MULTIPLE ENCRYPTION OF A SINGLE DOCUMENT PROVIDING MULTIPLE LEVEL ACCESS PRIVILEGES

摘要

A method and system for selectively encrypting and decrypting different sections of a document provides different access levels in a technique employing different keys. The documents may be encrypted at a document section level ("section" here used according to its general meaning) and uses a different set of encryption keys for each section. A user A with an access level 1 may access only those section encoded with access level 1 plus unencoded sections. An application example of this technique is in hospitals. A patients records may each be segmented into separately-encrypted portions giving access to nurses for only suitable material while giving broader access to doctors. The nurse would be provided with his/her access level private key to gain access to those parts of the document for which nurses have rights. There could also be a level to which only the primary care physician or health care proxy has access.