IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
15 June 2023
Alessandro Gecchele
14 June 2023
Nicolas Aragon, Victor Dyseryn, Philippe Gaborit
Kaartik Bhushan, Venkata Koppula, Manoj Prabhakaran
Christoph Dobraunig, Bart Mennink
Ben Nassi, Etay Iluz, Or Cohen, Ofek Vayner, Dudi Nassi, Boris Zadov, Yuval Elovici
Marco Cianfriglia, Elia Onofri, Marco Pedicini
Koji Nuida
Jitendra Bhandari, Likhitha Mankali, Mohammed Nabeel, Ozgur Sinanoglu, Ramesh Karri, Johann Knechtel
Satrajit Ghosh, Mark Simkin
In this work, we construct protocols with a quasilinear dependency on $t$ from simple assumptions like additively homomorphic encryption and oblivious transfer. All existing approaches, including ours, rely on protocols for computing a single bit, which indicates whether the intersection is larger than $n-t$ without actually computing it. Our key technical contribution, which may be of independent interest, takes any such protocol with secret shared outputs and communication complexity $\mathcal{O}(\lambda \ell \cdot\mathrm{poly}(t))$, where $\lambda$ is the security parameter, and transforms it into a protocol with communication complexity $\mathcal{O}(\lambda^2 \ell t \cdot\mathrm{polylog}(t))$.
Nils Fleischhacker, Kasper Green Larsen, Maciej Obremski, Mark Simkin
We present new constructions of IBLTs that are simultaneously more space efficient and require less randomness. For storing $n$ elements with a failure probability of at most $\delta$, our data structure only requires $\mathcal{O}(n + \log(1/\delta)\log\log(1/\delta))$ space and $\mathcal{O}(\log(\log(n)/\delta))$-wise independent hash functions.
As a key technical ingredient we show that hashing $n$ keys with any $k$-wise independent hash function $h:U \to [Cn]$ for some sufficiently large constant $C$ guarantees with probability $1 - 2^{-\Omega(k)}$ that at least $n/2$ keys will have a unique hash value. Proving this is highly non-trivial as $k$ approaches $n$. We believe that the techniques used to prove this statement may be of independent interest.
Tohru Kohrita, Patrick Towa
Mohsen Minaei, Panagiotis Chatzigiannis, Shan Jin, Srinivasan Raghuraman, Ranjit Kumaresan, Mahdi Zamani, Pedro Moreno-Sanchez
Tore Kasper Frederiksen, Julia Hesse, Bertram Poettering, Patrick Towa
In this work, we propose a new policy-based Single Sign-On service, i.e., a system that produces access tokens that are conditioned on the user's attributes fulfilling a specified policy. Our solution is based on multi-party computation and threshold cryptography, and generates access tokens of standardized format. The central idea is to distribute the role of the SSO provider among several entities, in order to shield user attributes and access patterns from each individual entity. We provide a formal security model and analysis in the Universal Composability framework, against proactive adversaries. Our implementation and benchmarking show the practicality of our system for many real-world use cases.
Dominik Hartmann, Eike Kiltz
In this work, we study the question whether these strong idealized models are necessary for proving the security of ECDSA. Specifically, we focus on the programmability of ECDSA's "conversion function" which maps an elliptic curve point into its $x$-coordinate modulo the group order. Unfortunately, our main results are negative. We establish, by means of a meta reductions, that an algebraic security reduction for ECDSA can only exist if the security reduction is allowed to program the conversion function. As a consequence, a meaningful security proof for ECDSA is unlikely to exist without strong idealization.
John Preuß Mattsson
12 June 2023
SandboxAQ; Remote, USA; Remote, Canada; Remote, Europe
Core Responsibilities
- Research and design new cryptographic primitives or protocols.
- Represent SandboxAQ’s interests in standard bodies.
- Contribute technically to the standardization of internal innovative designs and technologies.
- Work closely with the R&D, engineering teams and product manager teams, and help develop PoCs of the proposed standards.
- Help on organizing events related to standards or to research.
Closing date for applications:
Contact: Carlos Aguilar-Melchor <carlos.aguilar@sandboxaq.com>
Martin Albrecht <martin.albrecht@sandboxaq.com>
More information: https://www.sandboxaq.com/careers-list?gh_jid=4884446004
SandboxAQ; Remote, USA; Remote, Canada; Remote, Europe
Core Responsibilities:
- Design, develop, and implement cryptographic protocols and algorithms that are resistant to quantum attacks.
- Lead the development of a disruptive composable cryptographic library that can be used in various applications and systems.
- Work closely with software developers and researchers to ensure that the cryptographic library is robust, efficient, and easy to use.
- Stay up-to-date with the latest developments in post quantum cryptography and integrate them into the library.
- Collaborate with other cryptographers and security experts to ensure that the library meets the highest security standards.
- Provide technical guidance and mentorship to junior members of the team.
- Manage the Open Source version of the library including the publication pipeline (from the internal repository) as well as the resulting artifacts (e.g. Python/Rust/Go packages)
Closing date for applications:
Contact: Carlos Aguilar-Melchor <carlos.aguilar@sandboxaq.com>
More information: https://www.sandboxaq.com/careers-list?gh_jid=4872332004
SandboxAQ; Remote, USA
Core Responsibilities
- Participating in the development of our cryptographic framework:
- Design and implement various API along the cryptographic stack (from block ciphers to creating VPN tunnels)
- Support for new tunneling protocols
- Provide guidance on software development scope, capacity, prioritization and best practices
- Perform profiling, identify potential performance tradeoffs
Closing date for applications:
Contact: Carlos Aguilar-Melchor <carlos.aguilar@sandboxaq.com>
More information: https://www.sandboxaq.com/careers-list?gh_jid=4800134004
Ruhr University Bochum
We are inviting applications for a fully-funded PhD position at the Cluster of Excellence CASA. As the successful candidate, you will join the project Robust Certification of Quantum Devices and conduct fundamental research in the areas of:
At Bochum, you can expect a vibrant atmosphere of excellent research that spans across many areas of computer science and mathematics. In addition to an exciting research project and a friendly and stimulating work environment, we can offer a generous travel budget that allows for attending relevant conferences and summer schools to present your work to the international community, visiting collaborators, etc. The PhD program is entirely in English. You will be employed on a fully-funded position (100%, E13 salary) with an initial appointment of three years. The starting date is negotiable, but ideally in fall 2023. Your profile:
To apply, please email qi@rub.de with subject “CASA PhD Position” and the following information:
Applications received by July 10, 2023 will receive full consideration. We strongly encourage applications from members of any underrepresented group.
Closing date for applications:
Contact: qi@rub.de
NEAR - Pagoda
Pagoda is shepherding a future where NEAR becomes the blockchain operating system. We believe that re-inventing how software is made and distributed is our greatest opportunity to open economic access to those who are not fully integrated into the global economy. Our products empower people to find opportunity, invent new experiences, and collaborate. Let's build an Open Web world. A world where people control their assets, data, and power of governance.
About The Role
Pagoda is looking for a software engineer with experience building and maintaining cryptography and Zero-Knowledge projects. You will be the in-house expert on cryptography and Zero-Knowledge technology. You will initiate, implement, and lead a variety of projects in this area, including integrating the results of Zero-Knowledge research done by teams in the Near community into NEAR Protocol. Your work will have a major impact on the scalability and decentralization of NEAR Protocol.
What You'll Be Doing:
What We're Looking For:
Closing date for applications:
Contact: Jo Mount, Senior Recruiter - NEAR-Pagoda
More information: https://boards.greenhouse.io/pagoda/jobs/6736262002?gh_jid=6736262002