Catalin Leordeanu

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Providing an adequate security level in Cloud Environments is currently an extremely active research area. More specifically, malicious behaviors targeting large-scale Cloud data repositories (e.g. Denial of Service attacks) may drastically degrade the overall performance of such systems and cannot be detected by typical authentication mechanisms. In this(More)
In this paper we present a novel Intrusion Detection System which uses a hybrid approach based on a pattern matching engine and a neural network functioning in parallel to improve the detection efficiency. The attacks that this module is able to detect will be presented, as well as the methods used. This approach is based on the Netpy traffic monitoring and(More)
In this paper, based on a thorough analysis of different policies for DAG scheduling, an improved algorithm ICPDP (Improved Critical Path using Descendant Prediction) is introduced. The algorithm performs well with respect to the total scheduling time, the schedule length and load balancing. In addition, it provides efficient resource utilization, by(More)
The paper presents an extension of NetPy, a network traffic visualization tool using NetFlow records. NetPy offers traffic visualization as well as a traffic analysis, which is very useful for the network administrators. NetPy has been re-designed to include a better Graphical User Interface to make the application easier to use and to present the(More)
Cloud Systems provide computing resources in a flexible manner. There are several key requirements that need to be addressed regarding the resource allocation in Clouds and the most important of them is providing on demand elasticity. This paper focuses on adding new features to the Cloud resource allocation mechanism that enhance on demand elasticity. Most(More)
This paper presents a novel intrusion detection system for Grid Systems. It is intended to identify potential attackers who try to modify or compromise the applications sent to execution by various users or target different resource groups within the Grid. The system makes use of a number of available local intrusion detection systems which send data to a(More)
This paper presents an original approach to the development of models, methods and techniques for increasing reliability, availability, safety and security of large scale distributed systems, particularly Grids and Web-based distributed systems. The characteristics of these systems pose problems to ensuring dependability, especially because of the(More)
Cloud computing has developed into an ubiquitous distributed system model, offering services which range from storage to computing power or database infrastructure. The security aspect of such distributed systems is a very important and challenging issue. In this paper we propose a security solution which offers policy enforcement in order to detect denial(More)
High availability is a desired feature of a dependable distributed system. Replication is a well-known technique to achieve fault tolerance in distributed systems, thereby enhancing availability. We propose an approach relying on replication techniques and based on monitoring information to be applied in distributed systems for fault tolerance. Our approach(More)