Demo Data from EDBT 2026 / reviewers in the wild / expert
Hamid Nejatollahi
dblp:168/0960
· DBLP profile ↗
8ranked-venue papers
5as first author
1since 2021 · last 2021
0000-0002-5886-2290ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Systems, architecture and hardware · 6 · 4 first-authorGraphics, computer vision, multimedia, augmented reality and games · 1 · 1 first-author
Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.
| Computer architecture, parallel and distributed computing, and storage systems
3 papers |
Hardware accelerators and domain-specific architectures · 27% GPUs and heterogeneous computing · 27% Emerging computing paradigms · 27% | |
| Network and information security
1 paper |
Cryptographic primitives and cryptanalysis · 100% |
Topics — the 9 heaviest of 9, each with the papers that count most for it
| Topic | Weight | Papers | Last | Evidence papers |
|---|---|---|---|---|
Emerging computing paradigms
approximate computing |
0.8 | 2 | 2020 | Data Reuse for Accelerated Approximate Warps · IEEE Trans. Comput. Aided Des. Integr. Circuits Syst. 2020 ARGA: Approximate Reuse for GPGPU Acceleration · DAC 2019 |
Hardware accelerators and domain-specific architectures
cryptographic accelerator |
0.4 | 1 | 2020 | CryptoPIM: In-memory Acceleration for Lattice-based Cryptographic Hardware · DAC 2020 |
GPUs and heterogeneous computing
GPU computing |
0.4 | 1 | 2020 | Data Reuse for Accelerated Approximate Warps · IEEE Trans. Comput. Aided Des. Integr. Circuits Syst. 2020 |
Memory systems
processing-in-memory |
0.4 | 1 | 2020 | CryptoPIM: In-memory Acceleration for Lattice-based Cryptographic Hardware · DAC 2020 |
Hardware accelerators and domain-specific architectures
approximate computing accelerator |
0.4 | 1 | 2019 | ARGA: Approximate Reuse for GPGPU Acceleration · DAC 2019 |
GPUs and heterogeneous computing › GPU computing
GPGPU acceleration |
0.4 | 1 | 2019 | ARGA: Approximate Reuse for GPGPU Acceleration · DAC 2019 |
Cryptographic primitives and cryptanalysis › post-quantum cryptography
lattice-based cryptography |
0.1 | 1 | 2020 | CryptoPIM: In-memory Acceleration for Lattice-based Cryptographic Hardware · DAC 2020 |
Cryptographic primitives and cryptanalysis
post-quantum cryptography |
0.1 | 1 | 2020 | CryptoPIM: In-memory Acceleration for Lattice-based Cryptographic Hardware · DAC 2020 |
Energy-efficient computing › power-performance tradeoff
energy-delay product optimization |
0.1 | 1 | 2019 | ARGA: Approximate Reuse for GPGPU Acceleration · DAC 2019 |
Methods — techniques the papers use, named apart from their topics
processing-in-memory · 0.9approximate lookup table · 0.8number-theoretic transform · 0.4number theoretic transform · 0.4neuron-aware approximation · 0.4multi-table parallel lookup · 0.4
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2021 | High-Performance Parallel Fault Simulation for Multi-Core SystemsabstractFault simulation is a time-consuming process that requires customized methods and techniques to accelerate it. Multi-threading and Multi-core approaches are two promising techniques that can be exploited to accelerate the fault simulation process by using different parts of the hardware at the same time. However, an efficient parallelization is obtained only by the refinement of software with respect to the hardware platform. In this paper, a parallel multi-thread fault simulation technique is proposed to accelerate the simulation process on multi-core platforms. In this approach, the gate input values are independently assigned to each thread. Each input value carries the information of several parallel simulation processes. This provides a multithread parallel fault simulation environment. The experimental results show that the proposed technique can efficiently use the hardware platform. In a single-core platform, the proposed technique can reduce the time by 25% while in a dual-core increasing the thread approximately halves the execution time. Masoomeh Karami, M. H. Haghbayan, Masoumeh Ebrahimi, Hamid Nejatollahi, Hannu Tenhunen, Juha Plosila |
PDP | 4 |
| 2020 | CryptoPIM: In-memory Acceleration for Lattice-based Cryptographic HardwareabstractQuantum computers promise to solve hard mathematical problems such as integer factorization and discrete logarithms in polynomial time, making standardized public-key cryptosystems insecure. Lattice-Based Cryptography (LBC) is a promising post-quantum public key cryptographic protocol that could replace standardized public key cryptography, thanks to the inherent post-quantum resistant properties, efficiency, and versatility. A key mathematical tool in LBC is the Number Theoretic Transform (NTT), a common method to compute polynomial multiplication. It is the most compute-intensive routine and requires acceleration for practical deployment of LBC protocols. In this paper, we propose CryptoPIM, a high-throughput Processing In-Memory (PIM) accelerator for NTT-based polynomial multiplier with the support of polynomials with degrees up to 32k. Compared to the fastest FPGA implementation of an NTT-based multiplier, CryptoPIM achieves on average 31x throughput improvement with the same energy and only 28% performance reduction, thereby showing promise for practical deployment of LBC. Hamid Nejatollahi, Saransh Gupta, Mohsen Imani, Tajana Rosing, Rosario Cammarota, Nikil Dutt |
