A survey on security issues and solutions at different layers of Cloud computing

Cloud computing offers scalable on-demand services to consumers with greater flexibility and lesser infrastructure investment. Since Cloud services are delivered using classical network protocols and formats over the Internet, implicit vulnerabilities existing in these protocols as well as threats introduced by newer architectures raise many security and privacy concerns. In this paper, we survey the factors affecting Cloud computing adoption, vulnerabilities and attacks, and identify relevant solution directives to strengthen security and privacy in the Cloud environment

Security Auditing and Multi-Tenancy Threat Evaluation in Public Cloud Infrastructures

Cloud service providers typically adopt the multi-tenancy model to optimize resources usage and achieve the promised cost-effectiveness. However, multi-tenancy in the cloud is a double-edged sword. While it enables cost-effective resource sharing, it increases security risks for the hosted applications. Indeed, multiplexing virtual resources belonging to different tenants on the same physical substrate may lead to critical security concerns such as cross-tenant data leakage and denial of service. Therefore, there is an increased necessity and a pressing need to foster transparency and accountability in multi-tenant clouds. In this regard, auditing security compliance of the cloud provider’s infrastructure against standards, regulations and customers’ policies on one side, and evaluating the multi-tenancy threat on the other side, take on an increasing importance to boost the trust between the cloud stakeholders. However, auditing virtual infrastructures is challenging due to the dynamic and layered nature of the cloud. Particularly, inconsistencies in network isolation mechanisms across the cloud stack layers (e.g., the infrastructure management layer and the implementation layer), may lead to virtual network isolation breaches that might be undetectable at a single layer. Additionally, evaluating multi-tenancy threats in the cloud requires systematic ways and effective metrics, which are largely missing in the literature. This thesis work addresses the aforementioned challenges and limitations and articulates around two main topics, namely, security compliance auditing and multi-tenancy threat evaluation in the cloud. Our objective in the first topic is to propose an automated framework that allows auditing the cloud infrastructure from the structural point of view, while focusing on virtualization-related security properties and consistency between multiple control layers. To this end, we devise a multi-layered model related to each cloud stack layer’s view in order to capture the semantics of the audited data and its relation to consistent isolation requirements. Furthermore, we integrate our auditing system into OpenStack, and present our experimental results on assessing several properties related to virtual network isolation and consistency. Our results show that our approach can be successfully used to detect virtual network isolation breaches for large OpenStack-based data centers in a reasonable time. The objective of the second topic is to derive security metrics for evaluating the multi-tenancy threats in public clouds. To this end, we propose security metrics to quantify the proximity between tenants’ virtual resources inside the cloud. Those metrics are defined based on the configuration and deployment of a cloud, such that a cloud provider may apply them to evaluate and mitigate co-residency threats. To demonstrate the effectiveness of our metrics and show their usefulness, we conduct case studies based on both real and synthetic cloud data. We further perform extensive simulations using CloudSim and wellknown VM placement policies. The results show that our metrics effectively capture the impact of potential attacks, and the abnormal degrees of co-residency between a victim and potential attackers, which paves the way for the design of effective mitigation solutions against co-residency attacks

Cloud technology options towards Free Flow of Data

This whitepaper collects the technology solutions that the projects in the Data Protection, Security and Privacy Cluster propose to address the challenges raised by the working areas of the Free Flow of Data initiative. The document describes the technologies, methodologies, models, and tools researched and developed by the clustered projects mapped to the ten areas of work of the Free Flow of Data initiative. The aim is to facilitate the identification of the state-of-the-art of technology options towards solving the data security and privacy challenges posed by the Free Flow of Data initiative in Europe. The document gives reference to the Cluster, the individual projects and the technologies produced by them

