IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
23 February 2021
Lucerne University of Applied Sciences and Arts, Rotkreuz, Switzerland
Closing date for applications:
Contact: Dr. Esther Hänggi
More information: https://recruitingapp-2678.umantis.com/Vacancies/2063/Description/1
Lucerne University of Applied Sciences and Arts, Rotkreuz, Switzerland
Closing date for applications:
Contact: Dr. Esther Hänggi
More information: https://recruitingapp-2678.umantis.com/Vacancies/2062/Description/1
University of St. Gallen, School of Computer Science, Switzerland
Responsibilities: More specifically, the job includes:
- Development and implementation of concepts and research results, both individually and in collaboration with researchers and PhD students,
- Run of experiments and simulation of realistic conditions to test the performance of developed algorithms and protocols,
- Development, maintenance and organization of software,
- Support to BSc, MSc and PhD students, postdocs and researchers who use the lab,
- Responsibility for the daily routines in the lab, for example purchases, installations, bookings, inventory,
- Producing media content for our group web page and social media platforms.
- The successful applicant is expected to hold or to be about to receive a M.Sc. degree in Computer Science, Electrical Engineering, Applied Mathematics or similar fields, preferably with a focus in Security and Privacy for Computer Science Systems.
- We are looking for a strongly motivated and self-driven person who is able to work and learn new things independently. Good command of English is required.
- You should have a good academic track record and well developed analytical and problem solving skills.
- Excellent programming skills and familiarity with cryptographic libraries.
- Previous experience in implementation projects with C++, Matlab, Python is desired.
Deadline for applications: 15 of March 2021Closing date for applications:
Contact: Katerina Mitrokotsa
More information: https://jobs.unisg.ch/offene-stellen/research-engineer-security-and-privacy-m-f-d/d511efde-a54d-46df-8571-eb03d4089c6f
Inria and ENS, Paris, France
We are looking for talented and motivated Post-docs to work on the ERC Advanced Grant project PARQ: Lattices in a Parallel and Quantum World. The project aims at studying the best parallel and quantum algorithms for lattice problems, and proposing automated tools to select safe parameters for lattice-based cryptography. It is hosted by the Inria cryptography team Cascade, located at ENS in downtown Paris. (see https://crypto.di.ens.fr/web2py )
The ideal candidates should have a PhD degree from a leading university, and a proven record of lattice-related publications in top venues. We offer a competitive salary and a budget for conference travel and research visits. Positions can be filled from April 1st, 2021. If you're interested, please send as soon as possible (and before June 1st, 2021):
- Your curriculum vitae
- Your two best publications
- Research statement
- Reference letters if possible
To apply: https://jobs.inria.fr/public/classic/fr/offres/2021-03340
Closing date for applications:
Contact: Phong Q. Nguyen ( Phong.Nguyen at inria.fr )
More information: https://jobs.inria.fr/public/classic/fr/offres/2021-03340
University College Cork, Ireland
The School of Computer Science & IT at University College Cork is a partner in the Science Foundation Ireland Centre for Research Training on Artificial Intelligence, which funds a number of 4-year PhD scholarships. The scholarships include full payment of university fees and a monthly tax-free stipend of €1,500, as well as a budget for equipment, travel, and training.
We are currently looking for candidates interested to work on privacy-preserving machine learning/artificial intelligence. Topics of interests include: advanced encryption for neural networks; anonymity and differential privacy; model ownership (watermarking and fingerprinting) and related attacks.
Interested candidates should write to Dr Paolo Palmieri (p.palmieri@cs.ucc.ie). Expressions of interest for the 2021-2022 call need to be received by February 26, 2021. Early applications will be given priority.
Applicants should include:
- a brief cover letter (1 page max) explaining their interest in the project topic, and mentioning any previous experience in privacy/cryptography/security;
- a curriculum vitae, mentioning the final grade/CGPA for each degree.
Closing date for applications:
Contact: Dr. Paolo Palmieri (p.palmieri@cs.ucc.ie)
University of Calgary, Calgary, AB, Canada
Closing date for applications:
Contact: Prof. Andy Knight (Department Head) Email: eceinfo@ucalgary.ca
More information: https://engg.careers.ucalgary.ca/jobs/6242346-assistant-professor-secure-software-systems-department-of-electrical-and-computer-engineering
21 February 2021
Virtual event, Anywhere on Earth, 26 July - 28 July 2021
Submission deadline: 15 March 2021
Notification: 12 April 2021
Virtual event, Anywhere on Earth, 8 September - 10 September 2021
Submission deadline: 29 March 2021
Notification: 28 May 2021
20 February 2021
Yunwen Liu, Siwei Sun, Chao Li
Alessandro Chiesa, Eylon Yogev
The canonical construction of a SNARG in the ROM is due to Micali (FOCS 1994), who showed how to use a random oracle to compile any probabilistically checkable proof (PCP) with sufficiently-small soundness error into a corresponding SNARG. Yet, while Micali's construction is a seminal result, it has received little attention in terms of analysis in the past 25 years.
In this paper, we observe that prior analyses of the Micali construction are not tight and then present a new analysis that achieves tight security bounds. Our result enables reducing the random oracle's output size, and obtain corresponding savings in concrete argument size.
Departing from prior work, our approach relies on precisely quantifying the cost for an attacker to find several collisions and inversions in the random oracle, and proving that any PCP with small soundness error withstands attackers that succeed in finding a small number of collisions and inversions in a certain tree-based information-theoretic game.