DAC | 1 |
| 2020 | Exploring Energy Efficient Quantum-resistant Signal Processing Using Array ProcessorsabstractQuantum computers threaten to break public-key cryptography schemes such as DSA and ECDSA in polynomial time, which poses an imminent threat to secure signal processing. Ring learning with error (RLWE) lattice-based cryptography (LBC) is one of the most promising families of post-quantum cryptography (PQC) schemes in terms of efficiency and versatility. Two conventional methods to compute polynomial multiplication, the most compute-intensive routine in the RLWE schemes, are convolutions and Number Theoretic Transform (NTT).In this work, we explore the energy efficiency of polynomial multiplier using systolic architecture for the first time. As an early exploration, we design two high-throughput systolic array polynomial multipliers, including NTT-based and convolution-based, and compare them to our low-cost sequential (non-systolic) NTT-based multiplier. Our sequential NTT-based multiplier achieves 3x speedup over the state-of-the-art FGPA implementation of the polynomial multiplier in the NewHope-Simple key exchange mechanism on a low-cost Artix7 FPGA. When synthesized on a Zynq UltraScale+ FPGA, the NTT-based systolic and convolution-based systolic designs achieve on average 1.7x and 7.5x speedup over our sequential NTT-based multiplier respectively, which can lead to generating over 2x more signatures per second by CRYSTALS-Dilithium, a PQC digital signature scheme. These explorations help designers select the right PQC implementations for making future signal processing applications quantum-resistant. Hamid Nejatollahi, Sina Shahhosseini, Rosario Cammarota, Nikil Dutt |
ICASSP | 1 |
| 2020 | Data Reuse for Accelerated Approximate WarpsabstractMany data-driven applications, including computer vision, machine learning, speech recognition, and medical diagnostics show tolerance to computation error. These applications are often accelerated on GPUs, but the performance improvements require high energy usage. In this article, we present DRAAW, an approximate computing technique capable of accelerating GPGPU applications at a warp level. In GPUs, warps are groups of threads which issued together across multiple cores. The slowest thread dictates the pace of the warp, so DRAAW identifies these bottlenecks and avoids them during approximation. We alleviate computation costs by using an approximate lookup table which tracks recent operations and reuses them to exploit temporal locality within applications. To improve neural network performance, we propose neuron aware approximation, a technique which profiles operations within network layers and automatically configures DRAAW to ensure computations with more impact on the output accuracy are subject to less approximation. We evaluate our design by placing DRAAW within each core of an Nvidia Kepler Architecture Titan. DRAAW improves throughput by up to 2.8× and improves energy-delay product (EDP) by 5.6× for six GPGPU applications while maintaining less than 5% output error. We show neuron aware approximation accelerates the inference of six neutral networks by 2.9× and improves EDP by 6.2× with less than 1% impact on prediction accuracy. Daniel Peroni, Mohsen Imani, Hamid Nejatollahi, Nikil Dutt, Tajana Rosing |
IEEE Trans. Comput. Aided Des. Integr. Circuits Syst. | 3 |
| 2020 | Synthesis of Flexible Accelerators for Early Adoption of Ring-LWE Post-quantum CryptographyabstractThe advent of the quantum computer makes current public-key infrastructure insecure. Cryptography community is addressing this problem by designing, efficiently implementing, and evaluating novel public-key algorithms capable of withstanding quantum computational power. Governmental agencies, such as NIST, are promoting standardization of quantum-resistant algorithms that is expected to run for 7 years. Several modern applications must maintain permanent data secrecy; therefore, they ultimately require the use of quantum-resistant algorithms. Because algorithms are still under scrutiny for eventual standardization, the deployment of the hardware implementation of quantum-resistant algorithms is still in early stages. In this article, we propose a methodology to design programmable