A locked element and methodology are provided for use in a block diagram model of a graphical modeling environment. The locked element displays within the block diagram model but access to the functionality of the locked element requires authorization. Without authorization the locked element will not function. Authorization may also be required to access the implementation details of the locked element. Without authorization the implementation details of the locked element cannot be viewed or modified. In certain implementations, any code generated from a locked element without authorization is obfuscated.