I. Introduction
In the history of data processing to date, we can clearly distinguish two particular trends: the trends towards data independence and data usability in every area involving user/system interaction, we can trace a steady improvement in the quality and level of the human interface. The trend is always away from the irrelevant complexities of the underlying machine and physical data organization and towards a higher and more causal user oriented level of expression. At the same time, the computation power kept on increasing in a wide range as a result of computer networks and e-commerce systems. These evolutions have had a huge impact on the design of security systems in the DBMS. Initially, the security system was not an independent module of the DBMS. It relied heavily on the security system of the underlying operating system. Then the need for more powerful controls, for a finer grain of protection, and the inadequacy of identification/authentication schemes led to the design of security systems as a component of a DBMS. Data security is intrinsically two fold; it includes the privacy protection and soundness of the stored information. Privacy control dictates the access control so as to restrict users to retrieve only the data structures or values for which they receive authorization. Soundness of the stored information dictates integrity, which basically encompasses two major features; the updates synchronization of shard data by concurrent users (External integrity) and correctness of data modification depending on predefined constraints (Internal integrity). Thus data security mechanism must ensure that a user is authorized to have access to data for the performance of specified operations, that any changes resulting from a user's alternation of the database are valid without affecting the consistency of the whole database (13, 15). In the past several years, several new types of database have moved out of the academic world and have been released as commercial products. These new types of database are commonly referred to as next generation database and include object-oriented, object-relational active and deductive databases. Each of these types of database offers new features when compared to the more traditional relational databases. In turn, these new databases require new security models to correctly regulate access to their data.