International Association
for Cryptologic Research

[Number of Openings]: 1 [Area of Specialization]: Theoretical Computer Science, Theory and Practice of Cybersecurity, Theory of Cryptography, Theory of Algorithms, Theory of Computational Complexity, Programming Theory, Software Verification Theory, Blockchain Technology, Network Security, etc. [Job Description]: Research and education at Department of Mathematical and Computing Science. Assigned tasks on the management of the department. [Qualifications]: - Applicants must have a PhD degree or be expected to obtain the degree by the start of the employment in the specialized area given above or related areas. - Applicants must have ability to be in charge of exercises of undergraduate courses in computer science. - Applicants must be highly motivated on research and education. [Location]: Ookayama Campus (Nearest station: Ookayama Station (Tokyu Line)) [Term]: Fixed-term appointments will be for up to 5 years. Reappointment may be possible for one additional term of up to 5 years. The total term is limited to a maximum of 10 years from the original date of employment. [Proposed Start Date]: April 1st, 2021, or the earliest possible date thereafter [Closing Date for Application]: Applications must be received by January 17th, 2021 [Selection Process]: Selection will be based on a comprehensive review of applications and interviews. Interviews will be done remotely. Selected applicants may be asked to have interviews and/or give presentations and lectures. [How to Submit an Application]: Combine all of the required documents into a single PDF file, and send it via JREC-IN Portal Web application system. (https://jrecin.jst.go.jp/seek/SeekJorDetail?id=D120120992&ln_jor=1)

Closing date for applications:

Contact: Keisuke Tanaka, Professor, Chair of Department of Mathematical and Computing Science, School of Computing (Email: keisuke@is.titech.ac.jp)

More information: https://jrecin.jst.go.jp/seek/SeekJorDetail?id=D120120992&ln_jor=1

[Number of Openings]: 1 [Area of Specialization]: Theoretical Computer Science, Theory and Practice of Cybersecurity, Theory of Computational Complexity, Theory of Algorithms, Theory of Cryptography, Programming Theory, Software Verification Theory, Blockchain Technology, Network Security, etc. [Job Description]: - Designing and conducting graduate and undergraduate courses related to mathematical and computing science. - Managing a laboratory (research group) and supervising graduate and undergraduate students. - Research activities leading international research communities of the specialized area given above or related areas. - Tasks related to the management of the department and the institute. [Qualifications]: Applicants must have a PhD degree in the specialized area given above or related areas. [Location]: Ookayama Campus (Nearest station: Ookayama Station (Tokyu Line)) [Term]: Permanent Position (The Institute has mandatory retirement, requiring employees to retire at age 65.) [Proposed Start Date]: April 1st, 2021, or the earliest possible date thereafter [Closing Date for Application]: Applications must be received by January 17th, 2021 [Selection Process]: Selection will be based on a comprehensive review of applications and interviews. Interviews will be done remotely. Selected applicants may be asked to have interviews and to give presentations and lectures. [How to Submit an Application]: Combine all of the required documents into a single PDF file, and send it via JREC-IN Portal Web application system. (https://jrecin.jst.go.jp/seek/SeekJorDetail?id=D120120988&ln_jor=1)

Closing date for applications:

Contact: Keisuke Tanaka, Professor, Chair of Department of Mathematical and Computing Science, School of Computing (Email: keisuke@is.titech.ac.jp)

More information: https://jrecin.jst.go.jp/seek/SeekJorDetail?id=D120120988&ln_jor=1

ABOUT POLE LEONARD DE VINCI : The Leonard de Vinci Pole is made up of three higher education institutions offering recognized degree programs that cover complementary academic fields, particularly in the digital sector: a business school, EMLV (Leonard de Vinci Business School); an engineering school, ESILV (Leonard de Vinci Engineering School), and a digital/multimedia school, IIM (Institute of Internet and Multimedia). The schools share a common research laboratory: De Vinci Research Center (DVRC). The "De Vinci Research Center - DVRC" includes all the researchers from the two schools of the Leonard De Vinci Association: the School of Management (EMLV) and the School of Engineering (ESILV). The research, focused on innovation and digital technology, is structured within four research groups and a partnership research unit. CONTEXT: Through the Pôle Léonard de Vinci, DVRC is a member of the “Moneytrack” project on blockchain scalability, together with INRIA and Truffle Capital. Topic: The ambition of the Lightning Network is to provide a second layer to the Bitcoin network to enable transactions confirmed instantly, securely and anonymously with a world scale capacity using a decentralized protocol. However, some of the current propositions and implementations present some difficulties in anonymity, scaling and decentralization. The Ant Routing algorithm for the Lightning Network solves several problems such as channel information update and centralization by beacon nodes. It requires no landmark, no knowledge on the topology. The decentralization of the algorithm is achieved by making every node play exactly the same role in the routing process and using only knowledge about its neighbors. Routing tables are not required and transactions are completed instantaneously and anonymously. The algorithm is inspired by the behavior of ants. Although each ant individually seems to follow a random motion, their collective behavior finds efficiently the shortest path from their nest to a food source. This is achieved through a “stygmergic” communication of the ants with their environment through pheromones. See https://arxiv.org/abs/2002.0

