Hossein Hafezi

dblp:192/2291 · DBLP profile ↗
← Back
4ranked-venue papers
0as first author
4since 2021 · last 2026
0000-0003-1859-6263ORCID · conflict

Domains — the database's venue-derived domains; a paper can count in several

Security and privacy · 3 · 3 since 2021Systems, architecture and hardware · 1 · 1 since 2021
YearPublicationVenuePosition
2026 Single-Server Private Outsourcing of zk-SNARKs
Kasra Abbaszadeh, Hossein Hafezi, Jonathan Katz, Sarah Meiklejohn
SP2
2025 KZH-Fold: Accountable Voting from Sublinear Accumulation
abstract
Accumulation schemes are powerful primitives that enable distributed and incremental verifiable computation with less overhead than recursive SNARKs. However, existing schemes with constant-size accumulation verifiers, suffer from linear-sized accumulators and deciders, leading to linear-sized proofs that are unsuitable in distributed settings. Motivated by the need for bandwidth efficient accountable voting protocols, (I) We introduce KZH, a novel polynomial commitment scheme, and (II) KZH-fold, the first sublinear accumulation scheme with a constant-size verifier (3 group scalar multiplications) and O(n1/2 ) accumulator size and decider time. Our scheme generalizes to achieve accumulator and decider complexity of k • n1/k with a verifier of size k. Using the BCLMS compiler, (III) we build the first IVC/PCD scheme with sublinear proof and decider. (IV) Next, we propose a new approach to non-uniform IVC, where the cost of proving a step is proportional to the maximum size of all instruction circuits, and unlike previous approaches, the witness size is not linear in the number of instructions. (V) Leveraging these advancements, we demonstrate the power of KZH-fold by implementing an accountable voting scheme using a novel signature aggregation protocol supporting millions of nodes, significantly reducing communication overhead and verifier time compared to BLS-based aggregation. We implemented and benchmarked our protocols, and KZH-fold achieves a 2000x reduction in communication and a 50x improvement in decider time over Nova when proving 2000 Poseidon hashes, at the cost of 3x the prover time.
George Kadianakis, Arantxa Zapico, Hossein Hafezi, Benedikt Bünz
CCS3
2024 Hekaton: Horizontally-Scalable zkSNARKs Via Proof Aggregation
abstract
Zero-knowledge Succinct Non-interactive ARguments of Knowledge (zkSNARKs) allow a prover to convince a verifier of the correct execution of a large computation in private and easily-verifiable manner.These properties make zkSNARKs a powerful tool for adding accountability, scalability, and privacy to numerous systems such as blockchains and verifiable key directories.Unfortunately, existing zkSNARKs are unable to scale to large computations due to time and space complexity requirements for the prover algorithm.As a result, they cannot handle real-world instances of the aforementioned applications.In this work, we introduce Hekaton, a zkSNARK that overcomes these barriers and can efficiently handle arbitrarily large computations.We construct Hekaton via a new "distribute-and-aggregate" framework that breaks up large computations into small chunks, proves these chunks in parallel in a distributed system, and then aggregates the resulting chunk proofs into a single succinct proof.Underlying this framework is a new technique for efficiently handling data that is shared between chunks that we believe could be of independent interest.We implement a distributed prover for Hekaton, and evaluate its performance on a compute cluster.Our experiments show that Hekaton achieves strong horizontal scalability (proving time decreases linearly as we increase the number of nodes in the cluster), and is able to prove large computations quickly: it can prove computations of size 2 35 gates in under an hour, which is much faster than prior work.Finally, we also apply Hekaton to two applications of realworld interest: proofs of batched insertion for a verifiable key directory and proving correctness of RAM computations.In both cases, Hekaton is able to scale to handle realistic workloads with better efficiency than prior work.
Michael Rosenberg, Tushar Mopuri, Hossein Hafezi, Ian Miers, Pratyush Mishra 0001
CCS3
2022 Comprehensive Design and Experimental Verification of Shunt Active Power Filter
abstract
Harmonic pollution imposed by non-linear loads has become one of the main power quality challenges. In addition, reactive power absorption related to non-linear loads may result in serious power quality issues like voltage drop or voltage instability. Among different passive and active power filters (APFs), shunt active power filter (SAPF) is used a lot since it can compensate both complete harmonic and reactive components as well as high flexibility without any resonance. However, harmonic detection, hardware, and control design play vital role in the performance of the SAPF. From hardware point of view, design of the DC-link capacitor and series inductor are two main challenges. In this paper, a comprehensive design procedure is presented to design the suitable passive elements. In addition, high performance control design is also considered. Several simulation and experimental results are provided to verify the proper design and controller performance.
Mohammad Pichan, Hossein Hafezi, Hikmat Basnet, Tomi Roinila
IECON2