At a publisher location, multiple encrypted documents are assembled into a distribution archive that is also encrypted. The distribution archive is then downloaded into a content server at an unsecure site. When the content server receives the distribution archive, it decrypts the archive file and unpacks...http://www.google.co.uk/patents/US7299500?utm_source=gb-gplus-sharePatent US7299500 - Method and apparatus for secure delivery and rights management of digital content at an unsecure site
