Formal Approaches to Control System Security From Static Analysis to Runtime Enforcement

With the advent of Industry 4.0, industrial facilities and critical infrastructures are transforming into an ecosystem of heterogeneous physical and cyber components, such as programmable logic controllers, increasingly interconnected and therefore exposed to cyber-physical attacks, i.e., security breaches in cyberspace that may adversely affect the physical processes underlying industrial control systems. The main contributions of this thesis follow two research strands that address the security concerns of industrial control systems via formal methodologies. As our first contribution, we propose a formal approach based on model checking and statistical model checking, within the MODEST TOOLSET, to analyse the impact of attacks targeting nontrivial control systems equipped with an intrusion detection system (IDS) capable of detecting and mitigating attacks. Our goal is to evaluate the impact of cyber-physical attacks, i.e., attacks targeting sensors and/or actuators of the system with potential consequences on the safety of the inner physical process. Our security analysis estimates both the physical impact of the attacks and the performance of the IDS. As our second contribution, we propose a formal approach based on runtime enforcement to ensure specification compliance in networks of controllers, possibly compromised by colluding malware that may tamper with actuator commands, sensor readings, and inter-controller communications. Our approach relies on an ad-hoc sub-class of Ligatti et al.’s edit automata to enforce controllers represented in Hennessy and Regan’s Timed Process Language. We define a synthesis algorithm that, given an alphabet P of observable actions and a timed correctness property e, returns a monitor that enforces the property e during the execution of any (potentially corrupted) controller with alphabet P, and complying with the property e. Our monitors correct and suppress incorrect actions coming from corrupted controllers and emit actions in full autonomy when the controller under scrutiny is not able to do so in a correct manner. Besides classical requirements, such as transparency and soundness, the proposed enforcement enjoys deadlock- and diverge-freedom of monitored controllers, together with compositionality when dealing with networks of controllers. Finally, we test the proposed enforcement mechanism on a non-trivial case study, taken from the context of industrial water treatment systems, in which the controllers are injected with different malware with different malicious goals

Angiogenesis of atherosclerotic plaques in patients with metabolic syndrome. In memoriam V. Anestiaids

This article is the result of our long-term studies in the area of atherogenesis and continuing to date search for answers to unresolved issues, in cooperation with the Angiogenesis Research Center, the Victor Babes University of Medicine and Pharmacy (Timisoara, Romania). The results of these studies were presented at many national and international symposia and congresses. Numerous studies have demonstrated that endothelial damage is a precursory symptom of atherosclerosis, which leads to an increase of vascular permeability, activation of mast cells and migration of leukocytes, lymphocytes, macrophages, adhesion of platelets, proliferation of vascular smooth muscle cells and eventual vasospasm and pro-infl ammatory condition. All of the above listed components can be rightfully considered active pathogenetic participants in atherosclerosis and a result of aggregation of all risk factors that accompany a wide variety of cardiovascular diseases, such as coronary heart disease, hypertension, diabetes, dyslipidemia etc. The infl ux of monocytes and mast cells during the early stages of atherosclerosis leads to the most pronounced manifestations of vascular inflammation, especially in patients with metabolic disorders [1]. Angiogenesis is a very important pathogenetic element of atherosclerosis in stages of complicated plaques, along with mast cells and macrophages. CD-105 is a sensitive marker of newly formed endothelial cells, an effective index of activation and proliferation of microvessels, not only in aggressive forms of cancer, but also in atherosclerotic plaques of the affected vessels. The plaque neovascularization process often begins in intima, progresses and leads to further destabilization of atherosclerotic plaques (intramural hemorrhage, ruptures etc.). Also, anti- MCT (mast cell tryptase) and CD-68 demonstrate clearly the important pathogenetic stages and patterns of atherosclerosis development and its complications in patients with metabolic disorders. In our study, we analyzed the histotopographic distribution of newly formed blood vessels as a feature of angiogenesis, the extent of mast cell degranulation, the expression of macrophages in different types of plaques, as well as various arterial vessels in patients with atherosclerosis and metabolic syndrome, complicated by atherosclerosis. We have tried to analyze the importance of mast cells and macrophages, the patterns of development of atherosclerosis stages, along with diagnostic and prognostic features. The study included 34 patients, who died of atherosclerosis (no. =17) and atherosclerotic complications of metabolic syndrome (no. =17). Fragments of their cerebral (middle cerebral arteries), carotid, coronary arteries, aorta (thoracic and abdominal segments), renal, iliac and vertebral arteries were collected for research at autopsy. The fragments were processed using standard techniques. The type definition of plaques was based on morphological classification, as well as on macroscopic and histological images of hematoxylin-eosin stained sections and on histochemical methods – silver and orcein impregnation. To determine the expression of mast cells in the affected vessels, we have used anti-MCT immunohistochemical stain. Macrophages were identified using the CD-68 specific marker and the newly formed vessels – respectively, by using CD-105 (Endoglin), which is specific. The evaluation of the results was based on determining the density and intensity of the final reaction, reflected in the quantitative ratio of different zones of atheromatous plaques. Positively stained mast cells, macrophages and newly formed vessels were found in many types of atherosclerotic plaques, especially in adventitia and in the immediate vicinity of plaques and in subendothelial layers. We found a statistical correlation between the plaque type and clinical data. The immunohistochemical method is effective for determining mast cells, macrophages, and newly formed vessels of atherosclerotic plaques, directly reflecting many important pathogenetic elements of atherogenesis in patients with metabolic syndrom

Comparative Reconstruction Probabilistically: The Role of Inventory and Phonotactics

