A distributed content-based search engine based on mobile code and web service technology

Current search engines crawl the Web, download content, and digest this content locally. For multimedia content, this involves considerable volumes of data. Furthermore, this process covers only publicly available content because content providers are concerned that they otherwise loose control over the distribution of their intellectual property. We present the prototype of our secure and distributed search engine, which dynamically pushes content based feature extraction to image providers. Thereby, the volume of data that is transported over the network is significantly reduced, and the concerns mentioned above are alleviated. The distribution of feature extraction and matching algorithms is done by mobile software agents. Subsequent search requests performed upon the resulting feature indices by means of remote feature comparison can either be realized through mobile software agents, or by the use of implicitly created Web services which wrap the remote comparison functionality, and thereby improve the interoperability of the search engine. We give a description of the search engine's architecture and implementation, depict our concepts to integrate agent and Web service technology, and present quantitative evaluation results. Furthermore, we discuss related security mechanisms for content protection and server security.