Using Purpose Lattices to Facilitate Customisation of Privacy Agreements

Protecting the privacy of individuals demands that special care be taken with the handling of an individual's personal information. Either the system should store as little or no user data at all, or it should protect access to the data in cases where it is necessary that data has to be stored. A common approach to the protection of PII (in a privacy aware system) is to associate a set of purposes with the PII which indicates the enterprise's use of the data. Purposes placed in a hierarchical structure (such as a lattice) can subsume each other, which can provide flexibility in the customisation of a privacy agreement. In this article the customisation of privacy agreements using purposes placed in a lattice is considered. In particular minimal acceptance levels, maximal acceptance levels, validation and invalidation of agreements with respect to purpose lattices are introduced.