The Royal Air Force Logistics Information Technology System (LITS) is a ten year United Kingdom procurement programme to provide the Royal Air Force with a fully integrated IT system covering its supply and engineering functions. It will hold and process classified information and thus requires an IT security policy. Although a single integrated system, it will service many distinct locations and types of applications and will be developed and put into operational use over this extended period. It will also link to many related logistics and other support systems. It has been found necessary to define a hierarchy of security policies covering the full scope and extent of the system, and it may be necessary to have multiple security targets for security evaluation.>

An examination is made of questions concerning commercial computer security integrity policies. An example is given of a dynamic separation of duty policy which cannot be implemented by mechanisms based on TCSEC based mechanisms alone, yet occurs in the real commercial world and can be implemented efficiently in practice. A commercial computer security product in wide use for ensuring the integrity of financial transactions is presented. It is shown that it implements a well-defined and sensible integrity policy that includes separation of duty, yet fails to meet either the TCSEC or the D.D. Clark and D.R. Wilson (1987) rules.>

The authors explore a commercial security policy (the Chinese Wall) which represents the behavior required of those persons who perform corporate analysis for financial institutions. It can be distinguished from Bell-LaPadula-like policies by the way that a user's permitted accesses are constrained by the history of his previous accesses. It is shown that the formal representation of the policy correctly permits a market analyst to talk to any corporation which does not create a conflict of interest with previous assignments. The Chinese Wall policy combines commercial discretion with legally enforceable mandatory controls. It is required in the operation of many financial services organizations; the authors conclude that it is, therefore, perhaps as significant to the financial world as Bell-LaPadula's policies are to the military.>