公开(公告)号：US07296159B2

公开(公告)日：2007-11-13

申请号：US10667841

申请日：2003-09-22

申请人： Jian Zhang ,  Zong Wei Liu ,  Ling Shao ,  Dong Xie

发明人： Jian Zhang ,  Zong Wei Liu ,  Ling Shao ,  Dong Xie

IPC分类号： G06F1/24

CPC分类号： H04N21/26606 ,  H04L9/0822 ,  H04L9/0836 ,  H04L9/0891 ,  H04N7/163 ,  H04N21/25808 ,  H04N21/63345 ,  H04N21/6405

摘要： Methods and apparatus for key distribution in a conditional access system, assuming that the set of all user nodes which the system can accommodate is a complete set, and a subset is composed of all user nodes or part of user nodes. One method comprises: decomposing said subset into at least one secondary subset; assigning a different user key to each secondary subset, each said user key being transmitted to all users in a corresponding secondary subset; encrypting an entitlement key by using each said user key so as to generate a cipher text corresponding to each said secondary subset; and combining said cipher text to generate a media key control block and transmitting said media key control block to all users in said subset. Since a classification method of a binary tree and a multiple tree is used, the invention can save a lot of network resources.

摘要翻译： 在条件访问系统中密钥分发的方法和装置，假设系统可以容纳的所有用户节点的集合是完整集合，并且子集由所有用户节点或部分用户节点组成。 一种方法包括：将所述子集分解成至少一个次级子集; 将不同的用户密钥分配给每个次要子集，每个所述用户密钥被发送到对应次要子集中的所有用户; 通过使用每个所述用户密钥来加密授权密钥，以便生成对应于每个所述次要子集的密文; 以及组合所述密文以产生媒体密钥控制块，并将所述媒体密钥控制块发送到所述子集中的所有用户。 由于使用二叉树和多树的分类方法，本发明可以节省大量的网络资源。