Optimizing secure communication standards for disadvantaged networks

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 137-140).We present methods for optimizing standardized cryptographic message protocols for use on disadvantaged network links. We first provide an assessment of current secure communication message packing standards and their relevance to disadvantaged networks. Then we offer methods to reduce message overhead in packing Cryptographic Message Syntax (CMS) structures by using ZLIB compression and using a Lite version of CMS. Finally, we offer a few extensions to the Extensible Messaging and Presence Protocol (XMPP) to wrap secure group messages for chat on disadvantaged networks and to reduce XMPP message overhead in secure group transmissions. We present the design and implementation of these optimizations and the results that these optimizations have on message overhead, extensibility, and usability of both CMS and XMPP. We have developed these methods to extend CMS and XMPP with the ultimate goal of establishing standards for securing communications in disadvantaged networks.by Stephen Hiroshi Okano.M.Eng

XML security in XML data integrity, authentication, and confidentiality

The widely application of XML has increasingly required high security. XML security confronts some challenges that are strong relating to its features. XML data integrity needs to protect element location information and contextreferential meaning as well as data content integrity under fine-grained security situations. XML data authentication must satisfy a signing process under a dependent and independent multi-signature generation scenario. When several different sections are encrypted within the XML data, it cannot query the encrypted contents without decrypting the encrypted portions. The technologies relating to XML security demand further development. This thesis aims to improve XML security relative technologies, and make them more practicable and secure. A novel revocation information validation approach for X.509 certificate is proposed based on the XML digital signature technology. This approach reduces the complexity of XKMS or PKI systems because it eliminates the requirement for additional revocation checking from XKMS or CA. The communication burden between server and client could be alleviated. The thesis presents the context-referential integrity for XML data. An integrity solution for XML data is also proposed based on the concatenated hash function. The integrity model proposed not only ensures XML data content integrity, but also protects the structure integrity and elements’ context relationship within an XML data. If this model is integrated into XML signature technology, the signature cannot be copied to another document still keeping valid. A new series-parallel XML multi-signature scheme is proposed. The presented scheme is a mixed order specified XML multi-signature scheme according to a dependent and independent signing process. Using presented XML data integrity-checking pool to provide integrity-checking for decomposed XML data, it makes signing XPath expression practicable, rather than signing XML data itself. A new labeling scheme for encrypted XML data is presented to improve the efficiency of index information maintenance which is applied to support encrypted XML data query processing. The proposed labelling scheme makes maintenance index information more efficient, and it is easy to update XML data with decreasing the number of affected nodes to the lowest. In order to protect structural information for encrypted XML data, the encrypted nodes are removed from original XML data, and structural information is hidden. A case study is carried out to demonstrate how the proposed XML security relative approaches and schemes can be applied to satisfy fine-grained XML security in calibration certificate management.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Living conditions in Estonia five years later : NorBalt II

http://www.ester.ee/record=b1659012*es