IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
08 March 2023
Cathy Li, Jana Sotáková, Emily Wenger, Mohamed Malhou, Evrard Garcelon, Francois Charton, Kristin Lauter
Christopher Dunne
Nishat Koti, Varsha Bhat Kukkala, Arpita Patra, Bhavish Raj Gopal
In the work of Arun et al. (NDSS'20), which presents the state-of-the-art solution, we identify attacks that can leak sensitive information and compromise victim privacy. We also report issues present in prior works that were left unidentified. To arrest all these breaches, we put forth an SAE system that prevents the identified attacks and retains the salient features from all prior works. The cryptographic technique of secure multi-party computation (MPC) serves as the primary underlying tool in designing our system. At the heart of our system lies a new duplicity check protocol and an improved matching protocol. We also provide additional features such as allegation modification and deletion, which were absent in the state of the art. To demonstrate feasibility, we benchmark the proposed system with state-of-the-art MPC protocols and report the cost of processing an allegation. Different settings that affect system performance are analyzed, and the reported values showcase the practicality of our solution.
Kyungbae Jang, Dukyoung Kim, Yujin Oh, Sejin Lim, Yujin Yang, Hyunji Kim, Hwajeong Seo
Apurva K Vangujar, Buvana Ganesh, Paolo Palmieri
Thomas Aulbach, Fabio Campos, Juliane Krämer, Simona Samardjiska, Marc Stöttinger
In this work, we present a side-channel attack on the latest implementation of UOV. In the first part of the attack, a single side-channel trace of the signing process is used to learn all vinegar variables used in the computation. Then, we employ the reconciliation attack to reveal the complete secret key. Our attack, unlike previous work, targets the inversion of the central map and not the subsequent linear transformation. It further does not require the attacker to control the message to be signed.
We have verified the practicality of our attack on a ChipWhisperer-Lite board with a 32-bit STM32F3 ARM Cortex-M4 target mounted on a CW308 UFO board. We publicly provide the code and both reference and target traces. Additionally, we discuss several countermeasures that can at least make our attack less efficient.
Pierre-Alain Fouque, Adela Georgescu, Chen Qian, Adeline Roux-Langlois, Weiqiang Wen
Izumi Takeuti, Tomoko Adachi
Junzuo Lai, Gongxian Zeng, Zhengan Huang, Siu Ming Yiu, Xin Mu, Jian Weng
In this paper, we systematically explore message franking in group communication scenarios. We introduce the notion of asymmetric group message franking (AGMF), and formalize its security requirements. Then, we provide a framework of constructing AGMF from a new primitive, called $\text{HPS-KEM}^{\rm{\Sigma}}$. We also give a construction of $\text{HPS-KEM}^{\rm{\Sigma}}$ based on the DDH assumption. Plugging the concrete $\text{HPS-KEM}^{\rm{\Sigma}}$ scheme into our AGMF framework, we obtain a DDH-based AGMF scheme, which supports message franking in group communication scenarios.
07 March 2023
University of Amsterdam & QuSoft
Are you fascinated by security? Are you willing to take on the challenge of securing the next generation of computer systems and networks? Do you like to work in a team of young researchers? We are seeking a PhD candidate who is interested in interdisciplinary research on side-channel attacks against quantum devices used in quantum networks.
Quantum technologies are being developed at a fast page. On the one hand, progress on the development of quantum computers poses a serious threat for our security infrastructure, especially for public-key cryptography. On the other hand, quantum components bring novel opportunities since they will be integrated in our networks and could bring novel security functionalities. However, quantum components are mostly experimental, and their security is yet to be studied and assessed in depth. In particular, little is known about their susceptibility against side-channel and physical attacks and, as a direct consequence, we do not know if and which countermeasures can be applied.
This PhD position will study the problem of side channels and physical attacks against quantum devices, understanding the extent to which they could be considered a threat and exploring potential methodologies to counteract and mitigate them. In collaboration with experimental physicists, experiments on real quantum devices are expected to be carried out to assess their robustness.
The fully funded PhD position will be at University of Amsterdam and QuSoft. The position is a part of the Quantum Delta NL Groeifonds project CAT-2, development of a national quantum network and will also involve collaboration with the experimental and theoretical partners of the CAT-2 project.
Closing date for applications:
Contact: Christian Schaffner
More information: https://vacatures.uva.nl/UvA/job/PhD/742058802/
University of Connecticut, CT, USA
The positions provide a great opportunity for students with interest in interdisciplinary projects that combine knowledge from various fields towards the design of secure systems and protocols. We target real-world and timely problems and aim to develop secure and practical solutions backed by rigorous foundations and efficient implementations/thorough performance testing. We are also interested in conceptual projects that contribute in bridging the gap between theory and practice of Cryptography.
