3,800 research outputs found

    Use Trust Management Framework to Achieve Effective Security Mechanisms in Cloud Environment

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    Cloud Computing is an Internet based Computing where virtual shared servers provide software, infrastructure, platform and other resources to the customer on pay-as-you-use basis. Cloud Computing is increasingly becoming popular as many enterprise applications and data are moving into cloud platforms. However, with the enormous use of Cloud, the probability of occurring intrusion also increases. There is a major need of bringing security, transparency and reliability in cloud model for client satisfaction. One of the security issues is how to reduce the impact of any type of intrusion in this environment. To address this issue, a security solution is proposed in this paper. We provide a collaborative framework between our Hybrid Intrusion Detection System (Hy-IDS) based on Mobile Agents and virtual firewalls. Therefore, our hybrid intrusion detection system consists of three types of IDS namely IDS-C, IDS-Cr and IDS-M, which are dispatched over three layer of cloud computing. In the first layer, we use IDS-C over our framework to collect, analyze and detect malicious data using Mobile Agents. In case of attack, we collect at the level of the second layer all the malicious data detected in the first layer for the generation of new signatures using IDS-Cr, which is based on a Signature Generation Algorithm (SGA) and network intrusion detection system (NIDS). Finally, through an IDS-M placed in the third layer, the new signatures will be used to update the database NIDS belonging to IDS-Cr, then the database to NIDS belonging of IDS-Cr the cluster neighboring and also their IDS-C. Hardware firewall is unable to control communication between virtual machines on the same hypervisor. Moreover, they are blind to virtual traffic. Mostly, they are deployed at Virtual Machine Monitor- level (VMM) under Cloud provider’s control. Equally, the mobile agents play an important role in this collaboration. They are used in our framework for investigation of hosts, transfer data malicious and transfer update of a database of neighboring IDS in the cloud. With this technique, the neighboring IDS will use these new signatures to protect their area of control against the same type of attack. By this type of close-loop control, the collaborative network security management framework can identify and address new distributed attacks more quickly and effectively

    NIDH - Network Intrusion Detection Hierarchy: A model for gathering attack intelligence

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    Internet proxy systems such as Squid exchange intelligence relevant to their function as caching proxy servers via a distributed and trusted hierarchy of machines. The required intelligence is broadcast based along the network based upon established trust relationships throughout the connected network via specific port and protocols of exchange. An intrusion detection system that incorporates this functionality for gathering attack intelligence could be a formidable foe even for the wiliest attacker. This paper will outline a possible model for the deployment of a network/distributed network intrusion detection system utilising technologies and techniques already in existence to provide the supporting infrastructure

    RAPTOR: Routing Attacks on Privacy in Tor

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    The Tor network is a widely used system for anonymous communication. However, Tor is known to be vulnerable to attackers who can observe traffic at both ends of the communication path. In this paper, we show that prior attacks are just the tip of the iceberg. We present a suite of new attacks, called Raptor, that can be launched by Autonomous Systems (ASes) to compromise user anonymity. First, AS-level adversaries can exploit the asymmetric nature of Internet routing to increase the chance of observing at least one direction of user traffic at both ends of the communication. Second, AS-level adversaries can exploit natural churn in Internet routing to lie on the BGP paths for more users over time. Third, strategic adversaries can manipulate Internet routing via BGP hijacks (to discover the users using specific Tor guard nodes) and interceptions (to perform traffic analysis). We demonstrate the feasibility of Raptor attacks by analyzing historical BGP data and Traceroute data as well as performing real-world attacks on the live Tor network, while ensuring that we do not harm real users. In addition, we outline the design of two monitoring frameworks to counter these attacks: BGP monitoring to detect control-plane attacks, and Traceroute monitoring to detect data-plane anomalies. Overall, our work motivates the design of anonymity systems that are aware of the dynamics of Internet routing

    Sharing Computer Network Logs for Security and Privacy: A Motivation for New Methodologies of Anonymization

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    Logs are one of the most fundamental resources to any security professional. It is widely recognized by the government and industry that it is both beneficial and desirable to share logs for the purpose of security research. However, the sharing is not happening or not to the degree or magnitude that is desired. Organizations are reluctant to share logs because of the risk of exposing sensitive information to potential attackers. We believe this reluctance remains high because current anonymization techniques are weak and one-size-fits-all--or better put, one size tries to fit all. We must develop standards and make anonymization available at varying levels, striking a balance between privacy and utility. Organizations have different needs and trust other organizations to different degrees. They must be able to map multiple anonymization levels with defined risks to the trust levels they share with (would-be) receivers. It is not until there are industry standards for multiple levels of anonymization that we will be able to move forward and achieve the goal of widespread sharing of logs for security researchers.Comment: 17 pages, 1 figur

    Scalable schemes against Distributed Denial of Service attacks

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    Defense against Distributed Denial of Service (DDoS) attacks is one of the primary concerns on the Internet today. DDoS attacks are difficult to prevent because of the open, interconnected nature of the Internet and its underlying protocols, which can be used in several ways to deny service. Attackers hide their identity by using third parties such as private chat channels on IRC (Internet Relay Chat). They also insert false return IP address, spoofing, in a packet which makes it difficult for the victim to determine the packet\u27s origin. We propose three novel and realistic traceback mechanisms which offer many advantages over the existing schemes. All the three schemes take advantage of the Autonomous System topology and consider the fact that the attacker\u27s packets may traverse through a number of domains under different administrative control. Most of the traceback mechanisms make wrong assumptions that the network details of a company under an administrative control are disclosed to the public. For security reasons, this is not the case most of the times. The proposed schemes overcome this drawback by considering reconstruction at the inter and intra AS levels. Hierarchical Internet Traceback (HIT) and Simple Traceback Mechanism (STM) trace back to an attacker in two phases. In the first phase the attack originating Autonomous System is identified while in the second phase the attacker within an AS is identified. Both the schemes, HIT and STM, allow the victim to trace back to the attackers in a few seconds. Their computational overhead is very low and they scale to large distributed attacks with thousands of attackers. Fast Autonomous System Traceback allows complete attack path reconstruction with few packets. We use traceroute maps of real Internet topologies CAIDA\u27s skitter to simulate DDoS attacks and validate our design
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