Search results for "Oblivious"

Hits ?▲	Authors	Title	Venue	Year	Link	Author keywords
109	Bogdan S. Chlebus, Leszek Gasieniec, Andrzej Lingas, Aris Pagourtzis	Oblivious gossiping in ad-hoc radio networks.	DIAL-M	2001	DBLP DOI BibTeX RDF
98	Moni Naor, Benny Pinkas	Computationally Secure Oblivious Transfer.	J. Cryptol.	2005	DBLP DOI BibTeX RDF	Privacy preserving computation, Cryptography, Oblivious transfer, Secure function evaluation
84	Mohammad Taghi Hajiaghayi, Robert Kleinberg, Tom Leighton	Semi-oblivious routing: lower bounds.	SODA	2007	DBLP BibTeX RDF
84	Anupam Gupta 0001, Mohammad Taghi Hajiaghayi, Harald Räcke	Oblivious network design.	SODA	2006	DBLP DOI BibTeX RDF
84	Juraj Hromkovic, Martin Sauerhoff	The Power of Nondeterminism and Randomness for Oblivious Branching Programs.	Theory Comput. Syst.	2003	DBLP DOI BibTeX RDF
82	Miklós Ajtai	Oblivious RAMs without cryptogrpahic assumptions.	STOC	2010	DBLP DOI BibTeX RDF	RAM, oblivious
82	Mohammad Taghi Hajiaghayi, Jeong Han Kim, Tom Leighton, Harald Räcke	Oblivious routing in directed graphs with random demands.	STOC	2005	DBLP DOI BibTeX RDF	demand distributions, directed graphs, oblivious routing
76	Iftach Haitner	Semi-honest to Malicious Oblivious Transfer - The Black-Box Way.	TCC	2008	DBLP DOI BibTeX RDF
76	Mohammad Taghi Hajiaghayi, Robert D. Kleinberg, Frank Thomson Leighton, Harald Räcke	New lower bounds for oblivious routing in undirected graphs.	SODA	2006	DBLP DOI BibTeX RDF
76	Jürg Wullschleger	Oblivious-Transfer Amplification.	EUROCRYPT	2007	DBLP DOI BibTeX RDF	oblivious-transfer amplification, universal oblivious transfer, weak oblivious transfer, computational weak oblivious transfer, distributed leftover hash lemma, hard-core lemma
74	Constantinos Daskalakis, Christos H. Papadimitriou	On oblivious PTAS's for nash equilibrium.	STOC	2009	DBLP DOI BibTeX RDF	anonymous games, oblivious algorithms, PTAS, bimatrix games
74	Huafei Zhu	Fully-Simulatable Oblivious Set Transfer.	ACISP	2008	DBLP DOI BibTeX RDF	Oblivious set transfer, perfectly hiding commitment, perfectly binding commitment, real/ideal world simulation paradigm
74	Mohammad Taghi Hajiaghayi, Robert D. Kleinberg, Harald Räcke, Tom Leighton	Oblivious routing on node-capacitated and directed graphs.	ACM Trans. Algorithms	2007	DBLP DOI BibTeX RDF	node-capacitated graphs, directed graphs, communication networks, Oblivious routing
74	Xin Yuan 0001, Wickus Nienaber, Zhenhai Duan, Rami G. Melhem	Oblivious routing for fat-tree based system area networks with uncertain traffic demands.	SIGMETRICS	2007	DBLP DOI BibTeX RDF	oblivious routing, system area networks, fat-tree
68	Michael Langberg	Oblivious Communication Channels and Their Capacity.	IEEE Trans. Inf. Theory	2008	DBLP DOI BibTeX RDF
68	Gang Yao, Dengguo Feng	Proxy Oblivious Transfer Protocol.	ARES	2006	DBLP DOI BibTeX RDF
66	Kai-Yuen Cheong, Takeshi Koshiba	Reducing Complexity Assumptions for Oblivious Transfer.	IWSEC	2009	DBLP DOI BibTeX RDF	trapdoor one-way functions, oblivious transfer
66	Bingsheng He, Qiong Luo 0001	Cache-oblivious databases: Limitations and opportunities.	ACM Trans. Database Syst.	2008	DBLP DOI BibTeX RDF	cache-conscious, chip multiprocessors, data caches, simultaneous multithreading, Cache-oblivious
