IACR News
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06 April 2021
Elaine Shi, Ke Wu
ePrint ReportDeparting from all prior approaches, we propose a novel {\it non-interactive} abstraction called a Non-Interactive Anonymous Router (NIAR), which works even with a {\it single untrusted router}. In a NIAR scheme, suppose that $n$ senders each want to talk to a distinct receiver. A one-time trusted setup is performed such that each sender obtains a sending key, each receiver obtains a receiving key, and the router receives a {\it token} that ``encrypts'' the permutation mapping the senders to receivers. In every time step, each sender can encrypt its message using its sender key, and the router can use its token to convert the $n$ ciphertexts received from the senders to $n$ {\it transformed ciphertexts}. Each transformed ciphertext is delivered to the corresponding receiver, and the receiver can decrypt the message using its receiver key. Imprecisely speaking, security requires that the untrusted router, even when colluding with a subset of corrupt senders and/or receivers, should not be able to compromise the privacy of honest parties, including who is talking to who, and the message contents.
We show how to construct a communication-efficient NIAR scheme with provable security guarantees based on the standard Decisional Linear assumption in suitable bilinear groups. We show that a compelling application of NIAR is to realize a Non-Interactive Anonymous Shuffler (NIAS), where an untrusted server or data analyst can only decrypt a permuted version of the messages coming from $n$ senders where the permutation is hidden. NIAS can be adopted to construct privacy-preserving surveys, differentially private protocols in the shuffle model, and pseudonymous bulletin boards.
Besides this main result, we also describe a variant that achieves fault tolerance when a subset of the senders may crash. Finally, we further explore a paranoid notion of security called full insider protection, and show that if we additionally assume sub-exponentially secure Indistinguishability Obfuscation and as sub-exponentially secure one-way functions, one can construct a NIAR scheme with paranoid security.
Sonia Belaïd, Matthieu Rivain, Abdul Rahman Taleb
ePrint ReportIn this paper, we provide an in-depth analysis of the RPE security notion. We exhibit the first upper bounds for the main parameter of a RPE gadget, which is known as the amplification order. We further show that the RPE notion can be made tighter and we exhibit strong connections between RPE and the strong non-interference (SNI) composition notion. We then introduce the first generic constructions of gadgets achieving RPE for any number of shares and with nearly optimal amplification orders and provide an asymptotic analysis of such constructions. Last but not least, we introduce new concrete constructions of small gadgets achieving maximal amplification orders. This allows us to obtain much more efficient instantiations of the expanding compiler: we obtain a complexity of $\mathcal{O}(\kappa^{3.9})$ for a slightly better leakage probability, as well as $\mathcal{O}(\kappa^{3.2})$ for a slightly lower leakage probability.
Aaram Yun
ePrint ReportIn 2018, Mark Zhandry showed that, despite the apparent difficulties, it is in fact possible to record the quantum queries. He has defined the compressed oracle, which is indistinguishable from the quantum random oracle, and records information the adversary has gained through the oracle queries. It is a technically subtle work, which we believe to be a challenging work to grasp fully.
Our aim is to obtain a mathemathically clean, simple reinterpretation of the compressed oracle technique. For each partial function, we define what we call the formation and the completion of that partial function. The completions describe what happens to the real quantum random oracle, and the formations describe what happens to the compressed oracle. We will show that the formations are 'isomorphic' to the completions, giving an alternative proof that the compressed oracle is indistinguishable from the quantum random oracle.
Kevin Deforth, Marc Desgroseilliers, Nicolas Gama, Mariya Georgieva, Dimitar Jetchev, Marius Vuille
ePrint ReportPrabhanjan Ananth, Abhishek Jain, Zhengzhong Jin, Giulio Malavolta
ePrint ReportSimon Pohmann, Marc Stevens, Jens Zumbrägel
ePrint Report[fplll16] The FPLLL development team. fplll, a lattice reduction library. 2016. URL: https://github.com/fplll/fplll
Daniel Smith-Tone
ePrint ReportIn this article, we introduce a more fundamentally nonlinear modifier, called Q, that is inspired from relinearization. The effect of the Q modifier on multivariate digital signature schemes is to maintain inversion efficiency at the cost of slightly slower verification and larger public keys, while altering the algebraic properties of the public key. Thus the Q modifier is ideal for applications of digital signature schemes requiring very fast signing and verification without key transport. As an application of this modifier, we propose new multivariate digital signature schemes with fast signing and verification that are resistant to all known attacks.
Peter Schwabe, Benoît Viguier, Timmy Weerwag, Freek Wiedijk
ePrint ReportThe proofs are all computer-verified using the Coq theorem prover. To establish the link between C and Coq we use the Verified Software Toolchain (VST).
Xiaoyang Dong, Jialiang Hua, Siwei Sun, Zheng Li, Xiaoyun Wang, Lei Hu
ePrint ReportOlivier Blazy, Xavier Bultel, Pascal Lafourcade, Octavio Perez Kempner
ePrint ReportYuqing Zhao, Wenqi Yu, Chun Guo
ePrint ReportTakanori Isobe, Ryoma Ito, Kazuhiko Minematsu
ePrint ReportVasyl Ustimenko
ePrint Report05 April 2021
National University of Singapore
Job PostingClosing date for applications:
Contact: Arash Pashrashid (pashrashid.arash@u.nus.edu)
University of St. Gallen, Switzerland
Job PostingResearch area: Research areas include but are not limited to:
- Verifiable computation
- Secure Multi Party Computation
- Privacy-preserving authentication
- Cryptographic primitives
- A MsC degree in Computer Science, Applied Mathematics or a relevant field;
- Strong mathematical and algorithmic CS background;
- Excellent programming skills;
- Excellent written and verbal communication skills in English
Starting date: By mutual agreement
Apply online: https://jobs.unisg.ch/offene-stellen/phd-position-in-applied-cryptography-and-information-security-m-w-d/09f75f22-649c-48a6-9aa4-659bbd686a84
Closing date for applications:
Contact: Katerina Mitrokotsa
More information: https://jobs.unisg.ch/offene-stellen/phd-position-in-applied-cryptography-and-information-security-m-w-d/09f75f22-649c-48a6-9aa4-659bbd686a84
Friedrich-Alexander-University Erlangen-Nürnberg (FAU)
Job Posting- privacy-enhancing-technologies
- cryptocurrencies
- password-based cryptography
- proof systems
Work Environment: The Applied Cryptography Lab is part of FAU, which is one of the largest universities in Germany. With its five faculties, FAU offers a scope of subjects ranging from the Humanities to Law and Economics as well as Sciences, Medicine, and Engineering. FAU’s mission statement “Advance through Networks” reflects the close collaboration between the single disciplines. FAU has been ranked the third year in a row the most innovative University in Germany.
