an analysis to credibility of signature in electronic commerce law

about electronic signatures there are more or less some writings concerning their legal aspect. but in those writings there has been a little attention to credibility and evidential value of the electronic signatures. some questions and ambiguities despite being set before has not been answered at all or answered unsatisfactorily. meanwhile, some authors have made mistakes and some have set trivial subjects before. present article deals with the subject matter under the headings: definition of electronic signature, identification of the signor, sufficiency of the electronic signature, qualifications for secured electronic signature, valid and reliable signature, evidential value of the electronic signature, and at last electronic signatures certification service.