From security to assurance in the cloud: a survey

The cloud computing paradigm has become a mainstream solution for the deployment of business processes and applications. In the public cloud vision, infrastructure, platform, and software services are provisioned to tenants (i.e., customers and service providers) on a pay-as-you-go basis. Cloud tenants can use cloud resources at lower prices, and higher performance and flexibility, than traditional on-premises resources, without having to care about infrastructure management. Still, cloud tenants remain concerned with the cloud's level of service and the nonfunctional properties their applications can count on. In the last few years, the research community has been focusing on the nonfunctional aspects of the cloud paradigm, among which cloud security stands out. Several approaches to security have been described and summarized in general surveys on cloud security techniques. The survey in this article focuses on the interface between cloud security and cloud security assurance. First, we provide an overview of the state of the art on cloud security. Then, we introduce the notion of cloud security assurance and analyze its growing impact on cloud security approaches. Finally, we present some recommendations for the development of next-generation cloud security and assurance solutions

Secure Access Control Architectures for Multi-Tenancy Cloud Environments

RÉSUMÉ L'Infonuagique est un paradigme de système informatique distribué qui offre la possibilité aux usagers (clients) d’accéder à des services et ressources partagés hébergés chez des fournisseurs, afin de mieux répondre à leur besoin en matière de service et d’infrastructure informatiques. Dans l’environnement infonuagique, une même machine ou serveur physique peut héberger plusieurs machines virtuelles (VMs) qui sont partagées entre différents usagers ou clients, rendant ainsi transparent le partage des ressources matériels. De ce fait, l’Infonuagique crée un environnement propice à des cibles faciles, vulnérables et sujettes à des attaques accrues de pirates informatiques. A cause de la complexité des contrôles d’accès et de la difficulté à surveiller les interconnexions entre les différents systèmes, les applications et les données, l’on s’expose à de nouvelles opportunités. Il ne fait aucun doute que, en termes de sécurité, le plus grand défis auquel les fournisseurs et clients sont confrontés dans l’environnement Infonuagique multi-usager est le contrôle d’accès. La prévention des accès illicites et non autorisés aux ressources infonuagiques passe par un mécanisme de contrôle efficace des accès. D’un côté, les techniques de contrôle d’accès conçues originalement pour des systèmes locaux d’entreprise ne sont pas appropriées à l’Infonuagique et au système de colocation. D’un autre côté, un mécanisme de contrôle d’accès bien conçu ne devrait pas surcharger le système d’Infonuagique et devrait s’adapter avec facilité à l’infrastructure existante. De nos jours, on se fie au VLAN et Coupe-feu par exemple pour assurer le contrôle d’accès dans l’environnement infonuagique. Ces techniques sont tout à fait efficaces mais des techniques complémentaires spécifiques à l’Infonuagique sont nécessaires pour prévenir les accès non autorisés aux ressources partagées dans le système distribué. Dans le cadre de ce projet de recherche nous proposons CloudGuard, un système qui implémente un mécanisme de contrôle d'accès basé sur un hyperviseur. Suivant le concept de sécurité en profondeur (security-in-depth), CloudGuard ajoute une couche complémentaire de sécurité aux environnements en colocation de l'infonuagique et prévient les accès non autorisés et illicites aux ressources infonuagiques. Cette architecture de sécurité peut être simplement appliquée à l'hyperviseur et fourni un contrôle d'accès évolutif et plus robuste que les techniques basées sur les réseaux existants.----------ABSTRACT Cloud Computing is a distributed computing paradigm which allows the users to access the services and shared resources hosted by the various service providers, to meet their services or resources requirements. In a multi-tenancy cloud computing environment, multiple virtual machines (VMs) are collocated on the same physical server. In such system, physical resources are transparently shared by the VMs belonging to multiple users. Cloud computing also creates a suitable environment for easy targets, vulnerable and prone to sophisticated attacks. Also, due to the complexity of access and difficulty in monitoring all interconnection point between systems, applications and data sets, this can create new targets for intrusion. Undoubtedly, one of the most important security mechanisms in multi-tenancy cloud computing environment is access control. Implementing a proper access control mechanism can lead us to prevent unauthorized or illegal access to cloud resources. In one hand, most of current access control techniques were originally designed for enterprise environments that do not consider the characteristics of cloud computing and multi-tenancy environments. On the other hand, a well-designed access control mechanism should impose less possible overhead to the cloud computing system and it should easily leverage with the existing cloud infrastructure. Today, VLANs and firewalls are example of techniques that provide access control for cloud environments. These techniques are definitely effective but we need complimentary techniques that fit cloud computing and prevent unauthorized access to the resources in the distributed system. In this research project we propose CloudGuard, a system that implements a hypervisor-based access control mechanism. Based on the concept of security-in-depth, CloudGuard adds another layer of security to multi-tenancy cloud computing environments and prevents unauthorized and illegal access to the cloud resources. This security architecture can be simply implemented to hypervisor and provide scalable and more robust access control than existing network-based techniques

