IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
29 April 2021
Virtual event, Anywhere on Earth, 27 October -
Submission deadline: 21 June 2021
Notification: 19 July 2021
Virtual event, Anywhere on Earth, 15 August 2021
Submission deadline: 1 June 2021
Notification: 1 July 2021
28 April 2021
University of Klagenfurt, Austria
The Cybersecurity research group, headed by Elisabeth Oswald, is a relatively new group established in Austria's sunny south. The group currently features a diverse range of members (from France, Iran, India, and China). Current members work on topics such as leakage profiling, advanced leakage simulators, attacks (utilising deep learning), statistical foundations, and hardware aspects of side channels. The group receives funding from the ERC, as well as local funding, and thus offers a supportive research environment (both financially as well as from a human perspective).
The group is looking to grow by two more members: one post doc and one doctoral student. The group is particularly keen to expand their existing coverage of topics and seeks researchers with an interest in
- compilers/languages to support the secure implementation of cryptographic primitives
- machine/deep learning
- secure implementations w.r.t. the RISC-V instruction set
A good candidate for the Post-doc position will have some existing publications in relevant venues (IACR conferences or workshops, journals, or system security venues), enjoy working with people in an international context, and love water, sun, and mountains.
A good candidate for the PhD position will have a background in either computer science, maths, or statistics (an MSc level degree is required), will ideally have done some project in a crypto/security related topic, enjoy working with people in an international context, and love water, sun, and mountains.
The funding for the Post-Doc Position is available until 31.08.2023. The funding for the PhD position is for 40 months. Rates are set according to a standard collective agreement for such positions (Kollektivvertrag), but the salary for the Post-Doc position can be adjusted depending on previous experience.
Don't hesitate to get in touch with Elisabeth Oswald for informal enquiries, or to apply!Closing date for applications:
Contact: Please contact Elisabeth . Oswald @ aau . at
More information: http://www.cybersecurityresearch.at
Thijs Laarhoven, Michael Walter
In this work we provide an overview of cost estimates for dual algorithms for solving these ''classical'' closest lattice vector problems. Heuristically we expect to solve the search version of average-case CVPP in time and space $2^{0.293d + o(d)}$. For the distinguishing version of average-case CVPP, where we wish to distinguish between random targets and targets planted at distance approximately the Gaussian heuristic from the lattice, we obtain the same complexity in the single-target model, and we obtain query time and space complexities of $2^{0.195d + o(d)}$ in the multi-target setting, where we are given a large number of targets from either target distribution. This suggests an inequivalence between distinguishing and searching, as we do not expect a similar improvement in the multi-target setting to hold for search-CVPP. We analyze three slightly different decoders, both for distinguishing and searching, and experimentally obtain concrete cost estimates for the dual attack in dimensions $50$ to $80$, which confirm our heuristic assumptions, and show that the hidden order terms in the asymptotic estimates are quite small.
Our main take-away message is that the dual attack appears to mirror the approximate Voronoi cell line of work -- whereas using approximate Voronoi cells works well for approximate CVP(P) but scales poorly for BDD(P), the dual approach scales well for BDD(P) instances but performs poorly on approximate CVP(P).
Leo Robert, Daiki Miyahara, Pascal Lafourcade, Takaaki Mizuk
Nils Wisiol, Khalid T. Mursi, Jean-Pierre Seifert, Yu Zhuang
27 April 2021
Gyeongju Song, Kyungbae Jang, Hyunji Kim, Wai-Kong Lee, Hwajeong Seo
Daniel De Almeida Braga, Pierre-Alain Fouque, Mohamed Sabt
In this paper, we analyze the security of the SRP implementation inside the OpenSSL library. In particular, we identify that this implementation is vulnerable to offline dictionary attacks. Indeed, we exploit a call for a function computing modular exponentiation of big numbers in OpenSSL. In the SRP protocol, this function leads to the call of a non-constant time function, thereby leaking some information about the used password when leveraging cache-based \textsc{Flush+Reload} timing attack. Then, we show that our attack is practical, since it only requires one single trace, despite the noise of cache measurements. In addition, the attack is quite efficient as the reduction of some common dictionaries is very fast using modern resources at negligible cost. We also prove that the scope of our vulnerability is not only limited to OpenSSL, since many other projects, including Stanford's, ProtonMail and Apple Homekit, rely on OpenSSL, which makes them vulnerable. We find that our flaw might also impact projects written in Python, Erlang, JavaScript and Ruby, as long as they load the OpenSSL dynamic library for their big number operations. We disclosed our attack to OpenSSL who acknowledged the attack and timely fixed the vulnerability.
André Chailloux, Thomas Debris-Alazard, Simona Etinski
Seungwan Hong, Seunghong Kim, Jiheon Choi, Younho Lee, Jung Hee Cheon
The approximate homomorphic comparison, which is the only type of comparison working on approximate FHE, cannot be used for the construction of the $k$-sorter as it is because the result of the comparison is not binary, unlike the comparison in conventional bit-wise FHEs. To overcome this problem, we propose an efficient $k$-sorter construction utilizing the features of approximate homomorphic comparison. Also, we propose an efficient construction of a $k$-way sorting network using cryptographic SIMD operations. To use the proposed method most efficiently, we propose an estimation formula that finds the appropriate $k$ that is expected to reduce the total time cost when the parameters of the approximating comparisons and the performance of the operations provided by the approximate FHE are given. We also show the implementation results of the proposed method, and it shows that sorting $5^6=15625$ data using $5$-way sorting network can be about $23.3\%$ faster than sorting $2^{14}=16384$ data using $2$-way.
Amar Bapić, Samir Hodzić, Enes Pasalic
Benjamin Salling Hvass, Diego F. Aranha, Bas Spitters
Keiichi Iwamura, Ahmad Akmal Aminuddin Mohd Kamal
Yao Sun
Jin Hoki, Takanori Isobe, Ryoma Ito, Fukang Liu, Kosei Sakamoto
Muhammed F. Esgin, Ron Steinfeld, Raymond K. Zhao
To support its efficiency, we devise several novel techniques in our design of MatRiCT+ to achieve compact lattice-based zero-knowledge proof systems, exploiting the algebraic properties of power-of-2 cyclotomic rings commonly used in practical lattice-based cryptography. Along the way, we design an ``optimal'' challenge space with minimal $\ell_1$-norm and invertible challenge differences (with overwhelming probability), while supporting highly-splitting power-of-2 cyclotomic rings. We believe all these results to be widely applicable and of independent interest.
Jing Yang, Thomas Johansson, Alexander Maximov
Craig Costello
In the final section I will discuss the upcoming SIKE challenges: over $50k USD will be up for grabs for the solutions of mini instances that, according to the SIKE team's security analysis, provide significantly less than 64 bits of classical security. I conclude by urging the proponents of other schemes to construct analogous challenge instances.