The system cannot be put in defect. Even if the forger knows the rules' mode of encryption, he would only be able to discover the access point to the electronic copy of the document that he already have (besides the issuer can allow the access to his server only to some well identified organisms). He therefore won't be able to point on another document or be able to modify the electronic copy of the hidden document. He is forced to leave the rules in place on the document (the absence of the rules will automatically prevent any transaction).
This mechanism can be easily transplanted for the exploitation of an earnings statement in order to obtaining a credit. The banker will then be able to easily check by the employer's server the validity of the well-stocked document, and this server will also warn the banker in case of breach of contract. To keep control over the information distributed when producing a photocopy for a third party each one will be able to decide if this photocopy must be attached or not to the server of the issuer. In that case, he can then decide if the photocopy can lead or not to some additional documents or complementary information to the recipient according to the evolution of the situation bound to the transmitted document.

However, accepting access to additional documents and to the evolution of the situation bound to the document is also an advantage for each: it won't be necessary to regularly send insurance's certificates to its owner, since he is automatically informed in case of breach of the relative contract. This automatic device is also a guarantee to remain in legality by avoiding risks related to carelessness.