Different group members have different signing ability in the scheme, and no one can sign a message out of his purview.Meanwhile, the scheme satisfies ordinary security properties of group signature.

• 该方案中，群成员具有不等的签名权限，任何群成员均不能对一个超出自己签名权限的消息产生有效的签名，验证者可以通过公开的消息权限标志来验证签名。