Another research area which is receiving a lot of attention is the identification of vulnerabilities of existing protocols and equipment [56], [57], as well as on methodologies by which to analyse existing networks in order to detect and mitigate vulnerabilities. These methodologies generally focus on detecting chains of vulnerabilities [58] or developing attack trees [59], as overcoming even low levels of security on a network often involves exploiting a series of several vulnerabilities before effecting a meaningful compromise.