Security Evaluation of Support Vector Machines in Adversarial Environments

Support Vector Machines (SVMs) are among the most popular classification techniques adopted in security applications like malware detection, intrusion detection, and spam filtering. However, if SVMs are to be incorporated in real-world security systems, they must be able to cope with attack patterns that can either mislead the learning algorithm (poisoning), evade detection (evasion), or gain information about their internal parameters (privacy breaches). The main contributions of this chapter are twofold. First, we introduce a formal general framework for the empirical evaluation of the security of machine-learning systems. Second, according to our framework, we demonstrate the feasibility of evasion, poisoning and privacy attacks against SVMs in real-world security problems. For each attack technique, we evaluate its impact and discuss whether (and how) it can be countered through an adversary-aware design of SVMs. Our experiments are easily reproducible thanks to open-source code that we have made available, together with all the employed datasets, on a public repository.Comment: 47 pages, 9 figures; chapter accepted into book 'Support Vector Machine Applications

TRIDEnT: Building Decentralized Incentives for Collaborative Security

Sophisticated mass attacks, especially when exploiting zero-day vulnerabilities, have the potential to cause destructive damage to organizations and critical infrastructure. To timely detect and contain such attacks, collaboration among the defenders is critical. By correlating real-time detection information (alerts) from multiple sources (collaborative intrusion detection), defenders can detect attacks and take the appropriate defensive measures in time. However, although the technical tools to facilitate collaboration exist, real-world adoption of such collaborative security mechanisms is still underwhelming. This is largely due to a lack of trust and participation incentives for companies and organizations. This paper proposes TRIDEnT, a novel collaborative platform that aims to enable and incentivize parties to exchange network alert data, thus increasing their overall detection capabilities. TRIDEnT allows parties that may be in a competitive relationship, to selectively advertise, sell and acquire security alerts in the form of (near) real-time peer-to-peer streams. To validate the basic principles behind TRIDEnT, we present an intuitive game-theoretic model of alert sharing, that is of independent interest, and show that collaboration is bound to take place infinitely often. Furthermore, to demonstrate the feasibility of our approach, we instantiate our design in a decentralized manner using Ethereum smart contracts and provide a fully functional prototype.Comment: 28 page

Fast deep autoencoder for federated learning

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract]: This paper presents a novel, fast and privacy preserving implementation of deep autoencoders. DAEF (Deep AutoEncoder for Federated learning), unlike traditional neural networks, trains a deep autoencoder network in a non-iterative way, which drastically reduces training time. Training can be performed incrementally, in parallel and distributed and, thanks to its mathematical formulation, the information to be exchanged does not endanger the privacy of the training data. The method has been evaluated and compared with other state-of-the-art autoencoders, showing interesting results in terms of accuracy, speed and use of available resources. This makes DAEF a valid method for edge computing and federated learning, in addition to other classic machine learning scenarios.This work was supported in part by grant Machine Learning on the Edge - Ayudas Fundación BBVA a Equipos de Investigación Científica 2019; the Spanish National Plan for Scientific and Technical Research and Innovation (PID2019-109238GB-C22 and TED2021-130599A-I00); the Xunta de Galicia (ED431C 2022/44) and ERDF funds. CITIC is funded by Xunta de Galicia and ERDF funds. Funding for open access charge: Universidade da Coruña/CISUG.Xunta de Galicia; ED431C 2022/4

Towards privacy preserving cooperative cloud based intrusion detection systems

Les systèmes infonuagiques deviennent de plus en plus complexes, dynamiques et vulnérables aux attaques. Par conséquent, il est de plus en plus difficile pour qu'un seul système de détection d'intrusion (IDS) basé sur le cloud puisse repérer toutes les menaces, en raison des lacunes de connaissances sur les attaques et leurs conséquences. Les études récentes dans le domaine de la cybersécurité ont démontré qu'une coopération entre les IDS d'un nuage pouvait apporter une plus grande efficacité de détection dans des systèmes informatiques aussi complexes. Grâce à cette coopération, les IDS d'un nuage peuvent se connecter et partager leurs connaissances afin d'améliorer l'exactitude de la détection et obtenir des bénéfices communs. L'anonymat des données échangées par les IDS constitue un élément crucial de l'IDS coopérative. Un IDS malveillant pourrait obtenir des informations confidentielles d'autres IDS en faisant des conclusions à partir des données observées. Pour résoudre ce problème, nous proposons un nouveau système de protection de la vie privée pour les IDS en nuage. Plus particulièrement, nous concevons un système uniforme qui intègre des techniques de protection de la vie privée dans des IDS basés sur l'apprentissage automatique pour obtenir des IDS qui respectent les informations personnelles. Ainsi, l'IDS permet de cacher des informations possédant des données confidentielles et sensibles dans les données partagées tout en améliorant ou en conservant la précision de la détection. Nous avons mis en œuvre un système basé sur plusieurs techniques d'apprentissage automatique et de protection de la vie privée. Les résultats indiquent que les IDS qui ont été étudiés peuvent détecter les intrusions sans utiliser nécessairement les données initiales. Les résultats (c'est-à-dire qu'aucune diminution significative de la précision n'a été enregistrée) peuvent être obtenus en se servant des nouvelles données générées, analogues aux données de départ sur le plan sémantique, mais pas sur le plan synthétique.Cloud systems are becoming more sophisticated, dynamic, and vulnerable to attacks. Therefore, it's becoming increasingly difficult for a single cloud-based Intrusion Detection System (IDS) to detect all attacks, because of limited and incomplete knowledge about attacks and their implications. The recent works on cybersecurity have shown that a co-operation among cloud-based IDSs can bring higher detection accuracy in such complex computer systems. Through collaboration, cloud-based IDSs can consult and share knowledge with other IDSs to enhance detection accuracy and achieve mutual benefits. One fundamental barrier within cooperative IDS is the anonymity of the data the IDS exchanges. Malicious IDS can obtain sensitive information from other IDSs by inferring from the observed data. To address this problem, we propose a new framework for achieving a privacy-preserving cooperative cloud-based IDS. Specifically, we design a unified framework that integrates privacy-preserving techniques into machine learning-based IDSs to obtain privacy-aware cooperative IDS. Therefore, this allows IDS to hide private and sensitive information in the shared data while improving or maintaining detection accuracy. The proposed framework has been implemented by considering several machine learning and privacy-preserving techniques. The results suggest that the consulted IDSs can detect intrusions without the need to use the original data. The results (i.e., no records of significant degradation in accuracy) can be achieved using the newly generated data, similar to the original data semantically but not synthetically