防欺诈的动态(t,n)门限多秘密共享方案

现有的门限多秘密共享方案中，存在着参与者的秘密份额由秘密分发者生成，以及增加或删除成员时，系统需重新给所有参与者分配秘密份额等安全缺陷。为了解决此问题，在基于离散对数难题和拉格朗日插值公式，提出了一个可动态调整门限值的(t,n)多秘密分享方案。提出的方案具有如下主要特点：1)参与者的秘密份额由自己选取，且秘密分发者不知道任何参与者的秘密份额；2)秘密分发者与参与者之间不需建立安全信道；3)对于不同的共享秘密，秘密分发者可根据秘密的重要性，动态地调整恢复该秘密的门限值；4)可高效地增加或删除成员，无需更改其它成员的秘密份额。此外，方案还能有效地检测和识别成员的欺骗行为，因而具有较高的安全性和实用性。

A Cheat-proof Dynamic (t,n) Threshold Multi-secret Sharing Scheme

In the most present threshold multi-secret sharing scheme,there were some security problems,such as each participant's shadow was generated by the dealer and the dealer would regenerate participant's shadow when a participant was added or deleted.To overcome these problems,a(t,n) multi-secret sharing scheme based on the Discrete Logarithm Problem and Lagrange Interpolation Formula was proposed which could adjust the threshold value of a secret dynamically.This scheme has the following properties: 1)Each participant selected his shadow by himself and the dealer don't know the shadow of any participant;2)There was no secure channel between the dealer and the participants;3)The dealer could adjust the threshold value depending on the secure level of different secret;4)The participant could be dynamically added or deleted without having to redistribute new shadow to the older participant.Moreover,the efficient solutions against multiform cheating of any participant were proposed,therefore the proposed scheme has practicability and highly security.