Biblio
Machine learning is being used in a wide range of application domains to discover patterns in large datasets. Increasingly, the results of machine learning drive critical decisions in applications related to healthcare and biomedicine. Such health-related applications are often sensitive, and thus, any security breach would be catastrophic. Naturally, the integrity of the results computed by machine learning is of great importance. Recent research has shown that some machine-learning algorithms can be compromised by augmenting their training datasets with malicious data, leading to a new class of attacks called poisoning attacks. Hindrance of a diagnosis may have life-threatening consequences and could cause distrust. On the other hand, not only may a false diagnosis prompt users to distrust the machine-learning algorithm and even abandon the entire system but also such a false positive classification may cause patient distress. In this paper, we present a systematic, algorithm-independent approach for mounting poisoning attacks across a wide range of machine-learning algorithms and healthcare datasets. The proposed attack procedure generates input data, which, when added to the training set, can either cause the results of machine learning to have targeted errors (e.g., increase the likelihood of classification into a specific class), or simply introduce arbitrary errors (incorrect classification). These attacks may be applied to both fixed and evolving datasets. They can be applied even when only statistics of the training dataset are available or, in some cases, even without access to the training dataset, although at a lower efficacy. We establish the effectiveness of the proposed attacks using a suite of six machine-learning algorithms and five healthcare datasets. Finally, we present countermeasures against the proposed generic attacks that are based on tracking and detecting deviations in various accuracy metrics, and benchmark their effectiveness.
The development of future cyber terrorism scenarios is a key component in building a more comprehensive understanding of cyber threats that are likely to emerge in the near-to mid-term future. While developing concepts of likely new, emerging digital technologies is an important part of this process, this article suggests that understanding the psychological and social forces involved in cyber terrorism is also a key component in the analysis and that the synergy of these two dimensions may produce more accurate and detailed future cyber threat scenarios than either analytical element alone.
The smart grid aims to improve the efficiency, reliability and safety of the electric system via modern communication system, it's necessary to utilize cloud computing to process and store the data. In fact, it's a promising paradigm to integrate smart grid into cloud computing. However, access to cloud computing system also brings data security issues. This paper focuses on the protection of user privacy in smart meter system based on data combination privacy and trusted third party. The paper demonstrates the security issues for smart grid communication system and cloud computing respectively, and illustrates the security issues for the integration. And we introduce data chunk storage and chunk relationship confusion to protect user privacy. We also propose a chunk information list system for inserting and searching data.
During software evolution, it is important to evolve not only the source code, but also its architecture to prevent architecture drift and architecture erosion. This is a complex activity, especially for large software projects, with multiple development teams that might be located in different countries or on different continents. To ease this kind of evolution, we have developed a domain-specific language for making decisions about the evolution. It supports the definition of architectural changes based on multiple implementation tasks that can have temporal dependencies among each other. Then, by means of a model-to-model transformation, we automatically create a constraint model that we use to generate, by means of the Alloy model analyzer, the possible alternative decisions for executing the implementation tasks. The tight integration with architecture abstractions enables architects to automatically check the changes related to an implementation task in relation to the architecture description. This helps keeping architecture and code in sync, avoiding drift and erosion.
Security subsystems are often designed with flawed assumptions arising from system designers' faulty mental models. Designers tend to assume that users behave according to some textbook ideal, and to consider each potential exposure/interface in isolation. However, fieldwork continually shows that even well-intentioned users often depart from this ideal and circumvent controls in order to perform daily work tasks, and that "incorrect" user behaviors can create unexpected links between otherwise "independent" interfaces. When it comes to security features and parameters, designers try to find the choices that optimize security utility–-except these flawed assumptions give rise to an incorrect curve, and lead to choices that actually make security worse, in practice. We propose that improving this situation requires giving designers more accurate models of real user behavior and how it influences aggregate system security. Agent-based modeling can be a fruitful first step here. In this paper, we study a particular instance of this problem, propose user-centric techniques designed to strengthen the security of systems while simultaneously improving the usability of them, and propose further directions of inquiry.
As information security became an increasing concern for software developers and users, requirements engineering (RE) researchers brought new insight to security requirements. Security requirements aim to address security at the early stages of system design while accommodating the complex needs of different stakeholders. Meanwhile, other research communities, such as usable privacy and security, have also examined these requirements with specialized goal to make security more usable for stakeholders from product owners, to system users and administrators. In this paper we report results from conducting a literature survey to compare security requirements research from RE Conferences with the Symposium on Usable Privacy and Security (SOUPS). We report similarities between the two research areas, such as common goals, technical definitions, research problems, and directions. Further, we clarify the differences between these two communities to understand how they can leverage each other’s insights. From our analysis, we recommend new directions in security requirements research mainly to expand the meaning of security requirements in RE to reflect the technological advancements that the broader field of security is experiencing. These recommendations to encourage cross- collaboration with other communities are not limited to the security requirements area; in fact, we believe they can be generalized to other areas of RE.
Phishing is a social engineering tactic that targets internet users in an attempt to trick them into divulging personal information. When opening an email, users are faced with the decision of determining if an email is legitimate or an attempt at phishing. Although software has been developed to assist the user, studies have shown they are not foolproof, leaving the user vulnerable. Multiple training programs have been developed to educate users in their efforts to make informed decisions; however, training that conveys the real world consequences of phishing or training that increases a user’s fear level have not been developed. Conveying real world consequences of a situation and increasing a user’s fear level have been proven to enhance the effects of training in other fields. Ninety-six participants were recruited and randomly assigned to training programs with phishing consequences, training programs designed to increase fear, or a control group. Preliminary results indicate that training helped users identify phishing emails; however, little difference was seen among the three groups. Future analysis will include a factor analysis of personality and individual differences that influence training efficacy.
