10. The method of claim 1 , wherein the receiving station is a printer having a local user interface for inputting, by an operator, the character string used to form the decryption key.
10. The method of claim 1 , wherein the receiving station is a printer having a local user interface for inputting, by an operator, the character string used to form the decryption key. 13. The method of claim 10 , wherein the sending station first sends only the non-encrypted part of the transmission file to the printer, the receiving station uses data contained in the non-encrypted part to present the relevant document file at its local user interface to be selected by an operator for further processing, and the receiving station, upon an operator selection of a document file, sends a request to the sending station, to transmit the relevant transmission file.