Requirements: Candidates for this position should hold a Ph.D. degree in Computer Science or a related discipline (mathematics, ...). The ideal candidate shows strong enthusiasm about research, publishes at leading venues in cryptography or IT security, and has excellent teamworking abilities.
Program details and contact for application/questions: Funding is available for at least 36 months; the salary range is between 32.671 - 78.136 EUR year, depending on your background and experience. Prospective applicants should apply with a cover letter, a research statement, and an academic CV that includes the contact information for two references. Please send a single PDF file and include [PostDoc] in the subject. Applications will be accepted until the position is filled.
Closing date for applications:
Contact: Dominique Schroeder
More information: https://www.chaac.tf.fau.eu
Friedrich-Alexander-University Erlangen-Nürnberg
Job Posting- privacy-enhancing-technologies
- cryptocurrencies
- password-based cryptography
- proof systems
Work Environment: The Applied Cryptography Lab is part of FAU, which is one of the largest universities in Germany. With its five faculties, FAU offers a scope of subjects ranging from the Humanities to Law and Economics as well as Sciences, Medicine, and Engineering. FAU’s mission statement “Advance through Networks” reflects the close collaboration between the single disciplines. FAU has been ranked the third year in a row the most innovative University in Germany.
Requirements: Candidates for this position should have a master or comparable degree in Computer Science or a related discipline (mathematics, ...). Knowledge of one or several of the areas cryptography, IT security, complexity theory, privacy,... is desired. The ideal candidate shows strong enthusiasm about research and has excellent teamworking abilities.
Program details and contact for application/questions: The project start date is as soon as possible. Funding is available for at least 36 months; an extension is possible. Prospective applicants should apply with a cover letter, a list of attended (Master) courses, and an academic CV. Please send a single PDF file and include [PhD] in the subject. Applications will be accepted until the position is filled.
Closing date for applications:
Contact: Dominique Schröder
More information: https://www.chaac.tf.fau.eu
Award
Nominations for the 2021 award (for papers published in 2000-2002) are welcomed by the selection committee. Deadline for nomination is May 3, 2021 23:59 AoE.
The proceedings of the relevant conferences can be found here:
- CHES 2000: https://link.springer.com/book/10.1007/3-540-44499-8
- CHES 2001: https://link.springer.com/book/10.1007/3-540-44709-1
- CHES 2002: https://link.springer.com/book/10.1007/3-540-36400-5
email subject line: ches test of time award nomination
mention: paper title and publication year
provide short justification why the paper should receive the award by providing number of citations, describing influence in industry, etc. in a max. 2 pages document or text in the email body
More information about the CHES Test-of-Time award can be found here: https://ches.iacr.org/testoftime.shtml
The 2021 Selection Committee:
- Benedikt Gierlichs (chair)
- Ingrid Verbauwhede
- Jean-Sébastien Coron
- David Naccache
- Berk Sunar
02 April 2021
Wickr
Job PostingYou not only create and deliver, you have the opportunity to see your hard work in use by everyday users. Opportunities like this do not come around often and take the right person to deliver results. While Wickr is expanding exponentially, we are keeping our start-up feel, mentality and fun environment. You still have time to join as a groundbreaking team member for an organization that holds over 91 patents on crypto protocols.
Responsibilities:
> Work with our cryptographers to create prototypes of cutting edge cryptographic and security features such as advanced encryption, signature, and key agreement schemes.
> Work with our core engineering team to convert prototypes of new network protocols and security features into production ready implementations that can be used by Wickr applications.
> Help develop a new cross platform Wickr protocol library in Rust.
> Write benchmarks and optimize code to help our team take full advantage of new features.
> Write code that is modular and well-covered by automated unit and integration tests.
> Help write and test FFI wrappers for our Rust libraries in Java, Swift, and C++.
POSITION REQUIREMENTS
> Bachelor’s degree or equivalent in Computer Science, Engineering or related field.
> 4+ years of experience developing software libraries in a low-level language such as C and C++.
> Minimum of 2 years’ experience writing Rust code in a production environment.
> Experience working in an agile software development environment.
> Experience contributing to open source libraries is a plus.
> Experience working with Java, Swift, or NodeJS is a plus.
> Interest in cryptography and secure coding practices is a plus.
> Be a self-starter who is willing to take ownership of your work.
> Excellent communicator in both verbal
Closing date for applications:
Contact: Please enter your application into the careers page and our Technical Recruiter will contact you, if qualified. You can also find him on LinkedIn https://www.linkedin.com/in/mike-schultz-1509a22/
More information: https://wickr.com/careers/
Mohammed VI Polytechnic University
Job PostingClosing date for applications:
Contact: For more information an application , please visit: https://www.abg.asso.fr/fr/recruteurOffres/show/id_offre/97229