Julio López 0002

dblp:l/JulioLopezHernandez · also Julio César López-Hernández · DBLP profile ↗
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33ranked-venue papers
5as first author
1since 2021 · last 2024
0000-0001-5139-0158ORCID · conflict

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

Security and privacy · 15 · 2 first-authorSystems, architecture and hardware · 9Databases, data management, data science and information retrieval · 4 · 2 first-authorTheory of computation · 3 · 1 first-author · 1 since 2021Artificial intelligence and machine learning · 1Computer networks · 1Applied, interdisciplinary, general and emerging computing · 1
YearPublicationVenuePosition
2024 PQC-AMX: Accelerating Saber and FrodoKEM on the Apple M1 and M3 SoCs
abstract
As CPU performance cannot keep up with the dramatic growth of the past few decades, CPU architects turn to domain-specific architectures to accelerate certain tasks. A recent trend is the introduction of matrix-multiplication accelerators to CPUs by manufacturers such as IBM, Intel and ARM, some of them yet to launch commercially. Apple’s systems-on-chip (SoCs) for its mobile phones, tablets and personal computers include a proprietary, undocumented CPU-coupled matrix multiplication coprocessor called AMX. We leverage AMX to accelerate the post-quantum lattice-based cryptosystems Saber and FrodoKEM, and benchmark their performance on Apple M1 and M3 SoCs. We propose a variant of the Toeplitz Matrix-Vector Product algorithm for polynomial multiplication, which sets new speed records for Saber using AMX, improving up to 20% for the main KEM operations, and 152% for matrix-vector multiplication of polynomials, over the current state-of-the-art. We also set new FrodoKEM speed records using AMX, gaining up to 21% for the main KEM operations and 124% for matrix multiplication (with further improvements for 4×-batching), over our optimized NEON implementation, also introduced here, which already improves upon the previous state-of-the-art for ARMv8 CPUs.
Décio Luiz Gazzoni Filho, Guilherme Brandão, Gora Adj, Arwa Alblooshi, Isaac Andrés Canales Martinez, Jorge Chávez-Saab, Julio López 0002
ARITH7
2019 Koblitz Curves over Quadratic Fields
Thomaz Oliveira, Julio López 0002, Daniel Cervantes-Vázquez, Francisco Rodríguez-Henríquez
J. Cryptol.2
2019 High-performance Implementation of Elliptic Curve Cryptography Using Vector Instructions
abstract
Elliptic curve cryptosystems are considered an efficient alternative to conventional systems such as DSA and RSA. Recently, Montgomery and Edwards elliptic curves have been used to implement cryptosystems. In particular, the elliptic curves Curve25519 and Curve448 were used for instantiating Diffie-Hellman protocols named X25519 and X448. Mapping these curves to twisted Edwards curves allowed deriving two new signature instances, called Ed25519 and Ed448, of the Edwards Digital Signature Algorithm. In this work, we focus on the secure and efficient software implementation of these algorithms using SIMD parallel processing. We present software techniques that target the Intel AVX2 vector instruction set for accelerating prime field arithmetic and elliptic curve operations. Our contributions result in a high-performance software library for AVX2-ready processors. For example, our library computes digital signatures 19% (for Ed25519) and 29% (for Ed448) faster than previous optimized implementations. Also, our library improves by 10% and 20% the execution time of X25519 and X448, respectively.
Armando Faz-Hernández, Julio López 0002, Ricardo Dahab
ACM Trans. Math. Softw.2
2018 A Faster Software Implementation of the Supersingular Isogeny Diffie-Hellman Key Exchange Protocol
abstract
Since its introduction by Jao and De Feo in 2011, the supersingular isogeny Diffie-Hellman (SIDH) key exchange protocol has positioned itself as a promising candidate for post-quantum cryptography. One salient feature of the SIDH protocol is that it requires exceptionally short key sizes. However, the latency associated to SIDH is higher than the ones reported for other post-quantum cryptosystem proposals. Aiming to accelerate the SIDH runtime performance, we present in this work several algorithmic optimizations targeting both elliptic-curve and field arithmetic operations. We introduce in the context of the SIDH protocol a more efficient approach for calculating the elliptic curve operation$P+[k]Q$. Our strategy achieves a factor 1.4 speedup compared with the popular variable-three-point ladder algorithm regularly used in the SIDH shared secret phase. Moreover, profiting from pre-computation techniques our algorithm yields a factor 1.7 acceleration for the computation of this operation in the SIDH key generation phase. We also present an optimized evaluation of the point tripling formula, and discuss several algorithmic and implementation techniques that lead to faster field arithmetic computations. A software implementation of the above improvements on an Intel Skylake Core i7-6700 processor gives a factor 1.33 speedup against the state-of-the-art software implementation of the SIDH protocol reported by Costello-Longa-Naehrig in CRYPTO 2016.
