IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
15 October 2022
Rex Fernando, Elaine Shi, Pratik Soni, Nikhil Vanjani
In this work, we show how to construct a non-interactive anonymous router scheme with sub-quadratic router computation, assuming the existence of subexponential indistinguishability obfuscation and one-way permutation. To achieve this, we devise new techniques for reasoning about a network of obfuscated programs.
CEA-LIST , Paris-Saclay, France
We are seeking an internship candidate for their end of Master's internship at CEA-LIST crypto team on the aforementioned topic. Successful candidate will be joining a vibrant team working on Fully Homomorphic Encryption (FHE), with a strong collaboration with several academic and industrial partners around the globe.
FHE is a cryptographic technique that allow computations to be performed on encrypted data. The FHE represents an interesting solution to certain problems posed by multipartite computation (MPC). The internship will be focussed on developing a design and implementation of multipartite Brakerski-Gentry-Vaikuntanathan (BGV) scheme. For more details: please send an email.
Candidate profile :
Closing date for applications:
Contact: Olive Chakraborty (olive.chakraborty@cea.fr), Renaud Sirdey, Aymen Boudguiga
14 October 2022
Aarhus University, Denmark
The position is available from February 2023 or later.
Research area and project description:
This project is supported by the Danish DIREC research center. It is a collaboration between Aarhus University and the IT-university Copenhagen, the Alexandra Institute, Concordium ApS and the election commission of Greenland.
direc.dk/privacy-preserving-and-software-independent-voting-protocols/
The aim of the project is work towards secure implementations of Blockchain Voting Governance Protocols and Internet Voting Protocols.
Voting and blockchains are intimately connected. Voting is used in blockchains for consensus, governance, and decentralized organizations. Conversely, elections are based on trust, which means that election systems ideally should be based on algorithms and data structures that are already trusted. Blockchains provide such a technology. They provide a trusted bulletin board, which can be used as part of some voting protocols. Moreover, voting crucially depends on establishing the identity of the voter to avoid fraud and to establish eligibility verifiability.
Decades of research in voting protocols have shown how difficult it is to combine the privacy of the vote with the auditability of the election outcome. It is easy to achieve one without the other, but hard to combine both into one protocol. Thus, the topic of this proposed research proposal is to investigate voting protocols and their relation to blockchains.
The team in Aarhus will work on (machine-checked) security proofs of these protocols and their implementations, for instance using tools such as ConCert and SSProve which are build on the Coq proof assistant.
Closing date for applications:
Contact: Bas Spitters (spitters@cs.au.dk)
More information: https://phd.nat.au.dk/for-applicants/open-calls/november-2022/privacy-preserving-and-software-independent-voting-protocols
University of Georgia - School of Computing, Institute for Cybersecurity and Privacy
Closing date for applications:
Contact: Roberto Perdisci - Director, Institute for Cybersecurity and Privacy - School of Computing, University of Georgia
More information: https://www.ugajobsearch.com/postings/279983
Simula UiB, Bergen, Norway
The initial focus of the lab will depend on the selected candidate's skills and experience, but areas of interest include (but are not limited to): side-channel analysis and security, secure and optimised hardware (e.g. FPGA) implementations and designs, edge computing platforms design. The position comes with a large degree of autonomy, and the research fellow will be in charge of the research lab's daily operations. They will have the opportunity to work with PhD students and collaborate with other researchers at Simula UiB.
The main goals of the new research lab at Simula UiB are: to expand the centre’s activities into more applied and hands-on research; connect theoretical and applied research conducted at Simula UiB; and create opportunities for collaborations with industry and similar labs elsewhere. We expect that the research lab will build demonstrators and run demos to showcase the lab’s research to visitors from industry, government and other stakeholders. This is an exciting opportunity for an ambitious and independent researcher with the right skills and experience to develop their research career. Simula UiB can offer a vibrant, stimulating and inclusive work environment to the right candidate to build a research lab from the ground up with full support from management. The position is initially for two years, with a potential extension for further two years, subject to satisfactory evaluation of the lab activities and progress.
Closing date for applications:
Contact: Øyvind Ytrehus, Research Director
More information: https://www.simula.no/about/job/postdoctoral-fellow-simula-uib
University of St.Gallen, Switzerland
Key Responsibilities:
- The post-doctoral fellow is expected to perform exciting and challenging research in the area of information security and cryptography including the design of provably secure cryptographic protocols.
- The post-doctoral fellow shall be involved in the supervision of PhD and master students
- The post-doctoral researcher is expected to have a PhD degree in Computer Science, Engineering or Mathematics and a strong background in theoretical computer science and cryptography
- Have an excellent publication record in top venues Competitive research record in cryptography or information security
- Strong mathematical and algorithmic CS background
- Good skills in programming is beneficial
- Excellent written and verbal communication skills in English
Please apply by 15. Oktober 2022.
