Computer Engineering and Applications ›› 2009, Vol. 45 ›› Issue (22): 97-99.DOI: 10.3778/j.issn.1002-8331.2009.22.032

• 网络、通信、安全 • Previous Articles     Next Articles

Insider attack of threshold-proxy threshold-signature scheme

TANG Xi-lin1,YANG Chang-hai 1,2,YANG Zhi-yong1   

  1. 1.College of Science,South China University of Technology,Guangzhou 510640,China
    2.Department of Science and Arts,Nanchang Military Academy,Nanchang 330103,China
  • Received:2008-04-25 Revised:2008-07-31 Online:2009-08-01 Published:2009-08-01
  • Contact: TANG Xi-lin

一种门限代理门限签名方案的内部攻击

唐西林1,杨长海1,2,杨智勇1   

  1. 1.华南理工大学 理学院,广州 510640
    2.南昌陆军学院 科文教研室,南昌 330103
  • 通讯作者: 唐西林

Abstract: Hwang et al,have proposed a new threshold-proxy threshold-signature scheme in 2005.In this scheme,only any t or more original signers of n original signers can cooperatively authorize a proxy group of m proxy signers and then only c or more proxy signers can cooperatively generate threshold-proxy threshold-signature.Compared with other threshold multi-proxy multi-signature,this scheme has the advantage of providing the fair protection for the original and proxy groups.Unfortunately,this paper points out that Hwang’s scheme is vulnerable to insider attack.That is,malicious inside members can forge a threshold-proxy threshold-signature for a message while participating in a normal message signing process.Furthermore,this paper proposes two improved schemes on the base of analyzing the insider attack.

Key words: digital signature, proxy signature, threshold proxy signature, threshold-proxy threshold-signature

摘要: 2005年,Hwang等提出了一个新的(t,n)门限代理(c,m)门限签名方案。在该方案中,只有n个原始签名者中的t或多于t个合作才能授权给m个代理签名者组成的代理群,同时,只有c或多于c个代理签名者合作才能产生门限代理门限签名。与其他门限多代理多签名方案相比,该方案的优点是原始签名者和代理签名者的利益受到公平的保护。但指出Hwang方案存在内部攻击,即在对一个消息的正常签名中,恶意的内部成员能伪造出另一个消息的有效签名。进一步,在分析攻击原因的基础上给出了两种改进方案。

关键词: 数字签名, 代理签名, 门限代理签名, 门限代理门限签名