Diversity has long been regarded as a security mechanism for improving the resilience of software and networks against various attacks. More recently, diversity found new applications in cloud computing security, moving target defense, robustness network routing. However, most existing efforts rely on intuitive imprecise notions diversity, few models are mostly designed single system running diverse replicas or variants. At higher abstraction level, global property entire network, its effect...

The cyber situational awareness of an organization determines its effectiveness in responding to attacks. Mission success is highly dependent on the availability and correct operation complex computer networks, which are vulnerable various types Today, capabilities limited many ways, such as inaccurate incomplete vulnerability analysis, failure adapt evolving networks attacks, inability transform raw data into intelligence, for handling uncertainty. We describe advanced mission-centric...

Recognition of human activities in restricted settings such as airports, parking lots and banks is significant interest security automated surveillance systems. In settings, data usually the form videos with wide variation quality granularity. Interpretation identification requires an activity model that a) rich enough to handle complex multi-agent interactions, b) robust uncertainty low-level processing c) can ambiguities unfolding activities. We present a computational framework for...

Attack graph analysis has been established as a powerful tool for analyzing network vulnerability. However, previous approaches to hardening look exact solutions and thus do not scale. Further, elements have treated independently, which is inappropriate real environments. For example, the cost patching many systems may be nearly same single one. Or vulnerability effect blocking traffic with firewall, while port deny legitimate service. By failing account such interdependencies, resulting...

The extraordinary technological progress we have witnessed in recent years has made it possible to generate and exchange multimedia content at an unprecedented rate. As a consequence, massive collections of objects are now widely available large population users. the task browsing such could be daunting, Recommender Systems being developed assist users finding items that match their needs preferences. In this article, present novel approach recommendation systems, based on modeling as social...

Distributed Denial of Service attacks against high-profile targets have become more frequent in recent years. In response to such massive attacks, several architectures adopted proxies introduce layers indirection between end users and target services reduce the impact a DDoS attack by migrating new shuffling clients across so as isolate malicious clients. However, reactive nature these solutions presents weaknesses that we leveraged develop - proxy harvesting which enables collect...

One of the most important challenge in information access field is overload. To cope with this problem, paper, we present a strategy for semantic multimedia recommender system that computes customized recommendations using contents and low-level features objects, past behavior individual users users' community as whole. We have implemented prototype browsing Uffizi Gallery digital picture collection. Then, investigated effectiveness proposed approach, based on satisfaction. The obtained...

Techniques aimed at continuously changing a system's attack surface, usually referred to as Moving Target Defense (MTD), are emerging powerful tools for thwarting cyber attacks. Such mechanisms increase the uncertainty, complexity, and cost attackers, limit exposure of vulnerabilities, ultimately overall resiliency. In this paper, we propose an MTD approach protecting resource-constrained distributed devices through fine-grained reconfiguration different architectural layers. order show...

Botnets are increasingly being used for exfiltrating sensitive data from mission-critical systems. Research has shown that botnets have become extremely sophisticated and can operate in stealth mode by minimizing their host network footprint. In order to defeat exfiltration modern botnets, we propose a moving target defense approach dynamically deploying detectors across network. Specifically, several strategies based on centrality measures periodically change the placement of detectors. Our...

Moving Target Defense (MTD) has recently emerged as a game changer in the security landscape due to its proven potential introduce asymmetric uncertainty that gives defender tactical advantage over attacker. Many different MTD techniques have been developed, but, despite huge progress made this area, critical gaps still exist with respect problem of studying and quantifying cost benefits deploying MTDs. In fact, all existing address very narrow set attack vectors, and, lack shared metrics,...

Mechanisms for continuously changing or shifting a system's attack surface are emerging as game-changers in cyber security. In this paper, we propose novel defense mechanism protecting the identity of nodes Mobile Ad Hoc Networks and defeat attacker's reconnaissance efforts. The proposed turns classical - Sybil into an effective mechanism, with legitimate periodically their virtual order to increase uncertainty attacker. To preserve communication among nodes, modify network layer by...

There are numerous applications where we wish to discover unexpected activities in a sequence of time-stamped observation data--for instance, may want detect inexplicable events transactions at website or video an airport tarmac. In this paper, start with known set $({\cal A})$ (both innocuous and dangerous) that monitor. However, addition, identify "unexplained" subsequences poorly explained (e.g., because they contain occurrences have never been seen anticipated before, i.e., not A})$). We...

Distributed denial-of-service attacks are an increasing problem facing web applications, for which many defense techniques have been proposed, including several moving-target strategies. These strategies typically work by relocating targeted services over time, uncertainty the attacker, while trying not to disrupt legitimate users or incur excessive costs. Prior has shown, however, whether and how a rational defender would choose method against adaptive under what conditions. We formulate...

Today, numerous applications require the ability to monitor a continuous stream of fine-grained data for occurrence certain high-level activities. A number computerized systems-including ATM networks, web servers, and intrusion detection systems-systematically track every atomic action we perform, thus generating massive streams timestamped observation data, possibly from multiple concurrent In this paper, address problem efficiently detecting occurrences activities such interleaved streams....

In recent years, Moving Target Defense (MTD) has emerged as a potential game changer in the security landscape, due to its create asymmetric uncertainty that favors defender. Many different MTD techniques have then been proposed, each addressing an often very specific set of attack vectors. Despite huge progress made this area, there are still some critical gaps with respect analysis and quantification cost benefits deploying techniques. fact, common metrics assess performance these lacking...

Cyber attacks are typically preceded by a reconnaissance phase in which attackers aim at collecting valuable information about the target system, including network topology, service dependencies, and unpatched vulnerabilities. Unfortunately, when system configurations static, will always be able, given enough time, to acquire accurate knowledge engineer effective exploits. To address this important problem, many adaptive techniques have been devised dynamically change some aspects of...