Abstract: This paper is to investigate the impplementation of security
mechanism in object oriented database system. Formal methods
plays an essential role in computer security due to its powerful expressiveness
and concise syntax and semantics. In this paper, both issues
of specification and implementation in database security environment
will be considered; and the database security is achieved through
the development of an efficient implementation of the specification
without compromising its originality and expressiveness.
Abstract: The paper shows the necessity to increase the security
level for paper management in the cadastral field by using specific
graphical watermarks. Using the graphical watermarking will
increase the security in the cadastral content management;
furthermore any altered document will be validated afterwards of its
originality by checking the graphic watermark. If, by any reasons the
document is changed for counterfeiting, it is invalidated and found
that is an illegal copy due to the graphic check of the watermarking,
check made at pixel level