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N. Nakagawa, Y. Teshigawara, R. Sasaki.  2015.  "Development of a Detection and Responding System for Malware Communications by Using OpenFlow and Its Evaluation". 2015 Fourth International Conference on Cyber Security, Cyber Warfare, and Digital Forensic (CyberSec). :46-51.

Advanced Persistent Threat (APT) attacks, which have become prevalent in recent years, are classified into four phases. These are initial compromise phase, attacking infrastructure building phase, penetration and exploration phase, and mission execution phase. The malware on infected terminals attempts various communications on and after the attacking infrastructure building phase. In this research, using OpenFlow technology for virtual networks, we developed a system of identifying infected terminals by detecting communication events of malware communications in APT attacks. In addition, we prevent information fraud by using OpenFlow, which works as real-time path control. To evaluate our system, we executed malware infection experiments with a simulation tool for APT attacks and malware samples. In these experiments, an existing network using only entry control measures was prepared. As a result, we confirm the developed system is effective.

Na, L., Yunwei, D., Tianwei, C., Chao, W., Yang, G..  2015.  The Legitimacy Detection for Multilevel Hybrid Cloud Algorithm Based Data Access. Reliability and Security - Companion 2015 IEEE International Conference on Software Quality. :169–172.

In this paper a joint algorithm was designed to detect a variety of unauthorized access risks in multilevel hybrid cloud. First of all, the access history is recorded among different virtual machines in multilevel hybrid cloud using the global flow diagram. Then, the global flow graph is taken as auxiliary decision-making basis to design legitimacy detection algorithm based data access and is represented by formal representation, Finally the implement process was specified, and the algorithm can effectively detect operating against regulations such as simple unauthorized level across, beyond indirect unauthorized and other irregularities.

Na, Yoonjong, Joo, Yejin, Lee, Heejo, Zhao, Xiangchen, Sajan, Kurian Karyakulam, Ramachandran, Gowri, Krishnamachari, Bhaskar.  2020.  Enhancing the Reliability of IoT Data Marketplaces through Security Validation of IoT Devices. 2020 16th International Conference on Distributed Computing in Sensor Systems (DCOSS). :265—272.
IoT data marketplaces are being developed to help cities and communities create large scale IoT applications. Such data marketplaces let the IoT device owners sell their data to the application developers. Following this application development model, the application developers need not deploy their own IoT devices when developing IoT applications; instead, they can buy data from a data marketplace. In a marketplace-based IoT application, the application developers are making critical business and operation decisions using the data produced by seller's IoT devices. Under these circumstances, it is crucial to verify and validate the security of IoT devices.In this paper, we assess the security of IoT data marketplaces. In particular, we discuss what kind of vulnerabilities exist in IoT data marketplaces using the well-known STRIDE model, and present a security assessment and certification framework for IoT data marketplaces to help the device owners to examine the security vulnerabilities of their devices. Most importantly, our solution certifies the IoT devices when they connect to the data marketplace, which helps the application developers to make an informed decision when buying and consuming data from a data marketplace. To demonstrate the effectiveness of the proposed approach, we have developed a proof-of-concept using I3 (Intelligent IoT Integrator), which is an open-source IoT data marketplace developed at the University of Southern California, and IoTcube, which is a vulnerability detection toolkit developed by researchers at Korea University. Through this work, we show that it is possible to increase the reliability of a IoT data marketplace while not damaging the convenience of the users.
Nabipourshiri, Rouzbeh, Abu-Salih, Bilal, Wongthongtham, Pornpit.  2018.  Tree-Based Classification to Users' Trustworthiness in OSNs. Proceedings of the 2018 10th International Conference on Computer and Automation Engineering. :190-194.

In the light of the information revolution, and the propagation of big social data, the dissemination of misleading information is certainly difficult to control. This is due to the rapid and intensive flow of information through unconfirmed sources under the propaganda and tendentious rumors. This causes confusion, loss of trust between individuals and groups and even between governments and their citizens. This necessitates a consolidation of efforts to stop penetrating of false information through developing theoretical and practical methodologies aim to measure the credibility of users of these virtual platforms. This paper presents an approach to domain-based prediction to user's trustworthiness of Online Social Networks (OSNs). Through incorporating three machine learning algorithms, the experimental results verify the applicability of the proposed approach to classify and predict domain-based trustworthy users of OSNs.

