System och metod för säker dataöverföring över elektronisk länk

A system for data transmission over an electrical link (12) including at least one distribution server (10) and one client station (11), which requests transmission of a specific data set from a distributor, communicating with the distribution server (10). The server (10) is arranged to produce a first encrypted and with a password-locked package of said specific set of data, the password being generated at least partly based on the information received from the client station (11). The server (10) is provided to produce a second package (24) containing said first package and an instruction set, at least part of the second package being accessible if the client station (11) receives it in its entirety after a transmission. The encrypted set of the data is further provided to be accessed if the client station (11) performs instructions acceptable for the distributor, and supplies the password for unlocking said first package.