IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
09 October 2020
Jiaheng Zhang, Weijie Wang, Yinuo Zhang, Yupeng Zhang
Not only does our new protocol achieve optimal prover complexity asymptotically, but it is also efficient in practice. Our experiments show that it only takes 1 second to generate the proof for a circuit with 600,000 gates, which is 7 times faster than the original interactive proof protocol on the corresponding layered circuit. The proof size is 229 kilobytes and the verifier time is 0.56 second. Our implementation can take general arithmetic circuits generated by existing tools directly, without transforming them to layered circuits with high overhead on the size of the circuits.
Gianluca Brian, Antonio Faonio, Maciej Obremski, João Ribeiro, Mark Simkin, Maciej Skórski, Daniele Venturi
Our reductions between noisy and bounded leakage are achieved in two steps. First, we put forward a new leakage model (dubbed the dense leakage model) and prove that dense leakage can be simulated in the information-theoretic setting using a single query of bounded leakage, up to small statistical distance. Second, we show that the most common noisy-leakage models fall within the class of dense leakage, with good parameters. We also provide a complete picture of the relationships between different noisy-leakage models, and prove lower bounds showing that our reductions are nearly optimal.
Our result finds applications to leakage-resilient cryptography, where we are often able to lift security in the presence of bounded leakage to security in the presence of noisy leakage, both in the information-theoretic and in the computational setting. Additionally, we show how to use lower bounds in communication complexity to prove that bounded-collusion protocols (Kumar, Meka, and Sahai, FOCS'19) for certain functions do not only require long transcripts, but also necessarily need to reveal enough information about the inputs.
Handan Kilinc Alper, Jeffrey Burdges
Assuming AGM plus ROM plus KOSK and OMDL, we then prove security for a two-round trip Schnorr multi-signature protocol DWMS that creates its witness aka nonce by delinearizing two pre-witnesses supplied by each signer.
At present, DWMS and MuSig-DN are the only known provably secure two-round Schnorr multi-signatures, or equivalently threshold Schnorr signatures.
Konstantinos Chalkias, François Garillot, Valeria Nikolaenko
Hiroki Furue, Yasuhiko Ikematsu, Yutaro Kiyomura, Tsuyoshi Takagi
Fulei Ji, Wentao Zhang, Chunning Zhou, Tianyou Ding
Siang Meng Sim, Dirmanto Jap, Shivam Bhasin
Luca De Feo, David Kohel, Antonin Leroux, Christophe Petit, Benjamin Wesolowski
While the soundness of the identification protocol follows from classical assumptions, the zero-knowledge property relies on the second main contribution of this paper. We introduce a new algorithm to find an isogeny path connecting two given supersingular elliptic curves of known endomorphism rings. A previous algorithm to solve this problem, due to Kohel, Lauter, Petit and Tignol, systematically reveals paths from the input curves to a `special' curve. This leakage would break the zero-knowledge property of the protocol. Our algorithm does not directly reveal such a path, and subject to a new computational assumption, we prove that the resulting identification protocol is zero-knowledge.
Alin Tomescu, Yu Xia, Zachary Newman
Hao Lin, Yang Wang, Mingqiang Wang
Jianwei Li, Phong Q. Nguyen
Jun Wan, Hanshen Xiao, Srinivas Devadas, Elaine Shi
In this paper, we are the first to construct a BB protocol with sublinear round complexity in the corrupt majority setting. Specifically, assuming the existence of time-lock puzzles with suitable hardness parameters and that the decisional linear assumption holds in suitable bilinear groups}, we show how to achieve BB in $(\frac{n}{n-f})^2 \cdot \poly\log \lambda$ rounds with $1-\negl(\lambda)$ probability, where $n$ denotes the total number of players, $f$ denotes the maximum number of corrupt players, and $\lambda$ is the security parameter. Our protocol completes in polylogarithmically many rounds even when 99\% of the players can be corrupt.