Nace, L..  2020.  Securing Trajectory based Operations Through a Zero Trust Framework in the NAS. 2020 Integrated Communications Navigation and Surveillance Conference (ICNS). :1B1–1–1B1—8.
Current FAA strategic objectives include a migration to Trajectory Based Operations (TBO) with the integration of time-based management data and tools to increase efficiencies and reduce operating costs within the National Airspace System (NAS). Under TBO, integration across various FAA systems will take on greater importance than ever. To ensure the security of this integration without impacting data and tool availability, the FAA should consider adopting a Zero Trust Framework (ZTF) into the NAS.ZTF was founded on the belief that strong boundary security protections alone (traditionally referred to as the castle-moat approach) were no longer adequate to protecting critical data from outside threats and, with ever-evolving threat sophistication, contamination within a network perimeter is assumed to already exist (see Figure 1).To address this, theorists developed a framework where trust is controlled and applied to all internal network devices, users, and applications in what was termed a "Never Trust; Always Verify" approach to distinguish the authorized from the unauthorized elements wanting to access network data.To secure achievement of TBO objectives and add defensive depth to counter potential insider threats, the FAA must consider implementing a hybrid approach to the ZTF theory. This would include continued use of existing boundary protections provided by the FAA Telecommunications Infrastructure (FTI) network, with the additional strength afforded by the application of ZTF, in what is called the NAS Zero Trust eXtended (ZTX) platform.This paper discusses a proposal to implement a hybrid ZTX approach to securing TBO infrastructure and applications in the NAS.
Nachtigall, Troy Robert, Andersen, Kristina.  2018.  Making Secret Pockets. Extended Abstracts of the 2018 CHI Conference on Human Factors in Computing Systems. :LBW574:1–LBW574:6.
This paper describes an early design research exploration into the potential of folds and pockets to serve as places for safekeeping and secrecy in wearables. We explore what such secrecy may mean through woven data codes. We report on early material exploration, a pilot study with ten participants, and the personalization of a data object. We then outline, how we will make use of these early indications to build future stages of the project.
Nadeem, Humaira, Rabbani, Imran Mujaddid, Aslam, Muhammad, M, Martinez Enriquez A..  2018.  KNN-Fuzzy Classification for Cloud Service Selection. Proceedings of the 2Nd International Conference on Future Networks and Distributed Systems. :66:1-66:8.

Cloud computing is an emerging technology that provides services to its users via Internet. It also allows sharing of resources there by reducing cost, money and space. With the popularity of cloud and its advantages, the trend of information industry shifting towards cloud services is increasing tremendously. Different cloud service providers are there on internet to provide services to the users. These services provided have certain parameters to provide better usage. It is difficult for the users to select a cloud service that is best suited to their requirements. Our proposed approach is based on data mining classification technique with fuzzy logic. Proposed algorithm uses cloud service design factors (security, agility and assurance etc.) and international standards to suggest the cloud service. The main objective of this research is to enable the end cloud users to choose best service as per their requirements and meeting international standards. We test our system with major cloud provider Google, Microsoft and Amazon.

Naderi, Pooria Taghizadeh, Taghiyareh, Fattaneh.  2020.  LookLike: Similarity-based Trust Prediction in Weighted Sign Networks. 2020 6th International Conference on Web Research (ICWR). :294–298.
Trust network is widely considered to be one of the most important aspects of social networks. It has many applications in the field of recommender systems and opinion formation. Few researchers have addressed the problem of trust/distrust prediction and, it has not yet been established whether the similarity measures can do trust prediction. The present paper aims to validate that similar users have related trust relationships. To predict trust relations between two users, the LookLike algorithm was introduced. Then we used the LookLike algorithm results as new features for supervised classifiers to predict the trust/distrust label. We chose a list of similarity measures to examined our claim on four real-world trust network datasets. The results demonstrated that there is a strong correlation between users' similarity and their opinion on trust networks. Due to the tight relation between trust prediction and truth discovery, we believe that our similarity-based algorithm could be a promising solution in their challenging domains.
Nadgowda, S., Duri, S., Isci, C., Mann, V..  2017.  Columbus: Filesystem Tree Introspection for Software Discovery. 2017 IEEE International Conference on Cloud Engineering (IC2E). :67–74.

