The GUIDEC aims to draw together the key elements involved in electronic commerce, to serve as an indicator of terms and an exposition of the general background to the issue. It also addresses one of the key problems in talking about electronically signed messages, in that they are not signed physically , but require the intervention of an electronic medium. This in turn alters the function of the signer , and introduces problems which a physical signature does not encounter, most especially the possibility of use of the medium by a third party. The GUIDEC therefore adopts a specific term , "ensure", to describe what elsewhere is called a "digital signature" or "authentication", in an attempt to remove the element of ambiguity inherent to other terms employed.