IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
01 April 2024
István Vajda
Charalampos Papamanthou, Shravan Srinivasan, Nicolas Gailly, Ismael Hishon-Rezaizadeh, Andrus Salumets, Stjepan Golemac
We present and experimentally evaluate two applications of Reckle+ trees, dynamic digest translation and updatable BLS aggregation. In dynamic digest translation we are maintaining a proof of equivalence between Merkle digests computed with different hash functions, e.g., one with a SNARK-friendly Poseidon and the other with a SNARK-unfriendly Keccak. In updatable BLS aggregation we maintain a proof for the correct aggregation of a $t$-aggregate BLS key, derived from a $t$-subset of a Merkle-committed set of individual BLS keys. Our evaluation using Plonky2 shows that Reckle trees and Reckle+ trees have small memory footprint, significantly outperform previous approaches in terms of updates and verification time, enable applications that were not possible before due to huge costs involved (Reckle trees are up to 200 times faster), and have similar aggregation performance with previous implementations of batch proofs.
30 March 2024
University of Exeter, Department of Computer Science, Exeter, England, UK
Closing date for applications:
Contact: Achim D. Brucker
More information: https://jobs.exeter.ac.uk/hrpr_webrecruitment/wrd/run/etrec179gf.open?WVID=171839ediw&LANG=USA&VACANCY_ID=386422ijTy
Queensland University of Technology
Closing date for applications:
Contact: Paul Roe (p.roe@qut.edu.au)
27 March 2024
Cameron Foreman, Richie Yeung, Florian J. Curchod
Christian Badertscher, Monosij Maitra, Christian Matt, Hendrik Waldner
Carsten Baum, Ward Beullens, Shibam Mukherjee, Emmanuela Orsini, Sebastian Ramacher, Christian Rechberger, Lawrence Roy, Peter Scholl
In this work, we improve a crucial building block of the VOLEitH and MPCitH approaches, the so-called all-but-one vector commitment, thus decreasing the signature size of VOLEitH and MPCitH signature schemes. Moreover, by introducing a small Proof of Work into the signing procedure, we can improve the parameters of VOLEitH (further decreasing signature size) without compromising the computational performance of the scheme. Based on these optimizations, we propose three VOLEitH signature schemes FAESTER, KuMQuat, and MandaRain based on AES, MQ, and Rain, respectively. We carefully explore the parameter space for these schemes and implement each, showcasing their performance with benchmarks. Our experiments show that these three signature schemes outperform MPCitH-based competitors that use comparable OWFs, in terms of both signature size and signing/verification time.
Zhe CEN, Xiutao FENG, Zhangyi WANG, Yamin ZHU, Chunping CAO
Xavier Bonnetain, Rachelle Heim Boissier, Gaëtan Leurent, André Schrottenloher
26 March 2024
Zvika Brakerski, Nir Magrafta
Our analysis shows that an even simpler construction: applying a random (binary) phase followed by a random computational-basis permutation, would suffice, assuming that the input is orthogonal and flat (that is, has high min-entropy when measured in the computational basis).
Using quantum-secure one-way functions (which imply quantum-secure pseudorandom functions and permutations), we obtain an efficient cryptographic instantiation of the above.
Dario Catalano, Emanuele Giunta, Francesco Migliaro
In this work we make progress on the study of this primitive in three main directions. First, we show that two general and well established encryption paradigms, namely hybrid encryption and the IBE-to-CCA transform, admit very simple and natural anamorphic extensions. Next, we show that anamorphism, far from being a phenomenon isolated to "basic" encryption schemes, extends also to homomorphic encryption. We show that some existing homomorphic schemes, (and most notably the fully homomorphic one by Gentry, Sahai and Waters) can be made anamorphic, while retaining their homomorphic properties both with respect to the regular and the covert message.
Finally we refine the notion of anamorphic encryption by envisioning the possibility of splitting the anamorphic key into an encryption component (that only allows to encrypt covert messages) and a decryption component. This makes possible for a receiver to set up several, independent, covert channels associated with a single covert key.
