Security is already provided if the VDB is deployed to a Teiid server via the Console application. This sounds like it's really a question for the Teiid forum, not Teiid Designer.
Can you give more specifics? Are you looking for user authentication before some one can access your VDB?
If you are thinking of using "embedded" as runtime, and if it is deployed in a application sever, you can depend upon the it's identity management. If it is deployed to Teiid Server runtime ( which is due in 6.2.0) release, you can configure LDAP.
Teiid also supports "entitlements", with which you can control, table and column level Read/Update/Delete operations based on assigned roles to a given user. However this feature is only available in the Teiid Server, not in Embedded.