IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
08 April 2020
University of Copenhagen, Department of Computer Science
Job PostingWe are looking for an outstanding, experienced researcher with an innovative mind-set and intellectual curiosity to strengthen and complement the research profile of the Algorithms and Complexity Section, headed by Professor Mikkel Thorup. The Algorithms and Complexity Section is part of an exciting environment including the Basic Algorithms Research Copenhagen (BARC) centre, joint with the IT University of Copenhagen, and involving extensive collaborations with the Technical University of Denmark (DTU) and Lund University on the Swedish side of the Oresund Bridge. We aim to attract top talent from around the world to an ambitious, creative, collaborative, and fun environment. Using the power of mathematics, we strive to create fundamental breakthroughs in algorithms and complexity theory, but we also have a track record of start-ups and surprising algorithmic discoveries leading to major industrial applications.
The University of Copenhagen was founded in 1479 and is the oldest and largest university in Denmark. It is often ranked as the best university in Scandinavia and consistently as one of the top places in Europe. Within computer science, it is ranked number 1 in the European Union (post-Brexit) by the Shanghai Ranking.
The department offers a friendly and thriving international research and working environment with opportunities to build up internationally competitive research groups. Working conditions at the University of Copenhagen support a healthy work-life balance and Copenhagen is a family-friendly capital city.
The application deadline is May 24, 2020.
For more information, see https://candidate.hr-manager.net/ApplicationInit.aspx/?cid=1307&departmentId=18971&ProjectId=151668
Closing date for applications:
Contact: Head of Section, Professor Mikkel Thorup (mthorup@di.ku.dk; cell phone +45 2117 9123) and Head of Department, Professor Mads Nielsen (madsn@di.ku.dk; cell phone +45 2460 0599).
More information: https://candidate.hr-manager.net/ApplicationInit.aspx/?cid=1307&departmentId=18971&ProjectId=151668
Brisbane, Australie, 12 November - 13 November 2020
Event CalendarSubmission deadline: 26 July 2020
Notification: 16 August 2020
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Event CalendarSubmission deadline: 30 July 2020
University of Wollongong, Australia
Job PostingClosing date for applications:
Contact: Prof. Willy Susilo (wsusilo at uow dot edu dot au)
More information: https://uowjobs.taleo.net/careersection/in/jobdetail.ftl?job=200507&tz=GMT%2B10%3A00&tzname=Australia%2FSydney
07 April 2020
Award
The Test-of-Time award for Eurocrypt 2005 is awarded to "Fuzzy Identity-Based Encryption " (Amit Sahai and Brent Waters), for laying the foundations of attribute-based encryption and other advanced notions of encryption.
The Test-of-Time award for Crypto 2005 is awarded to "Finding collisions in the full SHA-1 " (Xiaoyun Wang, Yiqun Lisa Yin and Hongbo Yu), for a breakthrough in the cryptanalysis of hash functions.
The Test-of-Time award for Asiacrypt 2005 is awarded to "Discrete-Log-Based Signatures May Not Be Equivalent to Discrete Log" (Pascal Paillier and Damien Vergnaud), developing a new meta-reduction approach in the security proof of cryptosystems.
For more information, see https://www.iacr.org/testoftime.
03 April 2020
Daniel Cervantes-Vázquez, Eduardo Ochoa-Jiménez , Francisco Rodríguez-Henríquez
ePrint ReportJan Bobolz, Fabian Eidens, Stephan Krenn, Daniel Slamanig, Christoph Striecks
ePrint ReportIn this paper we construct an incentive system that improves upon the state-of-the-art in several ways: We improve efficiency of the Earn protocol by replacing costly zero-knowledge proofs with a short structure-preserving signature on equivalence classes. We enable tracing of remainder tokens from double-spending transactions without losing backward unlinkability. We allow for secure recovery of failed Spend protocol runs (where usually, any retries would be counted as double-spending attempts). We guarantee that corrupt users cannot falsely blame other corrupt users for their double-spending.
We propose an extended formal model of incentive systems and a concrete instantiation using homomorphic Pedersen commitments, ElGamal encryption, structure-preserving signatures on equivalence classes (SPS-EQ), and zero-knowledge proofs of knowledge. We formally prove our construction secure and present benchmarks showing its practical efficiency.