Closing date for applications:

Contact: APPLICATION PROCEDURE: Please provide your CV and a cover letter describing your research activities. Qualified candidates need to send their application package by email to recrutement@devinci.fr. Contacts: - Cyril Grunspan (cyril.grunspan@devinci.fr) - Jean Rohmer (jean.rohmer@devinci.fr)

More information: https://www.devinci.fr/

The IETR Lab in Rennes (FR) is looking for a motivated master student on the last year of their degree for a 5-6 month internship, which can serve as the mandatory internship to finish your degree.

CentraleSupélec is a top Engineering school in France with a established tradition of excellence in Cybersecurity. It is a great place for an internship at the IETR CNRS-affiliated laboratory in Rennes, a world-class research and innovation pole in cybersecurity.

Topic
To protect critical infrastructures and sensitive data managed by CPS running Machine Learning algorithms, we need robust implementations able to resist attacks. To this end, we are studying the vulnerabilities that physical SCA attacks pose to DNN/CNN accelerators in FPGAs. In this internship you will: (1) review the literature on power attacks to ML implementations and (2) build an experimental set-up to reverse engineer DNN accelerators using (power/EM) side-channel leakage from heterogeneous devices like Zynq SoC/MPSoC.

Profile
Master student in Computer/Electrical Eng, Electronics or Computer Science with strong background in one or various of the following topics

• HW security, SCA attacks
• HDL/HLS design for FPGAs (pref. Vivado), experience with actual implementations, use of lab. instruments as oscilloscopes
• DNN/CNN implementation in FPGAs
• Familiarity with C/C++/Python programming, Linux/Git as dev. environment

French is not required.

There might be options to continue working towards a PhD after the internship.

Information

• Location: CentraleSupélec, IETR Lab, Rennes (FR)
• Starting date: flexible, anytime from Feb/March
• Duration: 5-6 months
• Stipend: according to regulations, 550-600€/month

Deadline: mid January (interviews running now)

To apply: https://www.ietr.fr/spip.php?article2150

Contact for more info. regarding COVID-19 situation.

Closing date for applications:

Contact: Rubén Salvador: ruben.salvador@centralesupelec.org

More information: https://www.ietr.fr/spip.php?article2150

Prof. Taeho Jung is recruiting Ph.D. students for admission in Fall 2021. If you like doing research in applied cryptography, please take a look at this page. Preferred areas include, but not limited to: 1. Somewhat/Fully homomorphic encryption 2. Secure aggregation / Private stream aggregation 3. Lattice-based cryptography If you are interested, please take a look at his website: https://sites.nd.edu/taeho-jung/

Closing date for applications:

Contact: Taeho Jung

More information: https://sites.nd.edu/taeho-jung/

The School of Electrical Engineering and Computer Science at Oregon State University invites applications for several full-time, nine-month, tenure-track faculty positions. As a land grant institution committed to teaching, research, and outreach and engagement, Oregon State University promotes economic, social, cultural, and environmental progress for the people of Oregon, the nation, and the world. In support of this mission, the College of Engineering recently updated its strategic plan to advance its achievement in high impact research, excellent preparation of all our students, and developing a community of faculty, students, and staff that is increasingly more inclusive, collaborative, diverse, and centered on student success. Faculty candidates are sought in areas that include the following: Software Engineering, Artificial Intelligence/Machine Learning, Cybersecurity, Systems and Theoretical Computer Science. Applicants should demonstrate a strong commitment and capacity to initiate new funded research as well as to expand and complement existing research programs in the OSU College of Engineering and beyond. Furthermore, applicants should demonstrate a strong commitment to undergraduate and graduate teaching; some successful candidates may also have opportunity to teach in the school’s highly ranked online computer science program. Applicants are expected to mentor students and promote equitable outcomes among learners of diverse and underrepresented identity groups. Appointment is anticipated at the Assistant Professor rank, but candidates with exceptional qualifications may be considered for appointment at the rank of Associate or Full Professor. Applicants must hold a Ph.D. degree in Computer Science, Electrical and Computer Engineering, or a closely related discipline.

