门限RSA中的子密钥优化分配算法  

The Optimized Subkey Distribution Algorithm in Threshold RSA

作　　者：崔竞松[1] 彭蓉[2] 

机构地区：[1]武汉大学计算机学院,武汉430072 [2]武汉大学软件工程国家重点实验室,武汉430072

出　　处：《计算机学报》2005年第6期1027-1031,共5页Chinese Journal of Computers

摘　　要：无Dealer的(t,n)门限RSA算法能够使容侵系统在部分系统遭受攻击的情况下,继续保持系统私钥的安全性和可用性.在传统的无Dealer的环境中,为了使系统在遭受攻击时,以d=∑di方式共享私钥的n个参与方中的任意t个参与方有能力重构原始私钥d,要求每个参与方必须持有Ctn个子密钥.这种共享方式是诸多门限RSA的密钥共享方式中最简单、也是最有效的一种.然后Ctn随着容侵系统的规模增长太快.所以减少每个参与者所应拥有的子密钥对于提高容侵系统的容侵能力尤为重要.该文提出了一种弹性搜索算法并搜索得到优化的子密钥分配方案.该优化方案能够在不降低系统安全性的前提下,以更少的子密钥实现了相同的门限结构,从而降低了门限密码系统的密钥管理以及签名和解密的相关操作的复杂度.The ( t,n ) threshold RSA algorithm enables the system to keep the security and availability of the private key without a trusted dealer when parts of system are already under attack. In the traditional threshold RSA sub key distribution scheme, each party that shares the private key in the form of d=∑d i must keep C t n sub keys secretly in order to enable the whole system to reconstruct the original private key by any t out of n parties. It is the simplest one of all the forms of sharing RSA key and it has the best efficiency out of them. However C t n increases with the scale of intrusion tolerance (IT) system very quickly. So it is very important to decrease the number of sub keys which belong to each party to enhance the IT ability of the ITS. This paper presents a scalable searching algorithm, which can find out the optimized sub key distribution scheme that can decrease the number of sub keys that should be held by each party without weakening the system’s security. And an optimized scheme is found and listed in this paper. It can greatly reduce the complexity of key management and related operations in signing and decryption.

关 键 词：密钥分配 门限RSA 容侵系统 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]