Browsing by Author "Negussie, Solomon"

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    The Right to Secession: The Possibility of its Application with Regard to the Current Fiscal Set up in Ethiopia
    (Addis Ababa University, 2015) Addis, Abay; Negussie, Solomon
    One of the most crucial challenges to Ethiopia’s fiscal federalism is the inability of the states to raise, retain and manage revenue. Revenue bases at state level being small and unpredictable and resource problems that most states have create a problem in performance of their expenditure responsibilities. As a result, State and sub national governments are extremely dependent on the federal government’s grant even to cover their budgets. Interestingly, while a lot has been written about Ethiopian fiscal federalism, not much attention is paid to its possible effects on the application of the right to secession. Beginning with an evaluation of the current fiscal set up and the right to secession under the federal constitution, this study examines how the Ethiopian fiscal federalism impacts the possibility of application of the right to secession.
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    Securing Confidentiality and Integrity of SIP Based VoIP System in Reduced Call Setup Time
    (Addis Ababa University, 2014-06) Negussie, Solomon; Negash, Yalemzewd(PhD)
    Voice over IP is one of the quickest developing Internet services promised to have growing demand. However this demand is challenged by security pitfalls of the current internet security problems plus none flawlessness of the VoIP protocols themselves. Specially as any telecommunication service requires privacy, confidentiality, integrity and availability protection VoIP needs to assure its customers those information security principle concerns with tolerable quality of service, the concerns not raised frequently in PSTN(Public Switched Telephone Network) and other traditional telephone networks. Even though there are many protocols and security principles made available to be used by developers and service providers, however current applications are more on the quality and the extent of service they provide rather than the concern in security breach. However there are some VoIP application developers and service providers that provides the capability of encrypting the communication, which is not sufficient since the signaling is not protected due to fear of additional overhead. By this work we proposed new way of setting secure VoIP (Voice over Internet Protocol) session(secure in a context of confidentiality and integrity protection only) in SIP (Session Initiation Protocol) based VoIP system using the current recommended and best practices of securing VoIP so that the newly proposed system will have improved call setup time. We also designed and implemented the proposed secure call setup mechanism as a proof for the practicability of our recommendation and as a test bed to assess the effect of the proposed mechanism in modifying the time required to setup a secure call, i.e. confidentiality and integrity guaranteed session. We have compared our proposed mechanism of establishing a secure conversation and signaling session with a common secure session establishment technique and we have seen that our proposed system requires only 8.0 second to establish secure session, while the other common practices takes about 10.5 second. Hence the proposed system reduces the call setup time by about 2.5 seconds. Keywords: VoIP, SIP, TLS, SRTP, ZRTP, MZRTP, Call Setup Time, Confidentiality, Integrity.