66	Huafei Zhu	Black-Box Constructions for Fully-Simulatable Oblivious Transfer Protocols.	CANS	2008	DBLP DOI BibTeX RDF	Black-box constructions, defensible adversary, malicious adversary, oblivious transfer protocols
66	Bingsheng He, Qiong Luo 0001	Cache-oblivious nested-loop joins.	CIKM	2006	DBLP DOI BibTeX RDF	nested-loop join, recursive clustering, buffering, cache-oblivious, recursive partitioning
66	Hyun Sook Rhee, Jin Wook Byun, Dong Hoon Lee 0001, Jongin Lim 0001	Oblivious Conjunctive Keyword Search.	WISA	2005	DBLP DOI BibTeX RDF	Privacy, Anonymity, Storage system, Oblivious Transfer, Conjunctive Keyword Search
66	Rezaul Alam Chowdhury, Vijaya Ramachandran	Cache-oblivious shortest paths in graphs using buffer heap.	SPAA	2004	DBLP DOI BibTeX RDF	buffer heap, cache-aware model, cache-oblivious model, decrease-key, tournament tree, shortest paths, priority queue
64	Cheng-Kang Chu, Wen-Guey Tzeng	Conditional Oblivious Cast.	Public Key Cryptography	2006	DBLP DOI BibTeX RDF	oblivious cast, conditional oblivious transfer, secure computation
64	Kazuo Iwama, Yasuo Okabe, Toshiro Takase	Separating Oblivious and Non-oblivious BPs.	COCOON	2001	DBLP DOI BibTeX RDF
62	Lars Arge, Michael A. Bender, Erik D. Demaine, Charles E. Leiserson, Kurt Mehlhorn	04301 Abstracts Collection - Cache-Oblivious and Cache-Aware Algorithms.	Cache-Oblivious and Cache-Aware Algorithms	2004	DBLP BibTeX RDF
60	Raylin Tso, Takeshi Okamoto, Eiji Okamoto	1-out-of-.	ISPEC	2008	DBLP DOI BibTeX RDF	1-out-of-n signature, oblivious signature, Schnorr signature, oblivious transfer
60	Oded Goldreich 0001, Dana Ron	On proximity oblivious testing.	STOC	2009	DBLP DOI BibTeX RDF	graph propeties, property testing
60	Mohammad Taghi Hajiaghayi, Robert D. Kleinberg, Tom Leighton, Harald Räcke	Oblivious routing on node-capacitated and directed graphs.	SODA	2005	DBLP BibTeX RDF
60	Yuval Ishai, Joe Kilian, Kobbi Nissim, Erez Petrank	Extending Oblivious Transfers Efficiently.	CRYPTO	2003	DBLP DOI BibTeX RDF
60	Gerth Stølting Brodal, Rolf Fagerberg	Funnel Heap - A Cache Oblivious Priority Queue.	ISAAC	2002	DBLP DOI BibTeX RDF
60	Ventzislav Nikov, Svetla Nikova, Bart Preneel, Joos Vandewalle	On Unconditionally Secure Distributed Oblivious Transfer.	INDOCRYPT	2002	DBLP DOI BibTeX RDF
60	Oded Goldreich 0001, Rafail Ostrovsky	Software Protection and Simulation on Oblivious RAMs.	J. ACM	1996	DBLP DOI BibTeX RDF	simulation of random access machines, software protection, pseudorandom functions
58	Kai-Yuen Cheong, Takeshi Koshiba, Shohei Nishiyama	Strengthening the Security of Distributed Oblivious Transfer.	ACISP	2009	DBLP DOI BibTeX RDF	oblivious transfer, information theoretic security, secret sharing scheme
58	Kamen Yotov, Thomas Roeder, Keshav Pingali, John A. Gunnels, Fred G. Gustavson	An experimental comparison of cache-oblivious and cache-conscious programs.	SPAA	2007	DBLP DOI BibTeX RDF	cache-conscious algorithms, memory hierarchy, memory bandwidth, memory latency, numerical software, cache-oblivious algorithms
58	Ventzislav Nikov, Svetla Nikova, Bart Preneel	A Weakness in Some Oblivious Transfer and Zero-Knowledge Protocols.	ASIACRYPT	2006	DBLP DOI BibTeX RDF	Homomorphic Semantically Secure Cryptosystems, Paillier’s Public-Key Cryptosystem, Non-Interactive Zero-Knowledge Arguments, Oblivious Transfer
