IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
02 October 2023
Houda Ferradi, Antoine Houssais, David Naccache
Paulo L. Barreto, Devin D. Reich, Marcos A. Simplicio Jr., Gustavo H. M. Zanon
Willy Quach, LaKyah Tyner, Daniel Wichs
The work of [ACM22] presented a lower bound on anonymous transfer, ruling out constructions with strong anonymity guarantees (where the adversary's advantage in identifying the sender is negligible) against arbitrary polynomial-time adversaries. They also provided a (heuristic) upper bound, giving a scheme with weak anonymity guarantees (the adversary's advantage in identifying the sender is inverse in the number of rounds) against fine-grained adversaries whose run-time is bounded by some fixed polynomial that exceeds the run-time of the honest users. This leaves a large gap between the lower bound and the upper bound, raising the intriguing possibility that one may be able to achieve weak anonymity against arbitrary polynomial time adversaries, or strong anonymity against fine grained adversaries.
In this work, we present improved lower bounds on anonymous transfer, that rule out both of the above possibilities: - We rule out the existence of anonymous transfer with any non-trivial anonymity guarantees against general polynomial time adversaries. - Even if we restrict ourselves to fine-grained adversaries whose run-time is essentially equivalent to that of the honest parties, we cannot achieve strong anonymity, or even quantitatively improve over the inverse polynomial anonymity guarantees (heuristically) achieved by [ACM22].
Consequently, constructions of anonymous transfer can only provide security against fine-grained adversaries, and even in that case they achieve at most weak quantitative forms of anonymity.
Renas Bacho, Julian Loss, Stefano Tessaro, Benedikt Wagner, Chenzhi Zhu
In this work, we propose Twinkle, a new threshold signature scheme in the pairing-free setting which overcomes these limitations. Twinkle is the first pairing-free scheme to have a security proof under up to $t$ adaptive corruptions without relying on the algebraic group model. It is also the first such scheme with a security proof under adaptive corruptions from a well-studied non-interactive assumption, namely, the Decisional Diffie-Hellman (DDH) assumption.
We achieve our result in two steps. First, we design a generic scheme based on a linear function that satisfies several abstract properties and prove its adaptive security under a suitable one-more assumption related to this function. In the context of this proof, we also identify a gap in the security proof of Sparkle and develop new techniques to overcome this issue. Second, we give a suitable instantiation of the function for which the corresponding one-more assumption follows from DDH.
Daniel Smith-Tone
Worcester Polytechnic Institute, Worcester MA
Qualifications:
- A solid understanding of the hardware design flow, from system-level down to gate-level, is essential for this position.
- Previous experience in IC tape-out, cryptographic engineering, and implementation attacks is considered a strong advantage.
Inquiries are welcome. Formal applications should go to https://gradapp.wpi.edu/apply/
Closing date for applications:
Contact: Patrick Schaumont (pschaumont@wpi.edu)
Eindhoven University of Technology, Eindhoven, The Netherlands
We have an opening for a two-year (1+1) postdoc position in the applied and provable security (APS) group at Eindhoven University of Technology (TU/e). The APS group is working on provable security of cryptographic primitives and protocols considering quantum adversaries as well as the machine checking of such proofs. Recent works range from proposing new NIST standards (SPHINCS+) to new post-quantum secure communication protocols (PQWireGuard, PQNoise), and the formal verification of proofs for recent NIST standards and proposals (XMSS, Dilithium, Saber) in EasyCrypt. The group currently consists of two tenured professors and four PhD students.
The position is funded by a talent program grant of the Dutch Science Foundation (NWO). The successful candidate will carry out independent research in one of the research areas covered by the APS group under the supervision of Andreas Hülsing.
Applicants must hold a PhD and have a background in one of the topics related to the intended research area, including but not limited to: Cryptography, formal methods, or quantum information theory. This background should be demonstrated by relevant publications.
To apply, please visit https://jobs.tue.nl/en/vacancy/postdoc-applied-and-provable-security-1029137.htmlClosing date for applications:
Contact: Andreas Huelsing (email a.t.huelsing[at]tue.nl)
More information: https://jobs.tue.nl/en/vacancy/postdoc-applied-and-provable-security-1029137.html
30 September 2023
Abu Dhabi, Vereinigte Arabische Emirate, 5 March - 8 March 2024
Submission deadline: 15 November 2023
Notification: 22 December 2023
27 September 2023
Joël Alwen, Jonas Janneck, Eike Kiltz, Benjamin Lipp
Keigo Yamashita, Kenji Yasunaga
Alex Evans, Guillermo Angeris
Julien Devevey, Alain Passelègue, Damien Stehlé
Shalini Banerjee, Steven D. Galbraith
Jiale Chen, Dima Grigoriev, Vladimir Shpilrain
Seongkwang Kim, Jincheol Ha, Mincheol Son, Byeonghak Lee
Recently, Liu et al. proposed a fast exhaustive search attack on AIM (ePrint 2023), which degrades the security of AIM by up to 13 bits. While communicating with the authors, they pointed out another possible vulnerability on AIM. In this paper, we propose AIM2 which mitigates all the vulnerabilities, and analyze its security against algebraic attacks.
Noemi Glaeser, István András Seres, Michael Zhu, Joseph Bonneau
István András Seres, Noemi Glaeser, Joseph Bonneau
Cong Ling, Andrew Mendelsohn
Cyprien Delpech de Saint Guilhem, Ehsan Ebrahimi, Barry van Leeuwen
This paper presents a novel method to construct zero-knowledge protocols which takes advantage of the unique properties of MPC-in-the-Head and replaces commitments with an oblivious transfer protocol. The security of the new construction is proven in the Universal Composability framework of security and suitable choices of oblivious transfer protocols are discussed together with their implications on the security properties and computational efficiency of the zero-knowledge system.