IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
15 September 2020
Ruize Wang, Huanyu Wang, Elena Dubrova
Yongzhuang Wei , Rene Rodriguez, Enes Pasalic
Ambili K N, Jimmy Jose
Xichao Hu, Yongqiang Li, Lin Jiao, Shizhu Tian, Mingsheng Wang
Arka Rai Choudhuri, Vipul Goyal, Abhishek Jain
Recently, two round protocols for semi-honest MPC and four round protocols for malicious-secure MPC were constructed, both of which are optimal. While these results can be viewed as constituting two end points of a security spectrum, we investigate the design of protocols that potentially span the spectrum.
Our main result is an MPC protocol against covert adversaries with variable round complexity: when the detection probability is set to the lowest setting, our protocol requires two rounds and offers same security as semi-honest MPC. By increasing the detecting probability, we can increase the security guarantees, with round complexity five in the extreme case. The security of our protocol is based on standard cryptographic assumptions.
We supplement our positive result with a negative result, ruling out *strict* three round protocols with respect to black-box simulation.
Joachim Neu, Ertem Nusret Tas, David Tse
Andrew Morgan, Rafael Pass, Elaine Shi
Akinori Hosoyamada, María Naya-Plasencia, Yu Sasaki
The lower bound of the complexity of LBDs has been proved only against functions. In this paper, we prove for the first time the bound against permutations, which shows that the known upper bounds are tight.
Xiangyu Liu; Shengli Liu; Dawu Gu; Jian Weng
Keita Emura, Atsushi Takayasu, Yohei Watanabe
In this paper, we first triumph over the barrier by proposing simple but effective design methodologies to construct efficient HKIBE schemes. First, we show a generic construction from any hierarchical IBE (HIBE) scheme that satisfies a special requirement, called MSK evaluatability introduced by Emura et al. (ePrint, 2020). It provides several new and efficient instantiations since most pairing-based HIBE schemes satisfy the requirement. It is worth noting that it preserves all parameters' sizes of the underlying HIBE scheme, and hence we obtain several efficient HKIBE schemes under the $k$-linear assumption in the standard model. Since MSK evaluatability is dedicated to pairing-based HIBE schemes, the first construction restricts pairing-based instantiations. To realize efficient instantiation from various assumptions, we next propose a generic construction of an HKIBE scheme from any plain HIBE scheme. It is based on Hanaoka et al.'s HKIBE scheme (Asiacrypt 2005), and does not need any special properties. Therefore, we obtain new efficient instantiations from various assumptions other than pairing-oriented ones. Though the sizes of secret keys and ciphertexts are larger than those of the first construction, it is more efficient than Hanaoka et al.'s scheme in the sense of the sizes of master public/secret keys.
14 September 2020
University of Surrey
The successful candidate will work on cyber security for Decentralisation in the Digital Economy through technologies such as Distributed Ledgers, and with a focus on self-sovereign identity and the human focused aspects of cyber security.
The project will concentrate on developing protocols and architectures for cyber security in decentralized systems for content provenance and content brokering, the initial scenarios to be considered by the project, and builds on Surrey’s previous work on Distributed Ledger Technologies. The project is within the new multidisciplinary and collaborative EPSRC DE Centre in the Decentralised Digital Economy led by Surrey.
The Department of Computer Science within the Faculty of Engineering and Physical Sciences has an international reputation for research and teaching. Security research in the department is focused within the Surrey Centre for Cyber Security, with Surrey recognized by the National Cyber Security Centre as an Academic Centre of Excellence in Cyber Security Research. Our research concentrates on protocol analysis, security verification, trusted computing, data privacy, access control, privacy preserving security, cryptography, distributed ledger technologies, digital forensics and human-centred computing.
The position offers the platform for the research fellow to work within a group and develop skills to become an independent researcher. The successful candidate will work under the direction of Professor Steve Schneider. The project is also collaborative with other Surrey research centres, with the University of Edinburgh and with the Digital Catapult.