58	Nikhil Bansal 0001, Avrim Blum, Shuchi Chawla 0001, Adam Meyerson	Online oblivious routing.	SPAA	2003	DBLP DOI BibTeX RDF	networks, online algorithms, competitive analysis, congestion, gradient descent, oblivious routing
58	Jonathan P. Lang, Vishal Sharma, Emmanouel A. Varvarigos	An analysis of oblivious and adaptive routing in optical networks with wavelength translation.	IEEE/ACM Trans. Netw.	2001	DBLP DOI BibTeX RDF	multi-fiber networks, wavelength translation, performance analysis, hypercube, Adaptive routing, wavelength division multiplexing, torus, oblivious routing, all-optical networks
58	Francesc Sebé, Josep Domingo-Ferrer	Oblivious Image Watermarking Robust against Scaling and Geometric Distortions.	ISC	2001	DBLP DOI BibTeX RDF	Oblivious watermarking, Multimedia copyright protection
58	Christian Cachin	On the Foundations of Oblivious Transfer.	EUROCRYPT	1998	DBLP DOI BibTeX RDF	Rényi Entropy, Statistical Security, Cryptographic Protocols, Oblivious Transfer, Multiparty Computation, Shannon Entropy
56	Avinash V. Varadarajan, Ramarathnam Venkatesan, C. Pandu Rangan	Data structures for limited oblivious execution of programs while preserving locality of reference.	Digital Rights Management Workshop	2007	DBLP DOI BibTeX RDF	oblivious data structures, oblivious execution, secure data structures, DRM, software protection, secure hardware
56	Wen-Guey Tzeng	Efficient 1-Out-of-n Oblivious Transfer Schemes with Universally Usable Parameters.	IEEE Trans. Computers	2004	DBLP DOI BibTeX RDF	distributed oblivious transfer, Oblivious transfer, private information retrieval
56	Yan-Cheng Chang, Chi-Jen Lu	Oblivious Polynomial Evaluation and Oblivious Neural Learning.	ASIACRYPT	2001	DBLP DOI BibTeX RDF
52	Lasse Kliemann, Anand Srivastav	Experimental Study of Non-oblivious Greedy and Randomized Rounding Algorithms for Hypergraph b-Matching.	SEA	2009	DBLP DOI BibTeX RDF	hypergraph matching, approximation algorithms, greedy algorithms, hybrid algorithms, NP-hard problems, randomized rounding
52	Andrew Y. Lindell	Efficient Fully-Simulatable Oblivious Transfer.	CT-RSA	2008	DBLP DOI BibTeX RDF
52	Jae-Won Cho, Rémy Prost, Ho-Youl Jung	An Oblivious Watermarking for 3-D Polygonal Meshes Using Distribution of Vertex Norms.	IEEE Trans. Signal Process.	2007	DBLP DOI BibTeX RDF
52	Hui-Feng Huang, Chin-Chen Chang 0001	A New Design for Efficient t-out-n Oblivious Transfer Scheme.	AINA	2005	DBLP DOI BibTeX RDF
52	Michael A. Bender, Gerth Stølting Brodal, Rolf Fagerberg, Dongdong Ge, Simai He, Haodong Hu, John Iacono, Alejandro López-Ortiz	The Cost of Cache-Oblivious Searching.	FOCS	2003	DBLP DOI BibTeX RDF
52	Marcin Bienkowski, Miroslaw Korzeniowski, Harald Räcke	A practical algorithm for constructing oblivious routing schemes.	SPAA	2003	DBLP DOI BibTeX RDF
50	Lars Arge, Michael A. Bender, Erik D. Demaine, Charles E. Leiserson, Kurt Mehlhorn (eds.)	Cache-Oblivious and Cache-Aware Algorithms, 18.07. - 23.07.2004	Cache-Oblivious and Cache-Aware Algorithms	2005	DBLP BibTeX RDF
50	Lars Arge, Mark de Berg, Herman J. Haverkort, Ke Yi 0001	The Priority R-Tree: A Practically Efficient and Worst-Case-Optimal R-Tree.	Cache-Oblivious and Cache-Aware Algorithms	2004	DBLP BibTeX RDF
50	Joachim Gudmundsson, Jan Vahrenhold	A Simple Algorithm for I/O-efficiently Pruning Dense Spanners.	Cache-Oblivious and Cache-Aware Algorithms	2004	DBLP BibTeX RDF
