A digital signature, which should not be confused with a digital certificate, is a mathematical technique used to validate the authenticity and integrity of a message, software or a digital document.

A digital signature, as opposed to a traditional signature, is not a name but two “keys” or sequences of separated characters. It applies cryptographic measures to the content of a message or document in order to show the following to the message’s recipient:

  • that the sender of the message is real (authentication);
  • that the sender cannot deny that they sent the message (non-repudiation);
  • that the message has not been altered since it was sent (integrity).

A digital signature is therefore a key part of the 

advanced electronic signature

 and qualified electronic signature, but 

not of the simple electronic signature

. A simple electronic signature would be, for example, a personal identification number (PIN) entered at a cash machine or clicking on “accept” or “do not agree” on a “terms and agreements” electronic contract.

This type of electronic signature cannot attribute the electronic signature of a signatory to a specific signatory, therefore, it is does not have the same features as a digital signature.

All digital signatures are electronic,
but not all electronic signatures are digital.

A digital signature is legal, but its aim is not to attest to the signatory’s willingness like an electronic signature, but just to encrypt the data of a document to give it greater security.

Also a digital signature can be used for a wider range of file types, such as videos, sound, music, etc., making it more versatile than the traditional paper signature.