For more information about our current and previous projects please check https://ghadaalmashaqbeh.github.io/research/. For interested students, please send your CV to ghada@uconn.edu and provide any relevant information about your research interests, and relevant skills and background.
Closing date for applications:
Contact: Ghada Almashaqbeh
More information: https://ghadaalmashaqbeh.github.io/research/
06 March 2023
Nicky Mouha, Christopher Celi
Bernardo David, Anders Konring, Yuval Ishai, Eyal Kushilevitz, Varun Narayanan
In this work, we tackle the above two challenges simultaneously. We consider a layered MPC model, a simplified variant of the fluid MPC model of Choudhuri et al. (Crypto 2021). Layered MPC is an instance of standard MPC where the interaction pattern is defined by a layered graph of width $n$, allowing each party to send secret messages and broadcast messages only to parties in the next layer. We require perfect security against a malicious adversary who may corrupt at most $t$ parties in each layer. Our main result is a perfect, fully secure layered MPC protocol with an optimal corruption threshold of $t < n/3$, thus extending the BGW feasibility result to the layered setting. This implies perfectly secure MPC protocols against a maximally mobile adversary.
Martin R. Albrecht, Miro Haller, Lenka Mareková, Kenneth G. Paterson
We analyse these new sanity checks and show how they themselves can be exploited to mount novel attacks on MEGA that recover a target user's RSA private key with only slightly higher attack complexity than the original attacks. We identify the presence of an ECB encryption oracle under a target user's master key in the MEGA system; this oracle provides our adversary with the ability to partially overwrite a target user's RSA private key with chosen data, a powerful capability that we use in our attacks. We then present two distinct types of attack, each type exploiting different error conditions arising in the sanity checks and in subsequent cryptographic processing during MEGA's user authentication procedure. The first type appears to be novel and exploits the manner in which the MEGA code handles modular inversion when recomputing $u = q^{-1} \bmod p$. The second can be viewed as a small subgroup attack (van Oorschot and Wiener, EUROCRYPT 1996, Lim and Lee, CRYPTO 1998). We prototype the attacks and show that they work in practice.
As a side contribution, we show how to improve the RSA key recovery attack of Backendal-Haller-Paterson against the unpatched version of MEGA to require only 2 logins instead of the original 512.
We conclude by discussing wider lessons about secure implementation of cryptography that our work surfaces.
Jan Schoone, Joan Daemen
In this paper, we characterize the graph of $\chi$ on periodic sequences. It turns out that $\chi$ is surjective on the set of \emph{all} periodic sequences. We will show what sequences will give collisions after one application of $\chi$. We prove that, for odd $n$, the order of $\chi_n$ (in the group of bijective maps on $\mathbb{F}^n$) is $2^{\lceil \operatorname{lg}(\frac{n+1}2)\rceil}$.
A given periodic sequence lies on a cycle in the graph of $\chi$, or it can be represented as a polynomial. By regarding the divisors of such a polynomial one can see whether it lies in a cycle, or after how many iterations of $\chi$ it will.
Furthermore, we can see, for a given $\sigma$, the length of the cycle in its component in the state diagram. Finally, we extend the surjectivity of $\chi$ to $\mathbb{F}^{\mathbb{Z}}$, thus to include non-periodic sequences.
Yangru Zheng, Juntao Gao, Baocang Wang
Our results show that increasing the length of key seeds is not an effective way anymore to resist the quantum search attacks, and it is necessary to propose new measures to ensure the post-quantum security of symmetric ciphers.
Jean Liénardy, Frédéric Lafitte
Prabhanjan Ananth, Alexander Poremba, Vinod Vaikuntanathan
We define and construct several fundamental cryptographic primitives with key-revocation capabilities, namely pseudorandom functions, secret-key and public-key encryption, and even fully homomorphic encryption, assuming the quantum subexponential hardness of the learning with errors problem. Central to all our constructions is our approach for making the Dual-Regev encryption scheme (Gentry, Peikert and Vaikuntanathan, STOC 2008) revocable.
05 March 2023
Michael Rosenberg
In this work we present LATKE, an iPAKE from lattice assumptions in the random oracle model. In order to achieve security and correctness, we must make changes to CHIP's primitives, security models, and protocol structure.
Lorenzo Grassi, Dmitry Khovratovich, Markus Schofnegger
In this paper, we propose an optimized version of Poseidon, called Poseidon2. The two versions differ in two crucial points. First, Poseidon is a sponge hash function, while Poseidon2 can be either a sponge or a compression function depending on the use case. Secondly, Poseidon2 is instantiated by new and more efficient linear layers with respect to Poseidon. These changes allow to decrease the number of multiplications in the linear layer by up to 90% and the number of constraints in Plonk circuits by up to 70%. This makes Poseidon2 the currently fastest arithmetization-oriented hash function without lookups.
Besides that, we address a recently proposed algebraic attack and propose a simple modification that makes both Poseidon and Poseidon2 secure against this approach.