Software discovery is a key management function to ensure that systems are free of vulnerabilities, comply with licensing requirements, and support advanced search for systems containing given software. Today, software is predominantly discovered through querying package management tools, or using rules that check for file metadata or contents. These approaches are inadequate as not every software is installed through package managers, and agile development practices lead to frequent deployment of software. Other approaches to software discovery use machine learning methods requiring training phase, or require maintaining knowledge bases. Columbus uses the knowledge of the software packaging practices that evolved over time, and uses the information embedded in the file system impression created by a software package to discover it. Columbus is able to discover software in 92% of all official Docker images. Further, Columbus can be used in problem diagnosis and drift detection situations to compare two different systems, or to determine the evolution of a system overtime.

Nadi, Sarah, Krüger, Stefan, Mezini, Mira, Bodden, Eric.  2016.  Jumping Through Hoops: Why Do Java Developers Struggle with Cryptography APIs? Proceedings of the 38th International Conference on Software Engineering. :935–946.

To protect sensitive data processed by current applications, developers, whether security experts or not, have to rely on cryptography. While cryptography algorithms have become increasingly advanced, many data breaches occur because developers do not correctly use the corresponding APIs. To guide future research into practical solutions to this problem, we perform an empirical investigation into the obstacles developers face while using the Java cryptography APIs, the tasks they use the APIs for, and the kind of (tool) support they desire. We triangulate data from four separate studies that include the analysis of 100 StackOverflow posts, 100 GitHub repositories, and survey input from 48 developers. We find that while developers find it difficult to use certain cryptographic algorithms correctly, they feel surprisingly confident in selecting the right cryptography concepts (e.g., encryption vs. signatures). We also find that the APIs are generally perceived to be too low-level and that developers prefer more task-based solutions.

Nadi, Sarah, Krüger, Stefan.  2016.  Variability Modeling of Cryptographic Components: Clafer Experience Report. Proceedings of the Tenth International Workshop on Variability Modelling of Software-intensive Systems. :105–112.
Software systems need to use cryptography to protect any sensitive data they collect. However, there are various classes of cryptographic components (e.g., ciphers, digests, etc.), each suitable for a specific purpose. Additionally, each class of such components comes with various algorithms and configurations. Finding the right combination of algorithms and correct settings to use is often difficult. We believe that using variability modeling to model these algorithms, their relationships, and restrictions can help non-experts navigate this complex domain. In this paper, we report on our experience modeling cryptographic components in Clafer, a modeling language that combines feature modeling and meta-modeling. We discuss design decisions we took as well as the challenges we ran into. Our work helps expand variability modeling into new domains and sheds lights on modeling requirements that appear in practice.
Nadir, Ibrahim, Ahmad, Zafeer, Mahmood, Haroon, Asadullah Shah, Ghalib, Shahzad, Farrukh, Umair, Muhammad, Khan, Hassam, Gulzar, Usman.  2019.  An Auditing Framework for Vulnerability Analysis of IoT System. 2019 IEEE European Symposium on Security and Privacy Workshops (EuroS PW). :39–47.
Introduction of IoT is a big step towards the convergence of physical and virtual world as everyday objects are connected to the internet nowadays. But due to its diversity and resource constraint nature, the security of these devices in the real world has become a major challenge. Although a number of security frameworks have been suggested to ensure the security of IoT devices, frameworks for auditing this security are rare. We propose an open-source framework to audit the security of IoT devices covering hardware, firmware and communication vulnerabilities. Using existing open-source tools, we formulate a modular approach towards the implementation of the proposed framework. Standout features in the suggested framework are its modular design, extensibility, scalability, tools integration and primarily autonomous nature. The principal focus of the framework is to automate the process of auditing. The paper further mentions some tools that can be incorporated in different modules of the framework. Finally, we validate the feasibility of our framework by auditing an IoT device using proposed toolchain.
Naeem, H., Guo, B., Naeem, M. R..  2018.  A light-weight malware static visual analysis for IoT infrastructure. 2018 International Conference on Artificial Intelligence and Big Data (ICAIBD). :240–244.

