A Review of Trust Management for Mobile Ad Hoc Networks

Concept Of Trust And Its Characteristics

Each discipline has defined and considered trust from a different perspective. For example in psychology, trust is described by state of mind of an individual. It has three perspectives viz. cognitive, emotive and behavioral. (Deutsch, 1962) defined trust as “confidence that an individual will find, what is desired from another rather than what is feared”. If an individual finds an entity’s behavior good and according to expectations under different situations, then individual starts building psychological trust in his mind about that entity and disseminates this trust among others when it interacts with other individuals. Trust between a child and mother, husband and wife, brother and sister, cousins and friends takes different form and depends upon the psychological state of an individual. In sociology, trust can be defined and considered from two viewpoints: individual and societal. Trust from individual viewpoint is close to psychological trust. Societal trust is described by the societal setup and collective societal state of mind. Societal trust is important to understand the building and establishment of trust in social networks. Psychological and societal trusts if lost are difficult to regain. In philosophy, trust has been considered important but dangerous (Cho, Swami, & Chen, 2011). Trust is the foundation of birth, survival and end of relationships. In economics, trust is generally considered from utility point of view. From utility point of view, an entity may put more trust on another entity even in the presence of risk and uncertainty if the action maximizes utility. For example while giving credit card numbers for online purchase of items an individual puts trust on various stakeholders, which is close to economic trust. In economics, prisoner’s dilemma games are used to model trust and cooperation in systems (Sherchan, Nepal, & Paris, 2013). In law, trust is taken as a relationship between two parties in which one, the trustee, has the power to manage property and the other, the beneficiary, has the privilege of receiving benefits from that property. In the area of computer science also, researchers have made attempts to define trust in various disciplines like computer networks, internet applications, computing systems, security systems, operating systems etc. In social networks, trustworthiness of an individual is derived from its virtual presence. It depends upon several parameters like honesty, attitude, interests, behaviour, beliefs, reliability, courage, patience, compatibility, adaptability, responsibility, expectations, dependency etc. One of the popular definitions of trust which has been adopted by many computer scientists is the one given by Diego Gambetta as “a particular level of the subjective probability with which an agent assesses that another agent or group of agents will perform a particular action, both before he can monitor such action (or independently of his capacity ever to be able to monitor it) and in a context in which it affects his own action” (Chakrabarty, 2007). (Grandison & Sloman, 2000) also provides a working definition of trust for Internet applications as “the firm belief in the competence of an entity to act dependably, securely, and reliably within a specified context”. From the concept of trust in various disciplines, following characteristics of the trust are derived: