Protection Against Graph-Based False Data Injection Attacks on Power Systems

Graph signal processing (GSP) has emerged as a powerful tool for practical network applications, including power system monitoring. By representing power system voltages as smooth graph signals, recent research has focused on developing GSP-based methods for state estimation, attack detection, and topology identification. Included, efficient methods have been developed for detecting false data injection (FDI) attacks, which until now were perceived as non-smooth with respect to the graph Laplacian matrix. Consequently, these methods may not be effective against smooth FDI attacks. In this paper, we propose a graph FDI (GFDI) attack that minimizes the Laplacian-based graph total variation (TV) under practical constraints. In addition, we develop a low-complexity algorithm that solves the non-convex GDFI attack optimization problem using ell_1-norm relaxation, the projected gradient descent (PGD) algorithm, and the alternating direction method of multipliers (ADMM). We then propose a protection scheme that identifies the minimal set of measurements necessary to constrain the GFDI output to high graph TV, thereby enabling its detection by existing GSP-based detectors. Our numerical simulations on the IEEE-57 bus test case reveal the potential threat posed by well-designed GSP-based FDI attacks. Moreover, we demonstrate that integrating the proposed protection design with GSP-based detection can lead to significant hardware cost savings compared to previous designs of protection methods against FDI attacks.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Structural-constrained Methods for the Identification of Unobservable False Data Injection Attacks in Power Systems

Power system functionality is determined on the basis of the power system state estimation (PSSE). Thus, corruption of the PSSE may lead to severe consequences, such as financial losses, maintenance damage, and disruptions in electricity distribution. Classical bad data detection (BDD) methods, developed to ensure PSSE reliability, are unable to detect well-designed attacks, named unobservable false data injection (FDI) attacks. In this paper, we develop novel structural-constrained methods for the detection of unobservable FDI attacks, the identification of the attacked buses' locations, and PSSE under the presence of such attacks. The proposed methods are based on formulating structural, sparse constraints on both the attack and the system loads. First, we exploit these constraints in order to compose an appropriate model selection problem. Then, we develop the associated generalized information criterion (GIC) for this problem. However, for large networks, the GIC method's computational complexity grows exponentially with the network size. Thus, based on the proposed structural and sparse constraints, we develop two novel low-complexity methods for unobservable FDI attack identification: 1) a modification of the state-of-the-art orthogonal matching pursuit (OMP); and 2) a method that utilizes the graph Markovian property in power systems, i.e. the second-neighbor relationship between the power data at the system's buses. The methods' performance is evaluated on a IEEE-30 bus test case system

The occurence of methyl tert-butylether (MTBE) in drinking water and sources for drinking water

Het RIVM heeft in samenwerking met VEWIN in 2001 een meetprogramma uitgevoerd voor de stof methyl tert-butylether (MTBE) in drinkwater en drinkwaterbronnen. In de periode juni/juli 2001 is een orieenterend meetprogramma uitgevoerd. De concentratie MTBE in ruwwater van 22 pompstations (in totaal werden 63 pompstations bemonsterd) was lager dan de rapportagegrens (0.01) ug/l. De overige ruwwatermonsters hadden waarden tussen 0.01 ug/l en 0.42 ug/l. De gemiddelde concentratie was 0.07 ug/l. Naar aanleiding van deze resultaten werden in de periode september/oktober de pompstations met een waarde boven de rapportagegrens bemonsterd. De concentratie MTBE in ruwwater was gemiddeld 0.13 ug/l. In totaal werden 51 pompstations bemonsterd. De concentraties in de monsters oppervlaktewater waren relatief hoog, met als hoogste waarde 3.2 ug/l (oppervlaktewatermonster uit het Lekkanaal bij Nieuwegein). De hoogste concentratie in de grondwatermonsters was 11.9 ug/l in een individuele grondwaterput nabij een benzinestation in Zutphen. De overige ruwwatermonsters (zowel grondwater als oppervlaktewater) bevatten oncentraties MTBE lager dan 0.5 g/l. De gemiddelde concentratie MTBE in reinwater (drinkwater) was 0.09 ug/l. De hoogste waarde was 2.9 ug/l bij het pompstation in Zutphen. Hiervoor is een aanwijsbare oorzaak, namelijk een verontreiniging in het waterwingebied. De gevonden waarde is lager dan de uit de literatuur bekende geur- en smaakgrens (range: 5 - 40 ug/l). De concentratie van 2.9 ug/l wordt uit gezondheidsoogpunt als veilig beschouwd. In alle overige reinwatermonsters was de concentratie MTBE lager dan 0.2 ug/l. Uit het onderzoek blijkt dat de concentratie MTBE in het Nederlandse drinkwater in het algemeen erg laag is. Voor de gevonden concentraties zijn, op basis van verschillende studies, geen gezondheidskundige effecten te verwachten.In 2001 the National Institute for Public Health and the Environment (RIVM) in the Netherlands conducted a drinking water measurement programme in co-operation with the Netherlands Waterworks Association (VEWIN) for methyl tert-butyl ether (MTBE) in drinking water and the corresponding sources. This study, consisting of two sampling periods, shows a generally low concentration of MTBE in drinking water at the selected drinking water plants. The selection of sampling locations was based on the vulnerability of the water catchment area. Measurements in the June/July period showed a concentration of VRO

