Paulo Matias

• PhD in Computational Physics
• Professor (Assistant) at Federal University of São Carlos

Pulse-type weakly electric fishes communicate through electrical discharges with a stereotyped waveform, varying solely the interval between pulses according to the information being transmitted. This simple codification mechanism is similar to the one found in various known neuronal circuits, which renders these animals as good models for the stud...

Dedicated systems are fundamental for neuroscience experimental protocols that require timing determinism and synchronous stimuli generation. We developed a data acquisition and stimuli generator system for neuroscience research, optimized for recording timestamps from up to 6 spiking neurons and entirely specified in a high-level Hardware Descript...

Capture the Flag (CTF) competitions are increasingly important for the Brazilian cybersecurity community as education and professional tools. Unfortunately, CTF platforms may suffer from security issues, giving an unfair advantage to competitors. To mitigate this, we propose NIZKCTF, the first open-audit CTF platform based on non-interactive zero-k...

This paper presents a detailed and up-to-date security analysis of the voting software used in Brazilian elections. It is based on results obtained by the authors in a recent hacking challenge organized by the Superior Electoral Court (SEC), the national electoral authority. During the event, multiple serious vulnerabilities were detected in the vo...

Capture-The-Flag (CTF) are information security competitions. Even though they are organized by experts in the field, the platforms used to run the events are subject to vulnerabilities, just like any other software. Although literature has proposed the NIZKCTF (Non-Interactive Zero-Knowledge Capture the Flag) protocol, in which participants submit...

Updated version of the talk presented at Black Hat Asia 2019.

Background In today's world of big data, computational analysis has become a key driver of biomedical research. High-performance computational facilities are capable of processing considerable volumes of data, yet often lack an easy-to-use interface to guide the user in supervising and adjusting bioinformatics analysis via a tablet or smartphone....

In today's world of big data, computational analysis has become a key driver of biomedical research. Recent exponential growth in the volume of available omics data has reshaped the landscape of contemporary biology, creating demand for a continuous feedback loop that seamlessly integrates experimental biology techniques and bioinformatics tools. H...

Universidades e instituições de pesquisa frequentemente desejam oferecer serviços para colaboradores externos e visitantes. Federações são uma das formas mais consagradas de atingir esse objetivo. Eduroam é uma rede federada que facilita a itinerância no acesso à internet entre instituições participantes. No entanto, o acesso geralmente se dá por m...

This paper presents a detailed and up-to-date security analysis of the voting software used in Brazilian election based on results obtained by the authors in a recent hacking challenge organized the national electoral authority. During the event, multiple serious vulnerabilities were detected in the voting software, which when combined compromised...

Uma das ameças atualmente mais abundantes no ambiente computacional são os malwares. Uma das formas de preveni-los ou contra-atacá-los é realizando-se uma análise estática dos códigos maliciosos, visando entender a lógica de funcionamento, os algoritmos e especificações utilizadas sem arriscar-se à exposição de executar o código malicioso. Diversas...

Múltiplas vulnerabilidades graves foram detectadas nos últimos Testes Públicos de Segurança da urna eletrônica brasileira. Quando combinadas, comprometeram o sigilo do voto e a integridade do software, as principais propriedades de segurança do sistema. O armazenamento inseguro de chaves criptográficas, inseridas diretamente no código-fonte e compa...

This paper describes the current development and the main results of the πFlowMR Dataflow architecture prototype, inspired by the Manchester Dataflow Machine, implemented in a low cost FPGA cluster. Currently being developed in the Sao Carlos Institute of Physics, at the University of Sao Paulo, this prototype has presented interesting results, sho...

This talk presents a detailed and up-to-date security analysis of the voting software used in Brazilian elections by more than 140 million voters. It is based on results obtained recently by the authors in a restricted hacking challenge organized by the Superior Electoral Court (SEC), the national electoral authority. During the event, multiple ser...

Múltiplas vulnerabilidades graves foram detectadas nos últimos Testes Públicos de Segurança da urna eletrônica brasileira. Quando combinadas, comprometeram sigilo do voto e integridade do software, as principais propriedades de segurança do sistema. O armazenamento inseguro de chaves criptográficas, inseridas diretamente no código-fonte e compartil...