I introduce a novel quantitative methodology for evaluating manual comparative reconstructions. This method is incumbent on the existence of a manual comparative reconstruction and, unlike previous quantitative methods, cannot give a result contradictory to the reconstruction. The primary goal for this framework is to reconcile traditional and quantitative methodologies and act as an objective and accessible platform for comparative reconstruction, thereby extending the scope of historical linguistics further into the past. A few theoretical corollaries of the framework are also presented. It is shown that the likelihood that a reconstruction is spurious is related to some of the phonological properties of the descendent language. This likelihood is inversely correlated with mean word-length and segmental inventory size. Additionally, most active phonological processes and cooccurrence restrictions in the language – such as phonotactic constraints, prosodic effects, segment harmony, and neutralization – all serve to increase the likelihood that a reconstruction to that language is spurious

METHODOLOGICAL APPROACHES IN REALIZING AND APPLYING COST-BENEFIT ANALYSIS FOR THE INVESTMENT PROJECTS

Cost-benefit analysis represents the most frequent technique used for a rational allocation of resources. This modality of evaluating the expenditure programs is an attempt to measure the costs and gains of a community as a result of running the evaluatedcost-benefit analysis, social benefits, investment project, public funds, sensitivity analysis

Comparative study of the athersclerosis plaque neovascularisation of various types of artery in patients with metabolic syndrome

Introduction: Cardiovascular pathology occupies a dominant place in morbidity structure. The very rapid development of science and technology, that radically changes the level of physical activity by reducing it, the energy value of the food increment and chronic stress have a negative influence on human life. These changes in the society lead to an increase in the number of people with pathological changes in metabolism at different levels, which in turn were distributed into a group of pathologies called “metabolic”, and which originally foster the development of atherosclerosis. This article reflects aspects of neovascularisation of the atherosclerotic plaque (AP) in patients with metabolic syndrome (MS). Especially in childhood and adolescence these changes are less observed (slight hypertension, increased body weight, dyslipidemia), but afterwards they cause atherosclerotic lesions in organs and systems. Previous studies have shown that expression of CD 105 (endoglin) is a sensitive marker both for endothelial cells and for activation/proliferation of microcapillary in aggressive growth of solid tumors and atherosclerotic plaque lesions, because the intimai neovascularisation contributes significantly to the further stability or instability of atherosclerotic plaque, hemorrhage and rupture. Material and methods: We used morphological and immunohistochemical analysis to investigate the expression of CD34, SMA (smooth muscle actin) and CD 105-positive in the affected large-caliber (aorta, carotid, mesenteric, iliac), and medium (cerebral, coronary, renal, vertebral arteries) vessels samples taken during the necropsies of patients who died from atherosclerotic complications and/or metabolic syndrome. Results: The most dominant studied vessels were CD34 positive at the intimai level in the atherosclerotic plaque region; in the fibrous plaque - rarely; in adventitia, namely vasa vasorum, CD34 positive (small and medium vessels). Marker SMA is detected in smooth muscle cells, myoepithelial, myofibroblast cells, and, to a lesser extent, in pericytes. Internal positive control for SMA was featured by the positive reaction in myocytes from the tunica media of arterial vessels of muscular and musculo-elastic types as well as by smooth muscle cells and pericytes of blood vessels. Negative reaction was represented in the newly formed vessels (an explanation is that the newly formed vessels being immature are voided of pericytes). The CD 105-positive vessels density was higher in the plaque in close proximity to the atherosclerotic plaque (at adventitial and intimai level) and significantly decreased aloof from atherosclerotic lesion. Furthemore, noncomplicate plaques (intermediate and fibrous) have shown positive vessels for endoglin, which reflects angiogenic cell proliferation. Endoglin-positive vessels were grouped near the atherosclerotic lesions and had lower density distantly, similarly to the issues identified in complicated plaques (calcified and exulcerated). An eloquent fact is that expression of neovascularisation at intimai level of fibrous and complicated plaque is highly variable. Some of these newly formed CD 105-positive vessels were immature, thin walled; formation of plexuses, seams, and isolated CD 105-positive cells and without smooth muscle cell actin expression serves as an argument to consider them new-formed vessels. To a high degree of atherosclerotic plaques the proliferation of CD 105-positive new-formed vessels was varied in most types of arteries, videlicet a significantly increased number of adventitious vessels were associated with plaques regions in affected arteries. Another observed feature is that the neovascularisation process is expressed also from intimai part at plaque level of medium and small caliber vessels. Conclusion: Interpretation and vitality (stability and instability) of the atherosclerotic plaque depends to a large extent on the angiogenesis process of atherosclerotic plaque. Our results show that comparative immunohistochemical method with the application of specific vascular markers demonstrates important pathogenetic aspects in the atherosclerotic plaque formation. CD 105 is an useful marker of angiogenesis within the adventitious and intimai vessels and suggests the existence of significant differences in the pathological development of atherosclerosis in separate vascular beds, that can have important consequences when considering the management and actual treatment, and the perspective of this disease

A process calculus approach to correctness enforcement of PLCs

We define a simple process calculus, based on Hennessy and Regan\u2019s Timed Process Language, for specifying networks of communicating programmable logic controllers (PLCs) enriched with monitors enforcing specifications compliance. We define a synthesis algorithm that given an uncorrupted PLC returns a monitor that enforces the correctness of the PLC, even when injected with malware that may forge/drop actuator commands and inter-controller communications. Then, we strengthen the capabilities of our monitors by allowing the insertion of actions to mitigate malware activities. This gives us deadlock-freedom monitoring: malware may not drag monitored controllers into deadlock states