Closing date for applications:
Contact:
Eriane Breu, eriane.breu@unisg.ch (Administrative matters)
Prof. Katerina Mitrokotsa, katerina.mitrokotsa@unisg.ch (Research related questions)
More information: https://jobs.unisg.ch/offene-stellen/postdoc-fellow-in-cryptography-information-security-m-w-d/c35410fb-40bb-41f2-b298-8be150d8f9b6
Florian Stolz, Jan Philipp Thoma, Pascal Sasdrich, Tim Güneysu
Dario Fiore, Ida Tucker
In this paper, we identify and formalize a key primitive allowing one to achieve the above: homomorphic signatures which evaluate non-deterministic computations (HSNP). We provide a generic construction for an HSNP evaluating universal relations; instantiate the construction; and implement a library for HSNP. This in turn allows us to build SPHINX: a system for proving arbitrary computations over streamed authenticated data in a privacy-preserving manner. SPHINX improves significantly over alternative solutions for this model. For instance, compared to corresponding solutions based on Marlin (Eurocrypt'20), the proof generation of SPHINX is between $15\times$ and $1\,300\times$ faster for various computations used in sliding-window statistics.
Anju Alexander, Annapurna Valiveti, Srinivas Vivek
In this work, we propose a third-order TBM scheme for arbitrary S-boxes that is secure in the probing model and under compositions, i.e., 3-SNI secure. It is very efficient in terms of the overall running time, compared to the third-order instantiations of state-of-the-art HO-TBM schemes. It also supports the pre-processing functionality. For example, the overall running time of a single execution of the third-order masked AES-128 on a 32-bit ARM-Cortex M4 micro-controller is reduced by about 80% without any overhead on the online execution time. This implies that the online execution time of the proposed scheme is approximately eight times faster than the bit-sliced masked implementation at third order, and it is comparable to the recent scheme of Wang et al. (TCHES 2022) that makes use of reuse of shares. We also present the implementation results for the third-order masked PRESENT cipher. Our work suggests that there is a significant scope for tuning the performance of HO-TBM schemes at lower orders.
Reo Eriguchi, Atsunori Ichikawa, Noboru Kunihiro, Koji Nuida
Reo Eriguchi, Noboru Kunihiro, Koji Nuida
Practical Asynchronous High-threshold Distributed Key Generation and Distributed Polynomial Sampling
Sourav Das, Zhuolun Xiang, Lefteris Kokoris-Kogias, Ling Ren
William Diehl
Seongkwang Kim, Jincheol Ha, Mincheol Son, Byeonghak Lee, Dukjae Moon, Joohee Lee, Sangyup Lee, Jihoon Kwon, Jihoon Cho, Hyojin Yoon, Jooyoung Lee
In this paper, we refine algebraic cryptanalysis of power mapping based S-boxes over binary extension fields, and cryptographic primitives based on such S-boxes. In particular, for the Gröbner basis attack over $\mathbb{F}_2$, we experimentally show that the exact number of Boolean quadratic equations obtained from the underlying S-boxes is critical to correctly estimate the theoretic complexity based on the degree of regularity. Similarly, it turns out that the XL attack might be faster when all possible quadratic equations are found and used from the S-boxes. This refined cryptanalysis leads to more precise estimation on the algebraic immunity of cryptographic primitives based on algebraic S-boxes.
Considering the refined algebraic cryptanalysis, we propose a new one-way function, dubbed $\mathsf{AIM}$, as an MPCitH-friendly symmetric primitive with high resistance to algebraic attacks. The security of $\mathsf{AIM}$ is comprehensively analyzed with respect to algebraic, statistical, quantum, and generic attacks. $\mathsf{AIM}$ is combined with the BN++ proof system, yielding a new signature scheme, dubbed $\mathsf{AIMer}$. Our implementation shows that $\mathsf{AIMer}$ significantly outperforms existing signature schemes based on symmetric primitives in terms of signature size and signing time.
Gerald Gavin, Sandrine Tainturier
Nikolaos Papadis, Leandros Tassiulas
Qipeng Liu
In this work, we continue the study on quantum advice in the QROM. We provide a new idea that generalizes the previous multi-instance framework, which we believe is more quantum-friendly and should be the quantum analogue of multi-instance games. To this end, we match the bounds with quantum advice to those with classical advice by Chung et al., showing quantum advice is almost as good/bad as classical advice for many natural security games in the QROM.
Finally, we show that for some contrived games in the QROM, quantum advice can be exponentially better than classical advice for some parameter regimes. To our best knowledge, it provides some evidence of a general separation between quantum and classical advice relative to an unstructured oracle.
Andreea B. Alexandru, Julian Loss, Charalampos Papamanthou, Giorgos Tsimos
Thomas Kaeding
Tobias Hemmert
Our backdoor mechanism can be applied to public-key cryptosystems where the secret key is generated from a secret seed and the public key includes a public seed of the same length. This holds - though not exclusively - for many cryptosystems based on LWE. In particular, we point out that our construction can be applied to backdoor HQC, FrodoKEM, Kyber and Dilithium.
We also suggest a countermeasure that makes our backdoor detectable by users of the cryptosystem. To this end, we modify the key generation such that the public and secret key are pseudorandomly generated from a single seed which is included in the generated secret key. This allows any user of the key generation algorithm to regenerate keys using an independent implementation, making our backdooring attempt detectable.