Data protecting appts. for data network - uses programme segment capable of withholding permission for use of data from transmission side if user is unauthorised

摘要

The data carrier (1), e.g. a software house's processor, using a data carrier network (2), sends a structured data programme comprising parts (3a,3b) to an apparatus (4) e.g. a user's personal computer. Within the programme is a part (3c) shown as a key symbol, which gives an ''O.K.'' or ''not O.K.'' to the user's computer for the use of the complete programme (3) or parts of it, and over which the user terminal (4) has no control. ADVANTAGE - Prevents unauthorised use or alteration of transmitted data.