The LookUp application normally deletes the modified credential, because the dynamic PCP role assignment is only good for that specific set of context information. However, there may be application-specific scenarios where the modified credential can be cached for use across multiple HTTP requests from the same doctor. By introducing the concept of authorizing access to data types instead of specific Web resources, Privacy Manager makes it easy to map a customer s written privacy policy to a Policy Director and Privacy Manager configuration. For example, the Policy Director configuration listed above clearly indicates that only primary care physicians can modify a patient record, doctors and nurses can read the records, and administrators have no access. Using data types as protected objects in an authorization system also makes it easy to add new applications to the customer s site.
New applications can make their authorization requests against the same set of data types.
Finally, the customer s privacy policy is represented by the combined configurations of Policy Director and Privacy Manager. The applications do not contain any privacy policy encoded in their object code. This means that if the customer s privacy policy changes in the future, only the Policy Director and Privacy Manager configurations need to be updated. The protected applications do not have to be modified or redeployed. Calvin Powers is a software engineer in IBM Tivoli Security Systems Division.