50	Rasmus Pagh, Zhewei Wei, Ke Yi 0001, Qin Zhang 0001	Cache-oblivious hashing.	PODS	2010	DBLP DOI BibTeX RDF	hashing, cache-oblivious algorithms
50	Alexander Heinecke, Carsten Trinitis, Josef Weidendorfer	Porting existing cache-oblivious linear algebra HPC modules to larrabee architecture.	Conf. Computing Frontiers	2010	DBLP DOI BibTeX RDF	accelerator space-filling curve, openmp, matrix multiplication, cache-oblivious, lu decomposition, manycore
50	Matteo Frigo, Volker Strumpen	The Cache Complexity of Multithreaded Cache Oblivious Algorithms.	Theory Comput. Syst.	2009	DBLP DOI BibTeX RDF	Multithreading, Cache oblivious algorithms, Stencil computations
50	Helger Lipmaa	New Communication-Efficient Oblivious Transfer Protocols Based on Pairings.	ISC	2008	DBLP DOI BibTeX RDF	Computationally-private information retrieval, conditional disclosure of secrets, oblivious transfer, homomorphic encryption
50	Guangming Tan, Shengzhong Feng, Ninghui Sun	Cache oblivious algorithms for nonserial polyadic programming.	J. Supercomput.	2007	DBLP DOI BibTeX RDF	Nonserial polyadic, Dynamic programming, Data dependencies, Cache oblivious, Algorithmic transformation
50	Gerth Stølting Brodal, Rolf Fagerberg, Kristoffer Vinther	Engineering a cache-oblivious sorting algorithm.	ACM J. Exp. Algorithmics	2007	DBLP DOI BibTeX RDF	funnelsort, quicksort, Cache-oblivious algorithms
50	Ran Gal, Ariel Shamir, Daniel Cohen-Or	Pose-Oblivious Shape Signature.	IEEE Trans. Vis. Comput. Graph.	2007	DBLP DOI BibTeX RDF	Shape-signature, pose-oblivious, shape-matching
50	Rezaul Alam Chowdhury, Vijaya Ramachandran	The cache-oblivious gaussian elimination paradigm: theoretical framework, parallelization and experimental evaluation.	SPAA	2007	DBLP DOI BibTeX RDF	matrix multiplication, tiling, Gaussian elimination, cache-oblivious algorithm, all-pairs shortest path
50	Huafei Zhu, Feng Bao 0001	Oblivious Scalar-Product Protocols.	ACISP	2006	DBLP DOI BibTeX RDF	Oblivious scalar-product protocol, homomorphic commitment scheme, homomorphic public key encryption
50	Claude Crépeau, George Savvides	Optimal Reductions Between Oblivious Transfers Using Interactive Hashing.	EUROCRYPT	2006	DBLP DOI BibTeX RDF	interactive hashing, oblivious transfer, privacy amplification
50	Michael J. Freedman, Yuval Ishai, Benny Pinkas, Omer Reingold	Keyword Search and Oblivious Pseudorandom Functions.	TCC	2005	DBLP DOI BibTeX RDF	Secure keyword search, oblivious pseudorandom functions, secure two-party protocols, private information retrieval, privacy-preserving protocols
50	Huafei Zhu, Feng Bao 0001	Augmented Oblivious Polynomial Evaluation Protocol and Its Applications.	ESORICS	2005	DBLP DOI BibTeX RDF	Augmented oblivious polynomial evaluation, homomorphic commitment scheme, homomorphic public key encryption
50	Costas Busch, Malik Magdon-Ismail, Jing Xi	Oblivious routing on geometric networks.	SPAA	2005	DBLP DOI BibTeX RDF	disc graphs, congestion, oblivious routing, stretch, geometric networks
50	Helger Lipmaa	Verifiable Homomorphic Oblivious Transfer and Private Equality Test.	ASIACRYPT	2003	DBLP DOI BibTeX RDF	cryptographic auctions, verifiable oblivious transfer, verifiable private equality test, homomorphic encryption
