The Belgian law of 9 July 2001 on electronic signatures and certification services requires that you use a qualified certificate on a secure USB token or smart card to place an electronic signature that is automatically equivalent to a handwritten signature.

Article from the law:

§ 4. Without prejudice to article 1323 and following of the Civil Code, an advanced electronic signature based on a qualified certificate and created by a secure signature-creation device, is equal to a handwritten signature regardless of whether the signature is created by a natural or a legal person.