<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-20T13:19:00Z</responseDate><request verb="GetRecord" identifier="oai:ruor.uottawa.ca:10393/6529" metadataPrefix="oai_dc">https://ruor.uottawa.ca/server/oai/request</request><GetRecord><record><header><identifier>oai:ruor.uottawa.ca:10393/6529</identifier><datestamp>2024-02-23T09:07:38Z</datestamp><setSpec>com_10393_242</setSpec><setSpec>col_10393_244</setSpec></header><metadata><oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
   <dc:title>Improving the security services of the message handling systems in X.400.</dc:title>
   <dc:creator>Liu, Jingsong.</dc:creator>
   <dc:contributor>Cheung, To-Yat,</dc:contributor>
   <dc:subject>Computer Science.</dc:subject>
   <dc:description>This thesis studies some security problems in the X.400 Message Handling System (MHS). It focuses on the so-called message-token, a cryptological data structure, used to convey the security-related information and support several basic security services in X.400 MHS. The current X.400 message-token which conforms to the X.509 one-way authentication protocol cannot protect X.400 messages from the attack of impersonation. An exisiting solution in terms of the one-way authentication protocol still cannot solve this problem when it is applied as a message-token in MHS. This thesis develops three new message-tokens for solving the problem. Correctness of the new message-tokens is proved by means of the authentication logic, a formal analysis technique for checking if authentication protocols are able to achieve their goals. Through the study, some weaknesses have been found in the postulates known as the Hash-Function Rules. New Hash-Function Rules are proposed for improving the authentication logic. The newly proposed message-tokens are proved to be capable of ensuring the integrity and originality of the conveyed information and thus prevent the impersonation threat for X.400 messages.</dc:description>
   <dc:date>2009-03-23T14:12:36Z</dc:date>
   <dc:date>2009-03-23T14:12:36Z</dc:date>
   <dc:date>1994</dc:date>
   <dc:date>1994</dc:date>
   <dc:type>Thesis</dc:type>
   <dc:identifier>Source: Masters Abstracts International, Volume: 34-02, page: 0789.</dc:identifier>
   <dc:identifier>9780612004818</dc:identifier>
   <dc:identifier>http://hdl.handle.net/10393/6529</dc:identifier>
   <dc:identifier>http://dx.doi.org/10.20381/ruor-14882</dc:identifier>
   <dc:format>91 p.</dc:format>
   <dc:format>application/pdf</dc:format>
   <dc:publisher>University of Ottawa (Canada)</dc:publisher>
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