Thanks to the confirming electronic signature of the recognised certification service provider contained in the certificate, the recipient can trust the details about the signatory contained in the signatory's certificate, unless information is restricted (e.g. alias instead of real name). The certification service provider is also referred to as a trusted third party.
A signature on a document is, firstly, a determination of the origin of the statement of intent and of the state of the signed document at the time of signature. In the case of qualified signatures, the signatory also confirms their agreement with the content of the document («content commitment»). A qualified document is accordingly deemed equivalent to a handwritten signature (Art. 14 para. 2bis Code of Obligations).
In this way, qualified signatures or regulated seals, as well as advanced signatures issued by recognised certification service providers, guarantee the authenticity of the origin of a document. If the signature is valid, integrity is also guaranteed. This means that the content of the document has not been changed since the document was signed.
If the signature is additionally combined with a time stamp signature, the time of the signature is also guaranteed. Furthermore, only the presence of a time stamp enables a secure and comprehensive verification of the signature with regard to the validity of the certificate at the time the signature is executed.
In addition to other legal effects, qualified signatures also have the property of non-repudiation. In the context of the eIDAS Regulation and Swiss signature legislation (ESigA and implementing provisions), non-repudiation is also referred to as content commitment.
In this way, electronic signatures create trust and security in legal and business transactions.