IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
07 November 2022
Sujaya Maiyya, Yuval Steinhart, Divyakant Agrawal, Prabhanjan Ananth, Amr El Abbadi
Noemi Glaeser, Dimitris Kolonelos, Giulio Malavolta, Ahmadreza Rahimi
In this work, we propose a new approach to construct RBE, from well-studied assumptions in bilinear groups. Our scheme is black-box, and it is concretely highly efficient---a ciphertext is 866 bytes. To substantiate this claim, we implemented a prototype of our scheme, and we show that it scales to "millions of users". The public parameters of the scheme are in the order of kilobytes. The most expensive operation (registration) takes a handful of seconds, whereas the encryption and decryption runtimes are in the order of milliseconds. This is the first-ever implementation of an RBE scheme and demonstrates that the practical deployment of RBE is already possible with today's hardware.
Bar Alon, Olga Nissenbaum, Eran Omri, Anat Paskin-Cherniavsky, Arpita Patra
We study the feasibility of obtaining perfect security for deterministic symmetric two-party functionalities (i.e., where both parties obtain the same output) in the face of malicious adversaries. We explore both the plain model as well as the correlated randomness model. We provide positive results in the plain model, and negative results in the correlated randomness model. As a corollary, we obtain the following results. \begin{enumerate} \item We provide a characterization of symmetric functionalities with (up to) four possible outputs that can be computed with perfect security. The characterization is further refined when restricted to three possible outputs and to Boolean functions. All characterizations are the same for both the plain model and the correlated randomness model. \item We show that if a functionality contains an embedded XOR or an embedded AND, then it cannot be computed with perfect security (even in the correlated randomness model). \end{enumerate}
06 November 2022
Jeremiah Blocki, Blake Holman, Seunghoon Lee
Balthazar Bauer, Pooya Farshim, Patrick Harasser, Adam O'Neill
We introduce a standard-model definition called pseudo-generic group (PGG), where we require exponentiations with base an (initially) unknown group generator to result in random-looking group elements. In essence, our framework delicately lifts the influential notion of Universal Computational Extractors of Bellare, Hoang, and Keelveedhi (BHK, CRYPTO 2013) to a setting where the underlying ideal reference object is a generic group. The definition we obtain simultaneously generalizes the Uber assumption family, as group exponents no longer need to be polynomially induced. At the core of our definitional contribution is a new notion of algebraic unpredictability, which reinterprets the standard Schwartz–Zippel lemma as a restriction on sources. We prove the soundness of our definition in the GGM with auxiliary-input (AI-GGM).
Our remaining results focus on applications of PGGs. We first show that PGGs are indeed a generalization of Uber. We then present a number of applications in settings where exponents are not polynomially induced. In particular we prove that simple variants of ElGamal meet several advanced security goals previously achieved only by complex and inefficient schemes. We also show that PGGs imply UCEs for split sources, which in turn are sufficient in several applications. As corollaries of our AI-GGM feasibility, we obtain the security of all these applications in the presence of preprocessing attacks.
Some of our implications utilize a novel type of hash function, which we call linear-dependence destroyers (LDDs) and use to convert standard into algebraic unpredictability. We give an LDD for low-degree sources, and establish their plausibility for all sources by showing, via a compression argument, that random functions meet this definition.
04 November 2022
Tokyo, Japan, 26 March 2023
Temasek Laboratories, National University of Singapore, Singapore
A candidate will work in the area of post-quantum cryptography. The candidate will conduct research on analysis of post-quantum cryptography; the emphasis is on quantum analysis on symmetric cipher and PQC. The work requires to carry out some simulations.
Applicants are expected to have a PhD degree in Mathematics/Physics/Computer Science and a strong background in quantum algorithm, algebra, linear algebra or algebraic number theory.
Preferred candidates are expected to be proficient in Magma software or SAGEMATH software; or have knowledge on quantum software (eg. Qiskit, etc), a team worker and able to conduct independent research.
Interested candidates will kindly include their full CV and transcripts in their applications and send to Dr Chik How Tan, tsltch@nus.edu.sg. Deadline for applications is January 31st, 2023. We encourage early applications and review of applications will begin immediately. Only shortlisted applications will be notified.
Closing date for applications:
Contact: Dr Chik How Tan (tsltch@nus.edu.sg)
Florida Atlantic University
- post-quantum cryptography
- lattice-based cryptography
- code-based cryptography
- cryptanalysis
- elliptic curves and isogenies
- zero-knowledge proofs
- ...
Closing date for applications:
Contact: Edoardo Persichetti (epersichetti@fau.edu); Shi Bai (sbai@fau.edu); Francesco Sica (sicaf@fau.edu)
Heliax, Remote
Closing date for applications:
Contact: Christopher Goes
More information: https://heliax.dev/jobs/research-cryptographer-FHE/
Lyon, Frankreich, 22 April - 23 April 2023
Submission deadline: 5 January 2023
Notification: 9 February 2023
Neuchâtel, Schweiz/Suisse/Svizzera/Svizra, 26 June - 29 June 2023
Submission deadline: 18 November 2022
Notification: 20 January 2023
Zhangjiajie, China, 28 December - 31 December 2022
Submission deadline: 30 October 2022
Notification: 30 November 2022
Zhangjiajie, China, 28 December - 31 December 2022
Submission deadline: 30 October 2022
Notification: 30 November 2022
02 November 2022
Lund University, Lund, Sweden
Third cycle studies at Lund University consist of full-time studies for 4 years. A doctoral studentship is a fixed-term employment of a maximum of 5 years (including 20% departmental duties). Starting salary is around 3100Euro per month. For further information and information on how to apply, see https://lu.varbi.com/en/what:job/jobID:557529/
Closing date for applications:
Contact: Thomas Johansson: thomas (at) eit.lth.se
More information: https://lu.varbi.com/en/what:job/jobID:557529/
atlanTTic Research Center, Universidade de Vigo; Vigo, Spain
PhD position available at the AtlanTTic Research Center (https://atlanttic.uvigo.es/en/), Universidade de Vigo, Spain. Start in early 2023, covering full PhD duration (3-4 years), and including travel budget for conferences and summer schools.