Fukang Liu, Takanori Isobe, Willi Meier, Kosei Sakamoto
Hemanta K. Maji, Hai H. Nguyen, Anat Paskin-Cherniavsky, Tom Suad, Mingyuan Wang
Towards this objective, we study the Shamir secret-sharing scheme's leakage-resilience over a prime-field $F$. The parties' secret-shares, which are elements in the finite field $F$, are naturally represented as $\lambda$-bit binary strings representing the elements $\{0,1,\dotsc,p-1\}$. In our leakage model, the adversary can independently probe $m$ bit-locations from each secret share. The inspiration for considering this leakage model stems from the impact that the study of oblivious transfer combiners had on general correlation extraction algorithms, and the significant influence of protecting circuits from probing attacks has on leakage-resilient secure computation.
Consider arbitrary reconstruction threshold $k\geq 2$, physical bit-leakage parameter $m\geq 1$, and the number of parties $n\geq 1$. We prove that Shamir's secret-sharing scheme with random evaluation places is leakage-resilient with high probability when the order of the field $F$ is sufficiently large; ignoring polylogarithmic factors, one needs to ensure that $\log \abs F \geq n/k$. Our result, excluding polylogarithmic factors, states that Shamir's scheme is secure as long as the total amount of leakage $m\cdot n$ is less than the entropy $k\cdot\lambda$ introduced by the Shamir secret-sharing scheme. Note that our result holds even for small constant values of the reconstruction threshold $k$, which is essential to several application scenarios.
To complement this positive result, we present a physical-bit leakage attack for $m=1$ physical bit-leakage from $n=k$ secret shares and any prime-field $F$ satisfying $\abs F=1\mod k$. In particular, there are (roughly) $\abs F^{n-k+1}$ such vulnerable choices for the $n$-tuple of evaluation places. We lower-bound the advantage of this attack for small values of the reconstruction threshold, like $k=2$ and $k=3$, and any $\abs F=1\mod k$. In general, we present a formula calculating our attack's advantage for every $k$ as $\abs F\rightarrow\infty.$
Technically, our positive result relies on Fourier analysis, analytic properties of proper rank-$r$ generalized arithmetic progressions, and B\'ezout's theorem to bound the number of solutions to an equation over finite fields. The analysis of our attack relies on determining the ``discrepancy'' of the Irwin-Hall distribution. A probability distribution's discrepancy is a new property of distributions that our work introduces, which is of potential independent interest.
Hwajeong Seo, Pakize Sanal, Wai-Kong Lee, Reza Azarderakhsh
Sravya Yandamuri, Ittai Abraham, Kartik Nayak, Michael K. Reiter
Dimitris Karakostas, Nikos Karayannidis, Aggelos Kiayias
István András Seres, Máté Horváth, Péter Burcsi
Therefore, in this work, we show that key-recovery attacks against the Legendre PRF are equivalent to solving a specific family of multivariate quadratic (MQ) equation system over a finite prime field. This new perspective sheds some light on the complexity of key-recovery attacks against the Legendre PRF. This allows us to take the first steps in settling the provable security of the Legendre PRF and other variants. We do this by conducting extensive algebraic cryptanalysis on the resulting MQ instance. We show how the currently best-known techniques and attacks fall short in solving these sparse quadratic equation systems. Another benefit of viewing the Legendre PRF as an MQ instance is that it facilitates new applications of the Legendre PRF, such as verifiable random function or oblivious (programmable) pseudorandom function. These new applications can be used in cryptographic protocols, such as state of the art proof-of-stake consensus algorithms or private set intersection protocols.
Jesus Diaz, Anja Lehmann
In this paper we propose a new variant of group signatures that provides linkability in a flexible and user-centric manner. Users and only they can decide before and after signature creation whether they should remain linkable or be correlated. To prevent attacks where a user omits certain signatures when a sequence of events in a certain section (e.g., time frame), should be linked, we further extend this new primitive to allow for sequential link proofs. Such proofs guarantee that the provided sequence of data is not only originating from the same signer, but also occurred in that exact order and contains all of the users signatures within the time frame. We formally define the desired security and privacy properties, propose a provably secure construction based on DL-related assumptions and report on a prototypical implementation of our scheme.
Adithya Bhat, Akhil Bandarupalli, Saurabh Bagchi, Aniket Kate, Michael Reiter
The observation that SMR commits do not have to be treated separately motivates this work. We propose UCC (Unique Chain Commit) rule, a novel yet simple rule for hash chains where extending a block by including its hash is treated as a vote for the block and all its direct and indirect parents. When a block obtains $f+1$ such votes, where $f$ is the maximum number of faulty nodes in the system, we commit the block and its parents. We use this UCC rule to design Apollo, an SMR protocol with rotating leaders which has a linear communication complexity. Apollo proposes and commits a block every $\delta$ time units with every block having a latency of $(f+1)\delta$. When compared to existing works which use equivocation detection, we improve the optimistic commit latency when $(f+1)\delta<2\Delta$. We prove the security of our protocol in both standard and weak synchrony models. We also implement and compare Apollo with the state of the art protocol, and demonstrate Apollo having commit latencies independent of and less than the $\Delta$ parameter, and also show significant gains in response rates with increasing $n$. For instance, when $n=3$, Apollo can commit blocks of size $2000$ as fast $3$ ms. For $n=65$, Apollo produces $3$x more committed transactions per second than the state of the art Sync HotStuff protocol.