Security Enforcement by Rewriting: An Algebraic Approach

Through Modeling to Synthesis of Security Automata

Mobile devices such as smartphones and tablets are widely used for personal and business uses. Compared to personal mobile subscribers, enterprises have more concerns about mobile device security. The challenges an enterprise may face include unlimited access to corporate resources, lack of encryption on corporate data, unwillingness to backup data, etc. Many of these issues have been resolved by auditing and enforcing security policies in enterprise networks. However, it is difficult to audit and enforce security policies on mobile devices. A substantial discrepancy exists between enterprise security policy administration and security policy enforcement. In this paper, we propose a framework, MobileGuardian, for security policy enforcement on mobile devices. Security policy enforcement is further divided into four issues, i.e., sensitive data isolation, security policy formulation, security policy testing, and security policy execution. The proposed framework is secure, flexible, and scalable. It can be adopted on any mobile platforms to implement access control, data confidentiality, security, and integrity.

The enforcement of security policies in outsourced environments is still an open challenge for policy-based systems. On the one hand, taking the appropriate security decision requires access to the policies. However, if such access is allowed in an untrusted environment then confidential information might be leaked by the policies. Current solutions are based on cryptographic operations that embed security policies with the security mechanism. Therefore, the enforcement of such policies is performed by allowing the authorised parties to access the appropriate keys. We believe that such solutions are far too rigid because they strictly intertwine authorisation policies with the enforcing mechanism. In this paper, we want to address the issue of enforcing security policies in an untrusted environment while protecting the policy confidentiality. Our solution ESPOON is aiming at providing a clear separation between security policies and the enforcement mechanism. However, the enforcement mechanism should learn as less as possible about both the policies and the requester attributes.

Security policies are enforced through the deployment of certain security functionalities within the applications. Applications can have different levels of security and thus each security policy is enforced by different security functionalities. Thus, the secure deployment of an application is not an easy task, being more complicated due to the existing gap between the specification of a security policy and the deployment, inside the application, of the security functionalities that are required to enforce that security policy. The main goal of this paper is to close this gap. This is done by using the paradigms of Software Product Lines and Aspect-Oriented Programming in order to: (1) link the security policies with the security functionalities, (2) generate a configuration of the security functionalities that fit a security policy, and (3) weave the selected security functionalities into an application. We qualitatively evaluate our approach, and discuss its benefits using a case study.

The enforcement of fine-grained access control policies in constrained dynamic networks can become a challenging task. The inherit constraints present in those networks, which result from the limitations of the edge devices in terms of power, computational capacity and storage, require an effective and efficient access control mechanism to be in place to provide suitable monitoring and control of actions and regulate the access over the resources. In this article, we present RESPOnSE, a framework for the specification and enforcement of security policies within such environments, where the computational burden is transferred to high-tier nodes, while low-tier nodes apply risk-aware policy enforcement. RESPOnSE builds on a combination of two widely used access control models, Attribute-Based Access Control and Role-Based Access Control, exploiting the benefits each one provides. Moreover, the proposed mechanism is founded on a compensatory multicriteria decision-making algorithm, based on the calculation of the Euclidean distance between the run-time values of the attributes present in the security policy and their ideal values, as those are specified within the established policy rules.

The paper presents a policy-based approach to detect security violations by enforcing security policy at run-time for providing secure email service. As email service usage is increasing day by day, hackers or attackers are also playing a vital role to destruct email service and even to crash the email server. Due to this, it is a challenging task today to the system administrators to provide secure email service. In this paper, security policy is defined at operating system level, mail application level and network infrastructure level. A policy at system level specifies mandatory usage profile, usages of system sensitive resources such as file system objects, processes, system memory and inter process communication objects. Policies for mail application are defined with sensitive files/directories and parameters, which have impact in delivering a service. Policies for network are defined for controlling inbound and outbound traffic, specifying demilitarized zone, denying misuse of public IP and detecting suspicious network activity. The proposed system architecture supports the layered approach in policy enforcement, proactive defensive mechanism against security violations and scope for new policy discovery. The approach is prototyped on Linux-2.4.21-4 and have built rules for squirrel mail version 1.4.5 to detect security violations in a mail service at run-time.

