IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
04 June 2018
Michael Kounavis, David Durham, Sergej Deutsch, Antonios Papadimitriou, Amitabh Das
We discuss that implicit integrity can be associated with a notion of security which is different from the typical requirement that the output of cryptographic systems should be indistinguishable from the output of a random permutation. The notion of security we discuss is that it should be computationally difficult for an adversary to corrupt some ciphertext so that the resulting plaintext demonstrates specific patterns. We further introduce two kinds of adversaries. First, an input perturbing adversary performs content corruption attacks. Second an oracle replacing adversary performs content replay attacks. We discuss requirements for supporting implicit integrity in these two adversary models, and provide security bounds for a construction called IVP, a three-level confusion diffusion network which can support implicit integrity and is inexpensive to implement.
Alice Pellet-Mary
As an additional contribution, we explain how the same ideas can be adapted to mount a quantum polynomial time attack against the DGGMM obfuscator of D\"ottling et al. (ePrint 2016), which was also proved secure in the weak multilinear map model.
Daniele Micciancio, Jessica Sorrell
Claude Carlet, Abderrahman Daif, Sylvain Guilley, Cédric Tavernier
Zvika Brakerski, Nico Döttling
Technically, we rely on the transference principle: Either a lattice or its dual must have short vectors. Short vectors, in turn, can be translated to information loss in encryption. Thus encrypting one message with respect to the lattice and one with respect to its dual guarantees that at least one of them will be statistically hidden.
Sanjam Garg, Mohammad Hajiabadi
Alain Couvreur, Matthieu Lequesne, Jean-Pierre Tillich
Achiya Bar-On, Orr Dunkelman, Nathan Keller, Eyal Ronen, Adi Shamir
Daniel J. Bernstein, Edoardo Persichetti
Aurélien Dupin, Jean-Marc Robert, Christophe Bidan
Bing Zeng
In this paper, we press a new SPH variant, which enables a positive answer to above question. In more details, it even makes fully-simulatable $\mbox{OT}^{n}_{t}$ ($n,t\in \mathbb{N}$ and $n>t$) possible. We instantiate this new SPH variant under not only the decisional Diffie-Hellman assumption, the decisional $N$-th residuosity assumption and the decisional quadratic residuosity assumption as currently existing SPH constructions, but also the learning with errors (LWE) problem. Before this paper, there is a folklore that it is technically difficult to instantiate SPH under the lattice assumption (e.g., LWE). Considering quantum adversaries in the future, lattice-based SPH makes important sense.
Adam Bobowski, Marcin Słowik
Yosuke Todo, Takanori Isobe, Willi Meier, Kazumaro Aoki, Bin Zhang
Gil Segev, Ido Shahaf
This unsettling state of affairs was recently changed by Chenette et al. (FSE '16), who rigorously relaxed the above ``best-possible'' notion and constructed a scheme satisfying it based on any pseudorandom function. In addition to revealing the ordering of any two encrypted plaintexts, ciphertexts in their scheme reveal only the position of the most significant bit on which the plaintexts differ. A significant drawback of their scheme, however, is its substantial ciphertext expansion: Encrypting plaintexts of length $m$ bits results in ciphertexts of length $m \cdot \ell$ bits, where $\ell$ determines the level of security (e.g., $\ell = 80$ in practice).
In this work we prove a lower bound on the ciphertext expansion of any order-preserving encryption scheme satisfying the ``limited-leakage'' notion of Chenette et al. with respect to non-uniform polynomial-time adversaries, matching the ciphertext expansion of their scheme up to lower-order terms. This improves a recent result of Cash and Zhang (ePrint '17), who proved such a lower bound for schemes satisfying this notion with respect to computationally-unbounded adversaries (capturing, for example, schemes whose security can be proved in the random-oracle model without relying on cryptographic assumptions). Our lower bound applies, in particular, to schemes whose security is proved in the standard model.
Mridul Nandi
In this paper, we show that the Bernstein bound is tight by describing two attacks (one in the ``chosen-plaintext model" and other in the ``known-plaintext model") which recover the hash-key (hence forges) with probability at least $\frac{1}{2}$ based on $\sqrt{n} \times 2^{n/2}$ message-tag pairs. We also extend the forgery adversary to the Galois Counter Mode (or GCM). More precisely, we recover the hash-key of GCM with probability at least $\frac{1}{2}$ based on only $\sqrt{\frac{n}{\ell}} \times 2^{n/2}$ encryption queries, where $\ell$ is the number of blocks present in encryption queries.
02 June 2018
Abertay University (Dundee Scotland)
The University now seeks to appoint two Lecturers in Computing and Cybersecurity within the Division of Cybersecurity, part of the School of Design and Informatics.
The School of Design and Informatics is the home of Abertay’s undergraduate and postgraduate degree programmes in games, digital arts, cybersecurity and applied computer science. Abertay was the first university to offer degrees in Computer Games Technology and Ethical Hacking, and the School continues to be recognised as an international leader in its fields. The School has long-established professional links with Dundee’s thriving computer games community and the UK\'s cybersecurity community.
