which subclass of information filtering system was work of John Thomas Riedl
John T. Riedl John Thomas Riedl (January 16, 1962 – July 15, 2013) was an American computer scientist and the McKnight Distinguished Professor at the University of Minnesota. His published works include highly influential research on the social web, recommendation systems, and collaborative systems.
Confusion and diffusion In cryptography, confusion and diffusion are two properties of the operation of a secure cipher identified by Claude Shannon in his 1945 classified report "A Mathematical Theory of Cryptography""." These properties, when present, work to thwart the application of statistics and other methods of cryptanalysis.