IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
08 January 2024
Huiwen Jia, Yupu Hu, Chunming Tang, Lin Wang
Siavash Riahi, Orfeas Stefanos Thyfronitis Litos
Clique enables a pool of users to pay each other off-chain, i.e., without interacting with the blockchain, thus sidestepping its bottlenecks. A user can directly send its coins to any other user in the Clique: In contrast to payment channels, its funds are not tied to a specific counterparty, avoiding the need for multi-hop payments. An untrusted operator facilitates payments by verifiably recording them.
Furthermore, we define and construct a novel primitive, Two-Shot Adaptor Signatures, which is needed for Bitcoin Clique while being of independent interest. This primitive extends the functionality of normal Adaptor Signatures by allowing the extraction of the witness only after two signatures are published on the blockchain.
Muhammed Ali Bingol, Sermin Kocaman, Ali Dogan, Sibel Kurt Toplu
Mustafa Khairallah
In this paper, we address some of the remaining gaps in this area. Our main result is to show that, for a fixed stretch, Pseudo-Random Injection security implies IND-CCA security as long as the minimum ciphertext size is at least as large as the required IND-CCA security level. We also show that this bound is tight and that any AEAD scheme that allows empty plaintexts with a fixed stretch cannot achieve IND-CCA security beyond the tag length.
Next, we look at the weaker notion of MRAE security, and show that two-pass schemes that achieve MRAE security do not achieve IND-CCA security beyond the tag size. This includes SIV and rugged PRPs.
San Ling, Khoa Nguyen, Duong Hieu Phan, Khai Hanh Tang, Huaxiong Wang, Yanhong Xu
In the construction process, we put forward a new theoretical abstraction of Stern-like zero-knowledge (ZK) protocols, which are the major tools for privacy-preserving cryptography from codes. Our main insight here actually lies in the questions we ask about the fundamental principles of Stern-like protocols that have remained unchallenged since their conception by Stern at CRYPTO'93. We demonstrate that these long-established principles are not essential, and then provide a refined framework generalizing existing Stern-like techniques and enabling enhanced constructions.
Gerald Gavin, Sandrine Tainturier
Michael Klooß, Andy Rupp, Daniel Schadt, Thorsten Strufe, Christiane Weis
In this paper, we provide the first packet format that protects against the tagging attack with an acceptable overhead. At the cost of doubling the payload size, we are able to build a provably private solution from basic cryptographic primitives. Our implementation demonstrates that our solution is as computationally efficient as Sphinx, beating previous schemes by a large margin. For our security proof, we first strengthen the state-of-the-art proof strategy, before applying it to our solution to demonstrate that not only the tagging attack is prevented, but our scheme is provably private.
Randy Kuang, Maria Perepechaenko, Dafu Lou, Brinda Tank
The unique integration of asymmetric, symmetric, and homomorphic cryptography within HPPK necessitates a careful examination of its performance metrics. This study focuses on the thorough benchmarking of HPPK KEM and DS across key cryptographic operations, encompassing key generation, encapsulation, decapsulation, signing, and verification. The results highlight the exceptional efficiency of HPPK, characterized by compact key sizes, cipher sizes, and signature sizes. The use of symmetric encryption in HPPK enhances its overall performance. Key findings underscore the outstanding performance of HPPK KEM and DS across various security levels, emphasizing their superiority in crucial cryptographic operations. This research positions HPPK as a promising and competitive solution for post-quantum cryptographic applications in a wide range of applications, including blockchain, digital currency, and Internet of Things (IoT) devices.
Scott Fluhrer, Quynh Dang
06 January 2024
Virginia Tech
Closing date for applications:
Contact: Sarah McDearis, sworl9@vt.edu
More information: https://jobs.vt.edu
ETH, Department of Computer Science; Zurich, Switzerland
The Post-Quantum Cryptography group is looking for a motivated PhD candidate on the topic of lattice-based cryptography. In particular, the candidate will work with dr. Cecilia Boschini and prof. Dennis Hofheinz on lattice-based distributed authentication (threshold and multi- signatures), from constructing and analyzing protocols to more foundational work in lattice theory. Besides research, the candidate is expected to do a small amount of teaching each semester, in accordance with ETH regulations.
