中文摘要：

向前安全的签名能保护签名 previous 的安全到关键暴露。帮助服务者的签名是签名人在结盟一个服务者生产签名的特殊数字签名。在这篇论文，帮助服务者的向前安全的阀值签名被建议。系统由 n ₁ 服务者和 n ₂ 用户组成。每个用户和各个服务者分别地保持一个部分秘密。为了生产有效签名，用户和服务者，需要合作完成工作。用户和服务器的部分秘密被一个单程的函数在常规间隔更新，当公钥总是被修理时。就算所有当前的部分秘密被暴露，与以前的时期相关的签名仍然是有效的。

英文摘要：

Forward secure signature can protect the security of signatures previous to the key exposure. Server-assisted signature is a special digital signature in which the signer allies one server to produce the signatures. In this paper, server-assisted for-ward-secure threshold signature is proposed. The system is composed of n1 servers and n2 users. Each user and each server holds a partial secret, respectively. To produce a valid signature, users and servers need to cooperate to complete the work. The partial secrets of the users and servers are updated by a one-way function at regular intervals, while the public key is always fixed. Even if all the current partial secrets are exposed, the signatures pertaining to previous periods are still valid.