Introduction - If you have any usage issues, please Google them yourself
Consider an organization with three roles: A, B and C. Whenever B has to issue some
instruction to A, B has to take permission via C and then only it will be obeyed by A. This
permission is issued with the help of a digital signature. A verifies the credibility of the
message using C s public key (and digital signature), like any other digital signature
scheme.