The Division of Cybersecurity is Abertay\'s centre for teaching and research in applied computing and cybersecurity, with particular interests in ethical hacking, digital forensics, IoT and secure software development. Reporting to the Head of Division, you will provide high-quality, research-informed teaching across all of our degree programmes, with a particular focus on specialist content within our Ethical Hacking and Computing degrees, and conduct internationally-recognised research that contributes to Abertay\'s strategic interests within the cybersecurity industries and wider digital sector.
The Lecturer in Computing and Cybersecurity will demonstrate relevant knowledge and practical ability in one or more of the following areas:, IoT, secure software development, Big Data for cybersecurity or AI for cybersecurity, ethical hacking or network security.
If you believe you have the skills and experience for this exciting and challenging role, please submit your application through our online recruitment system.
Closing date for applications: 29 June 2018
More information: https://www.jobs.ac.uk/job/BKB796/lecturer-in-computing-and-cybersecurity/
EMSEC team, IRISA, Rennes, France
- security proofs for lattice-based schemes,
- building and implementing lattice-based constructions,
- fully homomorphic encryption
The research will take place in the Embedded Security and Cryptography (EMSEC) team, within the IRISA computer science institute located in Rennes, France.
We are looking for candidates with a PhD in cryptography and with publications in cryptographic conferences.
To apply please send your detailed CV (with publication list), a motivation letter, and contact informations of at least two people who can provide reference letters.
The duration of the position is 2 years, it has flexible starting date (ideally between September and December). Review of applications will start immediately until the position is filled.
Closing date for applications: 31 August 2018
Contact: Adeline Roux-Langlois, adeline.roux-langlois (at) irisa.fr and Pierre-Alain Fouque, pierre-alain.fouque (at) irisa.fr
EPFL / Ecole Polytéchnique Fédérale de Lausanne
The Post-Doctoral Researcher will work closely with Prof. Ford, PhD and undergraduate students, senior researchers, and software engineers within the DEDIS lab, along with multiple external research and development partners from industry and academia. Some participation in teaching activities is also expected. Research activities will include notably the design, implementation, and experimental validation of state-of-the-art decentralized systems, including playing a core role in the ongoing design and development of DEDIS’s next-generation blockchain architecture and software infrastructure.
Closing date for applications: 31 July 2018
Contact: dedis (at) epfl.ch
More information: https://recruiting.epfl.ch/Vacancies/568/Description/2
30 May 2018
University of Luxembourg
The Ph.D. students and post-docs will be members of the Security and Trust (SnT) research center from the university of Luxembourg (>200 researchers in all aspects of IT security). We offer a competitive salary (about 34,000 euro/year gross for Ph.D, and 60,000 euro/year gros for post-doc). The duration of the position is 3 years (+ 1 year extension) for Ph.D., and 2.5 years for post-doc.
Profile:
For Ph.D. position: MSc degree or equivalent in Computer Science or in Mathematics.
For post-doc position: a PhD in cryptography, with publications in competitive cryptographic conferences
Candidates should submit the following documents:
- Motivation letter indicating your research interests.
- Curriculum vitae (including your contact address, work experience, publications)
- For Ph.D. position: transcripts of B.Sc. and M.Sc. grades
- For post-doc position: a short description of your PhD work (max 1 page).
- Contact information for 3 referees
Closing date for applications: 15 July 2018
Contact: Jean-Sebastien Coron - jean-sebastien.coron at uni dot lu
More information: http://www.crypto-uni.lu/vacancies.html
28 May 2018
Brandon Broadnax, Alexander Koch, Jeremias Mechler, Tobias Müller, Jörn Müller-Quade, Matthias Nagel
Our application of hardware modules is motivated by the fact that modules with very limited functionality can be implemented securely as fixed-function circuits and (formally) verified for correctness. They can therefore not be hacked remotely.
In comparison to the hardware tokens proposed by Katz at EUROCRYPT `07, our hardware modules are based on substantially weaker assumptions. Our hardware modules may be physically tampered. Hence, they cannot be passed to another (possibly malicious) party but only used and trusted by their owner. In particular, our remotely unhackable hardware modules do not constitute a setup for Universal Composability (UC).
Based on architectures with very few and very simple hardware modules, we are able to construct protocols that provide security against remote hacking if the hack occurs after a protocol party received its (first) input. More specifically, an adversary can neither learn nor change the inputs and outputs of a remotely hacked party in our constructions unless he has control over that party before it has received its (first) input (or controls all parties). In our constructions we assume erasing parties. However, we also show that this assumption can be substantially weakened.
Since the advantages provided by unhackable hardware modules cannot be adequately captured in existing composable security frameworks, we have conceived a new security framework based on the UC framework. We call our framework Fortified UC.