Secure Federated Learning Within Isolated Environments

Isolation of processes within operating systems enables portions of an application to run in a secure privacy-compliant sandbox. However, isolated processes are required to be stateless. Statelessness implies that no data can be stored, even for valid use cases such as federated learning. This disclosure describes techniques to perform federated learning within secure isolated data-processing environments and to share the results of federated learning via provably private means. A trusted trainer is deployed within the same secure sandbox as a trusted processor. The trusted processor requests the operating system to store data in a secure private cache inaccessible to the trusted processor and to the host application. The trusted trainer runs federated learning on data in the secure, private cache. The trusted trainer shares the results of its computation (e.g., updated machine-learning models) via provably private techniques, without compromising the security, confidentiality, or identity of training data

L'authentification sécurisée utilisant le trusted computing

La sécurité des systèmes informatiques demeure un sujet pertinent malgré les efforts sans cesse apportés pour l’améliorer. À cet effet, un nouveau concept prometteur, qui touche simultanément le matériel et le logiciel, a été déployé. Il s’agit du trusted computing. L’utilisation de ce concept a pour but de s’assurer de l’intégrité du système que nous utilisons à travers différents mécanismes, comme la vérification d’intégrité ou l’isolation logicielle et matérielle. Ce concept pourrait être utilisé dans différentes applications nécessitant une sécurité accrue. L’un des principaux domaines où nous sommes encore concernés par la sécurité est l’authentification en ligne, particulièrement pour les services critiques comme les services financiers ou le courriel. En effet, la sécurité des données d’authentification en ligne peut être compromise par des logiciels malveillants, tels les chevaux de Troie et les enregistreurs de frappes, ou encore par des attaques matérielles, les enregistreurs de frappes physiques à titre d’exemple. Dans le cadre de ce mémoire, nous utilisons le concept de trusted computing afin de proposer une solution d’authentification offrant un compromis entre la sécurité, la facilité d’utilisation et la facilité de déploiement tout en mettant l’accent sur la sécurité. Dans notre schéma nous voulons prévenir les attaques sur les données l’authentifications effectuées à partir de l’ordinateur de l’utilisateur. Un autre but est s’assurer de la compatibilité de notre solution avec la méthode d’authentification actuelle qui consiste en un nom d’utilisateur et un mot de passe. Notre objectif principal est d’implémenter une application utilisant les mécanismes du trusted computing sur un système embarqué. Cette application a pour rôle de fournir une authentification sécurisée aux sites web pour les utilisateurs. Nous avons débuté par étudier les différentes approches possibles en termes de trusted computing et d’exécution isolée. Ensuite, nous avons démontré l’utilisation du trusted computing sur un système embarqué. Nous avons alors implémenté notre application d’authentification sécurisée en utilisant les possibilités offertes par le trusted computing. Cette implémentation a permis d’étudier la viabilité de l’utilisation du trusted computing pour régler les problèmes de sécurité. Finalement, nous avons discuté des différents modèles d’attaques possibles ainsi que des limitations de notre système pour l’évaluer. Notre système nous protège contre plusieurs attaques possibles dans les schémas d’authentification actuels, nous pouvons encore le rendre plus résistant et plus sécuritaire. Nous constatons aussi que le trusted computing peut être utilisé dans d’autres contextes de sécurité, car même avec quelques difficultés de développement, il offre beaucoup d’avantages.----------ABSTRACT: Computer systems security remains a top priority for researchers and industry as cyber attacks are improving and costing millions of dollars to companies. One of the recent concepts introduced is trusted computing. It is used to guarantee the integrity of the system we are using. The main mechanisms used by trusted computing are integrity verification and software and hardware isolation; they are achieved via hardware and software implementations. The application domain of trusted computing is large and usually used in sensitive contexts. One of the areas where security is critical but with no definitive solution is online authentication, in particular for sensitive services like online banking or email. Currently, online authentication is vulnerable to multiple software and hardware attacks such as trojans, software and hardware keyloggers. We propose a scheme for online authentication offering a compromise between security, ease of use and backward compatibility, but focusing more on security. We use trusted computing concepts for our solution. We try to prevent attacks aiming user credentials exchanged from the computer of the user. Another objective was to assure backward compatibility with current authentication methods which usually consist of username and password through websites. Our goal throughout this dissertation is to implement an application using the mechanisms of trusted computing on an embedded system. This application will provide users with a secure authentication mechanism to connect to websites. We began by studying the different possible approaches in terms of trusted computing and isolated execution. Then we ran trusted computing on an embedded system. Next, we implemented the secure authentication application using trusted computing. Finally, we discussed the possible threat models and limitations of our solution. Our system protects us against a range of attacks under current authentication schemes, although there is room for improvement to make it even more resistant and secure. The concept of trusted computing can be explored further to solve security-related problems. Despite some development difficulties, it can offer many advantages

