摘要： 利用椭圆曲线离散对数问题的难解性，给出了一种新的双重更新秘密共享方案。该方案在保持共享秘密不变的情况下，能由更新中心独立于分发中心定期对子秘密进行更新，同时对处于更新周期内泄漏或有泄漏嫌疑的子秘密，由分发中心进行即时更新。双重更新有利于提高系统的安全性；独立于分发中心进行定期更新，则有利于减少分发中心的工作量。

关键词: 秘密共享；定期更新；即时更新；椭圆曲线离散对数

Abstract: By means of the intractability of ellipse curve discrete logarithm problem, a new secret sharing threshold scheme with double renewing is presented. This scheme can renew sub-share periodically without changing the shared-secret independently, at the same time, distribution center can renew insecure sub-share instantly. Because the sub-share is renewed doubly, the security is improved. Because the sub-share is renewed periodically by update center, amounts of calculation time are reduced

Key words: Secret sharing; Periodic renewing; Instant renewing; Ellipse curve discrete logarithm