IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
02 June 2021
Navid Nasr Esfahani, Douglas R. Stinson
In this paper, we replace the parameter $t$ by two parameters $t_o$ and $t_i$, where $t_i \leq t_o$. The requirement is that knowledge of all but $t_o$ outputs leaves any $t_i$ inputs completely undetermined. When $t_i < t_o$, we refer to the AONT as asymmetric.
We give several constructions and bounds for various classes of asymmetric AONTs, especially those with $t_i = 1$ or $t_i = 2$. We pay particular attention to linear transforms, where the alphabet is a finite field $F_q$ and the mapping is linear.
Felix Günther, Patrick Towa
This work proposes a variant of KEMTLS tailored to such scenarios. The protocol leverages the fact that clients know the server public keys in advance to decrease handshake latency while protecting client identities. It combines medium-lived with long-term server public keys to enable a delayed form of forward secrecy even from the first data flow on, and full forward secrecy upon the first round trip. The protocol is proved to achieve strong security guarantees, based on the security of the underlying building blocks, in a new model for multi-stage key exchange with medium-lived keys.
01 June 2021
Dfns, Paris
We are looking for a highly motivated candidate to fill a cryptography researcher position at Dfns. Topics include:
Closing date for applications:
Contact: Houda Ferradi: Houda@dfns.io
More information: https://www.dfns.co/
Temasek Laboratories, National University of Singapore, Singapore
A candidate will work in the area of post-quantum cryptography. A candidate will conduct research on code-based, lattice-based cryptography in term of design, its security and performance analysis; and possibly its applications, etc. The work requires to carry out some simulations.
Applicants are expected to have a PhD degree in Mathematics/Computer Science and a strong background in algebra, linear algebra, algebraic number theory or algebraic coding theory.
Preferred candidates are expected to be proficient in Magma software or SAGEMATH software, 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.
Only shortlisted applicants will be notified. Review of applicants will start immediately.
Closing date for applications:
Contact: Dr Chik How Tan (tsltch@nus.edu.sg)
Copenhagen, Denmark, 9 November - 11 November 2021
Submission deadline: 1 July 2021
Notification: 15 August 2021
Virtual event, Anywhere on Earth, 6 October - 8 October 2021
Submission deadline: 7 July 2021
Notification: 10 August 2021
TU Wien
A successful candidate should have an excellent academic record from a completed master or diploma curriculum in Mathematics, Computer Science, or related fields. Previous knowledge or experience in the area of cryptography or security is a plus.
The Security and Privacy research unit at TU Wien is internationally renowned with its expertise in the fields of cryptography, security and privacy. Our working language is English.
Formal applications must be submitted via https://jobs.tuwien.ac.at/Job/153314. We look forward to receiving your application until 29.07.2021.
Closing date for applications:
Contact: Inquiries about the position and process to Asst. Prof. Elena Andreeva elena[dot]andreeva[at]tuwien[dot]ac[dot]at
More information: https://jobs.tuwien.ac.at/Job/153314
31 May 2021
Mohammad Sadeq Dousti, Alptekin Küpçü
Haopeng Fan; Wenhao Wang; Yongjuan Wang
Keywords: Side Channel, Cache attack, Flush+Reload, MISTY1, Key Scheduling Part
Yusaku Maeda, Koji Nuida
Sulamithe Tsakou, Sorina Ionica
Łukasz Chmielewski, Léo Weissbart
We propose and evaluate non-invasive and passive reverse engineering methods to recover NN designs deployed on GPUs through EM side-channel analysis. We employ a well-known technique of simple EM analysis and timing analysis of NN layers execution. We consider commonly used NN architectures, namely Multilayer Perceptron and Convolutional Neural Networks. We show how to recover the number of layers and neurons as well as the types of activation functions. Our experimental results are obtained on a setup that is as close as possible to a real-world device in order to properly assess the applicability and extendability of our methods.
We analyze the NN execution of a PyTorch python framework implementation running on Nvidia Jetson Nano, a module computer embedding a Tegra X1 SoC that combines an ARM Cortex-A57 CPU and a 128-core GPU within a Maxwell architecture. Our results show the importance of side-channel protections for NN accelerators in real-world applications.
Zhenzhen Bao, Jian Guo, Meicheng Liu, Li Ma, Yi Tu
Prasanna Ravi, Martianus Frederic Ezerman, Shivam Bhasin, Anupam Chattopadhyay, Sujoy Sinha Roy
Lichao Wu, Yoo-Seung Won, Dirmanto Jap, Guilherme Perin, Shivam Bhasin, Stjepan Picek
Angèle Bossuat, Raphael Bost, Pierre-Alain Fouque, Brice Minaud, Michael Reichle
Dionysis Zindros
Afifa Ishtiaq, Dr. Muhammad Shafique, Dr. Osman Hassan
Elie Bouscatié, Guilhem Castagnos, Olivier Sanders
The compromise between traffic analysis and privacy can be achieved through searchable encryption. However, as the traffic data is a stream and as the patterns to search are bound to evolve over time (e.g. new virus signatures), these applications require a kind of searchable encryption that provides more flexibility than the classical schemes. We indeed need to be able to search for patterns of variable sizes in an arbitrary long stream that has potentially been encrypted prior to pattern identification. To stress these specificities, we call such a scheme a stream encryption supporting pattern matching.
Recent papers use bilinear groups to provide public key constructions supporting these features. These solutions are lighter than more generic ones (e.g. fully homomorphic encryption) while retaining the adequate expressivity to support pattern matching without harming privacy more than needed. However, all existing solutions in this family have weaknesses with respect to efficiency and security that need to be addressed. Regarding efficiency, their public key has a size linear in the size of the alphabet, which can be quite large, in particular for applications that naturally process data as bytestrings. Regarding security, they all rely on a very strong computational assumption that is both interactive and specially tailored for this kind of scheme.
In this paper, we tackle these problems by providing two new constructions using bilinear groups to support pattern matching on encrypted streams. Our first construction shares the same strong assumption but dramatically reduces the size of the public key by removing the dependency on the size of the alphabet, while nearly halving the size of the ciphertext. On a typical application with large patterns, our public key is two order of magnitude smaller that the one of previous schemes, which demonstrates the practicality of our approach. Our second construction manages to retain most of the good features of the first one while exclusively relying on a simple (static) variant of DDH, which solves the security problem of previous works.
30 May 2021
Seoul, Südkorea, 19 November 2021
Submission deadline: 25 June 2021
Notification: 13 August 2021