Attack Trees
Bruce Schneier · 2015
Attack trees provide a methodical way of describing threats against, and countermeasures protecting, a system. By extension, attack trees provide a methodical way of representing the security of systems. They allow people to make calculations about security, compare the security of different systems, and do a whole bunch of other cool things. This chapter starts with a simple attack tree for a noncomputer security system, and builds the concepts up slowly. it illustrates a simple attack tree against a physical safe, and an attack tree for the PGP e-mail security program. Once people build up a library of attack trees against particular computer programs, door and window locks, network security protocols, or whatever, they can reuse them whenever they need to. For a national security agency concerned about compartmentalizing attack expertise, this kind of system is very useful.