IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
20 November 2015
Tianren Liu, Vinod Vaikuntanathan
UConn, Storrs
For full job description please visit our website at http://www.cse.uconn.edu/current-job-listings/. UConn is an EEO/AA Employer.
Zhejiang University City College
Interested applicants are advised to email the following documents to
Dr. Huafei Zhu (zhuhf (at) zucc.edu.cn)
CV
Three reference letters
Personal statement outlining your interest in the position
19 November 2015
Vikram Singh, Arjun Chopra
Previously in 2015, Singh considered the simpler case, as chosen by Bos, Costello, Naehrig and Steblia in 2014, of cyclotomic rings with power-of-two degree. In this work we focus on the case of cyclotomic rings with degree p-1 for prime p. This allows for a greater degree of flexibility in choosing lattice dimension, which determines the security level and efficiency of the scheme. We describe the necessary arithmetic setup and then present Peikert\'s Diffie-Hellman-like key exchange along with security, correctness and implementation analysis.
Stavros Kousidis, Andreas Wiemers
Eike Kiltz, Daniel Masny, Jiaxin Pan
This paper shows that, without key prefixing, single-user security of Schnorr signatures tightly implies multi-user security of the same scheme.
Daniele Micciancio, Michael Walter
One key technique to achieving this goal is a novel algorithm to solve the Shortest Vector Problem (SVP) in the dual without computing the dual basis. Our algorithm enjoys the same practical efficiency as the corresponding primal algorithm and can be easily added to an existing implementation of it.
Zhenzhen Bao, Peng Luo, Dongdai Lin
Rosario Giustolisi, Vincenzo Iovino, Peter B. Rønne
Graz, Austria, April 14 - April 15
Notification: 8 February 2016
From April 14 to April 15
Location: Graz, Austria
More Information: https://www.cosade.org/index.html
Queensland University of Technology, Brisbane, Queensland, Australia
Position Purpose: The successful candidate will teach and coordinate at both the undergraduate and postgraduate levels. This position will work closely with an ARC Future Fellow in the area of cryptographic protocol design, with a focus on lightweight, useable and human-driven cryptography. A strong theoretical background and familiarity with modern developments in mathematical cryptography, as well as demonstrated capacity for creative research are essential.
18 November 2015
Daniel Roche, Daniel Apon, Seung Geol Choi, Arkady Yerukhimovich
In this paper, we propose an alternative approach to range queries over encrypted data that is optimized for efficient insert while still maintaining search functionality. Specifically, we propose a new primitive called partial order preserving encoding (POPE) that achieves ideal OPE security while providing extremely fast insertion and efficient (amortized) search. Our scheme is better suited to today\'s insert-heavy database scenarios. For example, with about one million insertions and one thousand range queries, our POPE scheme is 20X faster than the scheme by Popa et al.
We also propose a new form of frequency-hiding security for POPE, as recently studied by Kerschbaum (CCS 2015) for OPE, and show how to extend our scheme to satisfy it.
Vipul Goyal, Divya Gupta, Amit Sahai
Unfortunately, so far this technique is limited to the setting of concurrent zero knowledge.
The goal of this paper is to study what can be achieved in the setting of concurrent secure computation using non-black box simulation techniques, building upon the work of Goyal.
The main contribution of our work is a secure computation protocol in the fully concurrent setting
with a straight-line simulator, that allows us to achieve several new results:
\\begin{itemize}
\\item We give first positive results for concurrent blind signatures and verifiable random functions in the plain model \\emph{as per the ideal/real world security definition}. Our positive result is somewhat surprising in light of the impossibility result of Lindell (STOC\'03) for black-box simulation. We circumvent this impossibility using non-black box simulation. This gives us a quite natural example of a functionality in concurrent setting which is impossible to realize using black-box simulation but can be securely realized using non-black-box simulation.
\\item Moreover, we expand the class of realizable functionalities in the concurrent setting. Our main theorem is a positive result for concurrent secure computation as long as the ideal world satisfies the \\emph{bounded pseudo-entropy condition} (BPC) of Goyal (FOCS\'12). The BPC requires that in the ideal world experiment, the total amount of information learnt by the adversary (via calls to the ideal functionality) should have ``bounded pseudoentropy\".
\\item We also improve the round complexity of protocols in the single-input setting of Goyal (FOCS\'12) both qualitatively and quantitatively. In Goyal\'s work, the number of rounds depended on the length of honest party inputs. In our protocol, the round complexity depends only on the security parameter, and is completely independent of the length of the honest party inputs.
\\end{itemize}
Our results are based on a non-black-box simulation technique using a new language (which allows the simulator to commit to an Oracle program that can access information with bounded pseudoentropy), and a simulation-sound version of the concurrent zero-knowledge protocol of Goyal (STOC\'13). We assume the existence of collision resistant hash functions and constant round semi-honest oblivious transfer.
Jun Wang, Qiang Tang
Bahram Rashidi, Sayed Masoud Sayedi, Reza Rezaeian Farashahi
Hannes Gross, Marko Hölbl, Daniel Slamanig, Raphael Spreitzer
Cedric Marchand, Lilian Bossuet, AbdelKarim Cherkaoui
Prastudy Fauzi, Helger Lipmaa
Vipul Goyal, Aayush Jain, Adam O\' Neill
The previous constructions of MIFE due to Goldwasser \\emph{et al.} (EUROCRYPT 2014) based on indistinguishability obfuscation had a major shortcoming: it could only support encrypting an \\emph{a priori bounded} number of message. Once that bound is exceeded, security is no longer guaranteed to hold. In addition, it could only support \\emph{selective-security}, meaning that the challenge messages and the set of ``corrupted\'\' encryption keys had to be declared by the adversary up-front.
In this work, we show how to remove these restrictions by relying instead on \\emph{sub-exponentially secure} indistinguishability obfuscation. This is done by carefully adapting an alternative MIFE scheme of Goldwasser \\emph{et al.} that previously overcame these shortcomings (except for selective security wrt.~the set of ``corrupted\'\' encryption keys) by relying instead on differing-inputs obfuscation, which is now seen as an implausible assumption. Our techniques are rather generic, and we hope they are useful in converting other constructions using differing-inputs obfuscation to ones using sub-exponentially secure indistinguishability obfuscation instead.
Michał Wroński
In the first we show that using twisted Edwards curves over F_{p²} with fast computable endomorphism (GLV-GLS method) may be nowadays on of the fastest (or even the fastest) solution in hardware applications.
In the second we show how we can speed-up point scalar multiplication on NIST P-224 and NIST P-256 curves. We use field extension (F_{p²}) to find isomorphic to these curves twisted Hessian curves over F_{p²}. Our solution is faster than classic solutions up to 28.5% for NIST P-256 and up to 27.2% for NIST P-224 if we consider solution invulnerable for side channel attacks. We can also use different formula for point doubling and points addition and then our solution is faster up to 21.4% for NIST P-256 and up to 19.9% for NIST P-224 comparing to classic solutions.