Trust in Computer Systems and the Cloud

CHAPTER 13A World of Explicit Trust

At the beginning of this book, we explored what it means to say that we trust, and we stated that our interest was more in computer-to-computer trust than in trust involving humans. As we have gone further into what trust may mean to us, we have come full circle when we looked at trust domains, which can mix humans and trust but which use the same building blocks to be explicit about what we are trusting to do what, how, with what assurances, and when. While our focus has been on trust as related to security, we have tried to avoid talking about trust as a mechanism solely in that context but instead have considered it as a tool that can be used to address other characteristics or properties of systems, such as resilience. Most important, we have presented trust as a tool to help manage risk, but one that, when applied to the realm of computer-to-computer interactions, can provide more quantifiable information around risk than is typically available using current techniques. This last chapter allows us to consider what looks different in a world where risk is explicit within the context of computer-to-computer interactions.

Tools for Trust

None of the tools we have presented in this book are revolutionary, but all provide new ways of modelling systems that allow various parties to consider the impact of trust relationships. We present some of the key concepts and tools here as a summary:

• Trustor/Trustee Separation   One of the core aspects ...