Voting must respect several criteria to be democratic. In this paper we determine whether electronic voting can simultaneously protect secrecy, be transparent, accessible and resistant to intimidation and fraud.We consider different types of e-voting ranging from Direct Recording Electronic voting systems to remote internet voting. We show that there are major contradictions between the constraints of democratic elections and the possibilities offered by computers. In particular, electronic voting appears to make massive and invisible fraud possible to achieve by small groups of people with the necessary skills. At present, it is not a realistic possibilility to design an electronic application, remote or not, that could cope with the demands of democratic elections.