual ACM Symposium on the Theory of Computing to be held during June 23-26, 2019 in Phoenix, AZ. The Prize is named in honor of Kurt Gödel in recognition of his major contributions to mathematical logic and of his interest, discovered in a letter he wrote to John von Neumann shortly before von Neumann’s death, in what has become the famous “P versus NP” question. The Prize includes an award of USD 5,000. Award Committee: The 2019 Award Committee consists of Anuj Dawar (Cambridge University), Robert Krauthgamer (Weizmann Institute), Joan Feigenbaum (Yale University), Giuseppe Persiano (Università di Salerno), Omer Reingold (Chair, Stanford University) and Daniel Spielman (Yale University). Eligibility: The 2019 Prize rules are given below and they supersede any different interpretation of the generic rule to be found on websites of both SIGACT and EATCS. Any research paper or series of papers by a single author or by a team of authors is deemed eligible if: - The main results were not published (in either preliminary or final form) in a journal or conference proceedings before January 1st, 2006. -
Download This PDF File
T G¨ P 2012 C N Deadline: December 31, 2011 The Gödel Prize for outstanding papers in the area of theoretical computer sci- ence is sponsored jointly by the European Association for Theoretical Computer Science (EATCS) and the Association for Computing Machinery, Special Inter- est Group on Algorithms and Computation Theory (ACM-SIGACT). The award is presented annually, with the presentation taking place alternately at the Inter- national Colloquium on Automata, Languages, and Programming (ICALP) and the ACM Symposium on Theory of Computing (STOC). The 20th prize will be awarded at the 39th International Colloquium on Automata, Languages, and Pro- gramming to be held at the University of Warwick, UK, in July 2012. The Prize is named in honor of Kurt Gödel in recognition of his major contribu- tions to mathematical logic and of his interest, discovered in a letter he wrote to John von Neumann shortly before von Neumann’s death, in what has become the famous P versus NP question. The Prize includes an award of USD 5000. AWARD COMMITTEE: The winner of the Prize is selected by a committee of six members. The EATCS President and the SIGACT Chair each appoint three members to the committee, to serve staggered three-year terms. The committee is chaired alternately by representatives of EATCS and SIGACT. The 2012 Award Committee consists of Sanjeev Arora (Princeton University), Josep Díaz (Uni- versitat Politècnica de Catalunya), Giuseppe Italiano (Università a˘ di Roma Tor Vergata), Mogens Nielsen (University of Aarhus), Daniel Spielman (Yale Univer- sity), and Eli Upfal (Brown University). ELIGIBILITY: The rule for the 2011 Prize is given below and supersedes any di fferent interpretation of the parametric rule to be found on websites on both SIGACT and EATCS. -
View This Volume's Front and Back Matter
Computational Complexity Theory This page intentionally left blank https://doi.org/10.1090//pcms/010 IAS/PARK CIT Y MATHEMATICS SERIES Volume 1 0 Computational Complexity Theory Steven Rudic h Avi Wigderson Editors American Mathematical Societ y Institute for Advanced Stud y IAS/Park Cit y Mathematics Institute runs mathematics educatio n programs that brin g together hig h schoo l mathematic s teachers , researcher s i n mathematic s an d mathematic s education, undergraduat e mathematic s faculty , graduat e students , an d undergraduate s t o participate i n distinc t bu t overlappin g program s o f researc h an d education . Thi s volum e contains th e lectur e note s fro m th e Graduat e Summe r Schoo l progra m o n Computationa l Complexity Theor y hel d i n Princeto n i n the summe r o f 2000 . 2000 Mathematics Subject Classification. Primar y 68Qxx ; Secondar y 03D15 . Library o f Congress Cataloging-in-Publicatio n Dat a Computational complexit y theor y / Steve n Rudich , Av i Wigderson, editors , p. cm . — (IAS/Park Cit y mathematic s series , ISS N 1079-563 4 ; v. 10) "Volume contain s the lecture note s fro m th e Graduate Summe r Schoo l progra m o n Computa - tional Complexit y Theor y hel d i n Princeton i n the summer o f 2000"—T.p. verso . Includes bibliographica l references . ISBN 0-8218-2872- X (hardcove r : acid-fre e paper ) 1. Computational complexity . I . Rudich, Steven . -