Recently a huge trend on the internet of things (IoT) and an exponential increase in automated tools are helping malware producers to target IoT devices. The traditional security solutions against malware are infeasible due to low computing power for large-scale data in IoT environment. The number of malware and their variants are increasing due to continuous malware attacks. Consequently, the performance improvement in malware analysis is critical requirement to stop rapid expansion of malicious attacks in IoT environment. To solve this problem, the paper proposed a novel framework for classifying malware in IoT environment. To achieve flne-grained malware classification in suggested framework, the malware image classification system (MICS) is designed for representing malware image globally and locally. MICS first converts the suspicious program into the gray-scale image and then captures hybrid local and global malware features to perform malware family classification. Preliminary experimental outcomes of MICS are quite promising with 97.4% classification accuracy on 9342 windows suspicious programs of 25 families. The experimental results indicate that proposed framework is quite capable to process large-scale IoT malware.

Nag, Soumyajit, Banerjee, Subhasish, Sen, Srijon.  2019.  A New Three Party Authenticated Key Agreement Protocol Which Is Defiant towards Password Guessing Attack. 2019 International Conference on Automation, Computational and Technology Management (ICACTM). :13–18.

In order to develop a `common session secret key' though the insecure channel, cryptographic Key Agreement Protocol plays a major role. Many researchers' cryptographic protocol uses smart card as a medium to store transaction secret values. The tampered resistance property of smart card is unable to defend the secret values from side channel attacks. It means a lost smart card is an easy target for any attacker. Though password authentication helps the protocol to give secrecy but on-line as well as off-line password guessing attack can make the protocol vulnerable. The concerned paper manifested key agreement protocol based on three party authenticated key agreement protocol to defend all password related attacks. The security analysis of our paper has proven that the accurate guess of the password of a legitimate user will not help the adversary to generate a common session key.

Nagamani, Ch., Chittineni, Suneetha.  2018.  Network Intrusion Detection Mechanisms Using Outlier Detection. 2018 Second International Conference on Inventive Communication and Computational Technologies (ICICCT). :1468–1473.
The recognition of intrusions has increased impressive enthusiasm for information mining with the acknowledgment that anomalies can be the key disclosure to be produced using extensive network databases. Intrusions emerge because of different reasons, for example, mechanical deficiencies, changes in framework conduct, fake conduct, human blunder and instrument mistake. Surely, for some applications the revelation of Intrusions prompts more intriguing and helpful outcomes than the disclosure of inliers. Discovery of anomalies can prompt recognizable proof of framework blames with the goal that executives can take preventive measures previously they heighten. A network database framework comprises of a sorted out posting of pages alongside programming to control the network information. This database framework has been intended to empower network operations, oversee accumulations of information, show scientific outcomes and to get to these information utilizing networks. It likewise empowers network clients to gather limitless measure of information on unbounded territories of utilization, break down it and return it into helpful data. Network databases are ordinarily used to help information control utilizing dynamic capacities on sites or for putting away area subordinate data. This database holds a surrogate for each network route. The formation of these surrogates is called ordering and each network database does this errand in an unexpected way. In this paper, a structure for compelling access control and Intrusion Detection using outliers has been proposed and used to give viable Security to network databases. The design of this framework comprises of two noteworthy subsystems to be specific, Access Control Subsystem and Intrusion Detection Subsystem. In this paper preprocessing module is considered which clarifies the preparing of preprocessing the accessible information. And rain forest method is discussed which is used for intrusion detection.
Nagano, Yuta, Uda, Ryuya.  2017.  Static Analysis with Paragraph Vector for Malware Detection. Proceedings of the 11th International Conference on Ubiquitous Information Management and Communication. :80:1–80:7.

