UMA Trust Model
Several documents produced by the UMA Work Group related to trust.
http://docs.kantarainitiative.org/uma/draft-uma-trust.html
Specification documenting the binding obligations on UMA participants. (You can see the old document that used to live on this page by visiting old revisions.)
http://kantarainitiative.org/confluence/display/uma/UMA+Trust+Model+User+guide
Domenico Catalano's latest work on leveraging UMA in an actual deployed ecosystem.
http://kantarainitiative.org/confluence/display/uma/Measuring+elements+of+Trust
Domenico's early study analyzing the UMA trust proposition.
More trust-related documents to come!
NOTE: The short link http://tinyurl.com/umatrust takes you to this page.