50	Loren Schwiebert	Deadlock-Free Oblivious Wormhole Routing with Cyclic Dependencies.	IEEE Trans. Computers	2001	DBLP DOI BibTeX RDF	channel dependency graph, unreachable configuration, Wormhole routing, oblivious routing, deadlock freedom
50	Gilles Brassard, Claude Crépeau	Oblivious Transfers and Privacy Amplification.	EUROCRYPT	1997	DBLP DOI BibTeX RDF	Reduction Between Protocols, Oblivious Transfer, Information-Theoretic Security, Privacy Amplification
48	Sandeep Prakash, Sourav S. Bhowmick, Sanjay Madria	Efficient Recursive XML Query Processing in Relational Database Systems.	ER	2004	DBLP DOI BibTeX RDF
48	Remo Meier, Bartosz Przydatek, Jürg Wullschleger	Robuster Combiners for Oblivious Transfer.	TCC	2007	DBLP DOI BibTeX RDF	robust combiners, weak oblivious transfer, oblivious transfer
48	Gilles Brassard, Claude Crépeau, Stefan Wolf 0001	Oblivious Transfers and Privacy Amplification.	J. Cryptol.	2003	DBLP DOI BibTeX RDF	Universal oblivious transfer, Reduction among information-theoretic primitives, Oblivious transfer, Information-theoretic security, Privacy amplification
46	Michele Flammini, Luca Moscardelli, Alfredo Navarra, Stéphane Pérennes	Asymptotically Optimal Solutions for Small World Graphs.	Theory Comput. Syst.	2008	DBLP DOI BibTeX RDF	Oblivious diameter, Social networks, Small world graph
46	Gerth Stølting Brodal, Rolf Fagerberg	On the limits of cache-obliviousness.	STOC	2003	DBLP DOI BibTeX RDF	Cache-oblivious model, tall cache assumption, lower bound, sorting, permuting
44	Amos Israeli, Evangelos Kranakis, Danny Krizanc, Nicola Santoro	Time-Message Trade-Offs for the Weak Unison Problem.	CIAC	1994	DBLP DOI BibTeX RDF	Chordalrings, t-step protocol, Non-oblivious, Time-message complexity, Unbalanced, Unison, Wakeup protocol, Weak unison, Balanced, Anonymous network, Oblivious
44	Shantanu Das 0001, Paola Flocchini, Nicola Santoro, Masafumi Yamashita	On the computational power of oblivious robots: forming a series of geometric patterns.	PODC	2010	DBLP DOI BibTeX RDF	distributed coordination
44	Yehuda Lindell, Hila Zarosim	Adaptive Zero-Knowledge Proofs and Adaptively Secure Oblivious Transfer.	TCC	2009	DBLP DOI BibTeX RDF
44	Peyman Afshani, Chris H. Hamilton, Norbert Zeh	A general approach for cache-oblivious range reporting and approximate range counting.	SCG	2009	DBLP DOI BibTeX RDF	data structures, memory hierarchies, range searching, cache-obliviousness
44	Carlo Blundo, Paolo D'Arco, Alfredo De Santis, Douglas R. Stinson	On Unconditionally Secure Distributed Oblivious Transfer.	J. Cryptol.	2007	DBLP DOI BibTeX RDF
44	Geeta Chaudhry, Thomas H. Cormen	Slabpose Columnsort: A New Oblivious Algorithm for Out-of-Core Sorting on Distributed-Memory Clusters.	Algorithmica	2006	DBLP DOI BibTeX RDF
44	Jiangtao Li 0001, Ninghui Li	OACerts: Oblivious Attribute Certificates.	IEEE Trans. Dependable Secur. Comput.	2006	DBLP DOI BibTeX RDF	privacy, access controls, Security and privacy protection, cryptographic controls
44	John A. Gunnels, Fred G. Gustavson, Keshav Pingali, Kamen Yotov	Is Cache-Oblivious DGEMM Viable?	PARA	2006	DBLP DOI BibTeX RDF
44	Jiangtao Li 0001, Ninghui Li	OACerts: Oblivious Attribute Certificates.	ACNS	2005	DBLP DOI BibTeX RDF
44	Lubica Staneková, Martin Stanek	Fast Contract Signing with Batch Oblivious Transfer.	Communications and Multimedia Security	2005	DBLP DOI BibTeX RDF
