“…Privacy-preserving collaborative filtering methods can be used to protect user privacy. Different protection methods can be found in the literature (Boutet, A., Frey, D., Guerraoui, R., Jégou, A., & Kermarrec, 2016;Polatidis, Georgiadis, Pimenidis, & Mouratidis, 2017;Songjie Gong, 2011;Tada, Kikuchi, & Puntheeranurak, 2010;Yakut & Polat, 2012). These methods add a level of noise to the data, thus providing a level of protection which comes with a decrease in terms of the quality of the top-N recommendations.…”