CSE608: Advanced Computer Security (Fall 2008)
			     Scott D. Stoller

Express the following policy in the SQL-based trust management language
defined in [stoller08trust].

1. NHS (the National Health Service) is trusted to declare that a
principal is a physician.

2. A physician is trusted to declare that a principal is an agent for a
patient.

3. A patient's agent can view the patient's health record.

you can assume the health records are stored in a table defined by

  create table HealthRec 
    (patient principal_type,
     ...)

				REFERENCES

[stoller08trust] Scott D. Stoller.  Trust Management and Trust Negotiation
in an Extension of SQL.  In Proceedings of the 4th International Symposium
on Trustworthy Global Computing (TGC).  Springer-Verlag, 2008 (to appear).
Available on Blackboard.