Testbeds são plataformas fundamentais para a criação e validação de novas tecnologias e arquiteturas de Internet do futuro. Uma vez que oferecem um ambiente totalmente controlável, escalável e próximo das características reais de uma rede como o ambiente da Internet, elas permitem a validação de arquiteturas elaboradas a partir do zero, com novos c...

Promoting Capture-The-Flag (CTF) competitions requires large operational costs, due to the number of participants scale and problems computing requirements. In problems that involve server exploitation, it is important to provide guarantees that each participant solution do not interfere with others. Thus, to save resources, we propose an automated...

In 1999, the Brazilian National Council for Scientific and Technological Development (CNPq) launched the Lattes CV Platform, and all Brazilian HEIs oblige their researchers and staff to inform and update their publication metadata on the Platform. The Lattes CVs thus represent a rich source of metadata for Brazilian HEIs needing to identify which p...

The brazilian federal educational institutions have the great challenge of managing their teaching, research and extension data, transforming them into open data, according to the current governmental precepts aimed at promoting transparency, and encouraging people's participation into the improvement of public services. In addition, institutions a...

Pulse-type weakly electric fish present a rich repertoire of spatio-temporal electrical patterns used in electrolocation and electrocommunication. Common characteristic patterns, such as pulse rate changes, offs and chirps, are often associated with important behavioral contexts, including aggression, hiding, and mating. However these behaviors are...

Electric fishes modulate their electric organ discharges with a remarkable variability. Some patterns can be easily identified, such as pulse rate changes, offs and chirps, which are often associated with important behavioral contexts, including aggression, hiding and mating. However, these behaviors are only observed when at least two fish are fre...

Pulse-type weakly electric fishes communicate through electrical discharges with a stereotyped waveform, varying solely the interval between pulses according to the information being transmitted. This simple codification mechanism is similar to the one found in various known neuronal circuits, which renders these animals as good models for the stud...

Os repositórios institucionais de acesso aberto maximizam as ações voltadas para a preservação e promoção do livre acesso à informação científica, apesar dos inúmeros desafios de caráter político,tecnológico, de recursos humanos e gestão que tangem à sua implementação, nota-se um crescimento do número de repositórios no país, contudo esses apresent...

We have compared two different resource arbitration architectures in our developed data acquisition and stimuli generator system for neuroscience research, entirely specified in a high-level Hardware Description Language (HDL). One of them was designed with a decoupled and latency insensitive modular approach, allowing for easier code reuse, while...

Many problems are related to network projects, such as electric distribution, telecommunication and others. Most of them can be represented by graphs, which manipulate thousands or millions of nodes, becoming almost an impossible task to obtain real-time solutions. Many efficient solutions use Evolutionary Algorithms (EA), where researches show tha...

A complete data acquisition and signal output control system for synchronous stimuli generation, geared towards in vivo neuroscience experiments, was developed using the Terasic DE2i-150 board. All emotions and thoughts are an emergent property of the chemical and electrical activity of neurons. Most of these cells are regarded as excitable cells (...

Many problems involving network design can be found in the real world, such as electric power circuit planning, telecommunications and phylogenetic trees. In general, solutions for these problems are modeled as forests represented by a graph manipulating thousands or millions of input variables, making it hard to obtain the solutions in a reasonabl...

In video conferencing, if two people talk at the same time howling noises can appear due to failures in the echo cancellation system. In order to reduce these noise situations, a novel AEC (Acoustic Echo Cancellation) system is proposed by using audio and video information. Through image processing techniques we have developed a new DTD (Double Tal...

This article describes the development of a visual stimulus generator to be used in neuroscience experiments with invertebrates such as flies. The experiment consists in the visualization of a fixed image that is displaced horizontally according to the stimulus data. The system is capable of displaying 640 × 480 pixels with 256 intensity levels at...

Problems involving network design can be found in many real world applications such as power systems, vehicle routing, telecommunication networks, phylogenetic trees, among others. These problems involve thousands or millions of input variables and often need information and solution in real time. In general, they are computationally complex (NP-Ha...