On Understanding the Existence of a Deep Torrent Rodríguez-Gómez, Rafael Macía Fernández, Gabriel Casares Andrés, Alberto Peer-to-peer computing Crawlers Traffic monitoring Search engines Protocols Computer security Search engines Telecommunication traffic Nowadays, a great part of the Internet content is not reachable from search engines. Studying the nature of these contents from a cyber security perspective is of a high interest, as they could be part of many malware distribution processes, child pornography or copyrighted material exchange, botnet command and control messages, etc. Although the research community has put a big effort on this challenge, most of the existing works are focused on contents that are hidden in Web sites. Yet, there exist other relevant services that are used to keep and transmit hidden resources, such as P2P protocols. In the present work, we suggest the concept of Deep Torrent to refer to those torrents available in BitTorrent that cannot be found by means of public Web sites or search engines. We present an implementation of a complete system to crawl the Deep Torrent and evaluate its existence and size. We describe a basic experiment crawling the Deep Torrent for 39 days, in which an initial estimation of its size is 67% of the total number of resources shared in BitTorrent network. 2019-04-01T06:19:39Z 2019-04-01T06:19:39Z 2017-07 journal article http://hdl.handle.net/10481/55281 https://doi.org/10.1109/MCOM.2017.1600959 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España