Malware damages computers and the threat is a serious problem. Malware can be detected by pattern matching method or dynamic heuristic method. However, it is difficult to detect all new malware subspecies perfectly by existing methods. In this paper, we propose a new method which automatically detects new malware subspecies by static analysis of execution files and machine learning. The method can distinguish malware from benignware and it can also classify malware subspecies into malware families. We combine static analysis of execution files with machine learning classifier and natural language processing by machine learning. Information of DLL Import, assembly code and hexdump are acquired by static analysis of execution files of malware and benignware to create feature vectors. Paragraph vectors of information by static analysis of execution files are created by machine learning of PV-DBOW model for natural language processing. Support vector machine and classifier of k-nearest neighbor algorithm are used in our method, and the classifier learns paragraph vectors of information by static analysis. Unknown execution files are classified into malware or benignware by pre-learned SVM. Moreover, malware subspecies are also classified into malware families by pre-learned k-nearest. We evaluate the accuracy of the classification by experiments. We think that new malware subspecies can be effectively detected by our method without existing methods for malware analysis such as generic method and dynamic heuristic method.

Naganuma, K., Suzuki, T., Yoshino, M., Takahashi, K., Kaga, Y., Kunihiro, N..  2020.  New Secret Key Management Technology for Blockchains from Biometrics Fuzzy Signature. 2020 15th Asia Joint Conference on Information Security (AsiaJCIS). :54–58.

Blockchain technology is attracting attention as an innovative system for decentralized payments in fields such as financial area. On the other hand, in a decentralized environment, management of a secret key used for user authentication and digital signature becomes a big issue because if a user loses his/her secret key, he/she will also lose assets on the blockchain. This paper describes the secret key management issues in blockchain systems and proposes a solution using a biometrics-based digital signature scheme. In our proposed system, a secret key to be used for digital signature is generated from the user's biometric information each time and immediately deleted from the memory after using it. Therefore, our blockchain system has the advantage that there is no need for storage for storing secret keys throughout the system. As a result, the user does not have a risk of losing the key management devices and can prevent attacks from malware that steals the secret key.

Nagar, S., Rajput, S. S., Gupta, A. K., Trivedi, M. C..  2017.  Secure routing against DDoS attack in wireless sensor network. 2017 3rd International Conference on Computational Intelligence Communication Technology (CICT). :1–6.

Wireless sensor network is a low cost network to solve many of the real world problems. These sensor nodes used to deploy in the hostile or unattended areas to sense and monitor the atmospheric situations such as motion, pressure, sound, temperature and vibration etc. The sensor nodes have low energy and low computing power, any security scheme for wireless sensor network must not be computationally complex and it should be efficient. In this paper we introduced a secure routing protocol for WSNs, which is able to prevent the network from DDoS attack. In our methodology we scan the infected nodes using the proposed algorithm and block that node from any further activities in the network. To protect the network we use intrusion prevention scheme, where specific nodes of the network acts as IPS node. These nodes operate in their radio range for the region of the network and scan the neighbors regularly. When the IPS node find a misbehavior node which is involves in frequent message passing other than UDP and TCP messages, IPS node blocks the infected node and also send the information to all genuine sender nodes to change their routes. All simulation work has been done using NS 2.35. After simulation the proposed scheme gives feasible results to protect the network against DDoS attack. The performance parameters have been improved after applying the security mechanism on an infected network.

