IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
10 December 2022
Alexandra Mai
ePrint ReportTo investigate current commonalities and differences in SSI understanding, I contribute the first qualitative user study (N=13) on expert mental models of SSI and its associated threat landscape. The study results highlight the need for a general definition of SSI and further standards for such systems, as experts' perceptions of SSI requirements vary widely. Based on the expert interviews, I constructed a minimal knowledge map for (potential) SSI end-users and formulated design guidelines for SSI to facilitate broad adoption in the wild and improve privacy-preserving usage.
Sacha Servan-Schreiber, Simon Beyzerov, Eli Yablon, Hyojae Park
ePrint ReportIn this paper, we initiate the study of access control for FSS. Given the shares of f, the evaluators can ensure that the dealer is authorized to share the provided function. For a function family F and an access control list defined over the family, the evaluators receiving the shares of f ∈ F can efficiently check that the dealer knows the access key for f.
This model enables new applications of FSS, such as: – anonymous authentication in a multi-party setting, – access control in private databases, and – authentication and spam prevention in anonymous communication systems.
Our definitions and constructions abstract and improve the concrete efficiency of several re- cent systems that implement ad-hoc mechanisms for access control over FSS. The main building block behind our efficiency improvement is a discrete-logarithm zero-knowledge proof-of-knowledge over secret-shared elements, which may be of independent interest.
We evaluate our constructions and show a 50–70× reduction in computational overhead com- pared to existing access control techniques used in anonymous communication. In other applications, such as private databases, the processing cost of introducing access control is only 1.5–3× when amortized over databases with 500,000 or more items.
Minjoo Sim, Siwoo Eum, Hyeokdong Kwon, Hyunjun Kim, Hwajeong Seo
ePrint ReportFelix Günther, Marc Ilunga Tshibumbu Mukendi
ePrint ReportIn this work, we formalize a multi-stage key exchange security model capturing the potential attack vectors introduced by non-unique credential identifiers. We show that EDHOC, in its draft version 17, indeed achieves session key security and user authentication even in a strong model where the adversary can register malicious keys with colliding identifiers, given that the employed signature scheme provides so-called exclusive ownership. Through our security result, we confirm cryptographic improvements integrated by the IETF working group in recent draft versions of EDHOC based on recommendations from our and others' analysis.
Damien Robert
ePrint ReportThe second application is an algorithm to compute the canonical lift of $E/\mathbb{F}_q$, $q=p^n$, (still assuming that $E$ is ordinary) to precision $m$ in time $\tilde{O}(n m \log^{O(1)} p)$. We deduce a point counting algorithm of complexity $\tilde{O}(n^2 \log^{O(1)} p)$. In particular the complexity is polynomial in $\log p$, by contrast of what is usually expected of a $p$-adic cohomology computation. This algorithm generalizes to ordinary abelian varieties.
Wei-Kai Lin, Ethan Mook, Daniel Wichs
ePrint ReportBuilding on top of our DEPIR, we construct general fully homomorphic encryption for random-access machines (RAM-FHE), which allows a server to homomorphically evaluate an arbitrary RAM program $P$ over a client's encrypted input $x$ and the server's preprocessed plaintext input $y$ to derive an encryption of the output $P(x,y)$ in time that scales with the RAM run-time of the computation rather than its circuit size. Prior work only gave a heuristic candidate construction of a restricted notion of RAM-FHE. In this work, we construct RAM-FHE under the RingLWE assumption with circular security. For a RAM program $P$ with worst-case run-time $T$, the homomorphic evaluation runs in time $T^{1+\varepsilon} \cdot polylog(|x| + |y|)$.
Fabio Banfi
ePrint ReportMark Carney
ePrint ReportManoj Srinivas Botla, Jai Bala Srujan Melam, Raja Stuthi Paul Pedapati, Srijanee Mookherji, Vanga Odelu, Rajendra Prasath
ePrint ReportHassan Asghar, Benjamin Zi Hao Zhao, Muhammad Ikram, Giang Nguyen, Dali Kaafar, Sean Lamont, Daniel Coscia
ePrint ReportAbdelhaliem Babiker
ePrint ReportHao Cheng, Johann Großschädl, Ben Marshall, Dan Page, Thinh Pham
ePrint ReportVarun Maram, Keita Xagawa
ePrint ReportSome starting steps were taken by Grubbs \(\textit{et al.}\) (EUROCRYPT 2022) and Xagawa (EUROCRYPT 2022) wherein they studied the anonymity properties of most NIST PQC third round candidate KEMs. Unfortunately, they were unable to show the anonymity of Kyber because of certain technical barriers.
