7. The method of claim 5 wherein said machine readable symbol also has encoded therein an encryption key associated with said source identifier data string, said encryption key is transposed by said computer input device, said transposed encryption key is used by said client computer to encrypt information specific to a user associated with said client computer, and said encrypted user information is assembled within said computer file transfer request word and transmitted to said target server computer.
7. The method of claim 5 wherein said machine readable symbol also has encoded therein an encryption key associated with said source identifier data string, said encryption key is transposed by said computer input device, said transposed encryption key is used by said client computer to encrypt information specific to a user associated with said client computer, and said encrypted user information is assembled within said computer file transfer request word and transmitted to said target server computer. 8. The method of claim 7 wherein said information specific to a user is obtained, prior to encryption thereof, from a user information data file stored on said client computer.