Nagaratna, M., Sowmya, Y..  2017.  M-sanit: Computing misusability score and effective sanitization of big data using Amazon elastic MapReduce. 2017 International Conference on Computation of Power, Energy Information and Commuincation (ICCPEIC). :029–035.
The invent of distributed programming frameworks like Hadoop paved way for processing voluminous data known as big data. Due to exponential growth of data, enterprises started to exploit the availability of cloud infrastructure for storing and processing big data. Insider attacks on outsourced data causes leakage of sensitive data. Therefore, it is essential to sanitize data so as to preserve privacy or non-disclosure of sensitive data. Privacy Preserving Data Publishing (PPDP) and Privacy Preserving Data Mining (PPDM) are the areas in which data sanitization plays a vital role in preserving privacy. The existing anonymization techniques for MapReduce programming can be improved to have a misusability measure for determining the level of sanitization to be applied to big data. To overcome this limitation we proposed a framework known as M-Sanit which has mechanisms to exploit misusability score of big data prior to performing sanitization using MapReduce programming paradigm. Our empirical study using the real world cloud eco system such as Amazon Elastic Cloud Compute (EC2) and Amazon Elastic MapReduce (EMR) reveals the effectiveness of misusability score based sanitization of big data prior to publishing or mining it.
Nagendra, Vasudevan, Yegneswaran, Vinod, Porras, Phillip.  2017.  Securing Ultra-High-Bandwidth Science DMZ Networks with Coordinated Situational Awareness. Proceedings of the 16th ACM Workshop on Hot Topics in Networks. :22–28.

The Science DMZ (SDMZ) is a special purpose network infrastructure that is engineered to cater to the ultra-high bandwidth needs of the scientific and high performance computing (HPC) communities. These networks are isolated from stateful security devices such as firewalls and deep packet inspection (DPI) engines to allow HPC data transfer nodes (DTNs) to efficiently transfer petabytes of data without associated bandwidth and performance bottlenecks. This paper presents our ongoing effort toward the development of more fine-grained data flow access control policies to manage SDMZ networks that service large-scale experiments with varying data sensitivity levels and privacy constraints. We present a novel system, called CoordiNetZ (CNZ), that provides coordinated security monitoring and policy enforcement for sites participating in SDMZ projects by using an intent-based policy framework for effectively capturing the high-level policy intents of non-admin SDMZ project users (e.g., scientists, researchers, students). Central to our solution is the notion of coordinated situational awareness that is extracted from the synthesis of context derived from SDMZ host DTN applications and the network substrate. To realize this vision, we present a specialized process-monitoring system and flow-monitoring tool that facilitate context-aware data-flow intervention and policy enforcement in ultra-highspeed data transfer environments. We evaluate our prototype implementation using case studies that highlight the utility of our framework and demonstrate how security policy could be effectively specified and implemented within and across SDMZ networks.

Nagesh, K., Sumathy, R., Devakumar, P., Sathiyamurthy, K..  2016.  A Survey on Denial of Service Attacks and Preclusions. Proceedings of the International Conference on Informatics and Analytics. :118:1–118:10.

Security is concerned with protecting assets. The aspects of security can be applied to any situation- defense, detection and deterrence. Network security plays important role of protecting information, hardware and software on a computer network. Denial of service (DOS) attacks causes great impacts on the internet world. These attacks attempt to disrupt legitimate user's access to services. By exploiting computer's vulnerabilities, attackers easily consume victim's resources. Many special techniques have been developed to protest against DOS attacks. Some organizations constitute several defense mechanism tools to tackle the security problems. This paper has proposed various types of attacks and solutions associated with each layers of OSI model. These attacks and solutions have different impacts on the different environment. Thus the rapid growth of new technologies may constitute still worse impacts of attacks in the future.

