Alireza Gharib Blog

Event Calendar: PBC 2025: Permutation-based Crypto 2025 Madrid, Spain, 4 May 2025 Event date: 4 May 2025 Submission deadline: 28 February 2025 Notification: 15 March 2025 Go to Source

ePrint Report: Forking the RANDAO: Manipulating Ethereum’s Distributed Randomness Beacon Ábel Nagy, János Tapolcai, István András Seres, Bence Ladóczki Proof-of-stake consensus protocols often rely on distributed randomness beacons (DRBs) to generate randomness for leader selection. This work analyses the manipulability of Ethereum’s DRB implementation, RANDAO, in its current consensus mechanism. Even with its efficiency, RANDAO…

ePrint Report: Scalable Post-Quantum Oblivious Transfers for Resource-Constrained Receivers Aydin Abadi, Yvo Desmedt It is imperative to modernize traditional core cryptographic primitives, such as Oblivious Transfer (OT), to address the demands of the new digital era, where privacy-preserving computations are executed on low-power devices. This modernization is not merely an enhancement but a necessity to…

ePrint Report: Long Paper: All-You-Can-Compute: Packed Secret Sharing for Combined Resilience Sebastian Faust, Maximilian Orlt, Kathrin Wirschem, Liang Zhao Unprotected cryptographic implementations are vulnerable to implementation attacks, such as passive side-channel attacks and active fault injection attacks. Recently, countermeasures like polynomial masking and duplicated masking have been introduced to protect implementations against combined attacks that…

ePrint Report: ZODA: Zero-Overhead Data Availability Alex Evans, Nicolas Mohnblatt, Guillermo Angeris We introduce ZODA, short for ‘zero-overhead data availability,’ which is a protocol for proving that symbols received from an encoding (for tensor codes) were correctly constructed. ZODA has optimal overhead for both the encoder and the samplers. Concretely, the ZODA scheme incurs essentially…

ePrint Report: Parametrizing Maximal Orders Along Supersingular $ell$-Isogeny Paths Laia Amorós, James Clements, Chloe Martindale Suppose you have a supersingular $ell$-isogeny graph with vertices given by $j$-invariants defined over $mathbb{F}_{p^2}$, where $p = 4 cdot f cdot ell^e – 1$ and $ell equiv 3 pmod{4}$. We give an explicit parametrization of the maximal orders in…

ePrint Report: A New Paradigm for Server-Aided MPC Alessandra Scafuro, Tanner Verber The server-aided model for multiparty computation (MPC) was introduced to capture a real-world scenario where clients wish to off-load the heavy computation of MPC protocols to dedicated servers. A rich body of work has studied various trade-offs between security guarantees (e.g., semi-honest vs…

ePrint Report: Round-Optimal Compiler for Semi-Honest to Malicious Oblivious Transfer via CIH Varun Madathil, Alessandra Scafuro, Tanner Verber A central question in the theory of cryptography is whether we can build protocols that achieve stronger security guarantees, e.g., security against malicious adversaries, by combining building blocks that achieve much weaker security guarantees, e.g., security only…