8,958 research outputs found

    Security Enhancements in Voice Over Ip Networks

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    Voice delivery over IP networks including VoIP (Voice over IP) and VoLTE (Voice over LTE) are emerging as the alternatives to the conventional public telephony networks. With the growing number of subscribers and the global integration of 4/5G by operations, VoIP/VoLTE as the only option for voice delivery becomes an attractive target to be abused and exploited by malicious attackers. This dissertation aims to address some of the security challenges in VoIP/VoLTE. When we examine the past events to identify trends and changes in attacking strategies, we find that spam calls, caller-ID spoofing, and DoS attacks are the most imminent threats to VoIP deployments. Compared to email spam, voice spam will be much more obnoxious and time consuming nuisance for human subscribers to filter out. Since the threat of voice spam could become as serious as email spam, we first focus on spam detection and propose a content-based approach to protect telephone subscribers\u27 voice mailboxes from voice spam. Caller-ID has long been used to enable the callee parties know who is calling, verify his identity for authentication and his physical location for emergency services. VoIP and other packet switched networks such as all-IP Long Term Evolution (LTE) network provide flexibility that helps subscribers to use arbitrary caller-ID. Moreover, interconnecting between IP telephony and other Circuit-Switched (CS) legacy telephone networks has also weakened the security of caller-ID systems. We observe that the determination of true identity of a calling device helps us in preventing many VoIP attacks, such as caller-ID spoofing, spamming and call flooding attacks. This motivates us to take a very different approach to the VoIP problems and attempt to answer a fundamental question: is it possible to know the type of a device a subscriber uses to originate a call? By exploiting the impreciseness of the codec sampling rate in the caller\u27s RTP streams, we propose a fuzzy rule-based system to remotely identify calling devices. Finally, we propose a caller-ID based public key infrastructure for VoIP and VoLTE that provides signature generation at the calling party side as well as signature verification at the callee party side. The proposed signature can be used as caller-ID trust to prevent caller-ID spoofing and unsolicited calls. Our approach is based on the identity-based cryptography, and it also leverages the Domain Name System (DNS) and proxy servers in the VoIP architecture, as well as the Home Subscriber Server (HSS) and Call Session Control Function (CSCF) in the IP Multimedia Subsystem (IMS) architecture. Using OPNET, we then develop a comprehensive simulation testbed for the evaluation of our proposed infrastructure. Our simulation results show that the average call setup delays induced by our infrastructure are hardly noticeable by telephony subscribers and the extra signaling overhead is negligible. Therefore, our proposed infrastructure can be adopted to widely verify caller-ID in telephony networks

    Madam Ambassador: A Statistical Comparison of Female Ambassadors across the U.S.,German, and EU Foreign Services. College of Europe EU Diplomacy Paper 03/2019

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    Since the end of the Cold War, transatlantic partners have championed enlightenment principles and progressive values around the world, including gender equality. The extent to which the actors tasked with spreading these fundamental values also embody them within their own organizations – in this case within the diplomatic profession – is the focus of this research. This paper examines how women’s representation at the ambassadorial level has changed from 1990 to 2018 across the foreign services of the U.S., Germany, and the European Union (EU). A dataset constructed especially for this study compares: (1) the numbers of female ambassadors over time, (2) the ‘types’ of posts they are sent to, and (3) recruitment pipelines and training, including special characteristics like political appointments in the U.S. and different origins of EU ambassadors. The results show that the U.S. foreign service peaks at 40% women’s representation in 2017, the EU at 22% in 2014, and Germany only at 14.5% in 2018. Females disproportionately serve in small African nations, multilateral organizations, and former Soviet states. Female U.S. ambassadors are more likely to come from the career track, while political appointees are overwhelmingly male, at a ratio of 4:1. In Europe, two-thirds of female ambassadors previously worked at the European Commission and one-third in their national foreign service, while founding Member States – especially France, Germany, and Italy – are dominant. Interviews with seasoned diplomats help illuminate and contextualize the underlying causes that potentially drive these trends, including policy, historical, or cultural factors. Looking towards the future, this work provides a small, yet important building block in rooting the concept of gender equality firmly within the success strategy of each diplomatic corps. A future generation of foreign policy leaders depends on it

    Convergence: the next big step

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    Recently, web based multimedia services have gained popularity and have proven themselves to be viable means of communication. This has inspired the telecommunication service providers and network operators to reinvent themselves to try and provide value added IP centric services. There was need for a system which would allow new services to be introduced rapidly with reduced capital expense (CAPEX) and operational expense (OPEX) through increased efficiency in network utilization. Various organizations and standardization agencies have been working together to establish such a system. Internet Protocol Multimedia Subsystem (IMS) is a result of these efforts. IMS is an application level system. It is being developed by 3GPP (3rd Generation Partnership Project) and 3GPP2 (3rd Generation Partnership Project 2) in collaboration with IETF (Internet Engineering Task Force), ITU-T (International Telecommunication Union – Telecommunication Standardization Sector), and ETSI (European Telecommunications Standards Institute) etc. Initially, the main aim of IMS was to bring together the internet and the cellular world, but it has extended to include traditional wire line telecommunication systems as well. It utilizes existing internet protocols such as SIP (Session Initiation Protocol), AAA (Authentication, Authorization and Accounting protocol), and COPS (Common Open Policy Service) etc, and modifies them to meet the stringent requirements of reliable, real time communication systems. The advantages of IMS include easy service quality management (QoS), mobility management, service control and integration. At present a lot of attention is being paid to providing bundled up services in the home environment. Service providers have been successful in providing traditional telephony, high speed internet and cable services in a single package. But there is very little integration among these services. IMS can provide a way to integrate them as well as extend the possibility of various other services to be added to allow increased automation in the home environment. This thesis extends the concept of IMS to provide convergence and facilitate internetworking of the various bundled services available in the home environment; this may include but is not limited to communications (wired and wireless), entertainment, security etc. In this thesis, I present a converged home environment which has a number of elements providing a variety of communication and entertainment services. The proposed network would allow effective interworking of these elements, based on IMS architecture. My aim is to depict the possible advantages of using IMS to provide convergence, automation and integration at the residential level

    Trends in Banking 2017 and onwards

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    The changing nature of the relationship between a retail bank and its customers is examined, particularly with respect to new financial concepts, debt and regulation. The traditional image of a bank is portrayed as a physical building a classical Doric portico. This image conveys concepts of service, soundness, strength, stability and security ("five-S"). That "five-S" concept is changing, and the evidence for changes that affect customers directly is considered. A fundamental legal problem associated with those changes is highlighted: a bank is no longer solely responsible for the safeguard of customer monies. A solution to this problem is proposed: banks should be jointly liable with perpetrators of criminal activity in the event of frauds as an encouragement to recognise and mitigate fraud.Comment: Proceedings 29th SASE Conference, Lyon France, June-July 201

    Sieve Email Filtering: Extension for Notifications

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