In the case of legal transactions with no formal requirement, electronic signatures serve as subsequent evidence that an electronic document has not been altered and that the statement of intent contained therein can be attributed to specific persons. If a time stamp is included, the evidential function also extends to the time of the statement of intent of each signatory.
Swiss procedural law is based on the principle of the free assessment of evidence. Judges decide whether or not to trust an electronic signature. The signatures and seals of organisations governed by the ESigA are more likely to be trusted than signatures whose certificates were issued by certification service providers not recognised in Switzerland.
In civil procedure law, moreover, all facts are considered true as long as they are not disputed by a party. Only in the event that a party disputes the validity of an electronic signature does the court have to assess whether it is genuine and valid.
An electronic signature is therefore a security element with regard to the integrity and authenticity of a document wherever it does not serve to fulfil a formal requirement – i.e. in the large majority of legal transactions – and primarily serves as evidence.