Malicious traffic detection on sampled network flow data with novelty-detection-based models.

Cyber-attacks are a major problem for users, businesses, and institutions. Classical anomaly detection techniques can detect malicious traffic generated in a cyber-attack by analyzing individual network packets. However, routers that manage large traffic loads can only examine some packets. These devices often use lightweight flow-based protocols to collect network statistics. Analyzing flow data also allows for detecting malicious network traffic. But even gathering flow data has a high computational cost, so routers usually apply a sampling rate to generate flows. This sampling reduces the computational load on routers, but much information is lost. This work aims to demonstrate that malicious traffic can be detected even on flow data collected with a sampling rate of 1 out of 1,000 packets. To do so, we evaluate anomaly-detection-based models using synthetic sampled flow data and actual sampled flow data from RedCAYLE, the Castilla y León regional subnet of the Spanish academic and research network. The results presented show that detection of malicious traffic on sampled flow data is possible using novelty-detection-based models with a high accuracy score and a low false alarm rate.

Biometric recognition through gait analysis.

The use of people recognition techniques has become critical in some areas. For instance, social or assistive robots carry out collaborative tasks in the robotics field. A robot must know who to work with to deal with such tasks. Using biometric patterns may replace identification cards or codes on access control to critical infrastructures. The usage of Red Green Blue Depth (RGBD) cameras is ubiquitous to solve people recognition. However, this sensor has some constraints, such as they demand high computational capabilities, require the users to face the sensor, or do not regard users' privacy. Furthermore, in the COVID-19 pandemic, masks hide a significant portion of the face. In this work, we present BRITTANY, a biometric recognition tool through gait analysis using Laser Imaging Detection and Ranging (LIDAR) data and a Convolutional Neural Network (CNN). A Proof of Concept (PoC) has been carried out in an indoor environment with five users to evaluate BRITTANY. A new CNN architecture is presented, allowing the classification of aggregated occupancy maps that represent the people's gait. This new architecture has been compared with LeNet-5 and AlexNet through the same datasets. The final system reports an accuracy of 88%.

A Framework for the Optimization of Complex Cyber-Physical Systems via Directed Acyclic Graph.

Mathematical modeling and data-driven methodologies are frequently required to optimize industrial processes in the context of Cyber-Physical Systems (CPS). This paper introduces the PipeGraph software library, an open-source python toolbox for easing the creation of machine learning models by using Directed Acyclic Graph (DAG)-like implementations that can be used for CPS. scikit-learn's Pipeline is a very useful tool to bind a sequence of transformers and a final estimator in a single unit capable of working itself as an estimator. It sequentially assembles several steps that can be cross-validated together while setting different parameters. Steps encapsulation secures the experiment from data leakage during the training phase. The scientific goal of PipeGraph is to extend the concept of Pipeline by using a graph structure that can handle scikit-learn's objects in DAG layouts. It allows performing diverse operations, instead of only transformations, following the topological ordering of the steps in the graph; it provides access to all the data generated along the intermediate steps; and it is compatible with GridSearchCV function to tune the hyperparameters of the steps. It is also not limited to (X,y) entries. Moreover, it has been proposed as part of the scikit-learn-contrib supported project, and is fully compatible with scikit-learn. Documentation and unitary tests are publicly available together with the source code. Two case studies are analyzed in which PipeGraph proves to be essential in improving CPS modeling and optimization: the first is about the optimization of a heat exchange management system, and the second deals with the detection of anomalies in manufacturing processes.

Flow-Data Gathering Using NetFlow Sensors for Fitting Malicious-Traffic Detection Models.

Advanced persistent threats (APTs) are a growing concern in cybersecurity. Many companies and governments have reported incidents related to these threats. Throughout the life cycle of an APT, one of the most commonly used techniques for gaining access is network attacks. Tools based on machine learning are effective in detecting these attacks. However, researchers usually have problems with finding suitable datasets for fitting their models. The problem is even harder when flow data are required. In this paper, we describe a framework to gather flow datasets using a NetFlow sensor. We also present the Docker-based framework for gathering netflow data (DOROTHEA), a Docker-based solution implementing the above framework. This tool aims to easily generate taggable network traffic to build suitable datasets for fitting classification models. In order to demonstrate that datasets gathered with DOROTHEA can be used for fitting classification models for malicious-traffic detection, several models were built using the model evaluator (MoEv), a general-purpose tool for training machine-learning algorithms. After carrying out the experiments, four models obtained detection rates higher than 93%, thus demonstrating the validity of the datasets gathered with the tool.

Automatic Extraction of Power Cables Location in Railways Using Surface LiDAR Systems.

The assembly and maintenance of electrified railway systems is of vital importance for its correct operation. Contact wires are critical elements since the correct collection of energy from trains through pantographs depends on them. Periodical inspection of the state of these installations is essential. This task traditionally implies a heavy manual workload subject to errors. A new system that allows one to check the state (height and stagger) of contact and messenger wires is presented on this article blueA new method based on seven steps for identifying the contact wires and measuring their height and stagger from point clouds recorded by means of a LiDAR system is presented. This system can be used both in assembly and maintenance phases, as well as afterwards, allowing the analysis of point clouds previously recorded. The new method was evaluated in both test bench and real environments against the commonly used measurement method. Results with the comparison between this new system and the commonly used measurement method in both test bench and real railway environments are presented. Results of this comparison show differences of less than a centimetre on average and the amount of time spent for the measuring phase is significantly decreased and not prone to human errors.

Tracking People in a Mobile Robot From 2D LIDAR Scans Using Full Convolutional Neural Networks for Security in Cluttered Environments.

Tracking people has many applications, such as security or safe use of robots. Many onboard systems are based on Laser Imaging Detection and Ranging (LIDAR) sensors. Tracking peoples' legs using only information from a 2D LIDAR scanner in a mobile robot is a challenging problem because many legs can be present in an indoor environment, there are frequent occlusions and self-occlusions, many items in the environment such as table legs or columns could resemble legs as a result of the limited information provided by two-dimensional LIDAR usually mounted at knee height in mobile robots, etc. On the other hand, LIDAR sensors are affordable in terms of the acquisition price and processing requirements. In this article, we describe a tool named PeTra based on an off-line trained full Convolutional Neural Network capable of tracking pairs of legs in a cluttered environment. We describe the characteristics of the system proposed and evaluate its accuracy using a dataset from a public repository. Results show that PeTra provides better accuracy than Leg Detector (LD), the standard solution for Robot Operating System (ROS)-based robots.