The security policies of an application can change at runtime due to several reasons, as for example the changes on the user preferences, the lack of enough resources in mobile environments or the negotiation of security levels between the interacting parties. As these security policies change, the application code that copes with the security functionalities should be adapted in order to enforce at runtime the changing security policies. In this paper we present the design, implementation and evaluation of a runtime security adaptation service. This service is based on the combination of autonomic computing and aspect-oriented programming, where the security functionalities are implemented as aspects that are dynamically configured, deployed or un-deployed by generating and executing a security adaptation plan. This service is part of the INTER-TRUST framework, a complete solution for the definition, negotiation and run-time enforcement of security policies.KeywordsSecurity enforcementSecurity policyAspect-Oriented ProgrammingDynamicity

The increasing use of wireless technologies in enterprise networks demands strong security management and policy enforcement mechanisms. The conventional security management frameworks used in wired LAN do not suit in wireless domain due to dynamic topology and mobility of hosts. The enforcement of organizational security policies in wireless LAN requires appropriate access control models as well as correct distribution of access control rules in the network access points. In this paper, we propose a WLAN security management framework supported by a spatio-temporal RBAC (STRBAC) model. The concept of mobile IP has been used to ensure a fixed layer 3 address of a mobile host. Each wireless policy zone consists of a Policy Zone Controller that coordinates with a dedicated Local Role Server to extract the low level access configurations corresponding to the zone access routers. The system can be mapped into a reconfigurable hardware to exploit the parallelism in computing. We also propose a formal STRBAC model to represent the global security policies formally and a SAT based decision procedure to verify the access configurations

Today there are many location technologies providing people or object location. However, location privacy must be ensured before providing widely disseminated location services. Privacy rules may depend not only on the identity of the requester, but also on past events such as the places visited by the person being located, or previous location queries. Therefore, location systems must support the specification and enforcement of security policies (including history-based) allowing users to specify when, how and whom may know their location. We propose a middleware platform named Jano [Jano (or JANVS in latin) is the god of doors and gates in the roman mythology. He is usually depicted with two or four faces turning in opposite directions.] supporting both pull and push location requests while enforcing configurable security policies. Policies are specified using the Security Policy Language, SPL, facilitating the use of well-known security models. In particular, Jano supports history-based policies applied to person’s or object’s location. Jano implementation integrates several location technologies (e.g. GPS, RFID, etc.) and deals with the related heterogeneity aspects. It provides a web-based interface that facilitates policy specification, and its evaluation shows good performance, embodying a number of optimizations regarding bandwidth, process and storage savings.

Security policies have different components; firewall, active directory, and IDS are some examples of these components. Enforcement of network security policies to low level security mechanisms faces some essential difficulties. Consistency, verification, and maintenance are the major ones of these difficulties. One approach to overcome these difficulties is to automate the process of translation of high level security policy into low level security mechanisms. This paper introduces a framework of an automation process that translates a high level security policy into low level security mechanisms. The framework is described in terms of three phases; in the first phase all network assets are categorized according to their roles in the network security and relations between them are identified to constitute the network security model. This proposed model extends the organization based access control (OrBAC) model to include not only access control policy but also some other administrative security policies like auditing policy. Besides, it enables matching of each rule of the high level security policy with the corresponding ones of the low level security policy. Through the second phase, the high level security policy is mapped into the network security model. The second phase could be considered as a translation of the high level security policy into an intermediate model level. Finally, the intermediate model level is translated automatically into low level security mechanism. The paper illustrates the applicability of proposed approach through an application example.

