In this work we propose a strategy using Intel SGX processors to guarantee the use of audited applications in insecure environments. A cloud-based toolchain allows auditors to assess if the user's application meets specifications and standards, to generate the final binaries, and to cryptographically sign them. It also generates a manifesto containing information to verify the authenticity of the audited software binaries. A SGX-based binary loader (inserted by the cloud-based toolchain during the applications building process) writes down auditing data that is encrypted and sealed by SGX functions to form reliable proofs that the original audited software is the one running. As a proof-of-concept, a Linux kernel was modified in order to cryptographically measure all processes being executed and send these results to a SGX application. An analysis was carried out to measure the performance of the altered system. On average, a system consistently running the audit increased the execution time of each process by 20 to 30%.

Modern systems are increasingly dependent on the integration of physical processes and information technologies. This trend is remarkable in applications involving sensor networks, cyberphysical systems, and Internet of Things. Despite its complexity, such integration results in physical context information that can be used to improve security, especially authentication. In this paper, we show that entities sharing the same physical context can use it for establishing a secure communication channel and protecting each other against external attacks. We present such approach proposing a theoretical model for generating unique bitstreams. Two different protocols are suggested. Each one is evaluated using probabilistic analysis and simulation. In the end, we implement the authentication mechanism in a case study using networks radio signal as physical event generator. The results demonstrate the performance of each of the protocols and their suitability for applications in real world.

The advantages of using communication networks to interconnect controllers and physical plants motivate the increasing number of networked control systems in industrial and critical infrastructure facilities. However, this integration also exposes such control systems to new threats, typical of the cyber domain. In this context, studies have been conducted, aiming to explore vulnerabilities and propose security solutions for cyber-physical systems. In this paper, a covert attack for service degradation is proposed, which is planned based on the intelligence gathered by another attack, herein proposed, referred as system identification attack. The simulation results demonstrate that the joint operation of the two attacks is capable to affect, in a covert and accurate way, the physical behavior of a system.

The unprecedented capabilities of monitoring and responding to stimuli in the physical world of wireless sensor and actuator networks (WSAN) enable these networks to provide the underpinning for several Smart City applications, such as structural health monitoring (SHM). In such applications, civil structures, endowed with wireless smart devices, are able to self-monitor and autonomously respond to situations using computational intelligence. This work presents a decentralized algorithm for detecting damage in structures by using a WSAN. As key characteristics, beyond presenting a fully decentralized (in-network) and collaborative approach for detecting damage in structures, our algorithm makes use of cooperative information fusion for calculating a damage coefficient. We conducted experiments for evaluating the algorithm in terms of its accuracy and efficient use of the constrained WSAN resources. We found that our collaborative and information fusion-based approach ensures the accuracy of our algorithm and that it can answer promptly to stimuli (1.091 s), triggering actuators. Moreover, for 100 nodes or less in the WSAN, the communication overhead of our algorithm is tolerable and the WSAN running our algorithm, operating system and protocols can last as long as 468 days.

This paper proposes a framework for embedding a software watermark using obfuscation and tamper-proofing techniques, called SensorWatermark in order to inhibit piracy of embedded software in sensor nodes in a WSN. The watermark scheme proposed is characterized as an ordered sequence of obfuscations and guards implemented in the software, where such sequence identifies the software author. SensorWatermark is able to correctly identify the author from the embedded watermark and does not affect negatively the constrained resources of a sensor device. Finally, SensorWatermark is resilient and stealthy to certain attacks, as demonstrated in the experiments.

This paper presents FraSEE, a framework whose goal is to increase the energy efficiency (EE) of smart grid applications, specifically for the Power Quality (PQ) application domain. The key idea is to use a Wireless Sensor and Actuator Network (WSAN) and decentralize the decision processes of such applications among WSAN nodes through information fusion. Experiments assessed FraSEE effectiveness in increasing the EE of a PQ application, its accuracy, i.e. correct PQ disturbance detections, considering the influence of environmental parameters in decision process, its overhead, i.e. WSAN resources consumption; and delay for performing control actions in response to decisions.

Program matching refers to the mapping between equivalent codes written in different languages — including high-level and low-level languages. This equivalence is useful for some software engineering scenarios such as determining whether rewritten code is correct, which version of a program is being used, and whether a malware is present in the program. In the present work, we propose a novel approach to solve the executable code traceability by using program code analysis and artificial neural networks. From the program code analysis we obtained execution behavior properties of the codes, and from the artificial neural networks we judge about their correspondence. Our evaluation using real code examples shows an acceptable correspondence rate between 62% and 100% with the very low rate of 4% false positives.

This work presents an algorithm that aims at maximizing the network efficiency while meeting QoS requirements for different classes of users mobile in a scenario that supports the integration of wireless broadband networks such as WiMAX. The presented algorithm exploits the behavior of the mobile user, depicted in a user profile, for (i) refining the set of cells foreseen for the next handover process, taking into account the class of user as well as both the service and the network contexts, and (ii) proactive reserving resources for the cell chosen for the next handover. This algorithm is validated through an extensive simulation approach, corroborating the expected improvements.

Designing distributed multimedia applications raises temporal and spatial synchronization issues related to processing, transport, storage, retrieval and presentation of data, sound, still images and video. Within this framework, the paper aims to define a general-purpose multimedia synchronization mechanism, known as the conditional delivery mechanism, capable of addressing both intraand inter-stream synchronization issues. The proposed mechanism, based on the identification of causal relations among information units of one or several streams, is designed to ensure that these causal relations, expressed at the user's level, are satisfied when delivering the streams. The conditional delivery mechanism is analyzed in depth and both informal and formal specifications of the mechanism are provided. The formal specification refers to an extension of the standard formal description technique LOTOS (RT-LOTOS for real-time LOTOS). Validation results of the conditional delivery mechanism are finally presented for a distance and interactive training application.

The design of a distributed multimedia application involves both temporal and spatial synchronization problems related to the processing, transport, storage, retrieval and presentation of data, sound, still images and video. Within this general framework, the paper aims at defining a new multimedia synchronization mechanism, the so-called conditional delivery mechanism, which appears particularly useful for achieving both intra- and inter-stream synchronization. Main motivations behind this synchronization mechanism are first discussed on a simple example, namely a distributed application in the area of distance and interactive training, and then the details of the mechanism are presented. This presentation starts with an informal discussion on simple examples, which is followed by a formal specification of the mechanism based on the use of a temporal extension of the Formal Description Technique LOTOS.