Discussion and considerations
Computer systems have long needed controls on access. Early software commonly fell into the category that became known as access control lists (ACL). But these were typically applied at a fairly low level in systems, and referred to basic computer operations. Further development brought software designed to tackle more general issues, such as control of confidential documents. Much work was done on discretionary access control (DAC), and mandatory access control (MAC).
A good deal of academic research has been devoted to the whole question of access controls. The culmination of this work is that the model most widely favored approach is now the role-based access control system, such a mouthful that the acronym RBAC is used hereafter. Now although the academic analysis can be abstruse, we need a practical solution to the problem of managing access to services on a website. Fortunately, rather like the relational database discussed in Chapter 3, Database and...