Leonard Kleinrock, Rafail Ostrovsky, Vassilis Zikas
ePrint ReportAnirban Chakraborty, Sarani Bhattacharya, Sayandeep Saha, Debdeep Mukhopdhyay
ePrint ReportAndreas Hülsing, Kai-Chun Ning, Peter Schwabe, Florian Weber, Philip R. Zimmermann
ePrint ReportShenghui Su, Ping Luo, Shuwang Lv, Maozhi Xu
ePrint Report02 April 2020
Kaushik Nath, Palash Sarkar
ePrint ReportSamuel Dittmer, Rafail Ostrovsky
ePrint ReportSarah Bordage, Julien Lavauzelle
ePrint ReportLeonie Reichert, Samuel Brack, Björn Scheuermann
ePrint ReportOur preliminary evaluation shows that the proposed approach is feasible indifferent scenarios derived from real-world case studies.
Megan Chen, Carmit Hazay, Yuval Ishai, Yuriy Kashnikov, Daniele Micciancio, Tarik Riviere, abhi shelat, Muthu Venkitasubramaniam, Ruihan Wang
ePrint ReportIn a nutshell, we design the ``best'' protocol for this scale that is secure against passive corruption, then amplify it to obtain active security using efficient non-interactive zero-knowledge arguments. Our protocol satisfies a stronger security guarantee where a deviating party can be identified when the protocol aborts (referred to as security with identifiable-abort) and allows for ``public verifiability''.
Our passively secure protocol extends the recent work of Chen et al. that, in turn, is based on the blueprint introduced in the original work of Boneh-Franklin protocol (CRYPTO 1997, J. ACM, 2001). Specifically, we reduce the task of sampling a modulus to secure distributed multiplication, which we implement via an efficient threshold additively homomorphic encryption (AHE) scheme based on the Ring-LWE assumption. This results in a protocol where the amortized per-party communication cost grows logarithmically in the number of parties. In order to keep the parties lightweight, we employ an ``untrusted'' coordinator that is connected to all parties and performs all public and broadcast operations.
We amplify this protocol to obtain active security (with identifiable-abort) by attaching zero-knowledge proofs. We instantiate our ZK proof system by composing two different types of ZK proof systems: (1) the Ligero sub-linear zero-knowledge proof system (Ames et al., CCS 2017), and (2) $$\Sigma$$-protocol for proving the knowledge of a discrete logarithm in unknown order groups (Shoup, Eurocrypt 2000).
We implemented both the passive and the active variants of our protocol and ran experiments using 2 to 4,000 parties. This is the first such implementation of any MPC protocol that can scale to more than 1,000 parties. For generating a 2048-bit modulus among 1,000 parties, our passive protocol executed in under 4 minutes and the active variant ran in 22 minutes.
Huanyu Wang, Elena Dubrova
ePrint ReportClaude Carlet
ePrint ReportMatthias J. Kannwischer, Peter Pessl, Robert Primas
ePrint ReportIn this paper, we change the above by presenting the first single-trace attack targeting Keccak. Our method is based on soft-analytical side-channel attacks and, thus, combines template matching with message passing in a graphical model of the attacked algorithm. As a straight-forward model of Keccak does not yield satisfactory results, we describe several optimizations for the modeling and the message-passing algorithm. Their combination allows attaining high attack performance in terms of both success rate as well as computational runtime.
We evaluate our attack assuming generic software (microcontroller) targets and thus use simulations in the generic noisy Hamming-weight leakage model. Hence, we assume relatively modest profiling capabilities of the adversary. Nonetheless, the attack can reliably recover secrets in a large number of evaluated scenarios at realistic noise levels. Consequently, we demonstrate the need for countermeasures even in settings where DPA is not a threat.
Megan Chen, Ran Cohen, Jack Doerner, Yashvanth Kondi, Eysa Lee, Schuyler Rosefield, abhi shelat
ePrint ReportOur protocol is highly modular, and its uppermost layer can be viewed as a template that generalizes the structure of prior works and leads to a simpler security proof. We introduce a combined sampling-and-sieving technique that eliminates both the inherent leakage in the approach of Frederiksen et al. (Crypto'18), and the dependence upon additively homomorphic encryption in the approach of Hazay et al. (JCrypt'19). We combine this technique with an efficient, privacy-free check to detect malicious behavior retroactively when a sampled candidate is not a biprime, and thereby overcome covert rejection-sampling attacks and achieve both asymptotic and concrete efficiency improvements over the previous state of the art.