Florette Martinez
In 2011 Simon Knellwolf et Willi Meier found a way to go around this hard problem and exhibited a weakness of this generator. In addition to be able to distinguish the outputs from the uniform distribution, they designed an algorithm that retrieves a large portion of the secret. We present here an alternate version of the attack, with similar costs, that works on the same range of parameters but retrieves a larger portion of the secret.
Harishma Boyapally, Durba Chatterjee, Kuheli Pratihar, Sayandeep Saha, Debdeep Mukhopadhyay, Shivam Bhasin
Orhun Kara
Ben Fisch, Arthur Lazzaretti, Zeyu Liu, Charalampos Papamanthou
All known constructions of single server client-preprocessing PIR rely on one of the following two paradigms: (1) a linear-bandwidth offline phase where the client downloads the whole database from the server, or (2) a sublinear-bandwidth offline phase where however the server has to compute a large-depth ($O_\lambda (N)$) circuit under FHE in order to execute the preprocessing phase.
In this paper, we construct a single server client-preprocessing PIR scheme which achieves both sublinear offline bandwidth (the client does not have to download the whole database offline) and a low-depth (i.e. $O_\lambda(1)$), highly parallelizable preprocessing circuit. We estimate that on a single thread, our scheme's preprocessing time should be more than 350x times faster than in prior single server client-preprocessing PIR constructions. Moreover, with parallelization, the latency reduction would be even more drastic. In addition, this construction also allows for updates in $O_\lambda (1)$ time, something not achieved before in this model.
Røros, Noorwegen, 12 May - 15 May 2025
Submission deadline: 16 October 2024
Notification: 5 February 2025
Madrid, Spain, 4 May - 8 May 2025
Shonan, Japan, 30 July - 2 August 2024
NXP Semiconductors Gratkorn/Austria, Hamburg/Germany, Eindhoven/Netherlands & Toulouse/France
Become part of a highly talented and dynamic international development team that develops state-of-the art secure cryptographic libraries which are protected against physical and logical attacks, which have applications across all different NXP domains and business lines (payment, identification, mobile, IoT, Automotive, Edge Processing, etc.).
When you join NXP you have the opportunity to broaden your technical knowledge in all of these areas.
Responsibilities
- You will develop crypto algorithms (incl. Post Quantum Crypto) based on specifications, being involved from the coding/programming, test, code review, release stages.
- You will align with our innovation team, architectural team, hardware teams and support teams to develop the algorithms which contribute to a complete security subsystem in all of NXP's business lines.
Your Profile
- Bachelor + 3-5 years of relevant experience Or You are a graduate with a Master or PhD Degree in Computer Science, Electronics Engineering, Mathematics, Information Technology, Cryptography
- You have a passion for technology, you bring ideas to the table and you are proud of your results.
We offer
- We offer you the opportunity to learn and build on your technical knowledge and experience in some of the following areas: algorithm development including post quantum cryptography (DES, AES, RSA, ECC, SHA and many more)
- embedded software development in C and Assembly
- work with ARM Cortex M and RISC V platforms
- Work on hardware and software countermeasures against side channel (SCA) and fault attacks, (FA).
Ready to create a smarter world? Join the future of Innovation. Join NXP. Apply online!
https://nxp.wd3.myworkdayjobs.com/fr-FR/careers/job/Gratkorn/Embedded-Crypto-Software-Developer--m-f-d-_R-10052127
Closing date for applications:
Contact: Veronika von Hepperger (veronika.vonhepperger@nxp.com)
More information: https://nxp.wd3.myworkdayjobs.com/fr-FR/careers/job/Gratkorn/Embedded-Crypto-Software-Developer--m-f-d-_R-10052127
Luxembourg Institute of Science and Technology
Closing date for applications:
Contact: SCHWARTZ Cathy
More information: https://bit.ly/3xa6NAy