IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
22 March 2024
Luca De Feo, Tako Boris Fouotsa, Lorenz Panny
Maya Chartouny, Benoit Cogliati, Jacques Patarin
Lena Heimberger, Florian Lugstein, Christian Rechberger
Yibin Yang, David Heath, Carmit Hazay, Vladimir Kolesnikov, Muthuramakrishnan Venkitasubramaniam
We formalize and design an efficient tight ZK CPU, where the cost (both computation and communication, for each party) of each step depends only on the instruction taken. This qualitatively improves over state-of-the-art, where cost scales with the size of the largest CPU instruction (largest CFG node).
Our technique is formalized in the standard commit-and-prove paradigm, so our results are compatible with a variety of (interactive and non-interactive) general-purpose ZK.
We implemented an interactive tight arithmetic (over $\mathbb{F}_{2^{61}-1}$) ZK CPU based on Vector Oblivious Linear Evaluation (VOLE) and compared it to the state-of-the-art non-tight VOLE-based ZK CPU Batchman (Yang et al. CCS’23). In our experiments, under the same hardware configuration, we achieve comparable performance when instructions are of the same size and a $5$-$18×$ improvement when instructions are of varied size. Our VOLE-based ZK CPU can execute $100$K (resp. $450$K) multiplication gates per second in a WAN-like (resp. LAN-like) setting. It requires ≤ $102$ Bytes per multiplication gate. Our basic building block, ZK Unbalanced Read-Only Memory (ZK UROM), may be of an independent interest.
21 March 2024
Virtual event, Anywhere on Earth, 19 December - 20 December 2024
Submission deadline: 9 July 2024
Notification: 13 August 2024
Rome, Italy, 25 September - 27 September 2024
Submission deadline: 22 April 2024
Notification: 9 July 2024
19 March 2024
Cambridge, United Kingdom, 24 September - 27 September 2024
Submission deadline: 14 April 2024
Notification: 17 June 2024
Nokia Bell Labs; Antwerp, Belgium
At Bell Labs, the research arm of Nokia, we are currently designing and building systems that offer (1) computational integrity, (2) confidentiality, and (3) low-latency operations.
Internship Details:
As an intern in our lab, you'll have the opportunity to contribute to applied research in one of these areas, including:
Zero-Knowledge Proofs: Dive into topics like SNARKs, STARKs, and MPC-in-the-Head to enhance computational integrity. Computing on Encrypted Data: Explore homomorphic encryption (FHE) and secure multiparty computation (MPC) to address confidentiality challenges.
Acceleration: Investigate optimized implementations, software architecture, novel ZKP/FHE/MPC circuits, systems and friendly primitives.
Any other relevant subjects in this area are also welcome, such as zkML, FHE+ML, verifiable FHE, applications of MPC, and beyond.
Candidate Profile:
- You are currently doing a PhD or PostDoc
- Some familiarity with one of the areas: FHE, MPC or ZKP
- Both applied and theoretical researchers are welcome
- Fully funded internship with benefits (based on Belgian income standards)
- Internship any time from now until the end of 2024
- Possibility to visit local university crypto groups (e.g. COSIC KU Leuven)
- A wonderful desk with a view of the Zoo of Antwerp (elephants and bisons visible)
- Having access to the best beers and chocolates in the world
Closing date for applications:
Contact: Emad Heydari Beni (emad.heydari_beni@nokia-bell-labs.com)
Monash University, Melbourne, Australia
At the Department of Software Systems and Cybersecurity (SSC) at Monash, we have several openings for PhD positions. The topics of interest are post-quantum cryptography (based on lattices and/or hash), their applications, and their secure and efficient software and hardware implementations.
- Amongst the benefits:
- We provide highly competitive scholarships opportunities to collaborate with leading academic and industry experts in the above-mentioned areas.
- There will be opportunities to participate in (inter)nationally funded projects.
- We have a highly collaborative and friendly research environment.
- You will have an opportunity to live/study in one of the most liveable and safest cities in the world.
The positions will be filled as soon as suitable candidates are found.
- Entry requirements include:
- Some mathematical and cryptography backgrounds.
- Some knowledge/experience in coding (for example, Python, C/C++, and/or SageMath) is a plus.
- Must have completed (or be about to complete within the next 6 months) a significant research component either as part of their undergraduate (honours) degree or masters degree.
- Should have excellent verbal and written communication skills in English.
