Data is secured in a computer network to transparently establish and manage a separation of user-based communities of interest based upon cryptographically separated, need to know, security levels. Data from a source document, data object or data stream is filtered to form subsets of extracted data and...http://www.google.co.uk/patents/US20020091975?utm_source=gb-gplus-sharePatent US20020091975 - Data security system and method for separation of user communities