Armando Faz-Hernández, Julio López 0002, Eduardo Ochoa-Jiménez, Francisco Rodríguez-Henríquez
IEEE Trans. Computers2
2017 PRESENT Runs Fast - Efficient and Secure Implementation in Software
Tiago B. S. Reis, Diego F. Aranha, Julio López 0002
CHES3
2017 How to (Pre-)Compute a Ladder - Improving the Performance of X25519 and X448
Thomaz Oliveira, Julio López 0002, Hüseyin Hisil, Armando Faz-Hernández, Francisco Rodríguez-Henríquez
SAC2
2016 Software Implementation of Koblitz Curves over Quadratic Fields
Thomaz Oliveira, Julio López 0002, Francisco Rodríguez-Henríquez
CHES2
2015 Implementing GCM on ARMv8
Conrado Porto Lopes Gouvêa, Julio López 0002
CT-RSA2
2014 Fast Point Multiplication Algorithms for Binary Elliptic Curves with and without Precomputation
Thomaz Oliveira, Diego F. Aranha, Julio López 0002, Francisco Rodríguez-Henríquez
Selected Areas in Cryptography3
2013 Lambda Coordinates for Binary Elliptic Curves
Thomaz Oliveira, Julio López 0002, Diego F. Aranha, Francisco Rodríguez-Henríquez
CHES2
2012 Secure-TWS: Authenticating Node to Multi-user Communication in Shared Sensor Networks
abstract
Recent works have shown the usefulness of network and application layer protocols that connect low-power sensor nodes directly to multiple applications and users on the Internet. We propose a security solution for this scenario. While previous works have provided security support for various communication patterns in sensor networks, such as among nodes, from nodes to a base station, and from users to nodes, the security of communication from sensor nodes to multiple users has not been sufficiently addressed. Specifically, we explore this design space and develop a security solution, named Secure Tiny Web Service, for efficient authentication of data sent by a resource-constrained sensor node to multiple users, using digital signatures. We investigate the resource overheads in communication and computation of four suitable signature schemes—the Elliptic Curve Digital Signature Algorithm, the (elliptic curve) Schnorr signature, and the Boneh–Lynn–Shacham and Zhang–Safavi-Naini–Susilo short signature schemes. We implement these schemes on two popular sensor node architectures (based on AVR ATmega128L and MSP430 processors with 802.15.4 radios) and experimentally characterize relevant trade-offs.
Leonardo B. Oliveira, Aman Kansal, Conrado Porto Lopes Gouvêa, Diego F. Aranha, Julio López 0002, Bodhi Priyantha, Michel Goraczko, Feng Zhao 0001
Comput. J.5
2011 Software Implementation of Binary Elliptic Curves: Impact of the Carry-Less Multiplier on Scalar Multiplication
Jonathan Taverne, Armando Faz-Hernández, Diego F. Aranha, Francisco Rodríguez-Henríquez, Darrel Hankerson, Julio López 0002
CHES6
2011 YCSB++: benchmarking and performance debugging advanced features in scalable table stores
abstract
Inspired by Google's BigTable, a variety of scalable, semi-structured, weak-semantic table stores have been developed and optimized for different priorities such as query speed, ingest speed, availability, and interactivity. As these systems mature, performance benchmarking will advance from measuring the rate of simple workloads to understanding and debugging the performance of advanced features such as ingest speed-up techniques and function shipping filters from client to servers. This paper describes YCSB++, a set of extensions to the Yahoo! Cloud Serving Benchmark (YCSB) to improve performance understanding and debugging of these advanced features. YCSB++ includes multi-tester coordination for increased load and eventual consistency measurement, multi-phase workloads to quantify the consequences of work deferment and the benefits of anticipatory configuration optimization such as B-tree pre-splitting or bulk loading, and abstract APIs for explicit incorporation of advanced features in benchmark tests. To enhance performance debugging, we customized an existing cluster monitoring tool to gather the internal statistics of YCSB++, table stores, system services like HDFS, and operating systems, and to offer easy post-test correlation and reporting of performance behaviors. YCSB++ features are illustrated in case studies of two BigTable-like table stores, Apache HBase and Accumulo, developed to emphasize high ingest rates and finegrained security.
