AFRICACRYPT 2025
16th International Conference on Cryptology
July 21-23, 2025 – Rabat, Morocco
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Technical Program > Program
P.S. 🚀 New Program just launched — check it out!
Sunday, July 20
20:00 – 22:00Registration at Rent-In Residence Atlas hotel:
https://www.rent-inn.ma
Monday, July 21
Registration
9:00 – 10:00Registration at ENSIAS College
Opening
10:00 – 10:30Opening Ceremony
10:30 – 11:00Coffee Break
Session 1: Homomorphic Encryption (I)
Chair: Jeongeun Park
11:00 – 11:30
One-Way Homomorphic Encryption: A Composite Group Approach
Mahdi Mahdavi, Helena Rifà-Pous Universitat Oberta de Catalunya, Spain; Shahid Beheshti University, Iran
Keynote Talk 1:
Fully Homomorphic Encryption — What, Why, and How?
11:30 – 12:30Speaker: Jeongeun Park Affiliation: Associate Professor at NTNU, Norway Chair: Vincent Rijmen
Show Abstract
This talk is about fully homomorphic encryption (FHE) which enables a computation over encrypted data without decrypting interme diate value. This talk will consist of the past, present, and the future of FHE. I will start with existing FHE schemes, focusing on how they have been developed over a decade. Also, the talk will focus on why it is important, and remaining challenges.
12:30 - 14:00
Lunch Break
Session 2: Homomorphic Encryption (II)
Chair: Jeongeun Park
14:00 – 14:30Activate Me!: Designing Efficient Activation Functions for Privacy-PML with Fully Homomorphic Encryption
Nges Brian Njungle, Michel A. Kinsy Arizona State University, USA
Session 3: Cryptanalysis
Chair: Olivier Blazy14:30 – 15:00Conjunctive Dynamic SSE Schemes under Scrutiny:
Exposing Privacy Issues in SDSSE-CQ-S and VCDSSE
Bibhas Chandra Das Institute for
Advancing Intelligence TCG CREST, India; Chennai Mathematical Institute, India
15:00 – 15:30Efficient and Optimized Modeling of S-Boxes
Anirudh Aitipamula, Debranjan Pal, Dipanwita Roy Chowdhury Indian Institute of Technology
Kharagpur, India; Indian Institute of Technology Kanpur, India
15:30 – 16:00Tearing Solutions for Tree Traversal in Stateful
Hash-based Cryptography
Solane El Hirch, Christine van Vredendaal, Frank Custers Radboud
University Nijmegen, The Netherlands; NXP Semiconductors Eindhoven, The Netherlands
Session 4: Designs (I)
Chair: Pascal Lafourcade16:00 – 16:30Attribute-based Encryption using Sum-Product
Decomposition of Boolean Functions
Arani Raychaudhuri, Ramprasad Sarkar, Mriganka Mandal
Indian Statistical Institute Kolkata, India
16:30 – 17:00 Simultaneously simple universal and
indifferentiable hashing to elliptic curves
Dimitri Koshelev University of Lleida,
Catalonia, Spain
17:00 - 17:30
Coffee Break
Session 5: Designs (II)
Chair: Pascal Lafourcade17:30 – 18:00Bivariate proximity test-based Asynchronous
Verifiable Secret Sharing
Lola-Baie Mallordy, Olivier Blazy, Daniel Augot, Hugo Delavenne
LIX, Ecole Polytechnique, Institut Polytechnique de Paris, Inria, France
18:00 – 18:30Behemoth: transparent polynomial commitment scheme
constant opening proof size and verifier time
Istvan Seres, Péter Burcsi
Eötvös Loránd University, Hungary
Tuesday, July 22
Session 6: Cryptanalysis of RSA
Chair: Driss Bouzidi09:00 – 09:30A Novel Partial Key Exposure Attack on Common Prime
RSA
Mengce Zheng and Abderrahmane Nitaj Zhejiang Wanli University, China; University of
Caen Normandie, France
09:30 – 10:00Improved Cryptanalysis of an RSA Variant Based on
Cubic Pell Curve
Mohammed Rahmani and Abderrahmane Nitaj Mohammed First University,
Oujda, Morocco; University of Caen Normandie, France
10:00 – 10:30A New Generalized Attack on RSA-like
Cryptosystems
Michel SECK, Oumar Niang, Djiby Sow, Abderrahmane Nitaj, Mengce Zheng, Maher
Boudabra Ecole Polytechnique de Thies, Senegal; UCAD Dakar, Senegal; University of Caen
Normandie, France; Zhejiang Wanli University Ningbo, China; KFUPM Dhahran, Saudi Arabia
10:30 - 11:00
Coffee Break
Session 7: Homomorphic Encryption (III)
Chair: Jeongeun Park11:00 – 11:30 Convolution-Friendly Image Compression with FHE
Georgio Nicolas, Sergi Rovira, Axel Mertens COSIC, KU Leuven, Belgium; Technology
Innovation Institute, UAE
11:30 – 12:00 Leveled Homomorphic Encryption over Composite
Groups
Mahdi Mahdavi, Ehsan Meamari, Emad Heydari Beni, Maryam Sheikhi Universitat
Oberta de Catalunya, Spain; University of Delaware, USA; COSIC, KU Leuven, Belgium & Nokia Bell
Labs; University of Hamburg, Germany
Keynote Talk 2:
A Proof of Behavior
12:00 - 13:00Speaker: Pascal Lafourcade Affiliation: Professor of Computer Science at IUT of Clermont Auvergne, France Chair: Tako Boris Fouotsa
Show Abstract
