Abstract: Provides encryption methods, and systems and apparatus corresponding decryption method systems and apparatus in which terminals belonging to a subset selected as a recipient group can collaborate to decrypt encrypted information. In an example embodiment, a sender and recipients communicate information over a network. The sender sends information encrypted by using a group key that can be decrypted by collaboration among a given number of recipients to the recipients in a predetermined recipient group. On the other hand, the recipients receive encrypted data from the sender, exchange partial information concerning the encrypted data among a plurality of recipients in the recipient group to obtain decryption information used for decrypting the encrypted data, and decrypt the sent information by using the decryption information.

Abstract: A method of facilitating the interworking of network elements of one or more communication networks some of which network elements support a given security mechanism and others of which do not. The method comprises, at each network element which does support the security mechanism, maintaining a database listing peer network elements and an indication of whether or not the peer network elements support the security mechanism. Upon initiation of a signalling communication from a peer network element supporting the security mechanism to another peer network element, inspecting the database of the initiating network element to determine whether or not the peer network element supports the security mechanism, and conducting the communication accordingly. The databases 9 stored at network elements are updated dynamically based upon signalling information received from peer network elements.

Abstract: A system and method in which the operating system of the user computer loads the software application and a DLL having a portion of the application execution code stored therein into memory is disclosed. At selected points during its execution, the software application calls the DLL to execute a portion of the application code that was saved into the DLL before delivery to the end user. Since this code is encrypted and the encryption key is stored in a hardware security device and not in the DLL or the software application, the application code portion cannot be executed without recovering the key.

Abstract: A method, apparatus and computer program product for transmitting data secures the data by adaptively transforming it and spreading the transformed data piecewise over plural transmission channels. The method, apparatus and computer program product may select low-cost channels preferentially to transmit greater amounts of the data; may disorder the data and transmit ordering information separately over a preferred channel of higher security; may conceal data in a lower-security channel by steganographic methods; and may conceal the sequence of the data by placing segments of it statically, for example, in a WWW website, while providing sequencing data on the preferred channel of higher security. A receiving method, apparatus and computer program product may also be provided for recovering information content from signals on the plural channels.

Abstract: Additional information is embedded in document data by inputting document data, inputting additional information, and inputting image data. The additional information is embedded in the input image data using a first digital watermark method, and the additional information is embedded in the input document data using a second digital watermark method. The document data embedded with the additional information is composited with the image data embedded with the additional information, with the image data as a background image. In a case where an original document containing information embedded using the second digital watermark method is copied by a copying machine, the information embedded in the copied document cannot be detected. The first digital watermark method has a robustness such that, when an original document containing information embedded using the first digital watermark method is copied by a copying machine, information embedded in the copied document can be detected.

Abstract: The present invention provides an additional-watermark embedding apparatus for embedding predetermined additional data into original data. The additional-watermark embedding apparatus includes an adder for summing the original data and the additional data, a first amplifier for amplifying the original data according to a predetermined non-linear input-output characteristic, a second amplifier for amplifying the summed data supplied from the adder according to a predetermined non-linear input-output characteristic, a subtractor for taking the difference between the amplified data obtained by the second amplifier and the amplified original data obtained by the first amplifier, and an embedder for embedding modified additional data which is obtained by modifying the waveform of the additional data according to the original data and which is supplied from the subtractor into the original data.