Evolution Assessment of Mining Subsidence Characteristics Using SBAS and PS Interferometry in Sanshandao Gold Mine, China

Ground subsidence is a common geological phenomenon occurring in mining areas. As an important Chinese gold mine, Sanshandao Gold Mine has a mining history of 25 years, with remarkable ground subsidence deformation. Mining development, life security, property security and ecological protection all require comprehension of the ground subsidence characteristics and evolution in the mining area. In this study, the mining subsidence phenomenon of the Sanshandao Gold Mine was investigated and analyzed based on Persistent Scatterer Interferometry (PSI) and small baseline subset (SBAS). The SAR (synthetic aperture radar) images covering the study area were acquired by the Sentinel-1A satellite between 2018 and 2021; 54 images (between 22 February 2018 and 25 May 2021) were processed using the PSI technique and 24 images (between 11 April 2018 and 12 July 2021) were processed using the SBAS technique. In addition, GACOS (generic atmospheric correction online service) data were adopted to eliminate the atmospheric error in both kinds of data processing. The interferometric synthetic aperture radar (InSAR) results showed a basically consistent subsidence area and a similar subsidence pattern. Both InSAR results indicated that the maximum LOS (line of sight) subsidence velocity is about 49 mm/year. The main subsidence zone is situated in the main mining area, extending in the northwest and southeast directions. According to the subsidence displacement of several representative sites in the mining area, we found that the PSI result has a higher subsidence displacement value compared to the SBAS result. Mining activities were accompanied by ground subsidence in the mining area: the ground subsidence phenomenon is exacerbated by the increasing mining quantity. Temporally, the mining subsidence lags behind the increase in mining quantity by about three months. In summary, the mining area has varying degrees of ground subsidence, monitored by two reliable time-series InSAR techniques. Further study of the subsidence mechanism is necessary to forecast ground subsidence and instruct mining activities.

Measuring Societal Vulnerability to Critical Infrastructure Failure due to Extreme Weather Events

Climate change and the associated more frequent and unpredictable occurrence of extreme weather events are according to the Global Risk Report (2020), published by the World Economic Forum, among the top five risks today. Although the effects of extreme weather vary around the world and in regions, their effects on social – economic and natural systems are becoming increasingly important and require an active solution. In this context, it is important to address the individual areas of human society vulnerability, as their assessment is the basic information necessary for improving risk reduction and preparedness to extreme weather events. The paper underlines the importance of critical infrastructure as an asset or system whose disruption or destruction could have a range of serious implications for the performance of economic and social functions of the state and thus on the inhabitants in terms of their life, health, security, property and environment protection. It provides selection of past cases of extreme weather events having impacts on critical infrastructure in sector energy and transportation throughout Europe and their impacts on society. Subsequently own approach to measuring societal vulnerability due to impact of extreme weather event on critical infrastructure is presented. In conclusion recommendations supporting the proactive approach to building resilient critical infrastructure which contributes to resilient society are presented.

A Noninterference Model for Mobile OS Information Flow Control and Its Policy Verification

Mobile operating systems such as Android are facing serious security risk. First, they have a large number of users and store a large number of users’ private data, which have become major targets of network attack; second, their openness leads to high security risks; third, their coarse-grained static permission control mechanism leads to a large number of privacy leaks. Recent decentralized information flow control (DIFC) operating systems such as Asbestos, HiStar, and Flume dynamically adjust the label of each process. Asbestos contains inherent covert channels due to this implicit label adjustment. The others close these covert channels through the use of explicit label change, but this impedes communication and increases performance overhead. We present an enhanced implicit label change model (EILCM) for mobile operating systems that can close the known covert channel in these models with implicit label change and supports dynamic constraints on tags for separation of duty. We also formally analyze the reasons why EILCM can close the known covert channels and prove that abstract EILCM systems have the security property of noninterference with declassification by virtue of the model checker tool FDR. We also prove that the problem of EILCM policy verification is NP-complete and propose a backtrack-based search algorithm to solve the problem. Experiments are presented to show that the algorithm is effective.

Persistent Stochastic Non-Interference

In this paper, we study an information flow security property for systems specified as terms of a quantitative Markovian process algebra, namely the Performance Evaluation Process Algebra (PEPA). We propose a quantitative extension of the Non-Interference property used to secure systems from the functional point view by assuming that the observers are able to measure also the timing properties of the system, e.g., the response time of certain actions or its throughput. We introduce the notion of Persistent Stochastic Non-Interference (PSNI) based on the idea that every state reachable by a process satisfies a basic Stochastic Non-Interference (SNI) property. The structural operational semantics of PEPA allows us to give two characterizations of PSNI: one based on a bisimulation-like equivalence relation inducing a lumping on the underlying Markov chain, and another one based on unwinding conditions which demand properties of individual actions. These two different characterizations naturally lead to efficient methods for the verification and construction of secure systems. A decision algorithm for PSNI is presented and an application of PSNI to a queueing system is discussed.

