PL/SQL Wrapper

Have you ever tried to see the contents of the object file in C ?
If not, then let me tell you that it contains all unreadable characters ie, given the object code, nobody can generate the C code from it.
If you want a similar kind of protection in PL/SQL code, you need to use wrap command. In this way, you can protect your source code. You can now distribute your wrapped code without the fear of it being copied. The PL/SQL compiler recognizes and loads wrapped code automatically.

Using PL/SQL Wrapper

wrap iname=plsqlsource.sql oname=plsqlwrapcode.plb

where the extension plb means PL/SQL binary.