Security system limiting access to data in multi-user computers - stores individual user data on hard disc in encrypted form

摘要

When the computer or network is first set up, the system administrator uses a primary password to control basic access to stored applications. Authorised users, in possession of the primary password can then use the applications to process their own data files. These data files can then be encrypted before storage on hard disc. Each user's data will be stored in a different encrypted form using an encryption key, known as "DESK". DESK is generated within the computer using a secret mathematical function "F1" which operates on a first machine code "MC1", and the user's primary password, known as "SAK". Further levels of encryption can be arranged in the same manner.