ERIC W. ALLENDER Department of Computer Science
ERIC W. ALLENDER Department of Computer Science, Rutgers University 110 Frelinghuysen Road Piscataway, New Jersey 08854-8019 (848) 445-7296 (office) [email protected] http://www.cs.rutgers.edu/ ˜ allender CURRENT POSITION: 2008 to present Distinguished Professor, Department of Computer Science, Rutgers University, New Brunswick, New Jersey. Member of the Graduate Faculty, Member of the DIMACS Center for Discrete Mathematics and Theoretical Computer Science (since 1989), Member of the Graduate Faculty of the Mathematics Department (since 1993). 1997 to 2008 Professor, Department of Computer Science, Rutgers University, New Brunswick, New Jersey. 1991 to 1997 Associate Professor, Department of Computer Science, Rutgers Uni- versity, New Brunswick, New Jersey. 1985 to 1991 Assistant Professor, Department of Computer Science, Rutgers Univer- sity, New Brunswick, New Jersey. VISITING POSITIONS: Aug.–Dec. 2018 Long-Term Visitor, Simons Institute for the Theory of Computing, Uni- versity of California, Berkeley. Jan.–Mar. 2015 Visiting Scholar, University of California, San Diego. Sep.–Oct. 2011 Visiting Scholar, Institute for Theoretical Computer Science, Tsinghua University, Beijing, China. Jan.–Apr. 2010 Visiting Scholar, Department of Decision Sciences, University of South Africa, Pretoria. Oct.–Dec. 2009 Visiting Scholar, Department of Mathematics, University of Cape Town, South Africa. Mar.–June 1997 Gastprofessor, Wilhelm-Schickard-Institut f¨ur Informatik, Universit¨at T¨ubingen, Germany. Dec. 96–Feb. 97 Visiting Scholar, Department of Theoretical Computer Science, Insti- tute of Mathematical Sciences, Chennai (Madras), India. 1992–1993 Visiting Research Scientist, Department of Computer Science, Prince- ton University. May – July 1989 Gastdozent, Institut f¨ur Informatik, Universit¨at W¨urzburg, West Ger- many. 1 RESEARCH INTERESTS: My research interests lie in the area of computational complexity, with particular emphasis on parallel computation, circuit complexity, Kol- mogorov complexity, and the structure of complexity classes. -
SIGACT News Complexity Theory Column 74
SIGACT News Complexity Theory Column 74 Lane A. Hemaspaandra Dept. of Computer Science, University of Rochester Rochester, NY 14627, USA Introduction to Complexity Theory Column 74 First, warmest congratulations to Scott Aaronson on winning the NSF’s Alan T. Waterman Award! The award is a huge honor and a wonderful recognition of all the tremendous work Scott has done as both a researcher and an expositor. (Wait. What is that overhead? Not bird, nor plane, nor even frog. It’s just... a 500-foot-tall robotic marmoset from Venus flying determinedly towards MIT! Scott, it may already be time to reconsider the answers you gave to Bill’s poll questions in this issue’s column—while you still can.) Those with very long memories will remember the September and December 1996 articles in this column on the future of computational complexity theory, featuring comments by Allender, Feigenbaum, Goldreich, Goldsmith, Papadimitriou, Pitassi, Razborov, Rudich, Sipser, and Wigder- son. Now, you’d sort of think they would have then buckled down and resolved P versus NP within a couple of years. But no, they did not. (And please don’t believe any rumor that one of them said, “Of course I have resolved P versus NP. Years ago. But why kill the goose that lays the golden eggs?” Totally untrue!) So in 2001 Bill Gasarch realized that it was time to look again toward the future, and he designed and conducted a terrific poll on the future of P versus NP, which ran as the June 2006 complexity theory column. And, as you surely know all too well dear reader, the oh-so-tricksy P versus NP question since then has continued to evade resolution (well, to evade any public resolution, give or take such flawed resolutions as those that are cataloged at http://www.win.tue.nl/~gwoegi/P-versus-NP.htm, the fascinating web site where Gerhard Woeginger provides links to more than eighty papers claiming to resolve P versus NP).