Die elektronische Form und das Präsentationsproblem

Electronic signatures shall enable anyone to prove the content, the ownership and authorisation of declarations in electronic form. However, the validity of a valid signature may be doubted, simply due to the differing presentation formats of various systems. Additionally, we face the risk of manipulation and faults of the used presentation system, especially if this system is not controlled by the signer or the verifier. The German Digital Signature Act and the related legal framework treat the presentation problem only partially and the technical specifications are not sufficient. In court, an opponent of the proof may raise many doubts against a presented signed document, which has an undisputed, valid signature. A prima facie proof for presentation is not justified. In only some cases can experts make additional findings through investigation of the document and the presentation system of the signer. Different approaches are necessary to solve the presentation problem. Document formats and presentation components are needet, which guarantee the unambiguity of signed data. The responsibility for the security of the system used by the signer must be verifiable. Portable signature devices controlled directly by the user are needed to sign in foreign controlled environments. Modifications of the Signature Act and restrictions of the prima facie proof are necessary.