IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
06 March 2023
Jean Liénardy, Frédéric Lafitte
ePrint ReportPrabhanjan Ananth, Alexander Poremba, Vinod Vaikuntanathan
ePrint ReportWe define and construct several fundamental cryptographic primitives with key-revocation capabilities, namely pseudorandom functions, secret-key and public-key encryption, and even fully homomorphic encryption, assuming the quantum subexponential hardness of the learning with errors problem. Central to all our constructions is our approach for making the Dual-Regev encryption scheme (Gentry, Peikert and Vaikuntanathan, STOC 2008) revocable.
05 March 2023
Michael Rosenberg
ePrint ReportIn this work we present LATKE, an iPAKE from lattice assumptions in the random oracle model. In order to achieve security and correctness, we must make changes to CHIP's primitives, security models, and protocol structure.
Lorenzo Grassi, Dmitry Khovratovich, Markus Schofnegger
ePrint ReportIn this paper, we propose an optimized version of Poseidon, called Poseidon2. The two versions differ in two crucial points. First, Poseidon is a sponge hash function, while Poseidon2 can be either a sponge or a compression function depending on the use case. Secondly, Poseidon2 is instantiated by new and more efficient linear layers with respect to Poseidon. These changes allow to decrease the number of multiplications in the linear layer by up to 90% and the number of constraints in Plonk circuits by up to 70%. This makes Poseidon2 the currently fastest arithmetization-oriented hash function without lookups.
Besides that, we address a recently proposed algebraic attack and propose a simple modification that makes both Poseidon and Poseidon2 secure against this approach.
R Radheshwar, Meenakshi Kansal, Pierrick Méaux, Dibyendu Roy
ePrint ReportCas Cremers, Julian Loss, Benedikt Wagner
ePrint ReportTo this end, we provide the first holistic security model for Monero's RingCT. In our model, we then prove the security of RingCT. Our framework is modular in that it allows to view RingCT as a combination of various different sub-protocols. This has the benefit that these components can be easily updated in future versions of RingCT with only minor modifications to our analysis. At a technical level, we introduce several new techniques that we believe to be of independent interest. First, we need to make several subtle modifications to the syntax and security properties of existing building blocks (e.g., linkable ring signatures), which result from the unusual way in which they are combined within RingCT. Then, we show how these building blocks can be combined in order to argue security of the top level transaction scheme. As a technical highlight of our proof, we show that our security goals can be mapped to a suitable graph problem. This allows us to take advantage of ideas from the theory of network flows in our analysis.
Fabrice Benhamouda, Mariana Raykova, Karn Seth
ePrint ReportDelft, Paesi Bassi, 7 July 2023
Event CalendarSubmission deadline: 15 March 2023
Notification: 17 April 2023
TU Wien, Vienna, Austria
Job PostingWe are looking for a candidate with strong scientific foundations and demonstrated expertise in the design of innovative privacy-enhancing technologies that fulfill the needs of our digital society. Desired core areas of competence include but are not limited to:
- Data Privacy
- Privacy in analytics and machine learning
- Theoretical foundations of and formal methods for privacy
- Privacy-preserving protocols, applications, and systems
- Anonymous communication, censorship-resistance
- Cryptographic techniques for privacy
- Human-centered design and usability of privacy technologies
Application deadline: 4 May 2023
For all details and to apply, see: jobs.tuwien.ac.at/Job/203700
Closing date for applications:
Contact: Carmen Keck
More information: https://jobs.tuwien.ac.at/Job/203700
Input Output Global - remote work opportunity
Job PostingAs a Senior Cryptography Engineer in Applied Cryptography at IOG you must be an engineer, an architect, an applied cryptographer and leader - it’s a multifaceted role. You have the exciting challenge of working with bleeding-edge research and technology, always with a focus on the market's needs. You will be a leader to an exceptional team. Working on everything from Post-Quantum prototypes to hand-optimisation of existing primitives to completely new products.
Your mission
- Champion of the applied cryptography team
- Captain end to end development and delivery of new products
- Spearhead prototyping of cryptographic products
- Translate research into rigorous engineering specifications & implementations
- Meticulously review cryptographic protocols and proposed primitives
- Expert knowledge of ZK protocols, including PlonK and IPA commitment scheme
- Expert knowledge of elliptic curve cryptography
- Familiarity with blockchain cryptography and constructions
- Practical experience with implementation of cryptographic primitives
- Expert in terms of secure design (constant time, operational security, management of key material)
- Document code and APIs concisely and unambiguously
- Pragmatically adhere to software engineering principles (modularity, incremental development, no premature optimization, no feature creep, no speculative generality, ...)
