Abstract: In a peer-to-peer network of peers which are interconnected for sharing content data, the peers store content files of content data in a file structure comprising a plurality of content folders each content folder containing any number of content files of related content data, and a description file containing both unique identification information and descriptive information in XML format describing the content file or files stored in the same content folder. Requesting peers transmit search query messages which specify search criteria for passage through the network. Peers receiving a search query message compare the search criteria with the descriptive information contained in the description files in each of their plurality of content folders and in the event of there being a matching content folder transmit a hit message including the identification information to identify the matching content folder for passage back through the network to the respective requesting peer.

Abstract: A client device for use in a system having a server, the client device including: a receiving device configured to receive information material from the server, the information material containing a reversible modification providing a visually perceptible disturbing effect having been applied to the information material by using an invertible algorithm which uses values generated from one or more keys, and to receive identifying information that distinguishes the information material from other information material available from the server and condition information which defines a predetermined condition that should be met in order for the reversible modification to be reversed.

Abstract: A client device for use in a system having a server, the client device including: a receiving device configured to receive information material from the server, the information material containing a reversible modification providing a perceptible disturbing effect to the information material, and to receive identifying information that distinguishes the information material from other information material available from the server and condition information which defines a predetermined condition that should be met in order for the reversible modification to be reversed; a transmission device which, in response to a user input providing enabling data which satisfies the predetermined condition, configured to transmit the identifying information and the enabling data to the server, wherein in response to the transmission of the enabling data and the identifying information, the receiving device is configured to receive a key and removing data defining an algorithm for removing the perceptible effect, the removi

Abstract: A system for watermarking and transferring watermarked material comprises a transaction server, first and second clients, first apparatus for applying a perceptible watermark to the material and second apparatus for removing the watermark. The server, clients and first and second apparatus are linked by one or more communications networks.

Abstract: In a peer-to-peer network of peers 10 which are interconnected for sharing content data, the peers 10 store content files of content data in a file structure comprising a plurality of content folders 21, 22, 23, each content folder 21, 22, 23 containing any number of content files 24 of related content data, and a description file 26 containing both unique identification information and descriptive information in XML format describing the content file or files 24 stored in the same content folder 21. Requesting peers 10 transmit search query messages which specify search criteria for passage through the network.

Abstract: A system for watermarking and transferring watermarked material comprises a transaction server, first and second clients, first apparatus for applying a perceptible watermark to the material and second apparatus for removing the watermark. The server, clients and first and second apparatus are linked by one or more communications networks.