The workplace is in the city of Vigo, being ranked by OCU as the Spanish city with the highest life quality (https://www.idealista.com/en/news/lifestyle-in-spain/2021/06/02/13426-quality-of-life-in-spain-spanish-cities-with-the-best-and-worst-quality-of-life).
The position will be part-time in two projects related to privacy and intellectual property protection for federated machine learning: 1) TRUMPET, an European project on privacy enhancing methods and privacy metrics for federated learning (FL); 2) FELDSPAR, a Spanish project to use DNN watermarking for protecting the intellectual property of FL models.
PhD candidates will carry out research on: 1) identifying threat models and measuring privacy leaks in FL; 2) develop novel DNN watermarking algorithms in FL robust to collusion attacks.
Intended tasks:
Your profile:
Closing date for applications:
Contact: For more details, send an email to Prof. Fernando Pérez-González (fperez@gts.uvigo.es).
Florida Atlantic University
Closing date for applications:
Contact: Informal inquiries can be addressed to: Dr. Edoardo Persichetti, Chair of the Search Committee, (epersichetti@fau.edu). Apply at https://fau.wd1.myworkdayjobs.com/FAU/job/Boca-Raton/Assistant-Professor--Cryptology_REQ14641
More information: https://fau.wd1.myworkdayjobs.com/FAU/job/Boca-Raton/Assistant-Professor--Cryptology_REQ14641
NYU Shanghai, Engineering and Computer Science; Shanghai, China
Closing date for applications:
Contact: NYU Shanghai NY Office of Faculty Recruitment: shanghai.faculty.recruitment@nyu.edu
More information: https://apply.interfolio.com/116511
Vernam Lab, Worcester Polytechnic Institute; Worcester, USA.
Requirements
-
• A degree in ECE or CS
• Strong background in mathematics and computer engineering
• Prior experience in one or more of the following is a plus:
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o Cryptography
o Machine learning
o Programming languages: Python (open to work with new libraries), VHDL/Verilog
o FPGA prototyping, lab equipment (hands-on experience)
What does Vernam Lab offer? A competitive salary and an international cutting-edge research program in an attractive working environment.
WPI is a highly-ranked research university in the Boston area and has been recently recognized by the 2020 HEED Award for its outstanding commitment to diversity and inclusion. In accordance with this mission and to broaden participation in STEM, we encourage all students, especially minority students, to apply. Interested students should contact us by sending an email with a CV to vernam.labs@gmail.com.
Closing date for applications:
Contact: vernam.labs@gmail.com
01 November 2022
Gora Adj, Luis Rivera-Zamarripa, Javier Verbel
MinRank is an NP-complete problem extensively studied due to its applications to cryptanalysis since its introduction in 1999. However, only a few schemes base their security on its intractability, and their signature size is large compared with other proposals based on NP problems. This paper introduces the first MinRank-based digital signature scheme that uses the MPC-in-the-head, enabling it to achieve small signature sizes and running times. For NIST's category I parameter set, we obtain signatures of 6.5KB, which is competitive with the shortest proposals in the literature that are based on non-structured problems.
Susan Hohenberger, George Lu, Brent Waters, David J. Wu
This work introduces registered ABE, a primitive that allows users to generate secret keys on their own and then register the associated public key with a "key curator" along with their attributes. The key curator aggregates the public keys from the different users into a single compact master public key. To decrypt, users occasionally need to obtain helper decryption keys from the key curator which they combine with their own secret keys. We require that the size of the aggregated public key, the helper decryption keys, the ciphertexts, as well as the encryption/decryption times to be polylogarithmic in the number of registered users. Moreover, the key curator is entirely transparent and maintains no secrets. Registered ABE generalizes the notion of registration-based encryption (RBE) introduced by Garg et al. (TCC 2018), who focused on the simpler setting of identity-based encryption.
We construct a registered ABE scheme that supports an a priori bounded number of users and policies that can be described by a linear secret sharing scheme (e.g., monotone Boolean formulas) from assumptions on composite-order pairing groups (the same pairing-based assumptions previously used to construct vanilla ABE). Notably, our approach deviates sharply from previous techniques for constructing RBE and only makes black-box use of cryptography. All existing RBE constructions (a weaker notion than registered ABE) rely on heavy non-black-box techniques. In fact, the encryption and decryption costs of our construction are comparable to those of vanilla pairing-based ABE. Finally, as a feasibility result, we show how to construct a registered ABE scheme that supports general policies and an arbitrary number of users from indistinguishability obfuscation and somewhere statistically binding hash functions.