Short Paper: Automatic Configuration for an Optimal Channel Protection in Virtualized Networks

Data confidentiality, integrity and authentication are security properties which are often enforced with the generation of secure channels, such as Virtual Private Networks, over unreliable network infrastructures. Traditionally, the configuration of the systems responsible of encryption operations is performed manually. However, the advent of software-based paradigms, such as Software-Defined Networking and Network Functions Virtualization, has introduced new arms races. In particular, even though network management has become more flexible, the increased complexity of virtual networks is making manual operations unfeasible and leading to errors which open the path to a large number of cyber attacks. A possible solution consists in reaching a trade-off between flexibility and complexity, by automatizing the configuration of the channel protection systems through policy refinement. In view of these considerations, this paper proposes a preliminary study for an innovative methodology to automatically allocate and configure channel protection systems in virtualized networks. The proposed approach would be based on the formulation of a MaxSMT problem and it would be the first to combine automation, formal verification and optimality in a single technique

Distributed Security Policy Analysis

Computer networks have become an important part of modern society, and computer network security is crucial for their correct and continuous operation. The security aspects of computer networks are defined by network security policies. The term policy, in general, is defined as ``a definite goal, course or method of action to guide and determine present and future decisions''. In the context of computer networks, a policy is ``a set of rules to administer, manage, and control access to network resources''. Network security policies are enforced by special network appliances, so called security controls.Different types of security policies are enforced by different types of security controls. Network security policies are hard to manage, and errors are quite common. The problem exists because network administrators do not have a good overview of the network, the defined policies and the interaction between them. Researchers have proposed different techniques for network security policy analysis, which aim to identify errors within policies so that administrators can correct them. There are three different solution approaches: anomaly analysis, reachability analysis and policy comparison. Anomaly analysis searches for potential semantic errors within policy rules, and can also be used to identify possible policy optimizations. Reachability analysis evaluates allowed communication within a computer network and can determine if a certain host can reach a service or a set of services. Policy comparison compares two or more network security policies and represents the differences between them in an intuitive way. Although research in this field has been carried out for over a decade, there is still no clear answer on how to reduce policy errors. The different analysis techniques have their pros and cons, but none of them is a sufficient solution. More precisely, they are mainly complements to each other, as one analysis technique finds policy errors which remain unknown to another. Therefore, to be able to have a complete analysis of the computer network, multiple models must be instantiated. An analysis model that can perform all types of analysis techniques is desirable and has three main advantages. Firstly, the model can cover the greatest number of possible policy errors. Secondly, the computational overhead of instantiating the model is required only once. Thirdly, research effort is reduced because improvements and extensions to the model are applied to all three analysis types at the same time. Fourthly, new algorithms can be evaluated by comparing their performance directly to each other. This work proposes a new analysis model which is capable of performing all three analysis techniques. Security policies and the network topology are represented by the so-called Geometric-Model. The Geometric-Model is a formal model based on the set theory and geometric interpretation of policy rules. Policy rules are defined according to the condition-action format: if the condition holds then the action is applied. A security policy is expressed as a set of rules, a resolution strategy which selects the action when more than one rule applies, external data used by the resolution strategy and a default action in case no rule applies. This work also introduces the concept of Equivalent-Policy, which is calculated on the network topology and the policies involved. All analysis techniques are performed on it with a much higher performance. A precomputation phase is required for two reasons. Firstly, security policies which modify the traffic must be transformed to gain linear behaviour. Secondly, there are much fewer rules required to represent the global behaviour of a set of policies than the sum of the rules in the involved policies. The analysis model can handle the most common security policies and is designed to be extensible for future security policy types. As already mentioned the Geometric-Model can represent all types of security policies, but the calculation of the Equivalent-Policy has some small dependencies on the details of different policy types. Therefore, the computation of the Equivalent-Policy must be tweaked to support new types. Since the model and the computation of the Equivalent-Policy was designed to be extendible, the effort required to introduce a new security policy type is minimal. The anomaly analysis can be performed on computer networks containing different security policies. The policy comparison can perform an Implementation-Verification among high-level security requirements and an entire computer network containing different security policies. The policy comparison can perform a ChangeImpact-Analysis of an entire network containing different security policies. The proposed model is implemented in a working prototype, and a performance evaluation has been performed. The performance of the implementation is more than sufficient for real scenarios. Although the calculation of the Equivalent-Policy requires a significant amount of time, it is still manageable and is required only once. The execution of the different analysis techniques is fast, and generally the results are calculated in real time. The implementation also exposes an API for future integration in different frameworks or software packages. Based on the API, a complete tool was implemented, with a graphical user interface and additional features

