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31 October 2016
Durga Prasad Sahoo, Debdeep Mukhopadhyay, Rajat Subhra Chakraborty, Phuong Ha Nguyen
Yuqiao Deng, Ge Song
Yuqiao Deng, Ge Song
Mihir Bellare, Asha Camper Singh, Joseph Jaeger, Maya Nyayapati, Igors Stepanovs
Rafael Pass, Elaine Shi, Florian Tramer
On one hand, we show that just like the common belief, attested execution is extremely powerful, and allows one to realize powerful cryptographic abstractions such as stateful obfuscation whose existence is otherwise impossible even when assuming virtual blackbox obfuscation and stateless hardware tokens. On the other hand, we show that surprisingly, realizing composable two-party computation with attested execution processors is not as straightforward as one might anticipate. Specifically, only when both parties are equipped with a secure processor can we realize composable two-party computation. If one of the parties does not have a secure processor, we show that composable two-party computation is impossible. In practice, however, it would be desirable to allow multiple legacy clients (without secure processors) to leverage a servers secure processor to perform a multi-party computation task. We show how to introduce minimal additional setup assumptions to enable this. Finally, we show that fair multi-party computation for general functionalities is impossible if secure processors do not have trusted clocks. When secure processors have trusted clocks, we can realize fair two-party computation if both parties are equipped with a secure processor; but if only one party has a secure processor (with a trusted clock), then fairness is still impossible for general functionalities.
Paulo S. L. M. Barreto, Patrick Longa, Michael Naehrig, Jefferson E. Ricardini, Gustavo Zanon
Wenlun Pan, Zhenzhen Bao, Dongdai Lin, Feng Liu
Rauf Mahmudlu, Valentina Banciu, Lejla Batina, Ileana Buhan
Michael Hutter, Michael Tunstall
Eleonora Guerrini, Laurent Imbert, Théo Winterhalter
Yan Yan, Elisabeth Oswald, Theo Tryfonas
Yu Chen, Jiang Zhang, Yi Deng, Jinyong Chang
\item On the positive side, we present two constructions that achieve KDM security in the adaptive-identity sense for the first time. One is generically built from identity-based hash proof system (IB-HPS) with homomorphic property, which indicates that the IBE schemes of Gentry (Eurocrypt 2006), Coron (DCC 2009), Chow et al. (CCS 2010) are actually KDM-secure in the multiple-key setting. The other is built from indistinguishability obfuscation and a new notion named puncturable unique signature, which is bounded KDM-secure in the single-key setting.
\item On the negative side, we separate $n$-circular security (which is a prototypical case of KDM security) from the standard IND-CPA/CCA security for IBE by giving a counterexample based on differing-inputs obfuscation and a new notion named puncturable IBE. \end{itemize}
Laila El Aimani
30 October 2016
This work received the test of time award for introducing the security notion of "indifferentiability", that had a significant impact on both the theory of cryptography and the design of practical cryptosystems.
The award will be presented on Tuesday Nov 1 at TCC 2016-B in Beijing.
San Diego, California, USA, 26 February 2017
Submission deadline: 1 December 2016
Notification: 21 January 2017
1 January - 31 January 2018
Submission deadline: 22 March 2017
University College London
A successful candidate will explore research topics such as developing consensus protocols that allow for scalable and efficient distributed ledgers, resisting de-facto centralisation, and coming up with ledgers for a diverse set of applications that nevertheless achieve some notion of interoperability.
We expect candidates to have a PhD in Computer Science or a related field, and a strong track record in systems and network security, distributed systems, or similar topics. The position is available starting September 2016 (but the start date is negotiable) and will last for two years, with the possibility to extend by another 6-12 months.
Closing date for applications: 26 November 2016
Contact: Sarah Meiklejohn, s.meiklejohn [at] ucl [dot] ac [dot] uk
More information: http://bit.ly/2dO72Yz
Department of Computing, The Hong Kong Polytechnic University, Hong Kong
Successful candidates are expected to contribute to one of the following topics:
- accountable anonymous credentials
- applications of blockchain technology
- searchable encryption
- lattice-based cryptography
The post has a flexible starting date. The initial appointment will be for 12 months, with a strong possibility for further appointment.
Review of applications will start immediately until the positions are filled.
Closing date for applications: 1 March 2017
Contact: Man Ho Allen Au (http://www.comp.polyu.edu.hk/~csallen/)
Email: csallen (at) comp.polyu.edu.hk