A hybrid and cross-protocol architecture with semantics and syntax awareness to improve intrusion detection efficiency in Voice over IP environments

Includes abstract.Includes bibliographical references (leaves 134-140).Voice and data have been traditionally carried on different types of networks based on different technologies, namely, circuit switching and packet switching respectively. Convergence in networks enables carrying voice, video, and other data on the same packet-switched infrastructure, and provides various services related to these kinds of data in a unified way. Voice over Internet Protocol (VoIP) stands out as the standard that benefits from convergence by carrying voice calls over the packet-switched infrastructure of the Internet. Although sharing the same physical infrastructure with data networks makes convergence attractive in terms of cost and management, it also makes VoIP environments inherit all the security weaknesses of Internet Protocol (IP). In addition, VoIP networks come with their own set of security concerns. Voice traffic on converged networks is packet-switched and vulnerable to interception with the same techniques used to sniff other traffic on a Local Area Network (LAN) or Wide Area Network (WAN). Denial of Service attacks (DoS) are among the most critical threats to VoIP due to the disruption of service and loss of revenue they cause. VoIP systems are supposed to provide the same level of security provided by traditional Public Switched Telephone Networks (PSTNs), although more functionality and intelligence are distributed to the endpoints, and more protocols are involved to provide better service. A new design taking into consideration all the above factors with better techniques in Intrusion Detection are therefore needed. This thesis describes the design and implementation of a host-based Intrusion Detection System (IDS) that targets VoIP environments. Our intrusion detection system combines two types of modules for better detection capabilities, namely, a specification-based and a signaturebased module. Our specification-based module takes the specifications of VoIP applications and protocols as the detection baseline. Any deviation from the protocol’s proper behavior described by its specifications is considered anomaly. The Communicating Extended Finite State Machines model (CEFSMs) is used to trace the behavior of the protocols involved in VoIP, and to help exchange detection results among protocols in a stateful and cross-protocol manner. The signature-based module is built in part upon State Transition Analysis Techniques which are used to model and detect computer penetrations. Both detection modules allow for protocol-syntax and protocol-semantics awareness. Our intrusion detection uses the aforementioned techniques to cover the threats propagated via low-level protocols such as IP, ICMP, UDP, and TCP

A Comprehensive Survey of Voice over IP Security Research

We present a comprehensive survey of Voice over IP security academic research, using a set of 245 publications forming a closed cross-citation set. We classify these papers according to an extended version of the VoIP Security Alliance (VoIPSA) Threat Taxonomy. Our goal is to provide a roadmap for researchers seeking to understand existing capabilities and to identify gaps in addressing the numerous threats and vulnerabilities present in VoIP systems. We discuss the implications of our findings with respect to vulnerabilities reported in a variety of VoIP products. We identify two specific problem areas (denial of service, and service abuse) as requiring significant more attention from the research community. We also find that the overwhelming majority of the surveyed work takes a black box view of VoIP systems that avoids examining their internal structure and implementation. Such an approach may miss the mark in terms of addressing the main sources of vulnerabilities, i.e., implementation bugs and misconfigurations. Finally, we argue for further work on understanding cross-protocol and cross-mechanism vulnerabilities (emergent properties), which are the byproduct of a highly complex system-of-systems and an indication of the issues in future large-scale systems

Security-centric analysis and performance investigation of IEEE 802.16 WiMAX

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INSTANT MESSAGING SPAM DETECTION IN LONG TERM EVOLUTION NETWORKS

The lack of efficient spam detection modules for packet data communication is resulting to increased threat exposure for the telecommunication network users and the service providers. In this thesis, we propose a novel approach to classify spam at the server side by intercepting packet-data communication among instant messaging applications. Spam detection is performed using machine learning techniques on packet headers and contents (if unencrypted) in two different phases: offline training and online classification. The contribution of this study is threefold. First, it identifies the scope of deploying a spam detection module in a state-of-the-art telecommunication architecture. Secondly, it compares the usefulness of various existing machine learning algorithms in order to intercept and classify data packets in near real-time communication of the instant messengers. Finally, it evaluates the accuracy and classification time of spam detection using our approach in a simulated environment of continuous packet data communication. Our research results are mainly generated by executing instances of a peer-to-peer instant messaging application prototype within a simulated Long Term Evolution (LTE) telecommunication network environment. This prototype is modeled and executed using OPNET network modeling and simulation tools. The research produces considerable knowledge on addressing unsolicited packet monitoring in instant messaging and similar applications

