Secure Content Management In Ambient Environments- how about(6)

In order to strengthen the research on security and ambient intelligence, as well as the relationship between the content management and security work at Philips Research and at Twente University, a joint research project is set up. The work will be carrie

occurred.This could be used as a pre-filtering stage in a search operation[Hac01 ] . Key diversificationTo enable searching in encrypted data, each relevant search target may beencrypted with its own specific key [Son00]. Homomorphic encryptionThis is the ability to compute with encrypted data such that the computations arealso meaningful to the unencrypted data [Aba90]. It is difficult if not impossibleto find crypto systems that have specific properties. Further, more, homomorphicencryption can be misused easily to infer information about encrypted data, forexample is we can check that E(a)+E(b)=E(a+b), we have some information abouta and b. The technique is often used in voting systems. Blind signaturesThe ability to sign something that you don't know [Cha92] can be used to endorseinformation by a third party. The classical example is Alice who wants Bob tosign a document for her, so that Carol (who trusts Bob but not Alice) may acceptit. Content hashingA secure hash of some information gives an identifier for that information that isunique with high probability [Mer87]. This has been used in many peer to peersystems, e.g. Freenet [C1a02], and distributed file systems [Maz99].Hashing is very sensitive to small changes in the information being hashed, somulti media information requires special treatment. For example audioinformation should ideally be hashed such that only perceptibly different audioyields different hashes. Licensing of meta-dataDescribing security policies and models formetadata [Cho02]. Security policiesfor meta-data can in principle be described independently from the securitypolicies for data.

References[Aba90]

[Ber00]

[B1o01]

[Cha92]M. Abadi and J. Feigenbaum. Secure circuit evaluation: A protocol basedon hiding information from an oracle. Journal of Cryptology, 2(1):1--12,1990.E. Bertino, S. Castano, E. Ferrari and M. Mesiti. Specifying and EnforcingAccess Control Policies for XML Document Sources. Intl. Journal ofWorld Wide Web, 3(3), 2000.H. E.Blok,M.Windhouwer,R.Zwol,M. Petkovic, P. M. G. Apers, , W.Jonker,M.Kersten,"Flexible and Scalable Digital Library Search", 27thInternationalConference on Very Large Databases, Roma, Italy,September 2001.D.Chaum.Achieving electronic privacy.ScientificAmerican,267(2):96--101,Aug1992.