Swapnil Patil 0001, Milo Polte, Kai Ren 0001, Wittawat Tantisiriroj, Julio López 0002, Garth A. Gibson, Adam Fuchs, Billie Rinaldi
SoCC6
2011 Faster Explicit Formulas for Computing Pairings over Ordinary Curves
Diego F. Aranha, Koray Karabina, Patrick Longa, Catherine H. Gebotys, Julio López 0002
EUROCRYPT5
2011 Clustering very large multi-dimensional datasets with MapReduce
abstract
Given a very large moderate-to-high dimensionality dataset, how could one cluster its points? For datasets that don't fit even on a single disk, parallelism is a first class option. In this paper we explore MapReduce for clustering this kind of data. The main questions are (a) how to minimize the I/O cost, taking into account the already existing data partition (e.g., on disks), and (b) how to minimize the network cost among processing nodes. Either of them may be a bottleneck. Thus, we propose the Best of both Worlds -- BoW method, that automatically spots the bottleneck and chooses a good strategy. Our main contributions are: (1) We propose BoW and carefully derive its cost functions, which dynamically choose the best strategy; (2) We show that BoW has numerous desirable features: it can work with most serial clustering methods as a plugged-in clustering subroutine, it balances the cost for disk accesses and network accesses, achieving a very good tradeoff between the two, it uses no user-defined parameters (thanks to our reasonable defaults), it matches the clustering quality of the serial algorithm, and it has near-linear scale-up; and finally, (3) We report experiments on real and synthetic data with billions of points, using up to 1,024 cores in parallel. To the best of our knowledge, our Yahoo! web is the largest real dataset ever reported in the database subspace clustering literature. Spanning 0.2 TB of multi-dimensional data, it took only 8 minutes to be clustered, using 128 cores.
Robson L. F. Cordeiro, Caetano Traina Jr., Agma J. M. Traina, Julio López 0002, U Kang, Christos Faloutsos
KDD4
2011 Recipes for Baking Black Forest Databases - Building and Querying Black Hole Merger Trees from Cosmological Simulations
Julio López 0002, Colin DeGraf, Tiziana di Matteo, Eugene Fink, Garth A. Gibson
SSDBM1
2011 TinyPBC: Pairings for authenticated identity-based non-interactive key distribution in sensor networks
Leonardo B. Oliveira, Diego F. Aranha, Conrado Porto Lopes Gouvêa, Michael Scott, Danilo F. Câmara, Julio López 0002, Ricardo Dahab
Comput. Commun.6
2010 High-Speed Parallel Software Implementation of the ηT Pairing
Diego F. Aranha, Julio López 0002, Darrel Hankerson
CT-RSA2
2010 DiscFinder: a data-intensive scalable cluster finder for astrophysics
abstract
DiscFinder is a scalable approach for identifying large-scale astronomical structures, such as galaxy clusters, in massive observation and simulation astrophysics datasets. It is designed to operate on datasets with tens of billions of astronomical objects, even in the case when the dataset is much larger than the aggregate memory of compute cluster used for the processing.
Kai Ren 0001, Julio López 0002, Eugene Fink, Garth A. Gibson
HPDC3
2010 BEMC: A Searchable, Compressed Representation for Large Seismic Wavefields
Julio López 0002, Leonardo Ramírez-Guzmán, Jacobo Bielak, David R. O'Hallaron
SSDBM1
2008 Materialized community ground models for large-scale earthquake simulation
abstract
Large-scale earthquake simulation requires source datasets which describe the highly heterogeneous physical characteristics of the earth in the region under simulation. Physical characteristic datasets are the first stage in a simulation pipeline which includes mesh generation, partitioning, solving, and visualization. In practice, the data is produced in an ad-hoc fashion for each set of experiments, which has several significant shortcomings including lower performance, decreased repeatability and comparability, and a longer time to science, an increasingly important metric. As a solution to these problems, we propose a new approach for providing scientific data to ground motion simulations, in which ground model datasets are fully materialized into octress stored on disk, which can be more efficiently queried (by up to two orders of magnitude) than the underlying community velocity model programs. While octrees have long been used to store spatial datasets, they have not yet been used at the scale we propose. We further propose that these datasets can be provided as a service, either over the Internet or, more likely, in a datacenter or supercomputing center in which the simulations take place. Since constructing these octrees is itself a challenge, we present three data-parallel techniques for efficiently building them, which can significantly decrease the build time from days or weeks to hours using commodity clusters. This approach typifies a broader shift toward science as a service techniques in which scientific computation and storage services become more tightly intertwined.
