The use of mobile ad-hoc networks (MANETs) is growing. The issue of security in MANETs is not trivial, since such networks have no fixed infrastructure and therefor centralised security is not applicable. MANETs are also more sensitive to attacks due to their wireless communication channels and their spontaneous nature.
All kind of cooperation requires a sense of trust. The opinion about trust in other entities can be used as a mean to dynamically allow for secure cooperation in MANETs, as soft security. And also to counter some of the inherited security problems of MANETs.
To use opinions as a security paradigm in MANETs the opinions about other nodes has to be spread as reputation about a node. This reputation spreading can be done through spreading of opinions or the spreading of evidences about a nodes behaviour.
In this work evidence and reputation spreading are compared to each other. This comparison shows that they are quite similar from a security point of view but that they differ in scalability.