IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
25 January 2019
Mathieu Carbone, Vincent Conin, Marie-Angela Cornelie, Francois Dassance, Guillaume Dufresne, Cecile Dumas, Emmanuel Prouff, Alexandre Venelli
Yongcheng Song, Xinyi Huang, Yi Mu, Wei Wu
Haodong Jiang, Zhenfeng Zhang, Zhi Ma
In this paper, we provide three generic constructions of an IND-CCA-secure KEM with explicit rejection, under the same assumptions and with the same tightness in the security reductions as the aforementioned KEM constructions with implicit rejection (Crypto 2018, Eurocrypt 2018). Specifically, we develop a novel approach to verify the validity of a ciphertext in the QROM and use it to extend the proof techniques for KEM constructions with implicit rejection (Crypto 2018, Eurocrypt 2018) to our KEM constructions with explicit rejection. Moreover, using an improved version of one-way to hiding lemma by Ambainis, Hamburg and Unruh (ePrint 2018/904), for two of our constructions, we present tighter reductions to the standard IND-CPA assumption. Our results directly apply to 9 KEM submissions with explicit rejection, and provide tighter reductions than previously known (TCC 2017).
Daode Zhang, Jie Li, Bao Li, Xianhui Lu, Haiyang Xue, Dingding Jia, Yamin Liu
Takahiro Matsuda, Kenta Takahashi, Takao Murakami, Goichiro Hanaoka
In this paper, we generalize the results by Dodis and Yu using the Rényi divergence, and show how the security of a cryptographic primitive whose security is guaranteed when the ideal distribution of a randomness is a general (possibly non-uniform) distribution $Q$, is degraded when the distribution is switched to another (real-world) distribution $R$. More specifically, we derive two general inequalities regarding the Rényi divergence of $R$ from $Q$ and an adversary's advantage against the security of a cryptographic primitive. As applications of our results, we show (1) an improved reduction for switching the distributions of distinguishing problems with public samplability, which is simpler and much tighter than the reduction by Bai et al. (ASIACRYPT 2015), and (2) how the differential privacy of a mechanism is degraded when its randomness comes from not an ideal distribution $Q$ but a real-world distribution $R$. Finally, we show methods for approximate-sampling from an arbitrary distribution $Q$ with some guaranteed upperbound on the Rényi divergence (of the distribution $R$ of our sampling methods from $Q$).
Lingchen Li, Wenling Wu, Yafei Zheng, Lei Zhang
Eyal Kushilevitz, Tamer Mour
In this paper, we present a family of distributed ORAM constructions that follow the hierarchical approach of Goldreich and Ostrovsky [GO96]. We enhance known techniques, and develop new ones, to take better advantage of the existence of multiple servers. By plugging efficient known hashing schemes in our constructions, we get the following results:
1. For any number $m\geq 2$ of servers, we show an $m$-server ORAM scheme with $O(\log N/\log\log N)$ overhead, and block size $\Omega(\log^2 N)$. This scheme is private even against an $(m-1)$-server collusion. 2. A three-server ORAM construction with $O(\omega(1)\cdot\log N/\log\log N)$ overhead and a block size almost logarithmic, i.e. $\Omega(\log^{1+\epsilon}N)$.
We also investigate a model where the servers are allowed to perform a linear amount of light local computations, and show that constant overhead is achievable in this model, through a simple four-server ORAM protocol. From theoretical viewpoint, this is the first ORAM scheme with asymptotic constant overhead, and polylogarithmic block size, that does not use homomorphic encryption. Practically speaking, although we do not provide an implementation of the suggested construction, evidence from related work (e.g. [DS17]) confirms that despite the linear computational overhead, our construction is practical, in particular when applied to secure computation.
Kanad Basu, Deepraj Soni, Mohammed Nabeel, Ramesh Karri
Alan Szepieniec, Bart Preneel
Ryo Nishimaki, Takashi Yamakawa
Ahmad Almorabea
23 January 2019
Chris Peikert, Vinod Vaikuntanathan, Brent Waters
Our OT protocols are round-optimal (one message each way), quite efficient in computation and communication, and can use a single common string for an unbounded number of executions. Furthermore, the protocols can provide \emph{statistical} security to either the sender or receiver, simply by changing the distribution of the common string. For certain instantiations of the protocol, even a common \emph{random} string suffices.
