1. A method for handling defined areas within an electronic document comprising: marking at least one area in an electronic source document as indecomposable area which can be processed as a whole content only; generating signature data for said indecomposable area; assigning said signature data to said indecomposable area to create an indecomposable area object; storing said indecomposable area object; encrypting and transmitting said indecomposable area object in response to a request of an enhanced content reader application comprising at least a part of said indecomposable area, wherein said enhanced content reader application decrypts said indecomposable area object and processes said indecomposable area in an electronic target document; and generating and transmitting a protected version of said indecomposable area in response to a request of a regular content reader application, comprising at least a part of said indecomposable area, wherein said regular content reader application outputs said protected version of said indecomposable area in an electronic target document.