Ting Rong Lee, Je Sen Teh, Jasy Liew Suet Yan, Norziana Jamil, Jiageng Chen
Masayuki Fukumitsu, Shingo Hasegawa
Farid Javani, Alan T. Sherman
BVOT works by using a multiparty threshold homomorphic encryption system in which each candidate is associated with a masked unique prime. Each voter engages in an oblivious transfer with an untrusted distributor: the voter selects the index of a prime associated with a candidate and receives the selected prime in masked form. The voter then casts their vote by encrypting their masked prime and broadcasting it to everyone. The distributor does not learn the voter's choice, and no one learns the mapping between primes and candidates until the audit phase. By hiding the mapping between primes and candidates, BVOT provides voters with insufficient information to carry out effective cheating. The threshold feature prevents anyone from computing any partial tally---until everyone has voted. Multiplying all votes, their decryption shares, and the unmasking factor yields a product of the primes each raised to the number of votes received.
In contrast to some existing boardroom voting protocols, BVOT does not rely on any zero-knowledge proof; instead, it uses oblivious transfer to assure ballot secrecy and correct vote casting. Also, BVOT can handle multiple candidates in one election. BVOT prevents cheating by hiding crucial information: an attempt to increase the tally of one candidate might increase the tally of another candidate. After all votes are cast, any party can tally the votes.
Nicolas Sendrier, Valentin Vasseur
Richard B. Riddick
08 October 2020
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Submission deadline: 30 December 2020
06 October 2020
Ph.D. position (full scholarship) on Side-Channel Attack at Villanova University (USA)
Interested ones are warmly welcomed to send their resume/CV to Dr. Xie through email: jiafeng.xie@villanova.edu
Requirements: preferred to be at the majors of Computer Science or Computer Engineering. Familiar with FPGA board related side-channel attack and analysis will be desirable. Proficiency in programming languages such as C/C++ and HDLs. Good at English communication and writing. Great enthusiasm of doing research oriented tasks. Excellent team work member.
Degree: both B.S. and M.S. graduates or similar are warmly welcomed to apply.
Deadline: better to start at Spring 2021, though Fall 2021 is also ok. It is always better to apply as early as possible. Position is open until it is filled.
The 2021 U.S. News & World Report ranks Villanova as tied for the 53th best National University in the U.S.
Closing date for applications:
Contact: Jiafeng Harvest Xie (jiafeng.xie@villanova.edu)
More information: https://www1.villanova.edu/villanova/engineering/departments/ece/facultyStaff/biodetail.html?mail=jiafeng.xie@villanova.edu&xsl=bio_long
Charles Sturt University, New South Wales, Australia
This PhD position will be supported by the CSCRC with excellent scholarship. The CSCRC aims to inspire the next generation of cyber security professionals through working with some of the best cyber security researchers in Australia, and engagement with the CSCRC Industry & Government Participants. Further details of the CSCRC Government and Industry Participants may be found at: https://www.cybersecuritycrc.org.au (Cyber Security Research Scholarships of up to AU$50,000 a year for outstanding PhD students; these scholarships are limited to Australian nationals or candidates from other 5-Eyes countries (US, UK, Canada, New Zealand); candidates from NATO countries will be considered on a case by case basis. Successful candidates must be eligible to obtain Australian Government Cyber Security Clearance (where appropriate).)
In order to be considered for the position, the candidate must:
• Hold a Master's degree in mathematics, computer science, cryptography or related fields with strong grades;
• Show strong background in mathematics, computer science and cryptography;
• Demonstrate experience in C/C++ or Java.
Having prior publications in security and privacy is highly desirable.
Please send (by e-mail) to below contact information:
• Transcripts,
• Curriculum vitae,
• Statement of Purpose, and
• Academic IELTS Test Report (or equivlent qualification).
In addition, three reference letters are required by e-mail from referees.
Closing date for applications:
Contact: Prof. Tanveer Zia (tzia@csu.edu.au)