Private Realm Gateway

IPv4-osoitteiden loppuminen on ollut maailmanlaajuinen huoli jo viimeisen kahden vuosikymmenen ajan. Lisääntynyt käyttäjien ja palvelujen lukumäärä on kuluttanut jo lähes kaikki mahdolliset osoitteet. Useita ratkaisuja on esitetty ongelman ratkaisemiseksi. Aikajärjestyksessä nämä ovat luokaton reititys (CIDR), osoitteenmuunnos (NAT) ja uusi versio IP protokollasta, IPv6. Osoitteenmuunnoksen käyttöönottaminen jakoi alueet yksityisiin ja julkisiin. NAT laitteet sallivat yksityisen verkon käyttäjien kommunikoida julkisen verkon käyttäjien kanssa jaetun IP osoitteen välityksellä. NAT toimii myös yksinkertaisena palomuurina estäen sisääntulevan liikenteen ja siten aiheuttaen ongelmia saavutettavuuden kanssa. Useista ratkaisuista huolimatta, yksikään ratkaisu ei ole täysin ongelmaton. Tässä työssä esitellään ratkaisu osoitteenmuutoksen aiheuttamaan saavutettavuusongelmaan. Ratkaisu on nimeltään Yksityisen Alueen Yhdyskäytävä (PRGW). Ratkaisun pääkomponentti on nimeltään kiertävä (renkaanmuotoinen) osoitevaranto joka käyttää rajoitettua määrää julkisia osoitteita mahdollistaen päästä-päähän kommunikoinnin useimmille sovelluksille. Loput sovellukset tarvitsevat sovellustason yhdyskäytävän tai välipalvelimen liitettävyyden luomiseksi. Prototyypin arviointi todistaa teorian ja toteutuksen toimivan erittäin hyvin. Yksityisen alueen yhdyskäytävä tarjoaa mekanismit saavutettavuuden ratkaisemiseksi ja samalla edistää ratkaisua osoitteiden loppumiseen.The IPv4 address exhaustion has been a global concern for the last two decades. The increased number of connected users and services has depleted almost entirely the addresses available. There have been several attempts to solve this problem. Chronologically they are Classless Inter-Domain Routing (CIDR), Network Address Translation (NAT) and a new version of the IP protocol, IPv6. The adoption of NAT introduced the separation of private and public realms. NAT devices allow the hosts located in the private realm to connect with hosts or services in the public realm by sharing a public IP address. NAT also provides the foremost kind of firewall blocking incoming connections towards the private realms and introducing the reachability problem. Although several alternatives have been developed to overcome this issue, none of them are exempt of drawbacks. This thesis introduces a new concept that solves the reachability problem introduced by NAT. The solution is called Private Realm Gateway (PRGW). The main component is called Circular Pool and it uses a limited number of public IP addresses to enable end-to-end communication to most applications. Other applications require the use of Application Layer Gateway (ALG) or proxy servers to grant connectivity. The evaluation of the prototype proves the concept and the implementation highly successful. The Private Realm Gateway provides mechanisms to overcome the reachability problem and also contributes to the solution of the address exhaustion problem

A Secure Peer-to-Peer Application Framework

The nature of the Internet has changed dramatically. From a modest research network, it has evolved into one of the most important fabrics of our modern society, affecting the lives of billions each day. We rely on it for everything from performing our daily chores to accessing rich media and keeping in touch with our friends. Despite this change, service provisioning has largely remained intact. Services are provided in a centralized manner, resulting in bottlenecks and vulnerable collections of, often unwittingly, submitted sensitive information. Peer-to-peer (P2P) technologies have the potential to provide a better alternative for future networking. P2P services distribute the load from a single node to a network of peers, relying on the resources of the end-users themselves. Not only does it remove the bottlenecks, it has the potential to provide a more personal and safe networking environment. In this dissertation, we inspect the feasibility and implications of a generic, cross-application, P2P framework. We present the design and implementation of a framework that uses existing infrastructure and advanced networking protocols to create a secure environment. Using this framework, applications are able to benefit from P2P networking without having to deploy new infrastructure or implement complex connection- and identity management. Users benefit from using a single, strong, cross-application identity management and having better control over their data. This improves the trust within the system and enables new ways of dealing with security threats. We demonstrate the feasibility of the framework by evaluating the performance and usability of the prototype implementation. This provides a model for future networking applications and insight into the security and usability issues these will face