SAT and SMT-Based Verification of Security Protocols Including Time Aspects

For many years various types of devices equipped with sensors have guaranteed proper work in a huge amount of machines and systems. For the proper operation of sensors, devices, and complex systems, we need secure communication. Security protocols (SP) in this case, guarantee the achievement of security goals. However, the design of SP is not an easy process. Sometimes SP cannot realise their security goals because of errors in their constructions and need to be investigated and verified in the case of their correctness. Now SP uses often time primitives due to the necessity of security dependence on the passing of time. In this work, we propose and investigate the SAT-and SMT-based formal verification methods of SP used in communication between devices equipped with sensors. For this, we use a formal model based on networks of communicating timed automata. Using this, we show how the security property of SP dedicated to the sensors world can be verified. In our work, we investigate such timed properties as delays in the network and lifetimes. The delay in the network is the lower time constraint related to sending the message. Lifetime is an upper constraint related to the validity of the timestamps generated for the transmitted messages.

Permissive runtime information flow control in the presence of exceptions

Information flow control (IFC) has been extensively studied as an approach to mitigate information leaks in applications. A vast majority of existing work in this area is based on static analysis. However, some applications, especially on the Web, are developed using dynamic languages like JavaScript where static analyses for IFC do not scale well. As a result, there has been a growing interest in recent years to develop dynamic or runtime information flow analysis techniques. In spite of the advances in the field, runtime information flow analysis has not been at the helm of information flow security, one of the reasons being that the analysis techniques and the security property related to them (non-interference) over-approximate information flows (particularly implicit flows), generating many false positives. In this paper, we present a sound and precise approach for handling implicit leaks at runtime. In particular, we present an improvement and enhancement of the so-called permissive-upgrade strategy, which is widely used to tackle implicit leaks in dynamic information flow control. We improve the strategy’s permissiveness and generalize it. Building on top of it, we present an approach to handle implicit leaks when dealing with complex features like unstructured control flow and exceptions in higher-order languages. We explain how we address the challenge of handling unstructured control flow using immediate post-dominator analysis. We prove that our approach is sound and precise.

ID-based key-insulated signcryption with equality test in cloud computing

Key-insulated encryption reduces the problem of secret key exposure in hostile setting while signcryption cryptosystem attains the benefits of digitally signing a ciphertext and public key cryptosystem. In this study, we merge the primitives of parallel key-insulation cryptosystem and signcryption with equality test to construct ID-based parallel key-insulated signcryption with a test for equality (ID-PKSET) in cloud computing. The construction prevent data forgery, data re-play attacks and reduces the leakage of secret keys in harsh environments. Our scheme attains the security property of existential unforgeable chosen message attack (EUF-CMA) and indistinquishable identity chosen ciphertext attack (IND-ID-CCA2) using random oracle model.

The relationship between fiduciary ownership as a means of ensuring the fulfilment of the obligation and pledge

The relationship between fiduciary transfer of ownership for security purposes and pledge as the ways to ensure the fulfilment of the obligation is examined in the article. The usefulness of the distinction of mentioned ways of ensuring the fulfilment of the obligations as two essentially different rights in nature is substantiated. The article endorses the feasibility to qualify a pledge as a proprietary right to another’s property. The article reveals that according to national civil law the pledge is a quasi – ownership right unlike the fiduciary transfer of ownership for security purposes which expressly designated by law as a kind of ownership for the property. It is suggested that the pledge and the fiduciary ownership for security purposes should be related as special and model right accordingly. It is proved that the difference between mentioned proprietary ways of ensuring the fulfilment of the obligation are: functional relationship of primary obligation (pledge is accessory means of ensuring the fulfilment of the obligation which shall be terminated after termination of primary obligation whereas fiduciary ownership is non – accessory thus it is not terminated immediately after termination of primary obligation); degree of autonomy of security estate including bankruptcy proceedings (to a fiduciary ownership object, separated from personal fiduciary’s property, does not apply the moratorium on satisfaction of creditors’ claims, the property secured by fiduciary ownership is not part of the debtor’s liquidation mass, by contrast the pledged object is part of the liquidation mass and falls within the scope of such moratorium); foreclosure procedure (recovery of pledge object as a rule is done on execution by a court decision, as opposed to fiduciary ownership for security purposes which allow fiduciary to recovery the security property without reference to judicial procedure through the sale it to any third party and makes it possible to take ownership of it without restrictions on use and disposal).