On the Trust and Trust Modeling for the Future Fully-Connected Digital World: A Comprehensive Study

With the fast development of digital technologies, we are running into a digital world. The relationship among people and the connections among things become more and more complex, and new challenges arise. To tackle these challenges, trust — a soft security mechanism — is considered a promising technology. Thus, in this survey, we do a comprehensive study on trust and trust modelling for the future digital world. We revisit the definitions and properties of trust, analyse the trust theories, and discuss their impact on digital trust modelling. We analyse the digital world and its corresponding environment where people, things, and infrastructure connect with each other. We detail the challenges that require trust in these digital scenarios. Under our analysis of trust and the digital world, we define different types of trust relationships and find out the factors that are needed to ensure a fully representative model. Next, to meet the challenges of digital trust modelling, comprehensive trust model evaluation criteria are proposed, and potential security and privacy issues of trust modelling are analysed. Finally, we provide a wide-ranging analysis of different methodologies, mathematical theories, and how they can be applied to trust modelling.