Cloud Forensic: Issues, Challenges and Solution Models

Cloud computing is a web-based utility model that is becoming popular every day with the emergence of 4th Industrial Revolution, therefore, cybercrimes that affect web-based systems are also relevant to cloud computing. In order to conduct a forensic investigation into a cyber-attack, it is necessary to identify and locate the source of the attack as soon as possible. Although significant study has been done in this domain on obstacles and its solutions, research on approaches and strategies is still in its development stage. There are barriers at every stage of cloud forensics, therefore, before we can come up with a comprehensive way to deal with these problems, we must first comprehend the cloud technology and its forensics environment. Although there are articles that are linked to cloud forensics, there is not yet a paper that accumulated the contemporary concerns and solutions related to cloud forensic. Throughout this chapter, we have looked at the cloud environment, as well as the threats and attacks that it may be subjected to. We have also looked at the approaches that cloud forensics may take, as well as the various frameworks and the practical challenges and limitations they may face when dealing with cloud forensic investigations.Comment: 23 pages; 6 figures; 4 tables. Book chapter of the book titled "A Practical Guide on Security and Privacy in Cyber Physical Systems Foundations, Applications and Limitations", World Scientific Series in Digital Forensics and Cybersecurit

Nature-inspired survivability: Prey-inspired survivability countermeasures for cloud computing security challenges

As cloud computing environments become complex, adversaries have become highly sophisticated and unpredictable. Moreover, they can easily increase attack power and persist longer before detection. Uncertain malicious actions, latent risks, Unobserved or Unobservable risks (UUURs) characterise this new threat domain. This thesis proposes prey-inspired survivability to address unpredictable security challenges borne out of UUURs. While survivability is a well-addressed phenomenon in non-extinct prey animals, applying prey survivability to cloud computing directly is challenging due to contradicting end goals. How to manage evolving survivability goals and requirements under contradicting environmental conditions adds to the challenges. To address these challenges, this thesis proposes a holistic taxonomy which integrate multiple and disparate perspectives of cloud security challenges. In addition, it proposes the TRIZ (Teorija Rezbenija Izobretatelskib Zadach) to derive prey-inspired solutions through resolving contradiction. First, it develops a 3-step process to facilitate interdomain transfer of concepts from nature to cloud. Moreover, TRIZ’s generic approach suggests specific solutions for cloud computing survivability. Then, the thesis presents the conceptual prey-inspired cloud computing survivability framework (Pi-CCSF), built upon TRIZ derived solutions. The framework run-time is pushed to the user-space to support evolving survivability design goals. Furthermore, a target-based decision-making technique (TBDM) is proposed to manage survivability decisions. To evaluate the prey-inspired survivability concept, Pi-CCSF simulator is developed and implemented. Evaluation results shows that escalating survivability actions improve the vitality of vulnerable and compromised virtual machines (VMs) by 5% and dramatically improve their overall survivability. Hypothesis testing conclusively supports the hypothesis that the escalation mechanisms can be applied to enhance the survivability of cloud computing systems. Numeric analysis of TBDM shows that by considering survivability preferences and attitudes (these directly impacts survivability actions), the TBDM method brings unpredictable survivability information closer to decision processes. This enables efficient execution of variable escalating survivability actions, which enables the Pi-CCSF’s decision system (DS) to focus upon decisions that achieve survivability outcomes under unpredictability imposed by UUUR