390 research outputs found
A model for the analysis of security policies in service function chains
Two emerging architectural paradigms, i.e., Software Defined Networking (SDN)
and Network Function Virtualization (NFV), enable the deployment and management
of Service Function Chains (SFCs). A SFC is an ordered sequence of abstract
Service Functions (SFs), e.g., firewalls, VPN-gateways,traffic monitors, that
packets have to traverse in the route from source to destination. While this
appealing solution offers significant advantages in terms of flexibility, it
also introduces new challenges such as the correct configuration and ordering
of SFs in the chain to satisfy overall security requirements. This paper
presents a formal model conceived to enable the verification of correct policy
enforcements in SFCs. Software tools based on the model can then be designed to
cope with unwanted network behaviors (e.g., security flaws) deriving from
incorrect interactions of SFs in the same SFC
IaaS-cloud security enhancement: an intelligent attribute-based access control model and implementation
The cloud computing paradigm introduces an efficient utilisation of huge computing
resources by multiple users with minimal expense and deployment effort
compared to traditional computing facilities. Although cloud computing has incredible
benefits, some governments and enterprises remain hesitant to transfer
their computing technology to the cloud as a consequence of the associated security
challenges. Security is, therefore, a significant factor in cloud computing
adoption. Cloud services consist of three layers: Software as a Service (SaaS), Platform
as a Service (PaaS), and Infrastructure as a Service (IaaS). Cloud computing
services are accessed through network connections and utilised by multi-users who
can share the resources through virtualisation technology. Accordingly, an efficient
access control system is crucial to prevent unauthorised access.
This thesis mainly investigates the IaaS security enhancement from an access
control point of view. [Continues.
Efficient Synthesis of Network Updates
Software-defined networking (SDN) is revolutionizing the networking industry,
but current SDN programming platforms do not provide automated mechanisms for
updating global configurations on the fly. Implementing updates by hand is
challenging for SDN programmers because networks are distributed systems with
hundreds or thousands of interacting nodes. Even if initial and final
configurations are correct, naively updating individual nodes can lead to
incorrect transient behaviors, including loops, black holes, and access control
violations. This paper presents an approach for automatically synthesizing
updates that are guaranteed to preserve specified properties. We formalize
network updates as a distributed programming problem and develop a synthesis
algorithm based on counterexample-guided search and incremental model checking.
We describe a prototype implementation, and present results from experiments on
real-world topologies and properties demonstrating that our tool scales to
updates involving over one-thousand nodes
On the Development and Management of Adaptive Business Collaborations.
Today’s business climate demands a high rate of change with which Information Technology (IT)-minded organizations are required to cope. Organizations face rapidly changing market conditions, new competitive pressures, new regulatory fiats that demand compliance, and new competitive threats. All of these situations and more drive the need for the IT infrastructure of an organization to respond quickly in support of new business models and requirements. This dissertation studies the adaptive development and management of such dynamic business models and requirements. A rule based environment is developed in which the people who develop and manage business collaborations in organizations can do so in a way that is as independent of specific implementation technologies as possible; and where they can take business requirements into consideration, and in which they can respond to changes as effectively as possible.
Knowledge Representation Concepts for Automated SLA Management
Outsourcing of complex IT infrastructure to IT service providers has
increased substantially during the past years. IT service providers must be
able to fulfil their service-quality commitments based upon predefined Service
Level Agreements (SLAs) with the service customer. They need to manage, execute
and maintain thousands of SLAs for different customers and different types of
services, which needs new levels of flexibility and automation not available
with the current technology. The complexity of contractual logic in SLAs
requires new forms of knowledge representation to automatically draw inferences
and execute contractual agreements. A logic-based approach provides several
advantages including automated rule chaining allowing for compact knowledge
representation as well as flexibility to adapt to rapidly changing business
requirements. We suggest adequate logical formalisms for representation and
enforcement of SLA rules and describe a proof-of-concept implementation. The
article describes selected formalisms of the ContractLog KR and their adequacy
for automated SLA management and presents results of experiments to demonstrate
flexibility and scalability of the approach.Comment: Paschke, A. and Bichler, M.: Knowledge Representation Concepts for
Automated SLA Management, Int. Journal of Decision Support Systems (DSS),
submitted 19th March 200
Improving the formal verification of reachability policies in virtualized networks
Network Function Virtualization (NFV) and Software Defined Networking (SDN) are new emerging paradigms that changed the rules of networking, shifting the focus on dynamicity and programmability. In this new scenario, a very important and challenging task is to detect anomalies in the data plane, especially with the aid of suitable automated software tools. In particular, this operation must be performed within quite strict times, due to the high dynamism introduced by virtualization. In this paper, we propose a new network modeling approach that enhances the performance of formal verification of reachability policies, checked by solving a Satisfiability Modulo Theories (SMT) problem. This performance improvement is motivated by the definition of function models that do not work on single packets, but on packet classes. Nonetheless, the modeling approach is comprehensive not only of stateless functions, but also stateful functions such as NATs and firewalls. The implementation of the proposed approach achieves high scalability in complex networked systems consisting of several heterogeneous functions
Modelling and Analysis of Network Security Policies
Nowadays, computers and network communications have a pervasive presence in all our daily activities. Their correct configuration in terms of security is becoming more and more complex due to the growing number and variety of services present in a network.