Closing date for applications:

Contact: Mike Rosulek <rosulekm at eecs.oregonstate.edu>

More information: https://jobs.oregonstate.edu/postings/96561

We are looking for an excellent, motivated, self-driven post-doctoral researcher to work in the area of information security and cryptography with a focus on secure and private cloud assisted computing. More precisely, the postdoctoral researcher shall be working on investigating efficient verifiable delegation of computation mechanisms that provide: i) provable security guarantees, and ii) rigorous privacy guarantees. The overall aim of the postdoctoral position will be to design and evaluate provably secure cryptographic protocols for privacy-preserving and verifiable delegation of computation protocols. The research shall also consider the case where multiple clients jointly outsource computations to untrusted cloud servers. Research area: Research areas include but are not limited to:

• Verifiable computation
• Secure Multi Party Computation
• Privacy-preserving authentication
• Cryptographic primitives

Your Profile:

• A PhD degree in Cryptography;
• Strong publication record;
• Strong mathematical and algorithmic CS background;
• Excellent programming skills;
• Excellent written and verbal communication skills in English

Final Deadline for applications: 8 January 2021. Starting date: Beginning of 2021 or by mutual agreement.

Closing date for applications:

Contact: Katerina Mitrokotsa

More information: https://www.chalmers.se/en/about-chalmers/Working-at-Chalmers/Vacancies/Pages/default.aspx?rmpage=job&rmjob=9112

We are looking for an excellent, motivated, self-driven post-doctoral researcher to work in the area of information security and cryptography. More precisely, we envision secure and privacy-preserving machine learning algorithms for artificial intelligence applications in everyday life that can provide confidentiality and integrity guarantees. In particular the main aims of the project are to: (i) Safeguard the privacy of individuals that participate by either providing their data to build the AI system or being end-users of the system, (ii) safeguard the integrity of the system by ensuring its robustness to adversarial inputs and cryptographically limiting the possible points of adversarial manipulation. You will be working with Prof. Mitrokotsa and Prof. Dimitrakakis. Full-time employment for three years.
Your Profile:

• A PhD degree in Cryptography with connections to Machine learning;
• Publications
• Strong mathematical and algorithmic CS background;
• Excellent programming skills;
• Excellent written and verbal communication skills in English

Final Deadline for applications: 3 January 2021 Starting date: Beginning of 2021 or by mutual agreement.

Closing date for applications:

Contact: Katerina Mitrokotsa

More information: https://www.chalmers.se/en/about-chalmers/Working-at-Chalmers/Vacancies/Pages/default.aspx?rmpage=job&rmjob=9089

The security of blockchains based on PoW-based blockchain relies on the total amount of mining power and the ratio of mining power possessed by the honest miners. Loosely speaking, a system with higher mining power makes an attack more difficult. To incentivise miners joining the network and contributing their mining power, reward mechanisms are designed to provide economic profit to miners in exchange for their mining power. We identify shutdown price as an overlooked factor that has an impact on the current incentive mechanisms. This work fills this knowledge gap. We formalise the concept of shutdown price, which represents the break-even point of operating a mining machine. Once the shutdown price of a type of mining machines is reached, mining coins by using such machines is more expensive than buying coins directly in the cryptocurrency market. Therefore a rational operator would shut these machines down. This reduces the mining power in the network. However, as the variance of the coin price can be very high and the coin price may recover from the break-even point within a short time interval, the miners may not shut down the break-even triggered machine immediately or choose a partial shutdown strategy to hedge risk. We define and analyse such shutdown tolerance by applying real option theory.

Attacks can take advantage of this shutdown threshold, and attackers can even cleverly utilise financial derivatives of cryptocurrencies (whose gain is primarily affected by the change of coin price) to increase their potential gains. As the coin price may drop when successful attacks (such as double spending attacks) on the associated cryptocurrency are discovered, the financial derivatives may be leveraged by a rational adversary to gain extra profit from the launched attacks.

Zero-Knowledge Proof is a crucial tool for privacy preserving and stake proving. It allows the Prover to convince the Verifier about the validity of some statement without leaking any knowledge of his own. Quantities of zero knowledge protocols have been proposed by now and one of the state-of-the-art works is Halo [1], which is brought about by Bowe, Grigg and Hopwood. Even though nested amortization technique used in Halo, the Verifier still has to compute an O(n) operation ultimately. As a result, Halo is not a fully succinct zero-knowledge scheme and infeasible to be utilized in some scenarios such as Ethereum Smart Contract applications. We propose Halo 1.1, which is an enhanced version of Halo aiming at the issue above. Specifically, we introduce the SRS in [2] as the substitute for the random vector in the inner product and thus transform the Pedersen vec-tor commitment to Kate polynomial commitment [2]. On the premise of original Halo protocol remained, the computation of Verifier is in logarith-mic time.