Central to the secure operation of a public key infrastructure (PKI) is the ability to revoke certificates. While much of users' security rests on this process taking place quickly, in practice, revocation typically requires a human to decide to reissue a new certificate and revoke the old one. Thus, having a proper understanding of how often systems administrators reissue and revoke certificates is crucial to understanding the integrity of a PKI. Unfortunately, this is typically difficult to measure: while it is relatively easy to determine when a certificate is revoked, it is difficult to determine whether and when an administrator should have revoked.
In this paper, we use a recent widespread security vulnerability as a natural experiment. Publicly announced in April 2014, the Heartbleed OpenSSL bug, potentially (and undetectably) revealed servers' private keys. Administrators of servers that were susceptible to Heartbleed should have revoked their certificates and reissued new ones, ideally as soon as the vulnerability was publicly announced.
Using a set of all certificates advertised by the Alexa Top 1 Million domains over a period of six months, we explore the patterns of reissuing and revoking certificates in the wake of Heartbleed. We find that over 73% of vulnerable certificates had yet to be reissued and over 87% had yet to be revoked three weeks after Heartbleed was disclosed. Moreover, our results show a drastic decline in revocations on the weekends, even immediately following the Heartbleed announcement. These results are an important step in understanding the manual processes on which users rely for secure, authenticated communication.
We consider several challenging problems in complex networks (communication, control, social, economic, biological, hybrid) as problems in cooperative multi-agent systems. We describe a general model for cooperative multi-agent systems that involves several interacting dynamic multigraphs and identify three fundamental research challenges underlying these systems from a network science perspective. We show that the framework of constrained coalitional network games captures in a fundamental way the basic tradeoff of benefits vs. cost of collaboration, in multi-agent systems, and demonstrate that it can explain network formation and the emergence or not of collaboration. Multi-metric problems in such networks are analyzed via a novel multiple partially ordered semirings approach. We investigate the interrelationship between the collaboration and communication multigraphs in cooperative swarms and the role of the communication topology, among the collaborating agents, in improving the performance of distributed task execution. Expander graphs emerge as efficient communication topologies for collaborative control. We relate these models and approaches to statistical physics.
In this work, we seek to optimize the efficiency of secure general-purpose obfuscation schemes. We focus on the problem of optimizing the obfuscation of Boolean formulas and branching programs – this corresponds to optimizing the "core obfuscator" from the work of Garg, Gentry, Halevi, Raykova, Sahai, and Waters (FOCS 2013), and all subsequent works constructing general-purpose obfuscators. This core obfuscator builds upon approximate multilinear maps, where efficiency in proposed instantiations is closely tied to the maximum number of "levels" of multilinearity required. The most efficient previous construction of a core obfuscator, due to Barak, Garg, Kalai, Paneth, and Sahai (Eurocrypt 2014), required the maximum number of levels of multilinearity to be O(l s3.64), where s is the size of the Boolean formula to be obfuscated, and l s is the number of input bits to the formula. In contrast, our construction only requires the maximum number of levels of multilinearity to be roughly l s, or only s when considering a keyed family of formulas, namely a class of functions of the form fz(x)=phi(z,x) where phi is a formula of size s. This results in significant improvements in both the total size of the obfuscation and the running time of evaluating an obfuscated formula. Our efficiency improvement is obtained by generalizing the class of branching programs that can be directly obfuscated. This generalization allows us to achieve a simple simulation of formulas by branching programs while avoiding the use of Barrington's theorem, on which all previous constructions relied. Furthermore, the ability to directly obfuscate general branching programs (without bootstrapping) allows us to efficiently apply our construction to natural function classes that are not known to have polynomial-size formulas.
Specifics of an alias-free digitizer application for compressed digitizing and recording of wideband signals are considered. Signal sampling in this case is performed on the basis of picosecond resolution event timing, the digitizer actually is a subsystem of Event Timer A033-ET and specific events that are detected and then timed are the signal and reference sine-wave crossings. The used approach to development of this subsystem is described and some results of experimental studies are given.
Rogue software, such as Fake A/V and ransomware, trick users into paying without giving return. We show that using a perceptual hash function and hierarchical clustering, more than 213,671 screenshots of executed malware samples can be grouped into subsets of structurally similar images, reflecting image clusters of one malware family or campaign. Based on the clustering results, we show that ransomware campaigns favor prepay payment methods such as ukash, paysafecard and moneypak, while Fake A/V campaigns use credit cards for payment. Furthermore, especially given the low A/V detection rates of current rogue software – sometimes even as low as 11% – our screenshot analysis approach could serve as a complementary last line of defense.
It can get the user's privacy and home energy use information by analyzing the user's electrical load information in smart grid, and this is an area of concern. A rechargeable battery may be used in the home network to protect user's privacy. In this paper, the battery can neither charge nor discharge, and the power of battery is adjustable, at the same time, we model the real user's electrical load information and the battery power information and the recorded electrical power of smart meters which are processed with discrete way. Then we put forward a heuristic algorithm which can make the rate of information leakage less than existing solutions. We use statistical methods to protect user's privacy, the theoretical analysis and the examples show that our solution makes the scene design more reasonable and is more effective than existing solutions to avoid the leakage of the privacy.