Nageswar Rao, A., Rajendra Naik, B., Nirmala Devi, L., Venkata Subbareddy, K..  2020.  Trust and Packet Loss Aware Routing (TPLAR) for Intrusion Detection in WSNs. 2020 12th International Conference on Computational Intelligence and Communication Networks (CICN). :386–391.
In this paper, a new intrusion detection mechanism is proposed based on Trust and Packet Loss Rate at Sensor Node in WSNs. To find the true malicious nodes, the proposed mechanism performs a deep analysis on the packet loss. Two independent metrics such as buffer capacity metric and residual energy metric are considered for packet loss rate evaluation. Further, the trust evaluation also considers the basic communication interactions between sensor nodes. Based on these three metrics, a new composite metric called Packet Forwarding Probability (PFP) is derived through which the malicious nodes are identified. Simulation experiments are conducted over the proposed mechanism and the performance is evaluated through False Positive Rate (FPR) and Malicious Detection Rate (MDR). The results declare that the proposed mechanism achieves a better performance compared to the conventional approaches.
Naghmouchi, M. Yassine, Perrot, Nancy, Kheir, Nizar, Mahjoub, A. Ridha, Wary, Jean-Philippe.  2016.  A New Risk Assessment Framework Using Graph Theory for Complex ICT Systems. Proceedings of the 8th ACM CCS International Workshop on Managing Insider Security Threats. :97–100.

In this paper, we propose a new risk analysis framework that enables to supervise risks in complex and distributed systems. Our contribution is twofold. First, we provide the Risk Assessment Graphs (RAGs) as a model of risk analysis. This graph-based model is adaptable to the system changes over the time. We also introduce the potentiality and the accessibility functions which, during each time slot, evaluate respectively the chance of exploiting the RAG's nodes, and the connection time between these nodes. In addition, we provide a worst-case risk evaluation approach, based on the assumption that the intruder threats usually aim at maximising their benefits by inflicting the maximum damage to the target system (i.e. choosing the most likely paths in the RAG). We then introduce three security metrics: the propagated risk, the node risk and the global risk. We illustrate the use of our framework through the simple example of an enterprise email service. Our framework achieves both flexibility and generality requirements, it can be used to assess the external threats as well as the insider ones, and it applies to a wide set of applications.

Naghmouchi, M. Yassine, Perrot, Nancy, Kheir, Nizar, Mahjoub, A. Ridha, Wary, Jean-Philippe.  2016.  A New Risk Assessment Framework Using Graph Theory for Complex ICT Systems. Proceedings of the 8th ACM CCS International Workshop on Managing Insider Security Threats. :97–100.

In this paper, we propose a new risk analysis framework that enables to supervise risks in complex and distributed systems. Our contribution is twofold. First, we provide the Risk Assessment Graphs (RAGs) as a model of risk analysis. This graph-based model is adaptable to the system changes over the time. We also introduce the potentiality and the accessibility functions which, during each time slot, evaluate respectively the chance of exploiting the RAG's nodes, and the connection time between these nodes. In addition, we provide a worst-case risk evaluation approach, based on the assumption that the intruder threats usually aim at maximising their benefits by inflicting the maximum damage to the target system (i.e. choosing the most likely paths in the RAG). We then introduce three security metrics: the propagated risk, the node risk and the global risk. We illustrate the use of our framework through the simple example of an enterprise email service. Our framework achieves both flexibility and generality requirements, it can be used to assess the external threats as well as the insider ones, and it applies to a wide set of applications.

Naghmouchi, M. Yassine, Perrot, Nancy, Kheir, Nizar, Mahjoub, A. Ridha, Wary, Jean-Philippe.  2016.  A New Risk Assessment Framework Using Graph Theory for Complex ICT Systems. Proceedings of the 8th ACM CCS International Workshop on Managing Insider Security Threats. :97–100.

In this paper, we propose a new risk analysis framework that enables to supervise risks in complex and distributed systems. Our contribution is twofold. First, we provide the Risk Assessment Graphs (RAGs) as a model of risk analysis. This graph-based model is adaptable to the system changes over the time. We also introduce the potentiality and the accessibility functions which, during each time slot, evaluate respectively the chance of exploiting the RAG's nodes, and the connection time between these nodes. In addition, we provide a worst-case risk evaluation approach, based on the assumption that the intruder threats usually aim at maximising their benefits by inflicting the maximum damage to the target system (i.e. choosing the most likely paths in the RAG). We then introduce three security metrics: the propagated risk, the node risk and the global risk. We illustrate the use of our framework through the simple example of an enterprise email service. Our framework achieves both flexibility and generality requirements, it can be used to assess the external threats as well as the insider ones, and it applies to a wide set of applications.