Our key technical contribution is a simple abstraction that we call a \emph{dual-mode} cryptosystem. We implement dual-mode cryptosystems by taking a unified view of several cryptosystems that have what we call ``messy'' public keys, whose defining property is that a ciphertext encrypted under such a key carries \emph{no information} (statistically) about the encrypted message.
As a contribution of independent interest, we also provide a multi-bit version of Regev's lattice-based cryptosystem (STOC 2005) whose time and space efficiency are improved by a linear factor in the security parameter $n$. The amortized encryption and decryption time is only $\tilde{O}(n)$ bit operations per message bit, and the ciphertext expansion can be made as small as a constant; the public key size and underlying lattice assumption remain essentially the same.
22 January 2019
Singapore University of Technology and Design (SUTD), Singapore
Interested candidates please send your CV with a research statement to Prof. Jianying Zhou . Only short-listed candidates will be contacted for interview.
Closing date for applications: 31 March 2019
Contact: Prof. Jianying Zhou
More information: http://jianying.space/
21 January 2019
Bogotá, Colombia, 5 June - 7 June 2019
Submission deadline: 30 March 2019
Notification: 30 April 2019
Stockholm, Sweeden, 16 June 2019
Submission deadline: 1 March 2019
Notification: 1 April 2019
Luxembourg, Luxembourg, 23 September - 27 September 2019
Submission deadline: 22 April 2019
Notification: 21 June 2019
ETH Zurich
Candidates for PhD positions should already have, or be near to completing, a Masters in Computer Science and/or Mathematics. They should have a demonstrable interest in Applied Cryptography.
Candidates for Postdoc positions should additionally be able to demonstrate creativity, independence and excellence in Applied Cryptography research. Applications from people with interests in all areas of the field are welcome.
Positions are available from Spring 2019. The selection process will run until suitable candidates have been found.
Initial enquiries should be sent by email, with subject line *Application for Postdoc* or *Application for PhD*, and addressed directly to Prof. Kenny Paterson.
Closing date for applications: 1 December 2019
Contact: Kenny Paterson - kenny.paterson (at) inf.ethz.ch
More information: https://www.inf.ethz.ch/
University of Hong Kong, Hong Kong
• Public Key Cryptography
• Privacy-enhancing technologies
• Blockchain security and privacy
• Applied cryptography, especially in the area of Fintech
Job requirements:
• Strong publication record in cryptography and cyber security area
• Good communication skills, self-motivated and good team players
• Some experience in programming is a plus
The funding is available for one year with a flexible starting date, a very competitive salary and a possibility of extension upon successful performance. Doing research in Hong Kong, an international financial center, allows you to have more collaboration opportunities with the industry and to apply your knowledge in the real world.
To apply for the above position, please send a copy of your recent CV to “thyuen at cs dot hku dot hk” with an email subject “Application for PDF/RA”.
Closing date for applications: 30 June 2019
Contact: Name: John Yuen
Email: thyuen at cs dot hku dot hk
18 January 2019
Eindhoven University of Technology, the Netherlands
Closing date for applications: 14 March 2019
Contact: Tanja Lange, TU/e, t.lange (at) tue.nl
More information: https://jobs.tue.nl/en/vacancy/tt-assistant-professor-coding-theory-449061.html
Ruhr University Bochum, Germany
The group is part of the Horst Görtz Institute for IT Security. It is regarded as one of the top research institutions, has Europe\'s largest IT security training programs, maintains extensive networks with the scientific communication and industry, and has produced numerous successful cyber security start-ups. This outstanding environment offers excellent working conditions in an extremely topical and exciting field.
The symmetric crypto group is looking for excellent M.Sc. graduates with outstanding grades and degrees in computer science, mathematics, or related disciplines.
In addition, we are looking for outstanding postdoctoral candidates with a strong track record in symmetric cryptography.
We offer three-year positions for M.Sc. graduates. Postdoctoral positions are limited to two years. The salary will be according to the remuneration group E 13 TV-L (full-time).
Are you interested?
Please send your complete application documents in one single pdf file (max. 10 MB) by January 31, 2019 to: gregor.leander (at) rub.de
Required documents are:
- Letter of motivation
- Curriculum vitae,
- Master\'s certificate,
- Doctoral certificate, if applicable.
At Ruhr University Bochum, we seek to promote the careers of women particularly in those areas in which they are underrepresented, and we are therefore particularly pleased to receive applications from female candidates. Applications by suitable candidates with severe disabilities and other applicants with equal legal status are likewise most welcome.
Closing date for applications: 31 January 2019