44	Cheng-Kang Chu, Wen-Guey Tzeng	Efficient k-Out-of-n Oblivious Transfer Schemes with Adaptive and Non-adaptive Queries.	Public Key Cryptography	2005	DBLP DOI BibTeX RDF
44	Gianni Franceschini	Proximity Mergesort: optimal in-place sorting in the cache-oblivious model.	SODA	2004	DBLP BibTeX RDF
44	Charles E. Leiserson	Cache-Oblivious Algorithms.	CIAC	2003	DBLP DOI BibTeX RDF
44	Michael A. Bender, Ziyang Duan, John Iacono, Jing Wu	A locality-preserving cache-oblivious dynamic dictionary.	SODA	2002	DBLP BibTeX RDF
44	Carlo Blundo, Paolo D'Arco, Alfredo De Santis, Douglas R. Stinson	New Results on Unconditionally Secure Distributed Oblivious Transfer.	Selected Areas in Cryptography	2002	DBLP DOI BibTeX RDF
44	Lars Arge, Michael A. Bender, Erik D. Demaine, Bryan Holland-Minkley, J. Ian Munro	Cache-oblivious priority queue and graph algorithm applications.	STOC	2002	DBLP DOI BibTeX RDF
44	Guillermo De Ita, David Eduardo Pinto, M. Nuño	Heuristics for Improving the Non-oblivious Local Search for MaxSAT.	IBERAMIA	1998	DBLP DOI BibTeX RDF
44	Yonatan Aumann, Michael A. Bender	Efficient Asynchronous Consensus with the Value-Oblivious Adversary Scheduler.	ICALP	1996	DBLP DOI BibTeX RDF
44	Claude Crépeau, Jeroen van de Graaf, Alain Tapp	Committed Oblivious Transfer and Private Multi-Party Computation.	CRYPTO	1995	DBLP DOI BibTeX RDF
44	Claude Crépeau	Equivalence Between Two Flavours of Oblivious Transfers.	CRYPTO	1987	DBLP DOI BibTeX RDF
42	Guy E. Blelloch, Phillip B. Gibbons, Harsha Vardhan Simhadri	Low depth cache-oblivious algorithms.	SPAA	2010	DBLP DOI BibTeX RDF	sparse-matrix vector multiply, schedulers, parallel algorithms, multiprocessors, sorting, graph algorithms, cache-oblivious algorithms
42	Lars Arge, Mark de Berg, Herman J. Haverkort	Cache-Oblivious R-Trees.	Algorithmica	2009	DBLP DOI BibTeX RDF	Cache-oblivious data structures, R-trees, Geometric data structures, I/O-efficiency
42	Huafei Zhu, Feng Bao 0001	Non-committing Encryptions Based on Oblivious Naor-Pinkas Cryptosystems.	INDOCRYPT	2009	DBLP DOI BibTeX RDF	non-committing encryption, oblivious Naor-Pinkas cryptosystem, Naor-Pinkas randomizer, adaptive security
42	Gérald Gavin, Marine Minier	Oblivious Multi-variate Polynomial Evaluation.	INDOCRYPT	2009	DBLP DOI BibTeX RDF	Homomorphic encryption schemes, Oblivious Polynomial Evaluation (OPE), semantic security
42	Huafei Zhu, Feng Bao 0001	Constructing Universally Composable Oblivious Transfers from Double Trap-Door Encryptions.	AFRICACRYPT	2009	DBLP DOI BibTeX RDF	simulator, Oblivious transfer, universally composable
42	Guy E. Blelloch, Phillip B. Gibbons, Harsha Vardhan Simhadri	Brief announcement: low depth cache-oblivious sorting.	SPAA	2009	DBLP DOI BibTeX RDF	schedulers, parallel algorithms, multiprocessors, sorting, merging, cache-oblivious algorithms
42	Yuichi Asahiro, Satoshi Fujita, Ichiro Suzuki, Masafumi Yamashita	A Self-stabilizing Marching Algorithm for a Group of Oblivious Robots.	OPODIS	2008	DBLP DOI BibTeX RDF	marching, oblivious algorithm, flocking, self-stabilizing algorithm, motion coordination
42	Huafei Zhu	Round Optimal Universally Composable Oblivious Transfer Protocols.	ProvSec	2008	DBLP DOI BibTeX RDF	Double trap-door cryptosystems, simulator, oblivious transfer, universally composable