基于LUC密码体制的动态多秘密共享方案

Dynamic Multi-secret Sharing Scheme Based on LUC Cryptosystem

在现有基于LUC密码体制的秘密共享方案基础上,提出一种新的动态多秘密共享方案。该方案无需在秘密分发者与成员之间建立安全信道,就能对成员和秘密进行动态添加或删除。在秘密重构过程中,合作成员只需向指定生成者提交影子份额,且验证者可对影子份额进行公开验证,从而使得系统无需更新成员的秘密份额即可实现一次性共享多个秘密和多组秘密。通过随机预言机模型对该方案进行验证,结果表明,在离散对数问题的假设下该方案是语义安全的,并且在计算量、安全性、总体性能方面均优于传统秘密共享方案。

On the basis of the existing secret sharing schemes based on LUC cryptosystem,this paper proposes a new dynamic multi-secret sharing scheme. The scheme does not need to build secure channel between secret dealer and members,and the members and secrets can be dynamically added and deleted. In the phase of secret recovery,cooperative members only need to submit shadow shares for designated combiner,and the verifier can verify the validity of shadow shares publicly. Thus the system does not need renew secret shares in sharing multiple secrets and multi-group multi-secret. The security of the scheme is proved in the random oracle model, under assumption of the discrete logarithm problem,the result shows that this scheme is semantic security, and in the aspect of calculation, security, the overall performance is superior to the traditional secret sharing scheme.