Abstract

Information and Communication Technologies (ICT) are becoming increasingly important in the way we organize our lives, our workplaces and our societies. ICT allows people and organisations, that have never interacted with each other in the past, to initiate new and mutually beneficial businesses across the world. This means that personal and business information is increasingly being communicated across interpersonal, inter-business and international borders. Keeping this information safe and protecting the fragile IT infrastructure from criminals is a growing problem in most societies. Unfortunately, traditional security technologies based on a strong perimeter defence work poorly in an inter-connected world that obeys Metcalfe’s law which states that “the value of a network is proportional to the square of the number of connected users of the system”, i.e., where there is a strong incentive for interactions across the different borders. During the past decade, trust management has emerged as a promising solution to many challenges in networks and distributed systems as well as emerging problems in computer security and privacy.