AACS设备密钥存储与吊销的改进方案

摘要

AACS是一种内容散布和数字版权管理的标准,通过吊销设备密钥来吊销非法的设备,并且采用子集差分树技术对数量庞大的设备密钥进行管理.根据子集差分树原理,每个设备需要存储大量的设备密钥.在被吊销设备的分布是随机和均匀的这一合理假设条件下,对AACS的设备密钥存储方案进行了改进.改进后,每个设备存储的密钥数量减少,并且合法设备被划分的子集个数仅仅稍微增加.%The advanced access content system is a standard for content distribution and digital rights management. It revokes compromised devices by revoking their corresponding device keys and manages them by using the subset cover tree method, which needs many device keys for storing each device. On the reasonable assumption that devices are revoked randomly and uniformly, a modified method is proposed for storage and revoking of the keys. Then, the number of the keys decreases greatly, while the number of the subset covers for legal devices only increases slightly.