664 Hits in 3.9 sec

Multi-Client Verifiable Computation with Stronger Security Guarantees [chapter]

S. Dov Gordon, Jonathan Katz, Feng-Hao Liu, Elaine Shi, Hong-Sheng Zhou
2015 Lecture Notes in Computer Science  
(Eurocrypt 2014) provided an alternative solution relying on multi-input functional encryption. Here we conduct a systematic study of MVC, with the goal of satisfying stronger security requirements.  ...  When server-client collusion is possible, we show (somewhat surprisingly) that simulation-based security cannot be achieved in general, even assuming semi-honest behavior.  ...  A.3 Extractable Witness Encryption Definition A.5 (Witness encryption [19] ) A witness encryption scheme for language L ∈ N P with witness relation R L consists of polynomial-time algorithms WE.  ... 
doi:10.1007/978-3-662-46497-7_6 fatcat:z23dup3urjh6jdia7lxdr4xxxa

On the Power of Secure Two-Party Computation [chapter]

Carmit Hazay, Muthuramakrishnan Venkitasubramaniam
2016 Lecture Notes in Computer Science  
In this work, we extend this technique and provide a generic transformation of any semi-honest secure two-party computation (2PC) protocol (with mild adaptive security guarantees) in the so called oblivious-transfer  ...  We show that if the 2PC protocol has mild adaptive security guarantees then the resulting randomized encoding (RE) can be decomposed to an offline/online encoding.  ...  Here, we only require semi-adaptive security and we can relax the OT requirement to the same semi-adaptive security which is satisfied in our instantiation.  ... 
doi:10.1007/978-3-662-53008-5_14 fatcat:o2gtgbyqfncfppt67cveqoe3ua

Encoding Functions with Constant Online Rate, or How to Compress Garbled Circuit Keys

Benny Applebaum, Yuval Ishai, Eyal Kushilevitz, Brent Waters
2015 SIAM journal on computing (Print)  
Yao's garbled circuit construction gives rise to such randomized encodings in which the online partx consists of n encryption keys of length κ each, where n = |x| and κ is a security parameter.  ...  More concretely, the online part x consists of an n-bit string and a single encryption key.  ...  Adaptive security.  ... 
doi:10.1137/130929643 fatcat:pwv2vdym4jeptaawxgca2pygxe

Encoding Functions with Constant Online Rate or How to Compress Garbled Circuits Keys [chapter]

Benny Applebaum, Yuval Ishai, Eyal Kushilevitz, Brent Waters
2013 Lecture Notes in Computer Science  
Yao's garbled circuit construction gives rise to such randomized encodings in which the online part x consists of n encryption keys of length κ each, where n = |x| and κ is a security parameter.  ...  More concretely, the online part x consists of an n-bit string and a single encryption key.  ...  Adaptive security.  ... 
doi:10.1007/978-3-642-40084-1_10 fatcat:e4bhvkik3vcpfccot3c6omgvtq

A Hybrid Scheme for Fine-Grained Search and Access Authorization in Fog Computing Environment

Min Xiao, Jing Zhou, Xuejiao Liu, Mingda Jiang
2017 Sensors  
Compared to existing schemes only supporting either index encryption with search ability or data encryption with fine-grained access control ability, the proposed hybrid scheme supports both abilities  ...  mechanism is also adopted to achieve instantaneous user revocation instead of re-encrypting ciphertexts with many copies in many fog nodes.  ...  [9] construct functional encryption schemes adaptively secure in continual memory leakage model (CML) to not only provide privacy preserving and fine-grained access control in fog computing but also  ... 
doi:10.3390/s17061423 pmid:28629131 pmcid:PMC5492313 fatcat:jxct7d77qrby5k3ziqxe2rbf2m

Functional Encryption for Bounded Collusions, Revisited [chapter]

Shweta Agrawal, Alon Rosen
2017 Lecture Notes in Computer Science  
We provide a new construction of functional encryption (FE) for circuits in the bounded collusion model.  ...  This makes it well suited for optimization in an online-offline model that allows a majority of the computation to be performed in an offline phase, before the data becomes available.  ...  The proof for BddFE inherits semi-adaptive IND security from the semi-adaptive IND security of the quadratic FE scheme provided in Section 4.  ... 
doi:10.1007/978-3-319-70500-2_7 fatcat:hfnrtum37nfnnce23dm5lou7hy

On-the-fly multiparty computation on the cloud via multikey fully homomorphic encryption

Adriana López-Alt, Eran Tromer, Vinod Vaikuntanathan
2012 Proceedings of the 44th symposium on Theory of Computing - STOC '12  
We propose a new notion of secure multiparty computation aided by a computationallypowerful but untrusted "cloud" server.  ...  This extends the standard notion of fully homomorphic encryption (FHE), where users can only enlist the cloud's help in evaluating functions on their own encrypted data.  ...  Constructions Gentry and Wichs [GW11] proved that standard-model security of SNARGs with adaptive soundness and proof size sublinear in the witness and statement sizes, cannot be based on any falsifiable  ... 
doi:10.1145/2213977.2214086 dblp:conf/stoc/Lopez-AltTV12 fatcat:2jw2ee3e7zahpchnpfjet366km

On-Line/Off-Line Leakage Resilient Secure Computation Protocols [chapter]