Bitcoin was the beginning of a digital revolution and it is also the birth of the blockchain technology. The security of this technology relies on the concept of Proof of Work (PoW). In order to validate a transaction, a miner needs to produce a PoW. In Bitcoin, a PoW is the computation of an objective of hash, which is find ing a number that satisfies an inequation. Finding this number requires to compute thousands of hash functions. PoW is one of the main negative aspect of this technology since it is highly energy consuming. More over in the case of Bitcoin, the performed hash computations are really useless. Our goal is to design an alternative to PoW, for this purpose we introduce the notion of Proof of Behavior (PoB). Our aim is to change the Proof of Work paradigm. Instead of wasting energy in dummy computations with hash computations, we propose a new approach based on the behavior of the users. We present the notion of PoB, the idea is to incentivize citizens to have responsible behaviors instead of doing useless computations as in PoW. Our idea is to design a mechanism that replaces the Proof of Work and that has a positive impact on the world and a social impact on the behaviors of the citizens. For this, we introduce the notion of Proof of Behavior. We propose a first application to design a new cryptocurrency for the mobility, called EcoMobiCoin for Ecological and Collaborative Mobility Coin. If you can prove that you are biking or walking or using pub lic transportation to go somewhere instead of using your car, or if you can prove that you are using your car with some passengers to go to somewhere, you are generating a Proof of Behavior for eco-responsible mobility and then creating new EcoMobiCoins. This approach aims at facilitating the energy transition that is a key point of the next years.
13:00 - 14:30
Lunch Break
15:00 – 19:00 Guided visit of Rabat
20:00 – --:-- Gala dinner
Wednesday, July 23
Session 8: Cryptography Arithmetic (I)
Chair: Abderrahmane Nitaj09:00 – 09:30An Improvement of the Congruence Solver of LIP over
Totally Real Number Fields and Applications
Nour-eddine Rahmani, Taoufik Serraj, Moulay Chrif
Ismaili Mohammed I University, Oujda, Morocco
09:30 – 10:00PMNS arithmetic for elliptic curve
cryptography
Fangan Yssouf Dosso, Sylvain Duquesne, Nadia EL Mrabet, Emma Gautier
École des Mines de Saint-Étienne, France; University of Rennes, France
10:00 – 10:30Constant-time Integer Arithmetic for SQIsign
Fatna Kouider, David Jacquemin, Anisha Mukherjee, Peter Kutas Eötvös Loránd
University, Hungary; ISEC, Graz University of Technology, Austria; University of Birmingham, United
Kingdom
10:30 - 11:00
Coffee Break
Session 9: Cryptography Arithmetic (II)
Chair: Abderrahmane Nitaj11:00 – 11:30FPTRU: Optimization of NTRU-Prime and TLS
Performance Assessment
Xiaowen Hu, Hanyu Wei, Hengchuan Zou, Zhichuang Liang, Wenqian Li, Yunlei
Zhao Fudan University, Shanghai, China; State Key Laboratory of Cryptology, Beijing, China
Keynote Talk 3:
HQC and the Future of Code-Based Cryptography: From Foundations to Hybridization
11:30 - 12:30Speaker: Olivier Blazy Affiliation: Professor at École Polytechnique, France Chair: Vincent Rijmen
Show Abstract
The approval of HQC (Hamming Quasi-Cyclic) for standardization by NIST marks a major milestone for code-based cryptography in the post-quantum landscape. This talk will first revisit the evolution of code-based encryption, from the seminal McEliece scheme of 1978 to the pioneering work of Alekhnovich, who introduced the a code-based encryption scheme with provable security with proper reduction — set ting the stage for modern constructions. We will then delve into the design of HQC itself, emphasizing its reliance on quasi-cyclic structures and the hardness of decoding random errors, which underpin its secu rity guarantees. Special attention will be given to the HHK transform, a refined framework that ensures an efficient full CCA-2 security (both in the ROM and the QROM), crucial for secure deployment in practice. In the final part of the talk, we will explore cryptographic agility through hybridization strategies, with a focus on a new technique inspired by the X-Wing framework. This approach enables the combination of classical and post-quantum encryption schemes, preserving security guarantees while facilitating a smooth and secure transition to post-quantum infrastructures. The presentation will offer both a historical perspective and a deep dive into the technical and practical innovations that lead to the selection of HQC.
12:30 - 14:00
Lunch Break
Session 10: Side-channel Attacks
Chair: Said Eddahmani14:00 – 14:30Simple Power Analysis Attack on SQIsign
Anisha Mukherjee, Maciej Czuprynko, David Jacquemin, Péter Kutas, Sujoy Sinha Roy Graz
University of Technology, Austria; Eötvös Loránd University, Hungary; University of
Birmingham, England
14:30 – 15:00Correlation power analysis of LESS and CROSS
Maciej Czuprynko, Anisha Mukherjee, Sujoy Sinha Roy ISEC, Graz University of Technology,
Austria
15:00 – 15:30TPL: Power Leakage Model Based on Technology
Library
Sumesh Manjunath, Hoda Alkhzaimi New York University Abu Dhabi, UAE
15:30 - 16:00
Closing Ceremony
16:00 - 16:30
Coffee Break