The position is fully funded for 4 years with a competitive salary (rate 5 according to ETH rules), and available already from Spring 2024; the exact starting date is negotiable. To be eligible, the candidate should have a master's (or equivalent) degree in Computer Science or Mathematics (or other relevant field), and already have some basic knowledge of cryptography and/or lattices.
ETH has a large and diverse community of cryptographers, with strong researchers in both theoretical and applied areas, and ties to the many other cryptography groups present in Switzerland. As a nice bonus, the department of Computer Science is located in the center of Zurich, a dynamic and international city where everything can be reached by public transport, including the Alps.
To apply, please send via email the following:
- your CV (max 2 pages)
- transcripts
- contact information of 2 references
Closing date for applications:
Contact: Dr. Cecilia Boschini (cecilia.boschini@inf.ethz.ch)
University of St.Gallen, Switzerland
Key Responsibilities:
- The post-doctoral fellow is expected to perform exciting and challenging research in the area of information security and cryptography including the design of provably secure cryptographic protocols.
- The post-doctoral fellow shall be involved in the supervision of PhD and master students
- The post-doctoral researcher is expected to have a PhD degree in Computer Science, Engineering or Mathematics and a strong background in theoretical computer science and cryptography
- Have an excellent publication record in top venues Competitive research record in cryptography or information security
- Strong mathematical and algorithmic CS background
- Good skills in programming is beneficial
- Excellent written and verbal communication skills in English
Please apply asap through the job link.
Closing date for applications:
Contact:
Eriane Breu (Administrative matters)
Prof. Katerina Mitrokotsa (Research related questions)
More information: https://jobs.unisg.ch/offene-stellen/postdoc-fellow-in-cryptography-information-security-m-f-d-m-w-d/831c6e8a-e191-48ec-92d5-320b2822a9ab
University of St.Gallen
The student is expected to work on topics that include security and privacy issues in authentication. More precisely, the student will be working on investigating efficient and privacy-preserving authentication that provides: i) provable security guarantees, and ii) rigorous privacy guarantees.
Key Responsibilities:
- Perform exciting and challenging research in the domain of information security and cryptography.
- Support and assist in teaching computer security and cryptography courses.
- The PhD student is expected to have a MSc degree or equivalent, and strong background in cryptography, network security and mathematics.
- Experience in one or more domains such as cryptography, design of protocols, secure multi-party computation and differential privacy is beneficial.
- Excellent programming skills.
- Excellent written and verbal communication skills in English
Please apply asap through the job link. Applications will be evaluated continuously.
Closing date for applications:
Contact:
Eriane Breu (Administrative matters)
Prof. Katerina Mitrokotsa (Research related questions)
More information: https://jobs.unisg.ch/offene-stellen/funded-phd-student-in-applied-cryptography-privacy-preserving-authentication-m-f-d-m-w-d/6ce1d454-47ca-4710-a9f2-33429243b4ac
Copper.co
Closing date for applications:
Contact: Clara Luna
More information: https://boards.eu.greenhouse.io/copperco/jobs/4248039101
05 January 2024
Yaroslav Balytskyi, Yevgen Kotukh, Gennady Khalimov, Sang-Yoon Chang
Sedigheh Khajouei-Nejad, Hamid Haj Seyyed Javadi, Sam Jabbehdari, Seyed Mohammad Hossein Moattar
Zhenkai Hu, Kang Yang, Yu Yu
In this paper, we present an unconditionally secure MPC protocol for Boolean circuits in the honest-majority setting, which has constant online communication complexity and the offline communication complexity linear to the number $n$ of parties. We first describe the semi-honest MPC protocol and then show how to extend it to achieve malicious security, where the maliciously secure protocol has the same communication cost as the semi-honest protocol. In particular, our protocol achieves the amortized communication cost $36$ bits per AND gate in the online phase and $30n+24$ bits per AND gate in the offline phase.
Ahmet Ramazan Ağırtaş, Oğuz YAYLA
Zhengjun Cao, Lihua Liu
Behnam Zahednejad, Gao Chong-zhi
We prove the security of our scheme under standard assumptions such as Discrete Logarithms (DL) and q-strong Diffie-Hellman(q-sDH) assumption in ID-eCK model. Finally, we conduct a proof-of-concept implementation of our scheme vs. previous single pairing-based schemes and show that our scheme imposes the least computation cost and stands in the middle of previous scheme regarding communication cost.