Network traffic classification is the process of analyzing traffic flows and associating them to different categories of network applications. Network traffic classification represents an essential task in the whole chain of network security. Some of the most important and widely spread applications of traffic classification are the ability to classify encrypted traffic, the identification of malicious traffic flows, and the enforcement of security policies on the use of different applications. Passively monitoring a network utilizing low-cost and low-complexity wireless local area network (WLAN) devices is desirable. Mobile devices can be used or existing office desktops can be temporarily utilized when their computational load is low. This reduces the burden on existing network hardware. The aim of this paper is to investigate traffic classification techniques for wireless communications. To aid with intrusion detection, the key goal is to passively monitor and classify different traffic types over WLAN to ensure that network security policies are adhered to. The classification of encrypted WLAN data poses some unique challenges not normally encountered in wired traffic. WLAN traffic is analyzed for features that are then used as an input to six different machine learning (ML) algorithms for traffic classification. One of these algorithms (a Gaussian mixture model incorporating a universal background model) has not been applied to wired or wireless network classification before. The authors also propose a ML algorithm that makes use of the well-known vector quantization algorithm in conjunction with a decision tree—referred to as a TRee Adaptive Parallel Vector Quantiser. This algorithm has a number of advantages over the other ML algorithms tested and is suited to wireless traffic classification. An average F-score (harmonic mean of precision and recall) > 0.84 was achieved when training and testing on the same day across six distinct traffic types.

Modern SoC designs contain a large number of sensitive assets that must be protected from unauthorized access. Authentication mechanisms which control the access to such assets are governed by complex security policies. The security policies affect multiple design blocks and may involve subtle interactions among hardware, firmware, OS kernel, and applications. The implementation of security policies in an SoC design, often referred to as its security architecture, is a subtle composition of coordinating design modules distributed across the different IPs. Toward this direction, this paper gives an overview of SoC security architectures in modern SoC designs and provides a glimpse of their implementation, as well as their design complexities and functional shortcomings. Design of security architectures involves a complex interplay of requirements from functionality, power, security, and validation. We also outline some of the research needs in the area for developing robust, trustworthy SoC designs.

Federated cloud networks are formed by federating virtual network segments from different clouds, e.g. in a hybrid cloud, into a single federated network. Such networks should be protected with a global federated cloud network security policy. The availability of network function virtualisation and service function chaining in cloud platforms offers an opportunity for implementing and enforcing global federated cloud network security policies. In this paper we describe an approach for enforcing global security policies in federated cloud networks. The approach relies on a service manifest that specifies the global network security policy. From this manifest configurations of the security functions for the different clouds of the federation are generated. This enables automated deployment and configuration of network security functions across the different clouds. The approach is illustrated with a case study where communications between trusted and untrusted clouds, e.g. public clouds, are encrypted. The paper discusses future work on implementing this architecture for the OpenStack cloud platform with the service function chaining API.

Information security is strongly dependent on access control models and cryptographic techniques. These are well established areas of research and practice in the enforcement of technical information security policies but are not capable of supporting development of comprehensive information security within organizations. Therefore, there is a need to study upper level issues to establish organizational models for specifying security enforcement mechanisms and coordinating policies. This paper proposes a model for dealing with high level information security policies. The core is to enforce a continuous refinement of information security requirements aiming at formally deriving technical security policies from high level security objectives. This refinement is carried out by in formation security harmonization functions. Contribution of this paper is on the specification of a notation for expressing information security requirements and on the specification of a mechanism to formulate harmonization functions.

Software systems are becoming heterogeneous: instead of a small number of large programs from well-established sources, a user's desktop may now consist of many smaller components that interact in intricate ways. Some components will be downloaded from the network from sources that are only partially trusted. A user would like to know that a number of security properties hold, e.g., that personal data is not leaked to the net, but it is typically infeasible to verify that such components are well-behaved. Instead, they must be executed in a secure environment that provides fine-grain control of the allowable interactions between them, and between components and other system resources.In this paper, we consider the problem of assembling concurrent software systems from untrusted or partially trusted off-the-shelf components, using wrapper programs to encapsulate components and enforce security policies. We introduce a model programming language, the box-π calculus, that supports composition of software components and the enforcement of information flow security policies. Several example wrappers are expressed using the calculus; we explore the delicate security properties they guarantee. We present a novel causal type system that statically captures the allowed flows between wrapped possibly-badly-typed components; we use it to prove that an example ordered pipeline wrapper enforces a causal flow property.