Method and system for determination of authenticity of an electronic document or copy thereof by comparing it with an earlier authentic version of the electronic document in question

An authentication system for determining the authenticity of a given document by comparing an original document with itself presented at a later date or with a copy made from the document, said determination is carried out in response to a request raised by a petitioner, comprising:

• a satellite system with at least one satellite station and a separate core system, wherein a communication connection is established between the satellite station and the core systems, the respective satellite stations each comprise a central processor, a coder, a memory, an interface for providing a connection with the core system, and when the original document is entered in the satellite station the satellite station requests a first code from the core system and after the receipt thereof the first code is inseparably associated with the original document, and the coder generates a transformed control value from the document after the first code has been associated therewith, or at a later authentication task for determination that a questionable document is identical to the original document the coder generates a questionable transformed control value from the questionable document which is presented for authentication with which a questionable first code has been associated, and the questionable transformed control value is forwarded to the core system;
• a core coder unit that generates the first code in response to the request received from the satellite station in such a way that the first code becomes a unique numeric sequence with a length of at least 20 bytes;
• and
• an attestation database in which the transformed control value generated from the original document in the satellite station and associated therewith will be written and stored at an address constituted by the first code or derived from the first code;
• and the core system comprises furthermore a digital comparator which when carrying out the authentication task compares the questionable transformed control value obtained from the satellite station and generated from the questionable document to be authenticated with the transformed control value stored in the attestation database at an address defined by the later generated questionable first code or derived from this questionable first code in the same way as previously but associated now with the questionable document to be authenticated, and the central processor forwards an authentication signal to the satellite station concerned if the comparison finds identity between the two transformed control values and the questionable transformed control value.