Zoom Meeting is an enterprise online video conferencing solution with real-time messaging and content sharing. However, they are lack of privacy protection since centralized Zoom servers are capable of monitoring user’s messages. Thereby, to solve the privacy problem, in May 2020, Zoom acquired Keybase so that Keybase’s team can help it to build end-to-end encryption meeting while remain Zoom’s current scalability and high-performance. Nonetheless, according to the latest released Zoom’s whitepaper, even with the new design of E2E(end to end) encryption meeting, the security threats can’t be erased completely since the new design is not fully decentralized. In this paper, we introduce a fully decentralized design of E2E encryption meeting via blockchain technology. With this new design, Zoom’s E2E meeting privacy can be further improved.

Hardware security tokens have now been used for several decades to store cryptographic keys. When deployed, the security of the corresponding schemes fundamentally relies on the tamper-resistance of the tokens – a very strong assumption in practice. Moreover, even secure tokens, which are expensive and cumbersome, can often be subverted.

We introduce a new cryptographic primitive called Encryption schemes with Password-protected Assisted Decryption (EPAD schemes), in which a user’s decryption key is shared between a user device (or token) on which no assumption is made, and an online server. The user shares a human-memorizable password with the server. To decrypt a ciphertext, the user launches, from a public computer, a distributed protocol with the device and the server, authenticating herself to the server with her password (unknown to the device); in such a way that her secret key is never reconstructed during the interaction. We propose a strong security model which guarantees that (1) for an efficient adversary to infer any information about a user’s plaintexts, it must know her password and have corrupted her device (secrecy is guaranteed if only one of the two conditions is fulfilled), (2) the device and the server are unable to infer any information about the ciphertexts they help to decrypt (even though they could together reconstruct the secret key), and (3) the user is able to verify that device and server both performed the expected computations. These EPAD schemes are in the password-only model, meaning that the user is not required to remember a trusted public key, and her password remains safe even if she is led to interact with a wrong server and a malicious device.

We then give a practical pairing-based EPAD scheme. Our construction is provably secure under standard computational assumptions, using non-interactive proof systems which can be efficiently instantiated in the standard security model, i.e., without relying on the random oracle heuristic.

We address security and privacy problems for digital devices and biometrics from an information-theoretic optimality perspective, where a secret key is generated for authentication, identification, message encryption/decryption, or secure computations. A physical unclonable function (PUF) is a promising solution for local security in digital devices and this review gives the most relevant summary for information theorists, coding theorists, and signal processing community members who are interested in optimal PUF constructions. Low-complexity signal processing methods such as transform coding that are developed to make the information-theoretic analysis tractable are discussed. The optimal trade-offs between the secret-key, privacy-leakage, and storage rates for multiple PUF measurements are given. Proposed optimal code constructions that jointly design the vector quantizer and error-correction code parameters are listed. These constructions include modern and algebraic codes such as polar codes and convolutional codes, both of which can achieve small block-error probabilities at short block lengths, corresponding to a small number of PUF circuits. Open problems in the PUF literature from a signal processing, information theory, coding theory, and hardware complexity perspectives and their combinations are listed to stimulate further advancements in the research on local privacy and security.

Byzantine Agreement (BA) is one of the most fundamental problems in distributed computing, and its communication complexity is an important efficiency metric. It is well known that quadratic communication is necessary for BA in the worst case due to a lower bound by Dolev and Reischuk. This lower bound has been shown to be tight for $f < n/3$ by Berman et al. but a considerable gap remains for $n/3 \le f < n/2$.

This paper provides two results towards closing this gap. Both protocols have a quadratic communication complexity and have different trade-offs in resilience and assumptions. The first protocol achieves the optimal resilience of $f < n/2$ but requires a trusted setup for threshold signature. The second protocol achieves near optimal resilience $f \le (1/2 - \varepsilon)n$ in the standard PKI model.

We introduce compact certificate schemes, which allow any party to take a large number of signatures on a message $M$, by many signers of different weights, and compress them to a much shorter certificate. This certificate convinces the verifiers that signers with sufficient total weight signed $M$, even though the verifier will not see---let alone verify---all of the signatures. Thus, for example, a compact certificate can be used to prove that parties who jointly have a sufficient total account balance have attested to a given block in a blockchain.