Advancing Federated Learning in 6G: A Trusted Architecture with Graph-based Analysis

Integrating native AI support into the network architecture is an essential objective of 6G. Federated Learning (FL) emerges as a potential paradigm, facilitating decentralized AI model training across a diverse range of devices under the coordination of a central server. However, several challenges hinder its wide application in the 6G context, such as malicious attacks and privacy snooping on local model updates, and centralization pitfalls. This work proposes a trusted architecture for supporting FL, which utilizes Distributed Ledger Technology (DLT) and Graph Neural Network (GNN), including three key features. First, a pre-processing layer employing homomorphic encryption is incorporated to securely aggregate local models, preserving the privacy of individual models. Second, given the distributed nature and graph structure between clients and nodes in the pre-processing layer, GNN is leveraged to identify abnormal local models, enhancing system security. Third, DLT is utilized to decentralize the system by selecting one of the candidates to perform the central server's functions. Additionally, DLT ensures reliable data management by recording data exchanges in an immutable and transparent ledger. The feasibility of the novel architecture is validated through simulations, demonstrating improved performance in anomalous model detection and global model accuracy compared to relevant baselines.Comment: Accepted by IEEE Global Communications Conference (GLOBECOM) 202

Identifying Native Applications with High Assurance

The work described in this paper investigates the problem of identifying and deterring stealthy malicious processes on a host. We point out the lack of strong application iden- tication in main stream operating systems. We solve the application identication problem by proposing a novel iden- tication model in which user-level applications are required to present identication proofs at run time to be authenti- cated by the kernel using an embedded secret key. The se- cret key of an application is registered with a trusted kernel using a key registrar and is used to uniquely authenticate and authorize the application. We present a protocol for secure authentication of applications. Additionally, we de- velop a system call monitoring architecture that uses our model to verify the identity of applications when making critical system calls. Our system call monitoring can be integrated with existing policy specication frameworks to enforce application-level access rights. We implement and evaluate a prototype of our monitoring architecture in Linux as device drivers with nearly no modication of the ker- nel. The results from our extensive performance evaluation shows that our prototype incurs low overhead, indicating the feasibility of our model

CamFlow: Managed Data-sharing for Cloud Services

A model of cloud services is emerging whereby a few trusted providers manage the underlying hardware and communications whereas many companies build on this infrastructure to offer higher level, cloud-hosted PaaS services and/or SaaS applications. From the start, strong isolation between cloud tenants was seen to be of paramount importance, provided first by virtual machines (VM) and later by containers, which share the operating system (OS) kernel. Increasingly it is the case that applications also require facilities to effect isolation and protection of data managed by those applications. They also require flexible data sharing with other applications, often across the traditional cloud-isolation boundaries; for example, when government provides many related services for its citizens on a common platform. Similar considerations apply to the end-users of applications. But in particular, the incorporation of cloud services within `Internet of Things' architectures is driving the requirements for both protection and cross-application data sharing. These concerns relate to the management of data. Traditional access control is application and principal/role specific, applied at policy enforcement points, after which there is no subsequent control over where data flows; a crucial issue once data has left its owner's control by cloud-hosted applications and within cloud-services. Information Flow Control (IFC), in addition, offers system-wide, end-to-end, flow control based on the properties of the data. We discuss the potential of cloud-deployed IFC for enforcing owners' dataflow policy with regard to protection and sharing, as well as safeguarding against malicious or buggy software. In addition, the audit log associated with IFC provides transparency, giving configurable system-wide visibility over data flows. [...]Comment: 14 pages, 8 figure

Trust Evaluation for Embedded Systems Security research challenges identified from an incident network scenario

This paper is about trust establishment and trust evaluations techniques. A short background about trust, trusted computing and security in embedded systems is given. An analysis has been done of an incident network scenario with roaming users and a set of basic security needs has been identified. These needs have been used to derive security requirements for devices and systems, supporting the considered scenario. Using the requirements, a list of major security challenges for future research regarding trust establishment in dynamic networks have been collected and elaboration on some different approaches for future research has been done.This work was supported by the Knowledge foundation and RISE within the ARIES project