Chaya Ganesh, Vipul Goyal, Satya Lokam
2012 Lecture Notes in Computer Science  
Our second construction (with a function independent input encoding phase) makes use of a fully homomorphic encryption scheme.  ...  We present two main constructions of secure computation protocols in the above model. Our first construction is based only on the existence of (semi-honest) oblivious transfer.  ...  The first general solutions for the problem of secure computation were presented by Yao [Yao86] for the two-party case (with security against semi-honest adversaries) and Goldreich, Micali and Wigderson  ... 
doi:10.1007/978-3-642-34931-7_7 fatcat:z52v3a7hungktepatkv5rogyv4

Semi-homomorphic Encryption and Multiparty Computation [chapter]

Rikke Bendlin, Ivan Damgård, Claudio Orlandi, Sarah Zakarias
2011 Lecture Notes in Computer Science  
Our offline phase is UC-secure against any dishonest majority, and it matches the lower bound for secure computation with dishonest majority of O(n 2 ) public-key operations per multiplication gate [HIK07  ...  security against an adaptive, malicious adversary that corrupts any dishonest majority of the parties.  ...  ΠAMPC can actually be shown to adaptively secure, but our implementation of FTRIP will only be statically secure.  ... 
doi:10.1007/978-3-642-20465-4_11 fatcat:wq746gda3bhmxpvuppubvokpky

Online/Offline Provable Data Possession

Yujue Wang, Qianhong Wu, Bo Qin, Shaohua Tang, Willy Susilo
2017 IEEE Transactions on Information Forensics and Security  
In this paper, we introduce and formalize an online/offline PDP (OOPDP) model, which divides the data processing procedure into offline and online phases.  ...  Provable data possession (PDP) allows a user to outsource data with a guarantee that the integrity can be efficiently verified.  ...  [39] presented a semi-generic transformation of ID-based online/offline encryption scheme, which is applicable to any ID-based encryption scheme such that the ciphertext has an ID header component.  ... 
doi:10.1109/tifs.2017.2656461 fatcat:yfbi3kip6begxceqtr5jntki2a

Schemes for Privately Computing Trust and Reputation [chapter]

Nurit Gal-Oz, Niv Gilboa, Ehud Gudes
2010 IFIP Advances in Information and Communication Technology  
The protocols in the paper are rigorously proved to be private against a semi-honest adversary given standard assumptions on the existence of an homomorphic, semantically secure, public key encryption  ...  The Knots model provides a member of a community with a method to compute the reputation of other community members.  ...  The paper starts with a method for "witness selection" which reduces the risk of selecting dishonest witnesses.  ... 
doi:10.1007/978-3-642-13446-3_1 fatcat:3lzrhz652redxcgngib2vzcb6u

Improving Cut-and-Choose in Verifiable Encryption and Fair Exchange Protocols Using Trusted Computing Technology [chapter]

Stephen R. Tate, Roopa Vishwanathan
2009 Lecture Notes in Computer Science  
In this paper, we examine one such protocol and explore the consequences of replacing the statistical trust gained from cut-and-choose with a level of trust that depends on the use of secure, trusted hardware  ...  In this paper we solve a generalized, more powerful version known as verifiable group encryption, in which there are multiple semi-trusted parties ("recovery agents" or "proxies") and authorized subsets  ...  Another interesting direction to pursue would be looking at whether the security our TPM-based techniques can be reasoned about in Canetti's strong universally composable model of security [10] .  ... 
doi:10.1007/978-3-642-03007-9_17 fatcat:vmjrdwkm7rezrkijibs53th6xq

How to Efficiently Evaluate RAM Programs with Malicious Security [chapter]

Arash Afshar, Zhangxiang Hu, Payman Mohassel, Mike Rosulek
2015 Lecture Notes in Computer Science  
It is possible to take a semi-honest secure protocol for RAM evaluation (e.g., [GKK + 12]) and adapt it to the malicious setting using standard techniques.  ...  In particular, it is non-trivial to reconcile run-time data dependence with offline batching optimizations.  ...  These commitments could be avoided by using an adaptively-secure garbling scheme. Online/offline tradeoff.  ... 
doi:10.1007/978-3-662-46800-5_27 fatcat:2syqr44de5ep7h2a2sjljsdsty

3-Message Zero Knowledge Against Human Ignorance [chapter]

Nir Bitansky, Zvika Brakerski, Yael Kalai, Omer Paneth, Vinod Vaikuntanathan
2016 Lecture Notes in Computer Science  
In this work, we present a three-message zero-knowledge argument system with soundness against uniform polynomial-time cheating provers.  ...  Concretely, we rely on a threemessage variant of their protocol based on a key-less collision-resistant hash functions secure against uniform adversaries as well as other standard primitives.  ...  Instantiation. 1-hop homomorphic encryption schemes can be instantiated based on any twomessage two-party computation protocol secure against semi-honest adversaries; in particular, using Yao's garbled  ... 
doi:10.1007/978-3-662-53641-4_3 fatcat:7s3dzvhiubgjpaosjwkhsrp4sa

Privacy-Aware Reversible Watermarking in Cloud Computing Environments

Ching-Chun Chang, Chang-Tsun Li, Yun-Qing Shi
2018 IEEE Access  
Both online and offline contentadaptive predictors are developed to assist watermark decoding for various operational requirements.  ...  INDEX TERMS Cloud computing, cyber security, homomorphic cryptosystems, information privacy, reversible watermarking, signal denoising, statistical inference, variational method.  ...  universality. • Both online and offline content-adaptive predictors are developed with flexibility for various operational requirements.  ... 
doi:10.1109/access.2018.2880904 fatcat:ui4yfv3qwfeqdjrqr47afbjnk4
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