On the design of a moving target defense framework for the resiliency of critical services in large distributed networks

2018 Fall.Includes bibliographical references.Security is a very serious concern in this era of digital world. Protecting and controlling access to secured data and services has given more emphasis to access control enforcement and management. Where, access control enforcement with strong policies ensures the data confidentiality, availability and integrity, protecting the access control service itself is equally important. When these services are hosted on a single server for a lengthy period of time, the attackers have potentially unlimited time to periodically explore and enumerate the vulnerabilities with respect to the configuration of the server and launch targeted attacks on the service. Constant proliferation of cloud usage and distributed systems over the last decade have materialized the possibilities of distributing data or hosting services over a group of servers located in different geographical locations. Existing election algorithms used to provide service continuity hosted in the distributed setup work well in a benign environment. However, these algorithms are not secure against skillful attackers who intends to manipulate or bring down the data or service. In this thesis, we design and implement the protection of critical services, such as access-control reference monitors, using the concept of moving target defense. This concept increases the level of difficulty faced by the attacker to compromise the point of service by periodically moving the critical service among a group of heterogeneous servers, thereby changing the attacker surface and increasing uncertainty and randomness in the point of service chosen. We describe an efficient Byzantine fault-tolerant leader election protocol for small networks that achieves the security and performance goals described in the problem statement. We then extend this solution to large enterprise networks by introducing random walk protocol that randomly chooses a subset of servers taking part in the election protocol

Secure data sharing and processing in heterogeneous clouds

The extensive cloud adoption among the European Public Sector Players empowered them to own and operate a range of cloud infrastructures. These deployments vary both in the size and capabilities, as well as in the range of employed technologies and processes. The public sector, however, lacks the necessary technology to enable effective, interoperable and secure integration of a multitude of its computing clouds and services. In this work we focus on the federation of private clouds and the approaches that enable secure data sharing and processing among the collaborating infrastructures and services of public entities. We investigate the aspects of access control, data and security policy languages, as well as cryptographic approaches that enable fine-grained security and data processing in semi-trusted environments. We identify the main challenges and frame the future work that serve as an enabler of interoperability among heterogeneous infrastructures and services. Our goal is to enable both security and legal conformance as well as to facilitate transparency, privacy and effectivity of private cloud federations for the public sector needs. © 2015 The Authors

Towards Data Protection Compliance

Privacy and data protection are fundamental issues nowadays for every organization. This paper calls for the development of methods, techniques and infrastructure to allow the deployment of privacy-aware IT systems, in which humans are integral part of the organizational processes and accountable for their possible misconduct. In particular, we discuss the challenges to be addressed in order to improve organizations privacy practices, as well as the approach to ensure compliance with legal requirements and increasing efficiency

Privacy In The Smart Grid: An Information Flow Analysis

Project Final Report prepared for CIEE and California Energy Commissio

Decentralized Runtime Enforcement of Message Sequences in Message-Based Systems

In the new generation of message-based systems such as network-based smart systems, distributed components collaborate via asynchronous message passing. In some cases, particular ordering among the messages may lead to violation of the desired properties such as data confidentiality. Due to the absence of a global clock and usage of o?-the-shelf components, there is no control over the order of messages at design time. To make such systems safe, we propose a choreography-based runtime enforcement algorithm that given an automata-based specification of unwanted message sequences, prevents certain messages to be sent, and assures that the unwanted sequences are not formed. Our algorithm is fully decentralized in the sense that each component is equipped with a monitor, as opposed to having a centralized monitor. As there is no global clock in message-based systems, the order of messages cannot be determined exactly. In this way, the monitors behave conservatively in the sense that they prevent a message from being sent, even when the sequence may not be formed. We aim to minimize conservative prevention in our algorithm when the message sequence has not been formed. The efficiency and scalability of our algorithm are evaluated in terms of the communication overhead and the blocking duration through simulation

Towards Practical Access Control and Usage Control on the Cloud using Trusted Hardware