The occurence of methyl tert-butylether (MTBE) in drinking water and sources for drinking water

In 2001 the National Institute for Public Health and the Environment (RIVM) in the Netherlands conducted a drinking water measurement programme in co-operation with the Netherlands Waterworks Association (VEWIN) for methyl tert-butyl ether (MTBE) in drinking water and the corresponding sources. This study, consisting of two sampling periods, shows a generally low concentration of MTBE in drinking water at the selected drinking water plants. The selection of sampling locations was based on the vulnerability of the water catchment area. Measurements in the June/July period showed a concentration of <0.01 ug/l in 22 samples of raw water; the average concentration was 0.07 ug/l and the highest 0.42 ug/l. The average concentration in drinking water in September/October was 0.09 ug/l and the maximum 2.9 ug/l. This maximum concentration was unusual, considering that the second highest value was 0.14 ug/l MTBE. The raw water (both groundwater and surface water) samples registered a concentration of <0.5 ug/l; the highest concentration in surface water was 3.2 ug/l. However, at one location a relatively high concentration (11.9 ug/l) was found in an individual groundwater well. This contamination could be attributed to a local source. The main conclusion here is that MTBE occurs in drinking water, although the concentrations are generally very low (<0.14 ug/l), with a maximum value of 2.9 ug/l. There are no effects on health expected. It is, however, recommended to screen for MTBE in groundwater at locations with a history of or experience with soil contamination. Taking precautions for future spills at petrol stations remains priority number one.Het RIVM heeft in samenwerking met VEWIN in 2001 een meetprogramma uitgevoerd voor de stof methyl tert-butylether (MTBE) in drinkwater en drinkwaterbronnen. In de periode juni/juli 2001 is een orieenterend meetprogramma uitgevoerd. De concentratie MTBE in ruwwater van 22 pompstations (in totaal werden 63 pompstations bemonsterd) was lager dan de rapportagegrens (0.01) ug/l. De overige ruwwatermonsters hadden waarden tussen 0.01 ug/l en 0.42 ug/l. De gemiddelde concentratie was 0.07 ug/l. Naar aanleiding van deze resultaten werden in de periode september/oktober de pompstations met een waarde boven de rapportagegrens bemonsterd. De concentratie MTBE in ruwwater was gemiddeld 0.13 ug/l. In totaal werden 51 pompstations bemonsterd. De concentraties in de monsters oppervlaktewater waren relatief hoog, met als hoogste waarde 3.2 ug/l (oppervlaktewatermonster uit het Lekkanaal bij Nieuwegein). De hoogste concentratie in de grondwatermonsters was 11.9 ug/l in een individuele grondwaterput nabij een benzinestation in Zutphen. De overige ruwwatermonsters (zowel grondwater als oppervlaktewater) bevatten oncentraties MTBE lager dan 0.5 g/l. De gemiddelde concentratie MTBE in reinwater (drinkwater) was 0.09 ug/l. De hoogste waarde was 2.9 ug/l bij het pompstation in Zutphen. Hiervoor is een aanwijsbare oorzaak, namelijk een verontreiniging in het waterwingebied. De gevonden waarde is lager dan de uit de literatuur bekende geur- en smaakgrens (range: 5 - 40 ug/l). De concentratie van 2.9 ug/l wordt uit gezondheidsoogpunt als veilig beschouwd. In alle overige reinwatermonsters was de concentratie MTBE lager dan 0.2 ug/l. Uit het onderzoek blijkt dat de concentratie MTBE in het Nederlandse drinkwater in het algemeen erg laag is. Voor de gevonden concentraties zijn, op basis van verschillende studies, geen gezondheidskundige effecten te verwachten

From discrete dilated cardiomyopathy to successful cardiac transplantation in congenital disorders of glycosylation due to dolichol kinase deficiency (DK1-CDG)

Congenital disorders of glycosylation are a growing group of inborn errors of protein glycosylation. Cardiac involvement is frequently observed in the most common form, PMM2-CDG, especially hypertrophic cardiomyopathy. Dilated cardiomyopathy, however, has been only observed in a few CDG subtypes, usually with a lethal outcome. We report on cardiac pathology in nine patients from three unrelated Israeli families, diagnosed with dolichol kinase deficiency, due to novel, homozygous DK1 gene mutations. The cardiac symptoms varied from discrete, mild dilation to overt heart failure with death. Two children died unexpectedly with acute symptoms of heart failure before the diagnosis of DK1-CDG and heart transplantation could take place. Three other affected children with mild dilated cardiomyopathy at the time of the diagnosis deteriorated rapidly, two of them within days after an acute infection. They all went through successful heart transplantation; one died unexpectedly and 2 others are currently (after 1-5 years) clinically stable. The other 4 children diagnosed with mild dilated cardiomyopathy are doing well on supportive heart failure therapy. In most cases, the cardiac findings dominated the clinical picture, without central nervous system or multisystem involvement, which is unique in CDG syndrome. We suggest to test for DK1-CDG in patients with dilated cardiomyopathy. Patients with discrete cardiomyopathy may remain stable on supportive treatment while others deteriorate rapidly. Our paper is the first comprehensive study on the phenotype of DK1-CDG and the first successful organ transplantation in CDG syndrome.status: publishe