10Electronic Signature

There are several reasons for introducing an electronic signature. On one hand, there was a need to introduce an equivalent to a conventional signature, and secondly, a large number of documents are produced in electronic form; some data even exist only in digital form, but - above all – its nature limits easy forgery of data.

In general, electronic signatures require identification of the signatory/entity, the integrity of the delivered document (data integrity), the undeniability and legal acceptability.

For an electronically signed document, we may also require to conceal the content of the message (i.e., encryption) and to determine, whether the document existed at a specific time (i.e. time stamp).

What is an electronic signature? The definition of electronic signature is based on Regulation No. 910/2014 of the European Parliament and of the Council on electronic identification and trust services for electronic transactions in the internal market (abbreviated as eIDAS (electronic IDentification, Authentication and trust Services)).

The regulation for eIDAS in Article 3 (10) defines an electronic signature as data in electronic form that is attached to a data message or is logically associated with this data message. Thus, the electronic signature serves as a method of unambiguous verification of identity of the signatory in relation to the data message.

This very general definition could also refer to a text signature of ordinary e-mail.

The electronic signature represents several possible options:

- electronic signature,
- guaranteed electronic signature,
- recognized electronic signature,
- qualified electronic signature.

The concept of a recognized electronic signature is/was specific for the Czech Republic (until 09/2018). It is a guaranteed electronic signature based on a qualified certificate. It is therefore applicable to communication with public authorities (but only in the Czech Republic!) There is no requirement for a secure HW repository. For a qualified electronic signature, the keys must be stored in a "safe" place.

In relation with the electronic signature, it is also worth mentioning the term digital signature. A digital signature uses the means of asymmetric cryptography. That is a specific technical solution for the electronic signature.

Digital signature is the safest way to implement electronic signatures.

The term electronic signature is more general in the context of digital signature; it is technologically neutral. It includes, in addition to digital signature, all other methods providing the required properties (e.g. biometric methods). For this reason, it is also applicable to legislative documents.

1. Digital signature is a cryptological/mathematical term.
2. Electronic signature is, in particular, a legal and normative term.
3. The definition of electronic signature itself sets the requirements, but does not address how they can be achieved.
4. On the contrary, digital signature tools are fully focused on fulfilling the requirements.