1. One or more computer-readable storage media having stored thereon executable instructions to perform a method of facilitating access to a resource, the method comprising: receiving a template that specifies one or more assertions; obtaining a first token that satisfies a first one of said one or more assertions; presenting, to a guard of the resource, (a) a set of one or more tokens that comprises said first token, and (b) an access request for a first principal to access the resource; receiving access to said resource from said guard; and accessing said resource.