Generally, the security configuration of a computer network is dictated by specifying the policies of the security controls (e.g. firewall, VPN gateway)
in the network. This implies that the specification of the network security policies is a crucial step to avoid errors in network configuration (e.g., blocking
legitimate traffic, permitting unwanted traffic or sending insecure data).
In the literature, an anomaly is an incorrect policy specification that an administrator may introduce in the network. In this thesis, we indicate as policy anomaly any conflict (e.g. two triggered policy rules enforcing contradictory actions), error (e.g. a policy cannot be enforced because it requires a cryptographic algorithm not supported by the security controls) or sub-optimization (e.g. redundant policies) that may arise in the policy specification phase.
Security administrators, thus, have to face the hard job of correctly specifying the policies, which requires a high level of competence. Several studies have
confirmed, in fact, that many security breaches and breakdowns are attributable to administrators’ responsibilities.
Several approaches have been proposed to analyze the presence of anomalies among policy rules, in order to enforce a correct security configuration. However, we have identified two limitations of such approaches. On one hand, current literature identifies only the anomalies among policies of a single security technology (i.e., IPsec, TLS), while a network is generally configured with many technologies. On the other hand, existing approaches work on a single policy type, also named domain (i.e., filtering, communication protection). Unfortunately, the complexity of real systems is not self-contained and each
network security control may affect the behavior of other controls in the same network.
The objective of this PhD work was to investigate novel approaches for modelling security policies and their anomalies, and formal techniques of anomaly analysis. We present in this dissertation our contributions to the current policy analysis state of the art and the achieved results.
A first contribution was the definition of a new class of policy anomalies, i.e. the inter-technology anomalies, which arises in a set of policies of multiple
security technologies. We provided also a formal model able to detect these new types of anomalies. One of the results achieved by applying the inter-technology analysis to the communication protection policies was to categorize twelve new types of anomalies. The second result of this activity was derived from an empirical assessment that proved the practical significance of detecting such new anomalies.
The second contribution of this thesis was the definition of a newly-defined type of policy analysis, named inter-domain analysis, which identifies any
anomaly that may arise among different policy domains. We improved the state of the art by proposing a possible model to detect the inter-domain
anomalies, which is a generalization of the aforementioned inter-technology model. In particular, we defined the Unified Model for Policy Analysis (UMPA)
to perform the inter-domain analysis by extending the analysis model applied for a single policy domain to comprehensive analysis of anomalies among many
policy domains. The result of this last part of our dissertation was to improve the effectiveness of the analysis process. Thanks to the inter-domain analysis,
indeed, administrators can detect in a simple and customizable way a greater set of anomalies than the sets they could detect by running individually any
other model
Automation for network security configuration: state of the art and research trends
The size and complexity of modern computer networks are progressively increasing, as a consequence of novel architectural paradigms such as the Internet of Things and network virtualization. Consequently, a manual orchestration and configuration of network security functions is no more feasible, in an environment where cyber attacks can dramatically exploit breaches related to any minimum configuration error. A new frontier is then the introduction of automation in network security configuration, i.e., automatically designing the architecture of security services and the configurations of network security functions, such as firewalls, VPN gateways, etc. This opportunity has been enabled by modern computer networks technologies, such as virtualization. In view of these considerations, the motivations for the introduction of automation in network security configuration are first introduced, alongside with the key automation enablers. Then, the current state of the art in this context is surveyed, focusing on both the achieved improvements and the current limitations. Finally, possible future trends in the field are illustrated
Formal assurance of security policies in automated network orchestration (SDN/NFV)
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Network Security Automation
L'abstract è presente nell'allegato / the abstract is in the attachmen
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