- Security sensibility related to cryptographic implementation
- Good theoretical cryptography and mathematical knowledge
- Ability to read cryptographic papers, explain them, and manage delivery of their implementation
Your expertise
Degree in Computer Science/Engineering or Applied Mathematics is desirable but not essential
A minimum of 4-5 years development experience (professional or otherwise) in Rust
Experience working with Git and version control
Expert knowledge of applied cryptographic engineering & best practices
Closing date for applications:
Contact: Marios Nicolaides
Input Output Global - remote work opportunity
Job PostingAs Cryptographic Engineer at IO Global, you will have the exciting challenge of working on cutting-edge research and technology focusing on the market’s needs. You will be working on Midnight, specifically on the zero-knowledge proofs that power Midnight.
The Cryptography Engineering team is growing with the goal of bringing recent academic papers into production. In this team, you will work closely with researchers and engineers, being the bridge between both teams. As Cryptography Engineer you are responsible for writing high-quality code. To support you, our products have software architects, product managers, delivery managers, formal methods specialists, and QA test engineers, with whom you must communicate professionally, effectively, and efficiently.
Your mission
- Working with teams across time zones
- Working independently on software development tasks
- Being proactive and requiring minimal supervision or mentoring to complete tasks
- Reviewing specifications produced by architects and formal methods specialists
- Contributing to the design of algorithms
- Troubleshooting, debugging, and upgrading software
- Writing documentation for the code
- Writing technical user manuals
- Understanding complex cryptographic concepts from academic papers
- Bridging ideas from academic papers to production-ready systems
Requirements
Your expertise
- Excellent Mathematical and Analytical skills.
- Experience with Rust. Not necessarily in industry.
- Knowledge of basic cryptographic concepts (Hash Functions,
- Signature Schemes or Elliptic Curves).
- Degree in computer science or mathematics is desirable, but not essential.
- Experience with systems programming (Rust)
- Skilled in software development methods such as agile programming and test-driven development
- Experience in developing cryptography protocols would be a bonus, as would blockchain experience.
Location IOG is a distributed organization and therefore this is a remote position.
Closing date for applications:
Contact: Marios Nicolaides marios.nicolaides@iohk.io
More information: https://apply.workable.com/io-global/j/4437128D09/
Télécom Paris, Paris, France
Job PostingClosing date for applications:
Contact: If you want to apply or have more information, please contact Sébastien Canard (sebastien.canard@telecom-paris.fr) or Duong Hieu Phan (hieu.phan@telecom-paris.fr).
Copenhagen, Denmark, 24 August - 25 August 2023
Event CalendarSubmission deadline: 15 April 2023
Notification: 15 June 2023
03 March 2023
Reza Ghasemi
ePrint ReportDanilo Gligoroski
ePrint ReportAdditionally, we construct an Arithmetic for power indices and propose generic recipe guidelines that we call "Entropic-Lift" for transforming some of the existing classical cryptographic schemes that depend on the hardness of Discrete Logarithm Problem to post-quantum cryptographic schemes that will base their security on the hardness of the Exponential Congruences Problem.
As concrete examples, we show how to transform the classical Diffie-Hellman key exchange, DSA and Schnorr signature schemes.
We also post one open problem: From the perspective of provable security, specifically from the standpoint of security of post-quantum cryptographic schemes, to precisely formalize and analyze the potentials and limits of the Entropic-Lift transformation.
Razvan Barbulescu, Adrien Poulalion
ePrint ReportSenpeng Wang, Dengguo Feng, Bin Hu, Jie Guan, Ting Cui, Tairong Shi, Kai Zhang
ePrint ReportThuat Do
ePrint ReportJoseph Jaeger, Akshaya Kumar
ePrint ReportThe reductions carefully combine recent proof techniques introduced by Bhattacharyya’20 and Ghoshal- Ghosal-Jaeger-Tessaro’22. Our proofs for the augmented ECIES version of Hashed-ElGamal make use of a new computational Diffie-Hellman assumption wherein the adversary is given access to a pairing to a random group, which we believe may be of independent interest.
Sajin Sasy, Ian Goldberg
ePrint ReportIn this work we survey 31 systems targeting metadata-protected communications, and present a unified view of the current state of affairs. We provide two different taxonomies for existing MPCS, first into three different categories by the precise type of metadata protections they offer, and next into six families based on the core techniques that underlie them. By contrasting these systems we identify potential vulnerabilities, as well as subtle privacy implications of design choices of existing MPCS. Furthermore, we identify promising avenues for future research for MPCS, and desirable properties that merit more attention.