199,109 research outputs found

    The Use of Firewalls in an Academic Environment

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    The battle between standards: TCP/IP vs OSI victory through path dependency or by quality?

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    Between the end of the 1970s and 1994 a fierce competition existed between two possible standards, TCP/IP and OSI, to solve the problem of interoperability of computer networks. Around 1994 it became evident that TCP/IP and not OSI had become the dominant standard. We specifically deal with the question whether the current dominance of the TCP/IP standard is the result of third degree path dependency or of choices based on assessments of it being technical-economically superior to the OSI standard and protocols

    Oral activated charcoal prevents experimental cerebral malaria in mice and in a randomized controlled clinical trial in man did not interfere with the pharmacokinetics of parenteral artesunate.

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    BACKGROUND: Safe, cheap and effective adjunct therapies preventing the development of, or reducing the mortality from, severe malaria could have considerable and rapid public health impact. Oral activated charcoal (oAC) is a safe and well tolerated treatment for acute poisoning, more recently shown to have significant immunomodulatory effects in man. In preparation for possible efficacy trials in human malaria, we sought to determine whether oAC would i) reduce mortality due to experimental cerebral malaria (ECM) in mice, ii) modulate immune and inflammatory responses associated with ECM, and iii) affect the pharmacokinetics of parenteral artesunate in human volunteers. METHODS/PRINCIPAL FINDINGS: We found that oAC provided significant protection against P. berghei ANKA-induced ECM, increasing overall survival time compared to untreated mice (p<0.0001; hazard ratio 16.4; 95% CI 6.73 to 40.1). Protection from ECM by oAC was associated with reduced numbers of splenic TNF(+) CD4(+) T cells and multifunctional IFNgamma(+)TNF(+) CD4(+) and CD8(+) T cells. Furthermore, we identified a whole blood gene expression signature (68 genes) associated with protection from ECM. To evaluate whether oAC might affect current best available anti-malarial treatment, we conducted a randomized controlled open label trial in 52 human volunteers (ISRCTN NR. 64793756), administering artesunate (AS) in the presence or absence of oAC. We demonstrated that co-administration of oAC was safe and well-tolerated. In the 26 subjects further analyzed, we found no interference with the pharmacokinetics of parenteral AS or its pharmacologically active metabolite dihydroartemisinin. CONCLUSIONS/SIGNIFICANCE: oAC protects against ECM in mice, and does not interfere with the pharmacokinetics of parenteral artesunate. If future studies succeed in establishing the efficacy of oAC in human malaria, then the characteristics of being inexpensive, well-tolerated at high doses and requiring no sophisticated storage would make oAC a relevant candidate for adjunct therapy to reduce mortality from severe malaria, or for immediate treatment of suspected severe malaria in a rural setting. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN64793756

    Making Code Voting Secure against Insider Threats using Unconditionally Secure MIX Schemes and Human PSMT Protocols

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    Code voting was introduced by Chaum as a solution for using a possibly infected-by-malware device to cast a vote in an electronic voting application. Chaum's work on code voting assumed voting codes are physically delivered to voters using the mail system, implicitly requiring to trust the mail system. This is not necessarily a valid assumption to make - especially if the mail system cannot be trusted. When conspiring with the recipient of the cast ballots, privacy is broken. It is clear to the public that when it comes to privacy, computers and "secure" communication over the Internet cannot fully be trusted. This emphasizes the importance of using: (1) Unconditional security for secure network communication. (2) Reduce reliance on untrusted computers. In this paper we explore how to remove the mail system trust assumption in code voting. We use PSMT protocols (SCN 2012) where with the help of visual aids, humans can carry out mod10\mod 10 addition correctly with a 99\% degree of accuracy. We introduce an unconditionally secure MIX based on the combinatorics of set systems. Given that end users of our proposed voting scheme construction are humans we \emph{cannot use} classical Secure Multi Party Computation protocols. Our solutions are for both single and multi-seat elections achieving: \begin{enumerate}[i)] \item An anonymous and perfectly secure communication network secure against a tt-bounded passive adversary used to deliver voting, \item The end step of the protocol can be handled by a human to evade the threat of malware. \end{enumerate} We do not focus on active adversaries

    Anonymous credit cards and their collusion analysis

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    Communications networks are traditionally used to bring information together. They can also be used to keep information apart in order to protect personal privacy. A cryptographic protocol specifies a process by which some information is transferred among some users and hidden from others. We show how to implement anonymous credit cards using simple cryptographic protocols. We pose, and solve, a collusion problem which determines whether it is possible for a subset of users to discover information that is designed to be hidden from them during or after execution of the anonymous credit card protocol

    APNET - ADEA study project on intra African book trade

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    Following on the ADEA/APNET study on inter-African Book trade that was commissioned in 1999, ADEA tasked APNET to facilitate the production of national book industry updates in each country. The updates are aimed at encouraging commercial development of inter-African book trade and to make available to the public, total systematic and current situations on the book trade in each country

    Improving the efficiency of spam filtering through cache architecture

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    Blacklists (BLs), also called Domain Name Systembased Blackhole List (DNSBLs) are the databases of known internet addresses used by the spammers to send out the spam mails. Mail servers use these lists to filter out the e-mails coming from different spam sources. In contrary, Whitelists (WLs) are the explicit list of senders from whom e-mail can be accepted or delivered. Mail Transport Agent (MTA) is usually configured to reject, challenge or flag the messages which have been sent from the sources listed on one or more DNSBLs and to allow the messages from the sources listed on the WLs. In this paper, we are demonstrating how the bandwidth (the overall requests and responses that need to go over the network) performance is improved by using local caches for BLs and WLs. The actual sender\u27s IP addresses are extracted from the e-mail log. These are then compared with the list in the local caches to find out if they should be accepted or not, before they are checked against the global DNSBLs by running \u27DNSBL queries\u27 (if required). Around three quarters of the e-mail sources have been observed to be filtered locally through caches with this method. Provision of local control over the lists and lower search (filtering) time are the other related benefits. © 2008 IEEE
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