Cloud-based platforms have become the principle way to store, share, and synchronize files online. For individuals and organizations alike, cloud storage not only provides resource scalability and on-demand access at a low cost, but also eliminates the necessity of provisioning and maintaining complex hardware installations. Unfortunately, because cloud-based platforms are frequent victims of data breaches and unauthorized disclosures, data protection obliges both access control and usage control to manage user authorization and regulate future data use. Encryption can ensure data security against unauthorized parties, but complicates file sharing which now requires distributing keys to authorized users, and a mechanism that prevents revoked users from accessing or modifying sensitive content. Further, as user data is stored and processed on remote ma- chines, usage control in a distributed setting requires incorporating the local environmental context at policy evaluation, as well as tamper-proof and non-bypassable enforcement. Existing cryptographic solutions either require server-side coordination, offer limited flexibility in data sharing, or incur significant re-encryption overheads on user revocation. This combination of issues are ill-suited within large-scale distributed environments where there are a large number of users, dynamic changes in user membership and access privileges, and resources are shared across organizational domains. Thus, developing a robust security and privacy solution for the cloud requires: fine-grained access control to associate the largest set of users and resources with variable granularity, scalable administration costs when managing policies and access rights, and cross-domain policy enforcement. To address the above challenges, this dissertation proposes a practical security solution that relies solely on commodity trusted hardware to ensure confidentiality and integrity throughout the data lifecycle. The aim is to maintain complete user ownership against external hackers and malicious service providers, without losing the scalability or availability benefits of cloud storage. Furthermore, we develop a principled approach that is: (i) portable across storage platforms without requiring any server-side support or modifications, (ii) flexible in allowing users to selectively share their data using fine-grained access control, and (iii) performant by imposing modest overheads on standard user workloads. Essentially, our system must be client-side, provide end-to-end data protection and secure sharing, without significant degradation in performance or user experience. We introduce NeXUS, a privacy-preserving filesystem that enables cryptographic protection and secure file sharing on existing network-based storage services. NeXUS protects the confidentiality and integrity of file content, as well as file and directory names, while mitigating against rollback attacks of the filesystem hierarchy. We also introduce Joplin, a secure access control and usage control system that provides practical attribute-based sharing with decentralized policy administration, including efficient revocation, multi-domain policies, secure user delegation, and mandatory audit logging. Both systems leverage trusted hardware to prevent the leakage of sensitive material such as encryption keys and access control policies; they are completely client-side, easy to install and use, and can be readily deployed across remote storage platforms without requiring any server-side changes or trusted intermediary. We developed prototypes for NeXUS and Joplin, and evaluated their respective overheads in isolation and within a real-world environment. Results show that both prototypes introduce modest overheads on interactive workloads, and achieve portability across storage platforms, including Dropbox and AFS. Together, NeXUS and Joplin demonstrate that a client-side solution employing trusted hardware such as Intel SGX can effectively protect remotely stored data on existing file sharing services

Towards trusted volunteer grid environments

Intensive experiences show and confirm that grid environments can be considered as the most promising way to solve several kinds of problems relating either to cooperative work especially where involved collaborators are dispersed geographically or to some very greedy applications which require enough power of computing or/and storage. Such environments can be classified into two categories; first, dedicated grids where the federated computers are solely devoted to a specific work through its end. Second, Volunteer grids where federated computers are not completely devoted to a specific work but instead they can be randomly and intermittently used, at the same time, for any other purpose or they can be connected or disconnected at will by their owners without any prior notification. Each category of grids includes surely several advantages and disadvantages; nevertheless, we think that volunteer grids are very promising and more convenient especially to build a general multipurpose distributed scalable environment. Unfortunately, the big challenge of such environments is, however, security and trust. Indeed, owing to the fact that every federated computer in such an environment can randomly be used at the same time by several users or can be disconnected suddenly, several security problems will automatically arise. In this paper, we propose a novel solution based on identity federation, agent technology and the dynamic enforcement of access control policies that lead to the design and implementation of trusted volunteer grid environments.Comment: 9 Pages, IJCNC Journal 201