People who do business on the Internet require security and trust in electronic commerce and communication. You can’t see the person you are speaking with, you can’t see the documents that prove one’s identity, and you can’t even know if the web site you are connected to belongs to the organisation it says it does.
Directive 1999/93/EC of the European Parliament and the council of December 13, 1999
To answer these juridical necessities, the European Union adopted a community framework for electronic signatures some time ago (directive 1999/93/EC of the European Parliament and the council of December 13, 1999) that has been implemented in various European countries. The European directive is used for business in which European partners (persons or societies) or public administrations are involved. It also means that if an American organization enters into an electronic contract with a European society it has to respect European requirements to ensure the contract is valid.
The directive 1999/99/EC defines, in article 5, the electronic signature as follow:
“[..] Member States shall ensure that an electronic signature is not denied legal effectiveness and admissibility as evidence in legal proceedings solely on the grounds that it is:
1- in electronic form, or
2- not based upon a qualified certificate, or
3- not based upon a qualified certificate issued by an accredited certification-service-provider, or
4- not created by a secure signature-creation device. [..]”
Nevertheless, it remains essential to guaranty a signature’s effectiveness to ensure its value. This is why this very same european directive also draws the contours of stronger electronic signatures, admissible as evidence in legal proceedings: the advanced electronic signature and the even more legally admissible qualified digital signature (also called a secure digital signature or strong digital signature).