hardware accelerators for lattice-based algorithms, and we use the proposed methodology to implement flexible and energy efficient post-quantum cache-based accelerators for NewHope , Kyber , Dilithium , Key Consensus from Lattice ( KCL ), and R.EMBLEM submissions to the NIST standardization contest. To the best of our knowledge, we propose the first efficient domain-specific, programmable cache-based accelerators for lattice-based algorithms. We design a single accelerator for a common kernel among various schemes with different kernel sizes, i.e., loop count, and data types. This is in contrast to the traditional approach of designing one special purpose accelerators for each scheme. We validate our methodology by integrating our accelerators into an HLS-based SoC infrastructure based on the X86 processor and evaluate overall performance. Our experiments demonstrate the suitability of the approach and allow us to collect insightful information about the performance bottlenecks and the energy efficiency of the explored algorithms. Our results provide guidelines for hardware designers, highlighting the optimization points to address for achieving the highest energy minimization and performance increase. At the same time, our proposed design allows us to specify and execute new variants of lattice-based schemes with superior energy efficiency compared to the main application processor without changing the hardware acceleration platform. For example, we manage to reduce the energy consumption up to 2.1× and energy-delay product (EDP) up to 5.2× and improve the speedup up to 2.5×. Hamid Nejatollahi, Felipe Valencia, Subhadeep Banik, Francesco Regazzoni 0001, Rosario Cammarota, Nikil Dutt |
ACM Trans. Embed. Comput. Syst. | 1 |
| 2019 | ARGA: Approximate Reuse for GPGPU AccelerationabstractMany data-driven applications including computer vision, speech recognition, and medical diagnostics show tolerance to error during computation. These applications are often accelerated on GPUs, but high computational costs limit performance and increase energy usage. In this paper, we present ARGA, an approximate computing technique capable of accelerating GPGPU applications. ARGA provides an approximate lookup table to GPGPU cores to avoid recomputing instructions with identical or similar values. We propose multi-table parallel lookup which enables computational reuse to significantly speed-up GPGPU computation by checking incoming instructions in parallel. The inputs of each operation are searched for in a lookup table. Matches resulting in an exact or low error are removed from the floating point pipeline and used directly as output. Matches producing highly inaccurate results are computed on exact hardware to minimize application error. We simulate our design by placing ARGA within each core of an Nvidia Kepler Architecture Titan and an AMD Southern Island 7970. We show our design improves performance throughput by up to 2.7× and improves EDP by 5.3× for 6 GPGPU applications while maintaining less than 5% output error. We also show ARGA accelerates inference of a LeNet NN by 2.1× and improves EDP by 3.7× without significantly impacting classification accuracy. Daniel Peroni, Mohsen Imani, Hamid Nejatollahi, Nikil Dutt, Tajana Rosing |
DAC | 3 |
| 2019 | Flexible NTT Accelerators for RLWE Lattice-Based CryptographyabstractIn this work, we propose methods to design flexible and energy-efficient hardware accelerators for ring learning with error (RLWE) lattice-based cryptographic protocols, such as key agreement and digital signature. We apply the proposed methods to design the first programmable DMA-based family of accelerators for the Number Theoretic Transform (NTT), a commonly used kernel inside variants of RLWE protocols NewHope and Kyber. We validate our methods by integrating the accelerators into an HLS-based System on Chip (SoC) simulator. Experiments confirm the suitability of the flexible DMA-based accelerators for their use as part of lattice-based schemes. Our proposed designs are capable of executing new variants of lattice-based schemes with superior energy efficiency compared to executing the scheme entirely on the main processor, but without modifying the hardware acceleration platform. Performance improvements are up to 2x, energy consumption improves up to 1.9x, and energy-delay product (EDP) improves up to 3.9x. Together with such improved energy efficiency and performance, the flexibility inherent in our accelerators provides insights for, while reducing the risk of early adoption of lattice-based PQC cryptographic protocols in hardware products. Hamid Nejatollahi, Rosario Cammarota, Nikil Dutt |
ICCD | 1 |
| 2015 | Voltage scaling and dark silicon in symmetric multicore processors
Hamid Nejatollahi, Mostafa E. Salehi |
J. Supercomput. | 1 |