syssec_red_book

10 Usable SecurityKeys, locks, and chains: security in computer systems is almost asold as computers themselves. Although the enforcement methods mayhave changed from physical security, which is still important, to amore conceptual and system-inherent form, the basic concept is still the same:How can a computer system be secured, so that only permitted personnel areable to use it? In the old days, it was simply a matter of giving the key to thebuilding where the computer was housed to the right person. Even then, oncean employee left the company, the key had to be recovered to ensure security.Neglecting this precaution, would create a potential security risk. Nowadays,the problems are conceptually similar. Instead of physical security keys, usersare provided with passwords, PIN codes and access tokens so that they mayenter restricted areas or access private information.10.1 What Is the Problem?Even though the majority of these problems are essentially the same as 30years ago, one key factor has changed: complexity. What was previously asingle device, is now a multitude of different accounts, Web gates and PINcodes. Additionally, connectivity is at an all-time high and is showing notendency to slow down. This Internet of things, as it is called by experts, isa future for communication and computing devices that has already begun.Unfortunately, this progress not only opens up opportunities for developmentand technological advance, it also enables miscreants to conduct their dailybusiness on a much broader scale. To mitigate present and future threats, alarge research community is constantly developing solutions to block incomingattacks and ultimately prevent users from falling victim to various forms ofattack. Commendable as these research results may be, they usually bearseveral important properties that often hinder their acceptance by normalusers. Even protection mechanisms that are already well-established can sufferfrom the following problems:• Simplicity: Useable security must be simple. A normal user cannot bewilling to deal with the task of creating a security policy for accessing the