727 research outputs found
Non-Repudiation in Internet Telephony
We present a concept to achieve non-repudiation for natural language
conversations over the Internet. The method rests on chained electronic
signatures applied to pieces of packet-based, digital, voice communication. It
establishes the integrity and authenticity of the bidirectional data stream and
its temporal sequence and thus the security context of a conversation. The
concept is close to the protocols for Voice over the Internet (VoIP), provides
a high level of inherent security, and extends naturally to multilateral
non-repudiation, e.g., for conferences. Signatures over conversations can
become true declarations of will in analogy to electronically signed, digital
documents. This enables binding verbal contracts, in principle between
unacquainted speakers, and in particular without witnesses. A reference
implementation of a secure VoIP archive is exhibited.Comment: Accepted full research paper at IFIP sec2007, Sandton, South Africa,
14-16 May 200
A secure archive for Voice-over-IP conversations
An efficient archive securing the integrity of VoIP-based two-party
conversations is presented. The solution is based on chains of hashes and
continuously chained electronic signatures. Security is concentrated in a
single, efficient component, allowing for a detailed analysis.Comment: 9 pages, 2 figures. (C) ACM, (2006). This is the author's version of
the work. It is posted here by permission of ACM for your personal use. Not
for redistribution. The definitive version was published in Proceedings of
VSW06, June, 2006, Berlin, German
Political institutions and the development of telecomunications
It has traditionally been argued that the development of telecommunications infrastructure is dependent on the quality of countries’ political institutions. We estimate the effect of political institutions on the diffusion of three telecommunications services and find it to be much smaller in cellular telephony than in the others. By evaluating the importance of institutions for technologies rather than for industries, we reveal important growth opportunities for developing countries and offer policy implications for alleviating differences between countries in international telecommunications development.Political constraints, Telecommunications, GMM, Economic development.
Telecommunications reform in Malawi
In 1998 the Government of Malawi decided to reform its telecommunications sector. Although the reform was ambitious in some ways, it was modest when compared with the most ambitious reforms adopted elsewhere in Sub-Saharan Africa. The two main accomplishments were splitting the incumbent fixed line monopoly, the Malawi Post and Telecommunications Corporation, into two companies-Malawi Telecommunications Limited (MTL) and Malawi Post Corporation (MPC)-and issuing two new cellular licenses to two new private entrants. In addition, the Government also established a new regulator which was separate from, but heavily dependent on, the Ministry of Information and liberalized entry in value-added and Internet services. However, the Government had neither privatized the fixed-line telecommunications operator nor introduced competition in fixed-line services by the end of 2002. Clarke, Gebreab, and Mgombelo discuss sector performance before reform, details of the reform, the political motivation for reform, and events in the five years following the reform. The reform yielded mixed results. Although cellular penetration and Internet use expanded dramatically following reform, prices increased, especially for cellular calls, and fixed-line penetration remains low by regional standards.Public Sector Economics&Finance,Rural Communications,Telecommunications Infrastructure,ICT Policy and Strategies,Knowledge Economy,ICT Policy and Strategies,Rural Communications,Education for the Knowledge Economy,Knowledge Economy,Public Sector Economics&Finance
Intrusion detection mechanisms for VoIP applications
VoIP applications are emerging today as an important component in business
and communication industry. In this paper, we address the intrusion detection
and prevention in VoIP networks and describe how a conceptual solution based on
the Bayes inference approach can be used to reinforce the existent security
mechanisms. Our approach is based on network monitoring and analyzing of the
VoIP-specific traffic. We give a detailed example on attack detection using the
SIP signaling protocol
Denial of Service in Voice Over IP Networks
In this paper we investigate denial of service (DoS) vulnerabilities in Voice over IP (VoIP) systems, focusing on the ITU-T H.323 family of protocols. We provide a simple characterisation of DoS attacks that allows us to readily identify DoS issues in H.323 protocols. We also discuss network layer DoS vulnerabilities that affect VoIP systems. A number of improvements and further research directions are proposed
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