Can I own the copyright if I only have a idea to implement a software and it have not been implement(it's design is documented)? or can I sell the idea if someone think it's useful?

Standard note: I am not an IP lawyer, so I may have got some of the specifics wrong (especially for international law where things can get tricky).

From my understanding of IP issues, copyright only protects the specific representation of your idea as a document, not the idea itself. In other words, copyright protects your idea documentation so people cannot make copies of the whole or part of your documents without your permission. However it does not stop people from reading your documents and implementing your idea, or writing it down in a different way.

If you want to ensure your idea is protected, you will either need to keep it secret from everyone who has not signed a NDA (non-disclosure agreement), or apply for a patent (as patents give you exclusivity to implement ideas, at least for a dozen years or so).

Quote:Original post by Trapper Zoid
If you want to ensure your idea is protected, you will either need to keep it secret from everyone who has not signed a NDA (non-disclosure agreement), or apply for a patent (as patents give you exclusivity to implement ideas, at least for a dozen years or so).

ofcourse patents for ideas aren't valid in most of the world. (the United States is one of the few nations that allow patents on ideas, software and business methods)