IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
15 December 2021
NTT Research, Sunnyvale, CA, USA
Job PostingThe CIS Lab continually seeks the top minds and rising stars in cryptography research, with internship and postdoctoral research positions available starting in 2022. All positions will be in-person at our Sunnyvale office. Applications should be submitted by December 20 to guarantee full consideration.
Postdoctoral research positions are available with an initial duration of one year, and the possibility of extension to two years. Postdocs will be matched with a host from the lab, but are welcome to collaborate with any of our world-class scientists. Applicants should have or expect to have a PhD degree relating to cryptography, computer security, or theoretical computer science by summer 2022.
For further information and to apply, please visit https://careers.ntt-research.com/cis
Closing date for applications:
Contact: cis.careers@ntt-research.com
More information: https://careers.ntt-research.com/cis
14 December 2021
Andrea Lesavourey, Thomas Plantard, Willy Susilo
ePrint ReportJeroen Delvaux, Santos Merino Del Pozo
ePrint ReportDmytro Tymokhanov, Omer Shlomovits
ePrint ReportJoachim von zur Gathen
ePrint ReportZhuoran Zhang, Fangguo Zhang
ePrint ReportMatteo Campanelli, Hamidreza Khoshakhlagh
ePrint ReportWe model and construct a new primitive, SPuC (Succinct Publicly-Certifiable System), where: a party can prove knowledge of a witness $w$ by publishing a proof $\pi_0$; the latter can then be certified non-interactively by a committee sharing a secret; any party in the system can now verify the proof through its certificates; the total communication complexity should be sublinear in $|w|$. We construct SPuCs generally from (leveled) Threshold FHE, homomorphic signatures and linear-only encryption, all instantiatable from lattices and thus plausibly quantum-resistant. We also construct them in the two-party case replacing TFHE with the simpler primitive of homomorphic secret-sharing.
Our model has practical applications in blockchains and in other protocols where there exist committees sharing a secret and it is necessary for parties to prove knowledge of a solution to some puzzle.
We show that one can construct a version of SPuCs with robust proactive security from similar assumptions. In a proactively secure model the committee reshares its secret from time to time. Such a model is robust if the committee members can prove they performed this resharing step correctly. Along the way to our goal we define and build Proactive Universal Thresholdizers, a proactive version of the Universal Thresholdizer defined in Boneh et al. [Crypto 2018].
Chao Chen, Fangguo Zhang
ePrint ReportRohit Chatterjee, Kai-Min Chung, Xiao Liang, Giulio Malavolta
ePrint ReportJean-Sébastien Coron, François Gérard, Simon Montoya, Rina Zeitoun
ePrint ReportYange Chen, Baocang Wang, Hang Jiang, Pu Duan, Benyu Zhang, Chengdong Liu, Zhiyong Hong, Yupu Hua
ePrint ReportYange Chen, Baocang Wang*, Rongxing Lu, Xu An Wang
ePrint ReportSri AravindaKrishnan Thyagarajan, Giulio Malavolta, Pedro Moreno-Sánchez
ePrint ReportFrom a theoretical standpoint, in this work we show a generic protocol to securely swap $n$ coins from any (possible multiple) currencies for $\tilde{n}$ coins of any other currencies, for any $n$ and $\tilde{n}$. We do not require any custom scripting language supported by the corresponding blockchains, besides the bare minimum ability to verify signatures on transactions. For the special case when the blockchains use ECDSA or Schnorr signatures, we design a practically efficient protocol based on adaptor signatures and time-lock puzzles. As a byproduct of our approach, atomic swaps transactions no longer include custom scripts and are identical to standard one-to-one transactions. We also show that our protocol naturally generalizes to any cycle of users, i.e., atomic swaps with more than two participants. To demonstrate the practicality of our approach, we have evaluated a prototypical implementation of our protocol for Schnorr/ECDSA signatures and observed that an atomic swap requires below one second on commodity machines. Even on blockchains with expressive smart contract support (e.g., Ethereum), our approach reduces the on-chain cost both in terms of transaction size and gas cost.
10 December 2021
Alessio Caminata, Elisa Gorla
ePrint ReportGiuseppe Vitto
ePrint Report09 December 2021
Hiroki Furue, Momonari Kudo
ePrint ReportAndre Esser, Sergi Ramos-Calderer, Emanuele Bellini, José I. Latorre, Marc Manzano
ePrint ReportAs another major contribution, we leverage the idea of classical co-processors to design hybrid classical-quantum trade-offs, that allow to tailor the necessary qubits to any available amount, while still providing quantum speedups. Interestingly, when constraining the width of the circuit instead of its depth we are able to overcome previous optimality results on constraint quantum search.