中文摘要：

P2P环境中缺少可信的第三方,节点上线率相对较低,而且网络成员与网络规模都处于不断的变动中,这些特性使现有的多秘密共享方案无法有效地工作。针对P2P环境的特点,提出了一种动态多秘密共享方案。首先,该方案无需可信分发者和安全通讯信道,且在保持密文不变的前提下参与者的身份、数量及系统门限值均能动态改变。其次,采用Byzantine Quorum方式在DHT上管理参与者的身份与验证信息,使秘密重构与改变系统参数的操作只需门限个参与者同时在线即可完成。再次,使用基于身份的公钥密码系统与二元多项式,减小了消息开销,同时得以有效地对抗成员欺骗。因此,提出的动态多秘密共享方案能较好地应用于P2P环境。

英文摘要：

Lack of a trusted third party,relatively low node availability and constantly changing membership and network size,make existing multi-secret schemes unsuitable for P2P environment.A dynamic multi-secret sharing scheme was proposed for P2P networks.Neither trusted dealers nor secure communication channels are necessary for the proposed scheme,which allows dynamic changes of participants and the system threshold in keeping ciphertext untouched.In the meantime,the participants＇ identity and public commitments together with system parameters are managed by Byzantine Quorums,which makes it possible to reconstruct a shared secret,add a participant or change the system threshold with only threshold participants online.Additionally,ID-based public key cryptosystem and bivariate polynomials are used to reduce message traffic and deal with participant cheating.Altogether,the proposed scheme overcomes the drawbacks of the previous schemes in P2P environment.