Abstract: It is significant in fact that access control schemes in hierarchy.In this paper，an access control scheme based on Hwang-Yang scheme has been proposed.It solves the security issues in Hwang-Yang scheme by using Chinese remainder theorem.This scheme needs smaller storage than Hwang-Yang scheme and its keys generation and derivation is more simple and efficient too.

摘要： 等级系统中的访问控制问题有着重要的实际意义。在Hwang-Yang方案的基础上提出了一个新的基于等级系统访问控制方案，该方案不仅利用中国剩余定理解决了Hwang-Yang方案中的安全问题，而且所需的储存空间更少，密钥的生成和导出的效率更加高效。