The method and system which assure tight security over access to document data which is being handled in a system during scanning, copying, printing and faxing modes of operation. Security takes place with (1) substantially complete blockage of outside-world (network, telephone line) access to such data during the handling time, (2) prevention of any data writing to a hard-drive memory device, and (3) job-completion destruction of any data temporarily stored in a random access memory, before there is any post-job restoration to outside-world connectivity.