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

SECURITY AND PRIVACY ISSUES IN MOBILE NETWORKS, DIFFICULTIES AND SOLUTIONS

Mobile communication is playing a vital role in the daily life for the last two decades; in turn its fields gained the research attention, which led to the introduction of new technologies, services and applications. These new added facilities aimed to ease the connectivity and reachability; on the other hand, many security and privacy concerns were not taken into consideration. This opened the door for the malicious activities to threaten the deployed systems and caused vulnerabilities for users, translated in the loss of valuable data and major privacy invasions. Recently, many attempts have been carried out to handle these concerns, such as improving systems’ security and implementing different privacy enhancing mechanisms. This research addresses these problems and provides a mean to preserve privacy in particular. In this research, a detailed description and analysis of the current security and privacy situation in the deployed systems is given. As a result, the existing shortages within these systems are pointed out, to be mitigated in development. Finally a privacy preserving prototype model is proposed. This research has been conducted as an extensive literature review about the most relevant references and researches in the field, using the descriptive and evaluative research methodologies. The main security models, parameters, modules and protocols are presented, also a detailed description of privacy and its related arguments, dimensions and factors is given. The findings include that mobile networks’ security along with users are vulnerable due to the weaknesses of the key exchange procedures, the difficulties that face possession, repudiation, standardization, compatibility drawbacks and lack of configurability. It also includes the need to implement new mechanisms to protect security and preserve privacy, which include public key cryptography, HIP servers, IPSec, TLS, NAT and DTLS-SRTP. Last but not least, it shows that privacy is not absolute and it has many conflicts, also privacy requires sophisticated systems, which increase the load and cost of the system.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Firewall Rule Set Analysis and Visualization

abstract: A firewall is a necessary component for network security and just like any regular equipment it requires maintenance. To keep up with changing cyber security trends and threats, firewall rules are modified frequently. Over time such modifications increase the complexity, size and verbosity of firewall rules. As the rule set grows in size, adding and modifying rule becomes a tedious task. This discourages network administrators to review the work done by previous administrators before and after applying any changes. As a result the quality and efficiency of the firewall goes down. Modification and addition of rules without knowledge of previous rules creates anomalies like shadowing and rule redundancy. Anomalous rule sets not only limit the efficiency of the firewall but in some cases create a hole in the perimeter security. Detection of anomalies has been studied for a long time and some well established procedures have been implemented and tested. But they all have a common problem of visualizing the results. When it comes to visualization of firewall anomalies, the results do not fit in traditional matrix, tree or sunburst representations. This research targets the anomaly detection and visualization problem. It analyzes and represents firewall rule anomalies in innovative ways such as hive plots and dynamic slices. Such graphical representations of rule anomalies are useful in understanding the state of a firewall. It also helps network administrators in finding and fixing the anomalous rules.Dissertation/ThesisMasters Thesis Computer Science 201

Selected aspects of security mechanisms for cloud computing – current solutions and development perspectives

The security aspects of cloud computing, especially the security of data, become more and more important. It is necessary to find and develop the new mechanisms to secure the cloud. The problem presented in the paper concerns the mechanisms for security of cloud computing with special attention paid to aspects of access control in clouds – the state of the art and the perspectives for the future

Network Security Automation

L'abstract è presente nell'allegato / the abstract is in the attachmen

REMOTE MOBILE SCREEN (RMS): AN APPROACH FOR SECURE BYOD ENVIRONMENTS

Bring Your Own Device (BYOD) is a policy where employees use their own personal mobile devices to perform work-related tasks. Enterprises reduce their costs since they do not have to purchase and provide support for the mobile devices. BYOD increases job satisfaction and productivity in the employees, as they can choose which device to use and do not need to carry two or more devices. However, BYOD policies create an insecure environment, as the corporate network is extended and it becomes harder to protect it from attacks. In this scenario, the corporate information can be leaked, personal and corporate spaces are not separated, it becomes difficult to enforce security policies on the devices, and employees are worried about their privacy. Consequently, a secure BYOD environment must achieve the following goals: space isolation, corporate data protection, security policy enforcement, true space isolation, non-intrusiveness, and low resource consumption. We found that none of the currently available solutions achieve all of these goals. We developed Remote Mobile Screen (RMS), a framework that meets all the goals for a secure BYOD environment. To achieve this, the enterprise provides the employee with a Virtual Machine (VM) running a mobile operating system, which is located in the enterprise network and to which the employee connects using the mobile device. We provide an implementation of RMS using commonly available software for an x86 architecture. We address RMS challenges related to compatibility, scalability and latency. For the first challenge, we show that at least 90.2% of the productivity applications from Google Play can be installed on an x86 architecture, while at least 80.4% run normally. For the second challenge, we deployed our implementation on a high-performance server and run up to 596 VMs using 256 GB of RAM. Further, we show that the number of VMs is proportional to the available RAM. For the third challenge, we used our implementation on GENI and conclude that an application latency of 150 milliseconds can be achieved. Adviser: Byrav Ramamurth

Operating System Response to Router Advertisement Packet in IPv6.

With growth of internet IPv4 address will run out soon. So the need of new IP protocol is indispensable. IPv6 with 128-bit address space is developed and maintain the support of IPv4 protocols with some upgrades such as BGP, OSPF and ICMP. ICMP protocol used for error reporting, neighbor discovering and other functions for diagnosis, ICMP version 6 has new types of packets to perform function similar to address resolution protocol ARP called Neighbor Discovery Protocol NDP. NDP is responsible for address auto configuration of nodes and neighbor discovery. It define new packets for the purposes of router solicitation, router advertisement and others discovery functions