The signed documents themselves are digitally encrypted using cryptographic methods. Only the owners of a document, or those who have been invited to sign, can edit the document or just sign it. Each document is provided with a unique cryptographic key at all times, which is impossible for any person and any computer to see. The validity and evidentiary value of the document is also independent of the signature platform used, as the cryptographic key (or “hash value”) is embossed in the pdf file itself. Consequently, any printing and physical filing of the document is also not the purpose of the matter, since traceability expires when the document is printed.