We are looking for applicants that demonstrate strong research and analytical skills, have strong communication skills and enthusiasm for developing their own research ideas. Applicants should also have skills in software engineering for web applications, and an understanding of cyber security. Knowledge of Distributed Ledger Technologies would be an advantage
Closing date for applications:
Contact: Professor Steve Schneider: s.schneider@surrey.ac.uk
More information: https://jobs.surrey.ac.uk/vacancy.aspx?ref=035220
10 September 2020
The award committee recognizes this paper “for introducing hyper-invertible matrices to perfectly secure multiparty computation, thus enabling significant efficiency improvements and, eventually, constructions with minimal communication complexity."
The TCC Test of Time Award recognizes outstanding papers, published in TCC at least eight years ago, making a significant contribution to the theory of cryptography, preferably with influence also in other areas of cryptography, theory, and beyond. The inaugural TCC Test of Time Award was given in TCC 2015 for papers published no later than TCC 2007.
Daniel Apon, Dustin Moody, Ray Perlner, Daniel Smith-Tone, Javier Verbel
In this work, we show that making the matrices rectangular, while decreasing the decryption failure rate, actually, and ironically, diminishes security. We show that the combinatorial rank methods employed in the original attack of Moody et al. can be enhanced by the same added degrees of freedom that reduce the decryption failure rate. Moreover, and quite interestingly, if the decryption failure rate is still reasonably high, as exhibited by the proposed parameters, we are able to mount a reaction attack to further enhance the combinatorial rank methods. To our knowledge this is the first instance of a reaction attack creating a significant advantage in this context.
Tapas Pal, Ratna Dutta
David Derler, Stephan Krenn, Kai Samelin, Daniel Slamanig
We show that, instead of perfectly correct PKE, non-interactive commitment schemes are sufficient. For the first time, this gives rise to efficient instantiations from plausible post-quantum assumptions and thus candidates of chameleon-hashes with strong collision-resistance guarantees and long-term security guarantees. On the more theoretical side, our results relax the requirement to not being dependent on public-key encryption.
Vancouver, Canada, 11 December 2020
Submission deadline: 2 October 2020
Notification: 23 October 2020
NCC Group, North America
Closing date for applications:
Contact: Danielle Owen
More information: https://nccgroup.wd3.myworkdayjobs.com/NCC_Group/job/USA-Remote---Eastern-Time/Senior-Cryptography-Researcher_R3223
AAU, Austria
The PhD post can be in any (fun) area of crypto; the candidate will be supervised by Elisabeth Oswald, and as co-supervisors A. Roy and E. Andreeva are potentially available.
The Post-Doc is related to ERC funding and therefore will work in the area of side channels; our areas of interest here are techniques for secure software development, and RISC-V.
Both posts are available immediately. The salary is around 32k per annum for the PhD student and 35k upwards (depending on prior experience) for the Post-Doc. Further information about the group is under www.cybersecurityresearch.at
Closing date for applications:
Contact: Elisabeth Oswald (firstname.lastname@aau.at)
More information: http://www.cybersecurityresearch.at
09 September 2020
Stefan Steinegger, Robert Primas
In this paper, we implement Ascon-p as an instruction extension for RISC-V that is tightly coupled to the processors register file and thus does not require any dedicated registers. This single instruction allows us to realize all cryptographic computations that typically occur on embedded devices with high performance. More concretely, with ISAP and Ascon's family of modes for AEAD and hashing, we can perform cryptographic computations with a performance of about 2 cycles/byte,or about 4 cycles/byte if protection against fault attacks and power analysis is desired.
As we show, our instruction extension requires only 4.7 kGE, or about half the area of dedicated Ascon co-processor designs, and is easy to integrate into low-end embedded devices like 32-bit ARM Cortex-M or RISC-V microprocessors. Finally, we analyze the provided implementation security of ISAP, when implemented using our instruction extension.