Steven W. Schlosser, Michael P. Ryan, Ricardo Taborda-Rios, Julio López 0002, David R. O'Hallaron, Jacobo Bielak
SC4
2008 Low-Complexity Bit-Parallel Square Root Computation over GF(2^{m}) for All Trinomials
abstract
In this contribution we introduce a low-complexity bit-parallel algorithm for computing square roots over binary extension fields. Our proposed method can be applied for any type of irreducible polynomials. We derive explicit formulae for the space and time complexities associated to the square root operator when working with binary extension fields generated using irreducible trinomials. We show that for those finite fields, it is possible to compute the square root of an arbitrary field element with equal or better hardware efficiency than the one associated to the field squaring operation. Furthermore, a practical application of the square root operator in the domain of field exponentiation computation is presented. It is shown that by using as building blocks squarers, multipliers and square root blocks, a parallel version of the classical square-and-multiply exponentiation algorithm can be obtained. A hardware implementation of that parallel version may provide a speedup of up to 50% percent when compared with the traditional version.
Francisco Rodríguez-Henríquez, Guillermo Morales-Luna, Julio López 0002
IEEE Trans. Computers3
2007 //TRACE: Parallel Trace Replay with Approximate Causal Events
Michael P. Mesnier, Matthew Wachs, Raja R. Sambasivan, Julio López 0002, James Hendricks, Gregory R. Ganger, David R. O'Hallaron
FAST4
2007 TinyTate: Computing the Tate Pairing in Resource-Constrained Sensor Nodes
abstract
After a few years of intense research, wireless sensor networks (WSNs) still demand new secure and cryptographic schemes. On the other hand, the advent of cryptography from pairings has enabled a wide range of novel cryptosystems. In this work we present TinyTate, the first known implementation of pairings for sensor nodes based on the 8-bit/7.3828-MHz ATmega128L microcontroller (e.g., MICA2 and MICAz motes). We then conclude that cryptography from pairings is indeed viable in resource-constrained nodes.
Leonardo B. Oliveira, Diego F. Aranha, Eduardo Morais, Felipe Daguano, Julio López 0002, Ricardo Dahab
NCA5
2006 New Point Compression Algorithms for Binary Curves
abstract
This paper presents two new algorithms for point compression for elliptic curves defined over F2m, m odd. The first algorithm works for curves with Tr(a) = 1 and offers computational advantages over previous methods. The second algorithm is based on the λ representation of an elliptic point. The proposed algorithms require m bits to compress an elliptic point and can be used for all random binary curves recommended by NIST.
Julio López 0002, Ricardo Dahab
ITW1
2006 Software Multiplication Using Gaussian Normal Bases
abstract
Fast algorithms for multiplication in finite fields are required for several cryptographic applications, in particular for implementing elliptic curve operations over binary fields F/sub 2m/. In this paper, we present new software algorithms for efficient multiplication over F/sub 2m/ that use a Gaussian normal basis representation. Two approaches are presented, direct normal basis multiplication and a method that exploits a mapping to a ring where fast polynomial-based techniques can be employed. Our analysis, including experimental results on an Intel Pentium family processor, shows that the new algorithms are faster and can use memory more efficiently than previous methods. Despite significant improvements, we conclude that the penalty in multiplication is still sufficiently large to discourage the use of normal bases in software implementations of elliptic curve systems.
Ricardo Dahab, Darrel Hankerson, Men Long, Julio López 0002, Alfred Menezes
IEEE Trans. Computers5
2005 A custom instruction approach for hardware and software implementations of finite field arithmetic over F263 using Gaussian normal bases
Marcio Juliato, Guido Araujo, Julio López 0002, Ricardo Dahab
FPT3
2004 Field Inversion and Point Halving Revisited
abstract
We present a careful analysis of elliptic curve point multiplication methods that use the point halving technique of Knudsen and Schroeppel and compare these methods to traditional algorithms that use point doubling. The performance advantage of halving methods is clearest in the case of point multiplication kP, where P is not known in advance and smaller field inversion to multiplication ratios generally favor halving. Although halving essentially operates on affine coordinate representations, we adapt an algorithm of Knuth to allow efficient use of projective coordinates with halving-based windowing methods for point multiplication.
Kenny Fong, Darrel Hankerson, Julio López 0002, Alfred Menezes
IEEE Trans. Computers3
2001 Software Implementation of the NIST Elliptic Curves Over Prime Fields
Darrel Hankerson, Julio López 0002, Alfred Menezes
CT-RSA3
2000 Software Implementation of Elliptic Curve Cryptography over Binary Fields
Darrel Hankerson, Julio López 0002, Alfred Menezes
CHES2
2000 PGP in Constrained Wireless Devices
Donny Cheung, Darrel Hankerson, Julio López 0002, Michael Kirkup, Alfred Menezes
USENIX Security Symposium4
1999 Fast Multiplication on Elliptic Curves over GF(2m) without Precomputation
Julio López 0002, Ricardo Dahab
CHES1
1998 Improved Algorithms for Elliptic Curve Arithmetic in GF(2n)
Julio López 0002, Ricardo Dahab
Selected Areas in Cryptography1