How to apply. Please fill out the following form (also clickable from the advertisement title): https://docs.google.com/forms/d/e/1FAIpQLSetFZLvDNug5SzzE-iH97P9TGzFGkZB-ly_EBGOrAYe3zUYBw/viewform?usp=sf_link
Closing date for applications:
Contact: Amin Sakzad (amin.sakzad@monash.edu)
More information: https://www.monash.edu/it/ssc/cybersecurity/people
18 March 2024
Connor Bell, Saba Eskandarian
This paper introduces a new threshold source tracking technique that allows a private messaging platform, with the cooperation of a third-party moderator, to operate a threshold reporting scheme with exact thresholds and no false positives. Unlike prior work, our techniques require no modification of the message delivery process for a standard source tracking scheme, affecting only the abuse reporting procedure, and do not require tuning of probabilistic data structures.
Zhengjun Cao, Zhenfu Cao
Stanislav Kruglik, Son Hoang Dau, Han Mao Kiah, Huaxiong Wang, Liang Feng Zhang
Most existing FSS schemes are based on the existence of one-way functions or pseudo-random generators, and as a result, hiding of function $f$ holds only against computationally bounded adversaries. Protocols employing them as building blocks are computationally secure. Several exceptions mostly focus on DPF for four, eight or $d(t+1)$ servers for positive integer $d$, and none of them provide verifiability.
In this paper, we propose DPF for $d(t+l-1)+1$ servers, where $d$ is a positive integer, offering a better key size compared to the previously proposed DPF for $d(t+1)$ servers and DCF for $dt+1$ servers, also for positive integer $d$. We introduce their verifiable extension in which any set of servers holding $t$ keys cannot persuade us to accept the wrong value of the function. This verifiability notion differs from existing verifiable FSS schemes in the sense that we verify not only the belonging of the function to class $\mathcal{F}$ but also the correctness of computation results. Our schemes provide a secret key size $O(n^{1/d}\cdot s\log(p))$ for DPF and $O(n^{1/d}\cdot s\log(p))$ for DCF, where $p^s$ is the size of group $\mathbb{G}$.
Hans Schmiedel, Runchao Han, Qiang Tang, Ron Steinfeld, Jiangshan Yu
This paper provides theoretical foundations and desired properties for consensus protocols that resist against targeted DoS attacks. In particular, we define the Mobile Crash Adaptive Byzantine (MCAB) model to capture such an attack. In addition, we identify and formalize two properties for consensus protocols under the MCAB model, and analyze their trade-offs. As case studies, we prove that Ouroboros Praos and Algorand are secure in our MCAB model, giving the first formal proofs supporting their security guarantee against targeted DoS attacks, which were previously only informally discussed. We also illustrate an application of our properties to secure a streamlined BFT protocol, chained Hotstuff, against targeted DoS attacks.
Louis Tremblay Thibault, Michael Walter
Ward Beullens, Lucas Dodgson, Sebastian Faller, Julia Hesse
OPRFs are a prime tool for building secure authentication and key exchange from passwords, private set intersection, private information retrieval, and many other privacy-preserving systems. While classical OPRFs run as fast as a TLS Handshake, current *quantum-safe* OPRF candidates are still practically inefficient.
In this paper, we propose a framework for constructing OPRFs from post-quantum multi-party computation. The framework captures a family of so-called "2Hash PRFs", which sandwich a function evaluation in between two hashes. The core of our framework is a compiler that yields an OPRF from a secure evaluation of any function that is key-collision resistant and one-more unpredictable. We instantiate this compiler by providing such functions built from Legendre symbols, and from AES encryption. We then give a case-tailored protocol for securely evaluating our Legendre-based function, built from oblivious transfer (OT) and zero-knowledge proofs (ZKP). Instantiated with lattice-based OT and ZKPs, we obtain a quantum-safe OPRF that completes in 0.57 seconds, with less than 1MB of communication.
Nabil Alkeilani Alkadri, Nico Döttling, Sihang Pu
Manjeet Kaur, Tarun Yadav, Manoj Kumar, Dhananjoy Dey
17 March 2024
CEA-LIST France & University of Paris-Saclay, France
Thus we are looking for a highly motivated PhD candidate with a string background in applied cryptography including FHE/MPC.
The candidate must meet the following requirements
The position is based at the CEA-LIST Nano-Innov campus in Palaiseau, France (30 mins from central Paris), fully funded for three years, no teaching duties, annual leaves, and the usual benefits.
Closing date for applications:
Contact: Olive Chakraborty (olive.chakraborty@cea.fr )
Contact us with your CV and Cover letter for more details on the subject.
15 March 2024
Jamshedpur, India, 20 November - 21 November 2024
Submission deadline: 20 June 2024
Notification: 10 September 2024