Security protection of database systems becomes necessary when the database is on a single computer or network which is shared by different people or when the developer turns the database over to an end-user but wishes to limit what that user can do. This article discusses electronic protection which may be used to keep some people out of the system, or parts of it, while allowing others access. Various security measures related to Microsoft Access databases are described, including network security, user-level security, hiding parts of the system, writing password programs, disabling menus, splitting a database for storage in different locations, and encryption. Some of these approaches are built into Access, but it is necessary to write programs for more flexible multi-user, multilevel security. Several such programs are shown.