After defining compact certificates, we demonstrate an efficient compact certificate scheme. We then show how to implement such a scheme in a decentralized setting over an unreliable network and in the presence of adversarial parties who wish to disrupt certificate creation. Our evaluation shows that compact certificates are 50--280$\times$ smaller and 300--4000$\times$ cheaper to verify than a natural baseline approach.

Smart grid has improved the security, efficiency of the power system and balanced the supply and demand by intelligent management, which enhanced stability and reliability of power grid. The key point to achieve them is real-time data and consume data sharing by using fine-grained policies. But it will bring the leakage of the privacy of the users and losing of control over data for data owners. The reported solutions can not give the best trade-off among the privacy protection, control over the data shared and confidentiality. In addition, they can not solve the problems of large computation overhead and dynamic management such as users’ revocation. This paper aims at these problems and proposes a decentralized attribute-based data sharing scheme. The proposed scheme ensures the secure sharing of data while removing the central authority and hiding user’s identity information. It uses attribute-based signcryption(ABSC) to achieve data confidentiality and authentication. Under this model, attribute-based encryption gives the access policies for users and keeps the data confidentiality, and the attribute-based signature is used for authentication of the primary ciphertextintegrity. It is more efficient than ”encrypt and then sign” or ”sign and then encrypt”. In addition, the proposed scheme enables user’s revocation and public verifiability. Under the random oracle model, the security and the unforgeability against adaptive chosen message attack are demonstrated.

Though Mobile Cloud Computing (MCC) and Mobile Edge Computing (MEC) technologies have brought more convenience to mobile services over past few years, but security concerns like mutual authentication, user anonymity, user untraceability, etc., have yet remained unresolved. In recent years, many efforts have been made to design security protocols in the context of MCC and MEC, but most of them are prone to security threats. In this paper, we analyze Jia et al.’s scheme, one of the latest authentication protocols for MEC environment and we show this scheme is vulnerable to user impersonation and ephemeral secret leakage attacks. Further, we demonstrate that the aforementioned attacks can be similarly applied to Li et al.’s scheme which recently derived from Jia et al.’s protocol. In this paper, we propose a provably secure authenticated key agreement protocol on the basis of Jia et al.’s scheme that not only withstands security weaknesses of it, but also offers low computational and communicational costs compared to the other related schemes. As a formal security proof, we simulate our scheme with widely used AVISPA tool. Moreover, we show the scalability and practicality of our scheme in a MEC environment through NS-3 simulation.

Several Central Bank Digital Currency (CBDC) projects are considering the development of a digital currency that is managed on a permissioned blockchain, i.e. only authorized entities are involved in transactions verification. In this paper, we explore the best possible balance between privacy and accountability in such a traceable digital currency. Indeed, in case of suspicion of fraud or money laundering activity, it is important to enable the retrieval of the identity of a payer or a payee involved in a specific transaction. Based on a preliminary analysis of achievable anonymity properties in a transferable, divisible and traceable digital currency systems, we first present a digital currency framework along with the corresponding security and privacy model. Then, we propose a pairing-free traceable digital currency system that reconciles user's privacy protection and accountability. Our system is proven secure in the random oracle model.

Prime integers form the basis for finite field and elliptic curve cryptography, as well as many other applications. Provable prime generation guarantees primality and is more efficient than probabilistic generation, and provides components for an efficient primality proof. This paper details a protocol which takes in the proof components from the generation process, proves primality, and as an added benefit, supplies the user with a subgroup generator.

A verifiable timed signature (VTS) scheme allows one to time-lock a signature on a known message for a given amount of time $T$ such that after performing a sequential computation for time $T$ anyone can extract the signature from the time-lock. Verifiability ensures that anyone can publicly check if a time-lock contains a valid signature on the message without solving it first, and that the signature can be obtained by solving the same for time $T$.

This work formalizes VTS, presents efficient constructions compatible with BLS, Schnorr, and ECDSA signatures, and experimentally demonstrates that these constructions can be employed in practice. On a technical level, we design an efficient cut-and-choose protocol based on the homomorphic time-lock puzzles to prove the validity of a signature encapsulated in a time-lock puzzle. We also present a new efficient {range proof} protocol that significantly improves upon existing proposals in terms of the proof size, and is also of independent interest.

While VTS is a versatile tool with numerous existing applications, we demonstrate VTS's applicability to resolve three novel challenging issues in the space of cryptocurrencies. Specifically, we show how VTS is the cryptographic cornerstone to construct: (i) Payment channel networks with improved on-chain unlinkability of users involved in a transaction, (ii) multi-party signing of transactions for cryptocurrencies without any on-chain notion of time and (iii) cryptocurrency-enabled fair multi-party computation protocol.