In this paper, we overcome said barriers and resolve the open problems posed by Grubbs \(\textit{et al.}\) (EUROCRYPT 2022) and Xagawa (EUROCRYPT 2022) by establishing the anonymity of Kyber, and the (hybrid) PKE schemes derived from it, in a post-quantum setting. Along the way, we also provide an approach to obtain tight IND-CCA security proofs for Kyber with \(\textit{concrete}\) bounds; this resolves another issue identified by the aforementioned works related to the post-quantum IND-CCA security claims of Kyber from a provable security point-of-view. Our results also extend to Saber, a NIST PQC third round finalist, in a similar fashion.
Mayank Rathee, Conghao Shen, Sameer Wagh, Raluca Ada Popa
ePrint ReportGeorge Teseleanu
ePrint ReportKyoichi Asano, Keita Emura, Atsushi Takayasu
ePrint Report09 December 2022
Eindhoven, Netherlands, 10 July - 14 July 2023
Event CalendarSubmission deadline: 20 February 2023
Notification: 20 March 2023
Kyoto Prefecture, Japan, 19 June - 22 June 2023
Event CalendarSubmission deadline: 15 March 2023
Notification: 19 April 2023
SnT, University of Luxembourg
Job Posting- applied or symmetric cryptography
- cryptofinance, cryptoeconomics, blockchains
- anonymity and privacy on the Internet
- M.Sc. degree in Computer Science, Applied Mathematics or a related field
- GPA of at least 80% in both the bachelor and master studies
- Strong mathematical and/or algorithmic CS background (math/CS Olympiads, CTFs a plus)
- Background in applied cryptography, or information security, or economics/finance - a plus
- Good skills in programming, scripting languages. Math tools - a plus.
- Commitment, team working and a critical mind
- Fluent written and verbal communication skills in English
- A very brief cover letter explaining the candidate's motivation and research interests
- Curriculum Vitae (including photo, education/research, work experience, interests)
- Transcripts of B.Sc. and M.Sc. grades
- Information about contributions to open-source projects, participation in research competitions, Olympiads, CTFs, etc.
Closing date for applications:
Contact: Prof. Alex Biryukov (e-mail: first name dot family name (at) uni.lu)
More information: http://cryptolux.org/index.php/Vacancies
Aalto University, Finland
Job PostingThe Department of Computer Science at Aalto University - in the top 20 young universities worldwide - invites applications for tenure-track positions at the assistant professor level. We welcome applications in all areas of computer science, with a special focus on candidates with expertise in the following areas.
- Programming languages; Programming methodologies
- Databases; Data management
- Software engineering: software systems specification, implementation, validation
- Operating Systems; Hardware-software interface
Women and others underrepresented in computer science are especially encouraged to apply.
The Department of Computer Science (https://www.aalto.fi/en/department-of-computer-science) is home to world-class research in modern computer science, combining research on foundations and innovative applications. An international community with 46 professors and more than 400 employees from 50 countries, it is the largest department at Aalto University and the largest computer science unit in Finland. The department consistently ranks high in global rankings, for example, the first in Nordic countries and Northeastern Europe and the 73rd overall in Times Higher Education ranking for 2023.
Finland is a great place for living with or without a family: it is a safe and well-organized Nordic society, where equality is highly valued and extensive social security supports people in all situations of life. Finland's free high-quality education system is also internationally renowned.
For more information and the application form visit: https://www.aalto.fi/en/open-positions/assistant-professors-computer-science
The call is open until January 15, 2023.
Closing date for applications:
Contact: Prof. Jussi Rintanen or for recruitment process-related questions HR Partner Laura Kuusisto-Noponen
More information: https://www.aalto.fi/en/open-positions/assistant-professors-computer-science